Modular Air Handling Units - airtd.com.sg · PDF fileAbout air handling units The air handling unit (AHU) is one of the most essential and critical units to be considered when designing

Modular Air Handling Units TECHNICAL CATALOGUE

>>> Modular Air Handing Units

Technological Innovation from NTU, Singapore 1

Preface

About air handling units

The air handling unit (AHU) is one of the most essential and critical units to be considered when designing

an air conditioning system. Air T&D provides a wide range of AHUs for use in various applications from small

office premises to larger commercial and industrial applications.

Air T&D AHUs, with their plug-and-play design and inherent flexibility, can be configured and combined

specifically to meet the exact requirements of any building, no matter what it is used for or who is to work

there. Our systems are designed to be the most environmentally friendly and the most energy efficient on

the market. This means they have a reduced ecological impact, while, at the same time, keeping costs down

by minimizing energy consumption. When combined with the small physical footprint of the system, these

features make our AHUs ideal for all markets.

About this catalogue

This catalogue presents Air T&D’s standardized range of AHUs, which includes equipment for air flows

between 1,500 m3/h and 100,000 m3/h, with static pressures of up to 1000 Pa.

Special care has been taken in the preparation of the catalogue to ensure a user-friendly document. Only a

little effort is needed to obtain a rather precise overview of the air handling unit required, with clear, concise

information on the most important characteristics. Based on our experience, these are key data for the

start of any project.

Additional information can be used to identify each of the characteristics to be taken into account in the

precise, complete definition of each apparatus.

About Air T&D

Air T&D is incorporated in January 2015 in Singapore as a high-tech spinoff of Nanyang Technological

University. The company specializes in providing energy efficiency air treatment solutions. Through years

of research, our team has developed several cutting edge technologies, such as liquid desiccant based

dehumidification and air-conditioning systems, new comfortable and energy efficient air treatment

terminals - passive & active thermosiphon beams, etc. So far, we have more than 10 patents granted/filed

in the air treatment and distribution topics. The company focuses on providing sustainable solutions for the

air treatment and distribution of ACMV systems. Starting from Singapore, the company aims to be a major

player in ACMV area in Southeast Asia even all over the world.

Our mission, and the essence of our existence, is to identify and realize our customers’ future needs and

dreams, even those that they themselves may not yet be aware of. We can accomplish this goal by paying

careful attention to changes in social trends and conducting extensive marketing to win the hearts and

minds of customers. It is essential that we offer customers optimum convenience and comfort that are

always one step ahead of our competitors by providing customers with the highest quality products,

materials, and services for which we, as a manufacturer, will be absolutely responsible. Moreover, we will

continue offering products and services that provide customers with fresh excitement and continued

enjoyment.



Table of Contents

1. Features and Benefits ................................................................................................................................. 3

2. Configurations and Selections ..................................................................................................................... 6

2.1 Model Representation .......................................................................................................................... 6

2.2 Judgment of Left and Right Type .......................................................................................................... 6

2.3 Quick Model Selection .......................................................................................................................... 7

3. Components and Options ........................................................................................................................... 8

3.1 Diagram of Functional Sections ............................................................................................................ 8

3.2 Pressure Drop of Functional Sections ................................................................................................... 9

3.3 Combination of Commonly Used Function Sections ..........................................................................10

4. Specifications and Performances ..............................................................................................................13

4.1 Cooling Coil .........................................................................................................................................13

4.2 Heating Coil .........................................................................................................................................15

4.3 Filter ....................................................................................................................................................16

4.4 Fan/ EC Fan/ Fan Matrix Wall ..............................................................................................................19

4.5 Humidifier ...........................................................................................................................................22

4.6 Dehumidifier .......................................................................................................................................23

4.7 Energy Recovery Unit .......................................................................................................................24

4.8 Air Disinfector .....................................................................................................................................26

4.9 Electronic Dust Precipitator ................................................................................................................27

4.10 Activated Carbon Filter .....................................................................................................................27

4.11 Silencer..............................................................................................................................................28

5. Electrical and Automation System ............................................................................................................30

5.1 Electrical System .................................................................................................................................30

5.2 Automation System .............................................................................................................................32

6. Installation and Maintenance ...................................................................................................................35

6.1 Installation of Air Handling Unit ..........................................................................................................35

6.2 Usage and Maintenance .....................................................................................................................37



1. Features and Benefits

Superior Performance

High Quality

Designed For Maximum Flexibility

Industry-leading Energy Efficiency

System Optimization

Lower Installed Time and Cost

Low Noise Emissions

Casing Casings are made of aluminum frame with none cold bridge technology. The skeleton and double panel was

combined with special designed plywood. The casings have smooth inner surface, which can prevent

bacteria accumulation, and effectively improve pre-treated air quality. The casings are suitable for

applications with clean air requirements.

Panel

Panel is designed with none cold bridge double sandwich structure in which the standard configuration

of the outer layer is color steel plate, a n d the inner layer is high-quality galvanized steel filling with

polyurethane foam material of density of 48 kg/m3. The Panels can effectively prevent heat transfer. The

thicknesses of panels are manufactured to select in three nominal values: 25mm, 35mm, and 50mm.

Airtightness

Air tightness is achieved by double sealing between the skeleton and panel. The reliable and flexible sealing

material ensures good air tightness under either positive or negative pressure conditions.

Heat Exchanger

Cooling coil is made by seamless copper and aluminum fins. The copper tube and fins are sealed by 12MPa

hydraulic pipe expander, which ensures to minimize thermal contact resistance and maximize heat transfer

efficiency.

We provide four types of standard coil: 2 rows, 4 rows, 6 rows and 8 rows. The standard aluminum fin

spacing is 2.5mm. We can also tailor fin spacing upon user request.

The coil selection software can calculate parameters such as the number of rows, fin spacing, number of

loops so as to optimize the design to meet user's needs.

Drain Pan

A water tray is located underneath the cooling coil; it is designed to ensure smooth draining of condensed

water. The drain pan is coated with PE insulation layer.

Filter

The basic function of filter is to prevent the accumulation of dust on the internal surfaces of coils and panels,

extending the lifetime of the air handling unit. Three types of filters below are provided.

1) Primary Efficiency Filter: The filter material is an up-to-date polypropylene fiber, which

provides high dust-holding capacity and high filtration efficiency with lower resistance; it is an

ideal choice for pre-filter cell.



2) Medium Efficiency Bag Filer: It is made of new composite fiber material, with low resistance, high

dust-holding capacity and long life span. The bag filter has reasonable interior space dimensions

and allows the filter to achieve the lowest operating cost.

3) High Efficiency Filter: The filter material is ultra-fine glass fiber, which possess low resistance and

high efficiency characteristics. Filtration efficiency could be customized by to customer

demands; the filter configuration is strictly followed by the air velocity requirement, which

ensures the service life under normal operation.

Fan/ EC Fan/ Fan Matrix Wall

Three options are provided to follow the user demands:

1) Centrifugal fan: The fan uses double- inlet-double-width centrifugal type, with high efficiency

and low noise. The fan bearings are from the mainstream brands, which provide self-aligning

and self-locking functions. The accuracy of fan dynamic balance is G4.0, and it can significantly

extend the lifetime of bearings. Fan selection software can select the most efficient fan model

based on actual operating conditions to ensure the fan running in energy-efficient mode. The fan

is installed on a damping bracket, and connected with the casing through high-intensity and

flame-retardant flexible couplings.

2) "EC" (Electronically Commutated) Fan: The option for fans with brushless motors allows for units

with reduced dimensions. Controlled by means of a 0-10V signal even without a frequency

inverter, these fans are very versatile and easy to be used. The Air T&D AHU can be equipped

with EC motors by customer demand. The advantages for the manufacturer and end user include

superior integrated PID control, low noise and vibration, access to a wide range of operation

details, etc.

3) Fan Matrix Wall: It is a combination of smaller fans built into a wall section to replace a

traditional single large fan. This technology incorporates multiple direct-drive centrifugal plenum

fans, assembled in a rectangular array of four to 9+ fans, all discharging into a single plenum. The

fans used are specially designed and optimized for use. The use of multiple direct-drive fans

operating in parallel improves reliability by providing redundancy. Optimized fan wheel

construction and improved internal aerodynamics further enhance energy performance. The

advantages are the following: shorten the unit; quiet operation; energy savings through

optimized performance; redundancy; lower maintenance costs; and food for retrofits.

Fan Drive and Motor

For general Air T&D AHU with centrifugal fan, standard V-belt transmission structure is used, with Taper

Lock to confine the bush pulleys and narrow side of the V-belt. The wide ramp configuration of the narrow

side of V-belt allows it has a higher drive efficiency and higher service life than ordinary V-belt.

The squirrel-cage three-phase AC motor will be used in general structure, complying with IP Enclosure

Ratings, and F class motor insulation. Motor is placed inside the fan section, and placed on top of the

damper bracket through special damping pads, together with the fan. An adjustment device is in the bottom

of the motor, which allows easy adjustment of belt tightness.

Dehumidifier

Air T&D provides the most energy efficient Liquid Desiccant Dehumidification System (LDDS) and Liquid

Desiccant Air-Conditioning (LDAC) on the world market. Through the breakthrough on the design and

operation of LDDS & LDAC technologies, our products can achieve 30% to 50% energy savings when applied

to residential and commercial building HVAC systems.



Both LDDS &LDAC have been effectively integrated with various energy sources, including two-way heat

pump, chilled water and condensation heat in existing system, and combination of renewable energy and

grid power. Some key innovations are implemented, such as Energy Recovery, Vacuum Regeneration,

Intelligent Control, Hybrid and Distributed Operation, and Zero crossovers, etc., resulting in industry-leading

energy efficiency.

Automation System

Air T&D provides a complete BMS system, called “BSTAR”, with controller hardware, data acquisition tool,

HMI designer, and control function modules. BSATR can be used as perfect control solution of air handling

unit. Using this powerful platform, customers can design basic controls and some advanced functions for

Air T&D air handling units:

• Temperature control

• Frequency converter operation for constant air flow or duct pressure

• On-demand control

• Heating and cooling shunts

• CO2 compension control of fans

• Control of different types of heat exchanger

• Control of extra fans

• Control of temperature zones

• Communication via BACnet or Modbus

• Monitoring via a C/S or B/S interface

Rigging

There is a dual-use device provided at the bottom of the container box which allows flexible hoisting

for site conditions. The container segments could be separated into different parts and allows easy

shipping. The modular design allows easy replacements of AHU components, and makes on-site

installation process very convenient.



2. Configurations and Selections

2.1 Nomenclature

KDZ E 20 12 D W

1.

2. r

i

m

a

r

y

E

f

f

i

c

i

e

3.

Model Sample:

KDZE2012DW AHU:

Horizontal type; panel thickness is 25 mm; unit width is 20 mm; unit height is 12 mm.

Unit height = 12 X 100 + 25 X 2 + 80 = 1330 mm

Unit width = 20 X 100 + 25 X 2 = 2050 mm

Unit module and size calculation formula:

(1) Unit height = height index X 100 + panel thickness X 2 + base height

(2) Unit width = width index X 100 + panel thickness X 2

2.2 Judgment of Left-handed and Right-handed Type

Criterion

When the unit have chilled/hot water pipe,

o if the chilled/hot water pipe is at right side, and in the same direction as air flow,

the unit is known as right-handed type;

o Otherwise the unit is known as left-handed type.

When the unit does not have chilled/hot water pipe,

o if the access door is at right side, and in the same direction as airflow, the unit is

known as right-handed type;

o Otherwise the unit is known as left-handed type.

W: horizontal type, L: vertical type

Design serial number

Unit height index

Unit width index

Panel thickness: E=25mm, S=35mm, W=50mm

Modular Air Handling Unit



Air Intake

Air Supply

Remark

For Air T&D standard units, the access door, electrical wiring connection, and hot water pipe

are all located at the same side.

If customer has special requirements, please indicate them in the purchase order.

2.3 Quick Model Selection

Unit

Model

Nominal

Air Flow

(m3/h)

Air Velocity (m/s) Fan Impeller

Diameter (mm) 2 2.25 2.5 2.75 3 3.25 3.5

Air Flow (m3/h)

0606 1500 1230 1390 1540 1690 1850 2000 2150 180

0706 2000 1560 1750 1940 2140 2330 2530 2720 180

0906 3000 2200 2480 2750 3030 3300 3580 3860 200

0907 3500 2690 3030 3370 3700 4040 4380 4710 225

1007 4000 3090 3470 3860 4250 4630 5020 5410 225

1008 5000 3650 4110 4560 5020 5480 5930 6390 250

1208 6000 4590 5160 5730 6310 6880 7450 8030 280

1308 7000 5050 5690 6320 6590 7580 8210 8850 315

1309 8000 5830 6560 7290 8020 8750 9480 10210 315

1310 9000 6610 7440 8260 9090 9910 10740 11570 355

1410 10000 7220 8120 9030 9930 10830 11740 12640 355

1411 11000 8070 9080 10090 11100 12110 13120 14120 355

1511 12000 8760 9850 10940 12040 13130 14230 15320 400

1512 13000 9680 10890 12100 13310 14520 15720 16930 400

1712 15000 11190 12590 13990 15380 16780 18180 19580 450

2012 18000 13460 15140 16820 18500 20190 23950 25790 500

2013 20000 14740 16580 18420 20270 22110 23950 25790 500

2114 23000 16920 19040 21150 23270 25380 27500 29610 560

2314 25000 18720 21060 23400 25740 28080 30420 32760 560

2415 28000 21190 23840 26490 29140 31780 34430 37080 630

2416 30000 22760 25600 28450 31290 34140 36980 39830 630

2417 33000 23920 26910 29900 32890 35880 38870 41860 630

2418 35000 25910 29150 32390 35630 38870 42110 45350 710

2420 40000 28900 32520 34160 39740 43360 46970 50580 710

2621 45000 33190 37340 41490 45630 48780 53930 58080 800

2821 50000 35980 40470 44970 49470 53970 58460 62960 800



2823 55000 39520 44460 49390 54330 59270 64210 69150 800

2924 60000 42890 48250 53610 58970 64330 69690 75050 900

3026 65000 47660 53620 59580 65540 71490 77450 83410 900

3226 70000 51090 57480 63870 70250 76640 83020 89410 900

3228 75000 55180 62080 68970 75870 82770 89670 96560 1000

3428 80000 58880 66240 73600 80960 88320 95680 103040 1000

3430 90000 63240 71150 79060 86960 94870 102770 110680 1000

3632 100000 72630 81710 90790 99870 108950 118030 127100 1600

Note:

1. We suggest choosing unit type under air velocity of 2.75 m /s, and then determining unit size by the

nominal air flow.

2. When air velocity > 2.75 m/s, we suggest to install water demister in the unit.

3. If user requests for a nominal air flow greater than 100,000 m3/h, please contact us.

3. Components and Options

3.1 Diagram of Functional Sections

Functional

Section Diagram Remarks

Functional

Section

Name

Diagram Remarks

Mixing Section

When mixing section is followed by filer, access door needs to be added.

Wet film humidification section

Could be installed in cooling coil; need not to have independent section; it takes 600mm section to place separately.

Fresh/ Return/ Exhaust air section

High-pressure/ spray/ micro-fog humidifier

Provide drain pan; Could be placed beside cooling coil and share water Demister .

Plate type primary efficiency filer section

There should have inspection section before this section.

Fan section

Should have equally air distribution when air supply in middle section; Should have access door for inspection and maintenances.

Bag type primary/medium efficiency filer section

There should have inspection section before this section.

Fan section with diffuser

(均流段) Distribution section

Generally be placed behind the fan.

Cooling coil Section

Water Demister can be eliminated when wet film is placed after cooling coil.

Silencer



Hot water heating coil section

中间段

Generally used for inspection and maintenances

Steam heating coil section

Supply air section

Electrical heating section

Electrical heater should have interlocking control with the fan.

Plat Energy Recovery unit

Dry steam/ Electrode humidification section

Wheel Energy Recovery unit

Should leave some room for inspection and maintenances before and after this section

3.2 Pressure Drop of Functional Sections

Functional Section Pressure Drop (Pa) Functional Section Pressure Drop (Pa)

Mixing section 20 Steam heating section (1 row) 20

Cooling coil (2 rows) 40 Steam heating section (2 rows) 40

Cooling coil (4 rows) 80 Fresh air / return air / exhausted air

sections 20

Cooling coil (6 rows) 120 Silencer section 30

Cooling coil (8 rows) 160 Fan section with diffuser 20

Water Demister 60 Humidifier (60mm wet membrane) 25

Heating coil (1 row) 20 Humidifier (100mm wet membrane) 30

Heating coil (2 rows) 40 Humidifier (150mm wet membrane) 45

Heating coil (4 rows) 70 Humidifier (200mm wet membrane) 60

* The testing is under air velocity of 2.75 m /s.



3.3 Combination of Commonly Used Function Sections

Section Combination 1: External Plate-type Filter + Cooling coil (Water Demister) + Fan

This is the most economic combination.

The combination 1 is allocated with the basic cooling coil and applied to general central air-conditioning

systems. It has the advantages with compact structures, small space occupation, and low investment.

Section Combination 2: Mixing + Plate-type Filter + Cooling coil (Water Demister) + Fan

It is the most economic combination with primary efficiency mixing air.

The combination 2 is allocated with the basic cooling coil and primary efficiency filter. It can handle fresh,

return, and mixing air, suitable for the temperature controlling requirements of the normal room. It has the

advantages such as compact structure and low cost.

Section Combination 3: Mixing Air + Plate-type Filter + Cooling coil (Water Demister) + Heating + Humidifying

+ Fan

It is most commonly used combination for air handling.

The combination 3 is allocated with the basic cooling coil, heater and humidifier, suitable for high

requirements of temperature and humidity control.



Section Combination 4: Mixing + Plate-type Filter + Cooling coil (Water Demister ) + Heating + Fan + Humidifying

+ Fan with Diffuser + Medium-Efficiency Filter + Air Supply

It is mainly used for purifying air.

The combination 4 is allocated with cooling coil, heater, humidifier and primary/ medium efficiency filter,

suitable for requirements of air purifying and temperature/humidity controlling.

Section Combination 5: Mixing + Primary/Medium Efficiency Filter + Cooling coil (Water demister) + Heating +

Humidifying + Fan + Diffuser + Silencer + Sub-high Efficiency Filter + Air Supply

It is used for high-purifying air-conditioning system.

The combination 5 is allocated with cooling coil, heater, humidifier and primary/medium efficiency filter,

suitable for requirements of air purifying, temperature, humidity and noise controlling.

Section Combination 6: (Top Layer) Air Supply + Medium Efficiency Filter + Middle Section; (Bottom Layer)

Mixing Air + Plate-type Filter + Cooling coil (Water Demister ) + Heating + Humidifying + Fan

The combination 6 is applied to the places which have the requirements of air purifying, temperature and

humidity controlling, and limited spaces.



Section Combination 7: (Top Layer) Fresh Air and Primary Efficiency + Plate-type Energy Recovery + Air Return

Primary Efficiency; (Bottom Layer) Ventilator + Plate-type Energy Recovery + Middle + Cooling coil (Water

demister) + Fan

It is an energy-saving air-conditioning system.

It is able to recover energy via ventilation, applied to the places which have small both Energy Recovery

and air flow.

Section Combination 8: (Top Layer) Air Return + Primary Efficiency Filter + Wheel Dehumidifier + Ventilation;

(Bottom Layer) Fan + Cooling coil (Water demister) + Middle + Wheel Dehumidifier + Primary Efficiency Filter

+ Fresh Air

It is an energy-saving air-conditioning system.

The combination is able to recover energy via ventilation, applied to the places which have large amount

of both Energy Recovery and air flow.



4. Specifications and Performances

4.1 Cooling Coil

User can select coils by accurate calculation from chilled water, hot water, steam and direct expansion types,

to provide optimum performance conditions. In accordance with system requirements, copper tube

aluminum fin or steel tube-steel fin coils are used in Air T&D air handling units. While copper tubes up to

2x105 Pa pressure is used in steam applications, the use of steel tubing is required for higher pressure steam

applications. Standard tube diameters used are 3/8”, 1/2” and 5/8”. In aluminum finned designs, fins are

coated with epoxy, providing high corrosion resistance.

Cooling Capacity and Water Flow VS Return Air Flow

Unit

Model

Nominal

Air Flow

(m3/h)

2 rows 4 rows 6 rows 8 rows

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

606 1500 4.7 0.8 8.6 1.5 11.5 2 13 2.2

706 2000 6.3 1.1 11.4 2 15.4 2.7 17.4 3

906 3000 9.4 1.6 17.1 3 23.1 4 26.1 4.5

907 3500 10.9 1.9 20 3.4 26.9 4.6 30.4 5.2

1007 4000 12.5 2.2 22.9 3.9 30.8 5.3 34.8 6

1008 5000 15.6 2.7 28.6 4.9 38.5 6.6 43.5 7.5

1208 6000 18.8 3.2 34.3 5.9 46.2 8 52.2 9

1308 7000 21.9 3.8 40 6.9 53.8 9.3 60.9 10.5

1309 8000 25 4.3 45.7 7.9 61.5 10.6 69.6 12

1310 9000 28.1 4.8 51.4 8.9 69.2 11.9 78.3 13.5

1410 10000 31.3 5.4 57.1 9.9 76.9 13.3 87 15



1411 11000 34.3 5.9 62.9 10.8 84.6 14.6 95.7 16.5

1511 12000 37.5 6.5 68.6 11.8 92.3 15.9 104.3 18

1512 13000 40.6 7 74.3 12.8 100 17.2 113 19.5

1712 15000 46.9 8.1 85.7 14.8 115.4 19.9 130.4 22.5

2012 18000 56.3 9.7 102.9 17.7 138.5 23.9 156.5 27

2013 20000 62.5 10.8 114.3 19.7 153.8 26.5 173.9 30

2114 23000 71.9 12.4 131.4 22.7 176.9 30.5 200 34.5

2314 25000 78.1 13.5 142.9 24.6 192.3 33.2 217.4 37.5

2415 28000 87.5 15.1 160 27.6 215.4 37.1 243.5 42

2416 30000 93.8 16.2 171.4 29.6 230.8 39.8 260.9 45

2417 33000 103.1 17.8 188.6 32.5 253.8 43.8 287 49.5

2418 35000 109.4 18.9 200 34.5 269.2 46.4 304.3 52.5

2420 40000 125 21.6 228.6 39.4 307.7 53.1 347.8 60

2621 45000 140.6 24.2 257.1 44.3 346.2 59.7 391.3 67.5

2821 50000 156.3 26.9 285.7 49.3 384.6 66.3 434.8 75

2823 55000 171.9 29.6 314.3 54.2 423.1 72.9 478.3 82.5

2924 60000 187.5 32.3 342.9 59.1 461.5 79.6 521.7 90

3026 65000 203.1 35 371.4 64 500 86.2 565.2 97.5

3226 70000 218.8 37.7 400 69 538.5 92.8 608.7 104.9

3228 75000 234.4 40.4 428.6 73.9 576.9 99.5 652.2 112.4

3428 80000 250 43.1 457.1 78.8 615.4 106.1 695.7 119.9

3430 90000 281.3 48.5 514.3 88.7 692.3 119.4 782.6 134.9

3632 100000 312.5 53.9 571.4 98.5 769.2 132.6 869.6 149.9

Note:

1. Chilled water is supplied at 7 °C, returned at 12 °C.

2. Under return air condition, entering dry bulb temperature is 27 °C, and wet bulb temperature is

19.5 °C.

3. The above parameters are for reference only; please contact us for customized working conditions, coil

configurations and cooling capacities.

4. The test is under air velocity of 2.75 m /s.

5. Please contact us if user requests for a nominal air flow greater than 100,000 m3/h.

Cooling Capacity and Water Flow VS Primary Air Flow

Unit

Model

Nominal

Air Flow

(m3/h)

2 rows 4 rows 6 rows 8 rows

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

Cooling

Capacity

(kW)

Water

Flow

(m3/h)

606 1500 10 1.7 19 3.3 24.6 4.2 27.8 4.8

706 2000 13.3 2.3 25.3 4.4 32.8 5.7 37 6.4

906 3000 20 3.4 38 6.5 49.2 8.5 55.6 9.6

907 3500 23.3 4 44.3 7.6 57.4 9.9 64.8 11.2

1007 4000 26.7 4.6 50.6 8.7 65.6 11.3 74.1 12.8

1008 5000 33.3 5.7 63.3 10.9 82 14.1 92.6 16

1208 6000 40 6.9 75.9 13.1 98.4 17 111.1 19.2

1308 7000 46.7 8 88.6 15.3 114.8 19.8 129.6 22.3

1309 8000 53.3 9.2 101.3 17.5 131.1 22.6 148.1 25.5

1310 9000 60 10.3 113.9 19.6 147.5 25.4 166.7 28.7



1410 10000 66.7 11.5 126.6 21.8 163.9 28.3 185.2 31.9

1411 11000 73.3 12.6 139.2 24 180.3 31.1 203.7 35.1

1511 12000 80 13.8 151.9 26.2 196.7 33.9 222.2 38.3

1512 13000 86.7 14.9 164.6 28.4 213.1 36.7 240.7 41.5

1712 15000 100 17.2 189.9 32.7 245.9 42.4 277.8 47.9

2012 18000 120 20.7 227.8 39.3 295.1 50.9 333.3 57.7

2013 20000 133.3 23 253.2 43.6 327.9 56.5 370.4 63.9

2114 23000 153.3 26.4 291.1 50.2 377 65 425.9 73.4

2314 25000 166.7 28.7 316.5 54.6 409.8 70.7 463 79.8

2415 28000 186.7 32.2 354.4 61.1 459 79.1 518.5 89.4

2416 30000 200 34.5 379.7 65.5 491.8 84.8 554.6 95.8

2417 33000 220 37.9 417.7 72 541 93.3 611.1 105.4

2418 35000 233.3 40.2 443 76.4 573.8 98.9 648.1 111.7

2420 40000 266.7 46 506.3 87.3 655.7 113.1 740.7 127.7

2621 45000 300 51.7 569.6 98.2 737.7 127.2 833.3 143.7

2821 50000 333.3 57.5 632.9 109.1 819.7 141.3 925.9 159.6

2823 55000 366.7 63.2 696.2 120 901.6 155.5 1018.5 175.6

2924 60000 400 69 759.5 130.9 983.6 169.6 1111.1 191.6

3026 65000 433.3 74.4 822.8 141.9 1065.6 183.7 1203.7 207.5

3226 70000 466.7 80.5 886.1 152.8 1147.5 197.9 1296.3 223.5

3228 75000 500 86.2 949.4 163.7 1229.5 212 1388.9 239.5

3428 80000 533.5 92 1012.7 174.6 1311.5 226.1 1481.5 255.4

3430 90000 600 103.4 1139.2 240.1 1475.4 254.4 1666.7 287.4

3632 100000 666.7 114.9 1265.8 218.2 1639.3 282.6 1851.9 319.3

Note:

1. Chilled water is supplied at 7 °C, and returned water at 12°C.

2. Under return air condition, entering dry bulb temperature is 35°C, and wet bulb temperature is 28°C.

3. The above parameters are for reference only; please contact us for customized working condition,

coil configuration and cooling capacity.


5. Please contact us if user requests for nominal air flow greater than 100,000 m3/h.

4.2 Heating Coil

Air T&D uses finned galvanized steel tubes as electrical heater coil material. We also provide stainless steel

tubes as alternative coil material. All electrical coils are placed into a galvanized sheet casing. High capacity

electrical heating coils can be split into the desired stages upon demand.

Heat Capacity and Water Flow VS Fresh/Return Air Flow

Unit

Model

Nominal

Air Flow

(m3/h)

Under return air condition (dry bulb

temperature is 15 °C)

Under fresh air condition (dry bulb

temperature is 7 °C)

Heat Capacity (kW) Heat Capacity (kW)

1 row 2 rows 3 rows 4 rows 1 row 2 rows 3 rows 4 rows

606 1500 4.7 9.6 12.7 14.9 5.7 11.1 15.2 18.3

706 2000 6.2 12.8 16.9 19.8 7.5 14.8 20.2 24.4

906 3000 9.3 19.2 25.4 29.7 11.3 22.2 30.3 36.6



907 3500 10.9 22.4 29.7 34.7 13.2 25.9 35.4 42.7

1007 4000 12.4 25.6 33.9 39.6 15.1 29.6 40.4 48.8

1008 5000 15.5 32.1 42.4 49.5 18.9 37 50.5 61

1208 6000 18.6 38.5 50.8 59.4 22.6 44.4 60.6 73.2

1308 7000 21.7 44.9 59.3 69.3 26.4 51.9 70.7 85.4

1309 8000 24.8 51.3 67.8 79.2 30.2 59.3 80.8 97.6

1310 9000 28 57.7 76.3 89.1 34 66.7 90.9 109.8

1410 10000 31.1 64.1 84.7 99 37.7 74.1 101 122

1411 11000 34.2 70.5 93.2 108.9 41.5 81.5 111.1 134.1

1511 12000 37.3 76.9 101.7 118.8 45.3 88.9 121.2 146.3

1512 13000 40.4 83.3 110.2 128.7 49.1 96.3 131.3 158.5

1712 15000 46.6 96.2 127.1 148.5 56.6 111.1 151.5 182.9

2012 18000 55.9 115.4 152.5 178.2 67.9 133.3 181.8 219.5

2013 20000 62.1 128.2 169.5 198 75.5 148.1 202 243.9

2114 23000 71.4 147.4 194.9 227.7 86.8 170.4 232.3 280.5

2314 25000 77.6 160.3 211.9 247.5 94.3 185.2 252.5 304.9

2415 28000 87 179.5 237.3 277.2 105.7 207.4 282.8 341.5

2416 30000 93.2 192.3 254.2 297 113.2 222.2 303 365.9

2417 33000 102.5 211.5 279.7 326.7 124.5 244.4 333.3 402.4

2418 35000 108.7 224.4 296.6 346.5 132.1 259.3 353.5 426.8

2420 40000 124.5 256.8 339.5 395.4 150.8 296.8 404.5 488.2

2621 45000 139.8 288.5 381.4 445.5 169.8 333.3 454.5 548.8

2821 50000 155.3 320.5 423.7 495 188.7 370.4 505.1 609.8

2823 55000 170.8 352.6 466.1 544.6 207.5 407.4 555.6 670.7

2924 60000 186.3 384.6 508.5 594.1 226.4 444.4 606.1 731.7

3026 65000 201.9 416.7 550.8 643.6 245.3 481.5 656.6 792.7

3226 70000 217.4 448.7 593.2 693.1 264.2 518.5 707.1 853.7

3228 75000 232.9 480.8 635.6 742.6 283 555.6 757.6 914.6

3428 80000 248.4 512.8 678 792.1 301.9 592.6 808.1 975.6

3430 90000 279.5 576.9 762.7 891.1 339.6 666.7 909.1 1097.6

3632 100000 310.6 641 847.5 990.1 377.4 740.7 1010.1 1219.5

Note：

1. Hot water is supplied at 60 °C, and returned at 50 °C.

2. Under return air condition, entering dry bulb temperature is 15 °C, and wet bulb temperature is 7 °C.

3. The above parameters are for reference only; please contact us for customized working condition, coil

configuration and cooling capacity.


5. Please contact us if user requests for nominal air volume greater than 100,000 m3/h.

4.3 Filter

The basic function of filter cells is to prevent the accumulation of dust on the internal surfaces of coils



and panels, extending the efficient lifetime of the air handling unit. Dust accumulation is an unwanted

condition which reduces the heat transfer efficiency of coils. Additionally, use of high particle efficiency

filters is required for environments where the air must be kept free of air-borne harmful

microorganisms (pharmacological production facilities, operating rooms, clean rooms, microchip

production facilities). For this reason, various filter classes with the ability to filter particles of various

diameters have been developed.

Air T&D filter cells are distinguished for their design which reduces filter pass pressure drop by

minimizing the rate of filtration. To this end, cell dimensions are designed in proportion to filter

dimensions. The special spring clip casing design provides a high level of impermeability. This feature

is particularly important for air handling units since it could prevent microbiological proliferation. In

addition to these features, filter cells have been designed to facilitate easy maintenance thanks to their

wide filter covers and spring clip filter casings. Differential pressure stats for measuring filter

occupancy can also be used as an option. In Air T&D air handling units, various filtering options are

applied and optimum options are offered depending on the place of use and upon requirements. Filter

selection should be done by considering all these properties to extend filter life span and lower

maintenance costs.

Panel Filter:

Manufactured in G3 and G4 classes, these filters are produced from high quality galvanized steel, PVC

or fiberglass material. The decisive point in the design of these filters which have a gravimetric

efficiency of 85 - 95%, is creating a corrugated structure and hence a larger filtering surface. Panel

filters which can withstand temperatures of up to 180°C are used in Air T&D air handling units for pre-

filtration to lengthen the usage lifetime of higher particle efficiency filters. Panel filters are allowed to

be reused after washing, which lowers the operational and maintenance costs, and thus becomes the

most popular filter type of choice.

Bag Filter:

Manufactured in various classes from G4 to F9, bag filters are produced with galvanized frames as a

standard. The filtering element is produced from fiberglass. Its extended surface design leads to low

air flow rates, thus facilitating low pressure drops, high dust capturing capacity, long usage lifespan

and low energy costs. Bag filters are capable of providing solutions for all types of air handling units.

For example, rigid type bag filters with a plastic frame design are popular in the market since they can

be used in both downstream and upstream.

Pressure Drop for Different Filters under Air Velocity of 2.75 m /s

Filter type Initial Pressure Drop (Pa) Final Pressure Drop (Pa) Design Pressure Drop (Pa)

G3 plate filter 35 80 65

G4 plate filter 40 100 80

G3 bag filter 30 60 50

G4 bag filter 35 70 55

F5 bag filter 55 110 90





H10 150 300 240

H11 180 360 290

H12 190 380 300



H13 220 440 350

Filtration Performance for Different Filters

Filter Type Filter Material Filtration Class Filtration Efficiency Test Method

Primary Efficiency

Panel Filter

Synthetic Fiber G3 80 – 90 % Gravimetric Method

G4 > 90 %

Primary Efficiency

Bag Filter

Synthetic Fiber G3 80 – 90 % Gravimetric Method

G4 > 90 %

Medium Efficiency

Bag Filter

Synthetic Fiber

Or Glass Fiber

F5 40 – 60 % Colorimetric Method

F6 60 – 80 %

F7 80 – 90 %

F8 90 – 95 %

F9 >= 95 %

Sub-High

Efficiency

Filter

Glass Fiber H10 85 % Most Penetration

Particle Size (MPPS)

Filter Efficiency Configuration for Different Types of AHU

Types General

configuration Configuration for electronic factory

Purification class − Class 5 Class 6 Class 7 Class 8 Class 8.3

Primary efficiency G3 G4(F5) G4(F5) G4(F5) G4 G3

Medium efficiency F6 F8 F8 F8 F7 F6

Higher medium /sub-

high efficiency − H10 F9 − − −

Types Configuration for

tobacco factory Configuration for pharmaceutical industry

Purification class − Class 5 Class 7 Class 8 Class 8.3

Primary efficiency G4 G4(F5) G4(F5) G4 G3

Medium efficiency F7 F8 F8 F7 F6

Higher medium / sub-

high efficiency − H10 − − −

Efficiency Comparisons of Air T&D Filer in Europe, U.S.A and China Protocol

Unit model 0606 0706 0906 0907 1007 1008 1208 1308 1309 1310 1410 1411 1511 1512 1712

Filter

dimension

592 * 592

- - - - 2 2 1 2 - 2 2 - - 2 -

287 * 592

- - - 1 1 1 - - 2 2 2 - - - -

490 * 592

- 1 1 1 - - 1 - 2 - - 4 4 2 3

490 * 490

1 - - - - - - - - - - - - - 3

Unit model 2012 2013 2114 2314 2415 2416 2417 2418 2420 2621 2821 2823 2924 3026 3226

Filter

dimension

592 * 592

3 6 4 6 6 6 6 6 9 12 12 12 12 16 20

287 * 592

- - 2 2 - 3 3 - 3 - 3 7 7 4 -

490 * 592

3 - 2 - 2 2 2 5 - - - - - - -



490 * 490

- - - - - - - 1 - - - - - - -

Unit model 3228 3428 3430 3632 3634 4034 4234 4535 4835 5135 5435 5735 6036 6236

Filter

dimension

592 * 592

- - - - 2 2 1 2 - 2 2 - - 2

287 * 592

- - - 1 1 1 - - 2 2 2 - - -

490 * 592

- 1 1 1 - - 1 - 2 - - 4 4 2

490 * 490

1 - - - - - - - - - - - - -

Note:

The table above could only be used as reference for build-in panel filter, filter bag filter. The filter

dimensions provided in above tables are under Air T&D’s standard.

4.4 Fan/ EC Fan/ Fan Matrix

The air handling unit includes a fan cell for the purpose of facilitating air circulation through an aspirator

and/or ventilator, depending on the requirements of the environment. While forward curved fans are

preferred for AHUs within the low pressure range, backward curved fans can be used for AHUs within the

medium and high pressure ranges. In addition to these, fans are commonly preferred due to their efficiency

and low noise level operation. Depending on design conditions, plug (without scroll case, single inlet, direct

coupled) fans can also be used.

Fans used in Air T&D air handling units are manufactured from galvanized sheet metal. Forward and

backward curved fans are statically balanced according to the ISO 1940-G6.3 standard. Flexible connection

is used between the air exhaust and the unit body to dampen vibrations. Flexible connections which used

to connect the ductwork from outside are also available. Diffusers are installed to build interconnections

between the fan and other cells. The basic purpose of the diffuser is to distribute the air flow in the

subsequent cell evenly within the cell.

Performance Features for Different Fans

Fan types Forward curved Backward curved Radial

Characteristics Wide range for air flow, low noise

level, low rotation speed

Competitive efficiency, low noise

level, flat curve behavior, high

strength

Competitive efficiency, low

noise level, flat curve

behavior, high strength

Application

range

Low air pressure, or for occasions

with special requirements (e.g.

noise level)

Large air pressure, large air flow,

wide performance range

Large air pressure, large air

flow

Principle of

selection

Small air flow range, avoiding to

use fans with high rotation speed

Medium/low air pressure, large

air flow

Large air flow, medium to

high air pressure, especially

for purification air-

conditioning units

EC (Electronically Commutated) Motor Fans

Depending on global and nationwide research, the highest potential whereby electrical energy saving can

be achieved has to do with electrical motors. The leading factor in implementing this responsibility is EC

technology with the high energy economy it provides.



The EC motor is a DC motor with electronic commutation. This means that the motor speed can be

controlled very effectively. The motor speed is controlled by how rapidly the magnetic flux in the motor

switches. The permanent magnets of the rotor create the magnetic flux in the motor. Speed control is

carried out using a control unit integrated with the motor. Control signal is in 0–10 V, starting at 1.4 V and

stopping at <1 V. The EC motor is efficient throughout its operating range and is brushless, requiring less

maintenance.

The Air T&D AHU can be equipped with an EC motors by customer demand. Details distinguishing it from

other products on the market, and some advantages for the manufacturer and end user are as follows:

- Process controller, speed control device or driver, electrical filters and overload protection (for

motor and electronics) elements are all within the motor.

- Low noise and vibration levels are achieved throughout the entire operational range.

- 100% speed control is available without using additional components.

- Fixed performance throughout the full supply current range.

- Integrated DC supply source for sensors.

- Programmable analogue outlet.

- Integrated PID, access to and ability to modify PID parameters depending on the algorithm.

- Integrated alarm, access to a wide range of failure, error and actual details throughout the

operation period depending on the EEP- ROM memory.

Fan Selection

System requirements influencing fan selection are air quantity, static pressure, non-standard air density,

noise level or use of the fan’s operating environment, as well as properties of the useable area and cooling

load. Air T&D will select fan types and customize fan schemes on user demands.

- The first step in a selection process is to select fan type. If that the fan is to be installed into an

AHU, the most common question is whether to select a centrifugal fan in casing or without

casing. Centrifugal fan in casing usually has slightly higher efficiency than a fan without casing,

but in an AHU it is more vulnerable to the installation effect, which reduces its efficiency.

Therefore, for AHUs, a backward curved centrifugal fan without casing is the preferred option for

majority of AHUs.

- The next step is to select a fan motor. Because of the high efficiency, EC motors should be used

whenever possible. Asynchronous AC motors with variable frequency drives are the second

option. When selecting the fan size, several sizes are usually able to provide the required airflow

and pressure in the operating point. The size, where the operating point is closest to the best

efficiency point and motor electrical input is the lowest, should be selected.

Fan Matrix

It is a combination of smaller fans built into a wall section to replace a traditional single large fan. The

custom air handling units they supply using this technology incorporate multiple direct-drive centrifugal

plenum fans, assembled in a rectangular array of 4 to 9+ fans, all discharging into a single plenum. The fans

used are specially designed and optimized for use. Each fan array is usually controlled by a single variable

speed drive, which controls the speed of all fans simultaneously. The use of multiple direct-drive fans

operating in parallel improves reliability by providing redundancy. Optimized fan wheel construction and

improved internal aerodynamics further enhance energy performance.

In a traditional system using direct drive motors, it is common to see motor loads at 1/4th to 1/8th of their

nameplate rating for a significant portion of their operation hours, resulting in reduced power factors and



lower fan and motor efficiencies. To more closely match site conditions, the fan matrix wall can be tuned

by turning one or more fans off to allow remaining fans and motors to be fully loaded at or near peak

efficiency. Air flow rates can be varied through use of a variable speed drive, by turning fans on and off, or

by using both control strategies in combination. The advantages are listed at the following as the key

reasons to employ this fan arrangement:

- Shorten the unit

- Quiet operation

- Energy savings through optimized performance

- Redundancy

- Lower maintenance costs

- Good for retrofits

The following is a sample drawing of Air T&D fan matrix wall (with 2 X 3 fan matrix).



4.5 Humidifier

The humidification unit is used to control the relative humidity of the ambient air by increasing the

absolute humidity of air in the air handling unit. The choice of humidification equipment is depending

on user requirements for the indoor environment. Various types of humidifiers can be used in Air

T&D air handling units according to the application type.

Saturated Steam Humidifier

The most commonly used humidification method is to use dry steam to humidify the air. The user

must provide 0.1 – 0.4MPa saturated steam source. We made use of double insulation steam

pipe clamp stainless steel as material for dry steam humidification equipment, which has a

beautiful appearance, corrosion resistance and extra-long lifetime. We provide a unique muffler

measures to enables absolutely silent injection process. The double insulation design ensures that

there is no condensed water discharge phenomenon occurs inside the tube, and can also achieve

high-precision humidification control.

Wet Film Humidifier

Wet film humidifier is the most simple and economical humidify equipment; users only need to

provide water. Wet film humidifier characterized by increase humidifying space, could also

eliminate or replace the use of water flap. However, due to the presence of humidification

hysteresis in control process, wet film humidifier are not suitable to be used in occasions with high

requirements on cleanliness and humidity. It is commonly used in comfort air conditioning systems.

Immersed Electrode Steam Humidifier

Electrode humidifier makes use of conductivity of water to heat up and produce steam for air

humidification, and it is suitable for offices, manufacturing plant, computer rooms and sterile field.

Due to its own characteristics, it will not cause fire when working under low water capacity; it is a

safe and reliable humidification method. However, it does have certain requirements on water

quality; generally, it uses tap water, but cannot use purified water or distilled water. The electrode

humidifier can perform precise adjustment of humidification.

Spray Air Washer Humidifier

T he working principle of h igh-pressure spray / high-pressure fog humidifier is to increase pump

pressure, and spray high-pressure water through the nozzle. Due to the small size of spray particles

ejected out from high-pressure nozzle, it has high humidification efficiency, humidity control

precision can be controlled within ±8 ~±12%. It is suitable to use in manufacturing industries.

Selection of Humidification Type

Humidification Type Isothermal humidification Equal-enthalpy humidification

Humidifier types Saturated steam

humidifier Electrode humidifier High-pressure spray humidifier Wet film humidifier

Humidification

principle

Introduce steam

directly

Current pass through

water and heat up the

water to produce steam

Spray high-pressure water

through nozzles, exchanging

heat with air and then

evaporating

Water evaporate

when air pass

through the wet film

Humidification

capacity Determined by humidifier itself

Determined air condition before humidification and

humidifier itself



Application range Suitable for high-precision control occasions Suitable for general precision control occasions

4.6 Dehumidifier

Quality HVAC systems that deliver consistent cooling and precision control are essential to the overall

operations and health of most commercial facilities. Nowadays, engineers and property owners are taking

dehumidification as a key consideration in the design of HVAC systems. The benefits are clear: the removal

of moisture in air could improve indoor air quality (IAQ), (or most of time we say IEQ, indoor environment

quality) as well as provide better indoor comfort level, in the meanwhile supporting facility operations and

maximizing the life of building, furnishings and equipment.

Air T&D dehumidification options help significantly reduce moisture-related damage and degradation to

the facility and other assets, preventing peeling paint, odor problems and loss of structural integrity. From

the moderate dehumidification requirements of typical office environments, to moisture-sensitive

museums, printing plants and surgical suites, the comprehensive approach of Air T&D offers solutions that

are right for users’ facility and budget.

Traditional Dehumidification solution

Name Cooling Dehumidification (Cooling Method) Rotor Dehumidification (Chemical Method)

Feature Cooling the air below the dew point, then

removing the condensed moisture Dehumidifying by the adsorption of solid drier

Scope of

Application

Applying for the temperature range higher

than the dew point Applying for low dew point

Rules of Selection Dehumidifier can remove all the indoor

moisture load

Reasonably distribute air flow, maximize the

dehumidifier capacity to achieve the best

dehumidifying effect

Note: Please contact our company if the customers have requirements of dehumidification; we will

design the units according to customers' specific parameters.

Air T&D Innovative Dehumidification Solution

Air T&D provides the most energy efficient Liquid Desiccant Dehumidification System (LDDS) and Liquid

Desiccant Air-Conditioning (LDAC) on the world market. Through the breakthrough on the design and

operation of LDDS & LDAC technologies, our products can achieve 30% to 50% energy savings when applied

to residential and commercial building HVAC systems.

LDDS: a series of standard products with single unit air treatment capacities ranging from 500

m3/h to 4,000m3/h. Since the products are modular designed, we can meet all users need

through module combination. Our professional design team can also tailor the design for any

special requirements from customers.

LDAC: The LDAC are designed for general building HVAC applications to realize independent

control of air temperature and humidity, with air flow ranging from 1000 m3/h to 40,000m3/h.

LDAC can integrate with existing HAVC components easily to supply cool, dry and clean air into

occupied space.

Both LDDS &LDAC have been effectively integrated with the following energy sources:



• Utilize two-way heat pump to supply cooling and heating energy for dehumidifier and

regenerator simultaneously. This integration enables the system to operate independently and is

suitable for the application that renewable and cooling energy are not conveniently available

• Integrate the LDDS with existing HVAC systems to employ chilled water and condensation heat as

external energy to drive the de-humidifier and regenerator, respectively.

• Combine the renewable energy and grid power to drive LDDS operation. Our intelligent control

technology enables the system to operate in hybrid mode and seek a maximum usage of

renewable energy while taking the grid power as an auxiliary.

Key Innovations

Hybrid Operation: In conventional systems, desiccant solutions continuously exchange between

dehumidification and regeneration columns in order to maintain the pre-specified concentrations. Our

patented hybrid operation technology makes the desiccant solutions cycling inside the each tower for a

specified concentration range, and exchanges the solutions once the limit is reached to avoid the energy

waste and improve the system efficiency.

Energy Recovery: Conventional systems require a large amount of heat energy for solution regeneration.

Most of the heat energy is wasted as the regenerated air is discharged directly. Our LDDS &LDAC are able

to recover most of the heat with a hot water pipe energy recovery device. This structure innovation results

in 60% regeneration energy saving com-pared with the current technologies.

Vacuum Regeneration: High desiccant solution regeneration temperature has been become a key barrier

for wide application of LDDS & LDAC. Our novel designed absorption-based liquid desiccant regenerator

can drastically reduce the regeneration temperature from 80°C (conventional type) to 40°C, thus most low

grade energy, such as solar energy, wasted heat from chiller, can be reused effectively to concentrate the

desiccant solution. Moreover, no fan is equipped so that the system is more energy-efficient and reliable.

Intelligent Control: The ability of liquid desiccant to remove water vapor from air is determined by the

temperature, flowrate and concentration of the solution. Air humidity ratio of dehumidifiers can be

controlled by regulating the three variables. We have developed an integrated controller with intelligent

algorithm. Through the advanced control technologies, the humidity ratio of supply air can be accurately

controlled from 3g water/kg dry air to 10g water/kg dry air.

Distributed Operation: In commercial and residential building applications, dehumidifiers are usually inside

the AHU rooms located in different floors. The heating sources, either waste heat from chiller or solar

energy, are available in plant room or on the roof top. The hybrid operation provides a possibility for

dehumidifier and regenerator running in different places which offers an opportunity for LDDS &LDAC being

efficiently applied in building ACMV systems.

Zero crossovers: Air T&D’s innovative design on solution distribution nozzle and vane type mist eliminator

can achieve both zero solution crossovers and minimal pressure drop.

4.7 Energy Recovery Unit

Energy Recovery units (ERUs) used in Air T&D air conditioning systems preheat or precool the fresh air taken

in outdoor conditions using exhaust air, bringing the enthalpy and temperature of fresh air to interior space

conditions. However, in these systems, if energy is taken from another system, Energy Recovery does not

occur. According to VDI 2071, the transfer of mass is not Energy Recovery. Thus, Energy Recovery cannot

be achieved by mixing air.



Sensible heat transfer is made primarily in ERUs. Latent heat can be transferred depending on the structure

of the HRUs. Air T&D provides three types of ERU for different application places, as shown in the following

table.

Selection of Energy Recovery Unit

Name Wheel Energy Recovery

equipment

Plate Energy Recovery

equipment Energy Recovery loop

Properties

High Energy Recovery efficiency,

cross contamination, high capital

cost. Sensible and latent heat (total

heat) recovery

Preventing air contaminations,

reliable operation, Sensible

and latent heat (total heat)

recovery

Completely isolated air

flow, sensible Energy

Recovery only

Range of

application

Products used in civil and industrial

buildings

Suitable for small air flow,

small recovery capacity

occasions such as hospital and

laboratories

Special occasions such as

animal laboratories

Note: Please contact us before ordering, we would provide dedicated design to meet user requirements.

Performance for wheel Energy Recovery

Air velocity m/s 1.5 2 2.5 3 3.5 4 4.5 5

H /W D Weight

Recovery

efficiency % 80 78 76 74 72 70 68 66

Air

pressure

drop

Pa 79 89 110 138 160 190 220 250

Models Air treatment capacity mm mm kg

500 m3/h 420 560 700 840 980 1120 1260 1400 750 320 94

600 m3/h 630 840 1050 1260 1470 1680 1890 2100 850 320 107

700 m3/h 890 1190 1480 1780 2080 2370 2670 2970 950 320 117

800 m3/h 1190 1590 1980 2380 2780 3170 3570 3970 1050 320 132

900 m3/h 1540 2050 2570 3080 3590 4110 4620 5130 1150 320 145

1000 m3/h 1920 2560 3200 3840 4480 5120 5760 6400 1200 320 161

1100 m3/h 2350 3130 3920 4700 5480 6270 7050 8300 1250 320 177

1200 m3/h 2810 3750 4680 5620 6560 7490 8430 9370 1350 320 204

1300 m3/h 3320 4430 5530 6640 7750 8850 9960 11070 1450 320 229

1400 m3/h 3870 5160 6450 7740 9030 10320 11610 12900 1550 320 252

1500 m3/h 4470 5960 7450 8940 10430 11920 13410 14900 1650 320 266

1600 m3/h 5060 6750 8430 10120 11810 13490 15180 16870 1750 320 301

1700 m3/h 5730 7640 8550 11460 13370 15280 17190 19100 1850 320 322

1800 m3/h 6450 8600 10750 12900 15050 17200 19350 21500 1950 320 346

1900 m3/h 7200 9600 12000 14400 16800 19200 21600 24000 2050 320 369

2000 m3/h 8000 10670 13330 16000 18670 21330 24000 26670 2150 320 392

2200 m3/h 9530 12710 15880 19060 22240 25410 28590 31770 2400 320 549

2400 m3/h 11410 15210 19020 22820 26620 30430 34230 38030 2600 320 693

2600 m3/h 13460 17950 22430 26920 31410 35890 40380 44870 2800 430 838



2800 m3/h 15680 20910 26130 31360 36590 41810 47040 52270 3000 430 913

3000 m3/h 18060 24080 30100 36120 42140 48160 54180 60200 3200 430 991

3200 m3/h 20610 27480 34350 41220 48090 54960 61830 68700 3400 430 1075

3400 m3/h 23330 31110 38880 46660 54440 62210 69990 77770 3600 430 1158

3600 m3/h 26220 34960 43700 52440 61180 69920 78660 87400 3800 430 1243

3800 m3/h 29270 39030 48780 58540 68300 78050 87810 97570 4000 430 1331

4000 m3/h 32490 43320 54150 64980 75810 86640 97470 108300 4200 430 1422

4200 m3/h 35880 47840 59800 71760 83720 95680 107640 119600 4400 430 1901

4400 m3/h 39440 52590 65730 78880 92030 105170 118320 131470 4600 430 2014

4600 m3/h 43160 57550 71930 86320 100710 115090 129480 143870 4800 430 2130

4800 m3/h 47050 62730 78420 94100 109780 125470 141150 156830 5000 430 2248

5000 m3/h 51110 68150 85180 102220 119260 136290 153330 170370 5200 430 2350

4.8 Air Disinfector

Building design and construction have been impacted by ever evolving ASHRAE standards, and owners are

becoming more and more focused on not only heating/cooling/moving so much air, but also making sure

the HVAC design provided is energy efficient. Along with energy efficiency, many owners are also looking

for HVAC designs which will maintain and/or enhance indoor air quality. Today people spend more time

indoors than ever before. It has been proven that the air we breathe can make us feel unhealthy, deficient

and tired. This in fact does affect our well-being along with productivity. People expect the air they breathe

to be reasonably safe and comfortable. Yet indoor air can be laden with mold, mildew, dander, bacteria,

and viruses. As a result of those paradigm shifts, many owners and engineering firms are turning to

disinfection to meet the new and emerging requirements.

Disinfection by UV and Ozone

Name Disinfection by UV Ozone Generator

Feature - The dose of Ultraviolet Germicidal Lamp for

Air-conditioning System needs to be in the

range of 6000-7000 µ W s/𝑐𝑚2 (the product

of the average intensity of illumination and

the time of wind through the UV field)

- the sterilization rate of the general bacteria

and viruses can reach more than 90%

- can prevent the cross-infection effectively

- Disinfection: Ozone is a kind of board-spectrum,

high-efficiency and fast sanitizer. It can kill all kinds

of bacteria, virus and microorganism which can

make people and animals sick.

- Detoxification: Ozone can efficiently remove the

toxic gases such as CO, NO, SO2 and mustard gas by

oxidation reaction. Ozone owns the functions of

deodorant and deodorization.

Scope of

Application

Disinfection on the functional segments of Air

Handling Units in static and dynamic states:

filter, cooling coil, condensate drain pan and

etc.

Dynamic disinfection of air flow.



Rules of

Selection

The selection for the power and position of UV

disinfection is according to the average

intensity of illumination and the exposure time.

The model selection is according to the room volume

and cleanliness class.

Clean class 0.1K 1K 10K 100K

Concentration

(mg/𝑚3) 40 38 30 20

4.9 Electronic Dust Precipitator

High-voltage electrostatic air-purifying sterilizer uses high voltage to ionize the air, let the particulate

matter and the microorganism in the air be charged through the polarized area, then collect the

charged particles through the duct-controlling area which is charged by opposite charges to break

the cell wall in a moment and kill the bacterial and virus. The creative points of such technology

are:

• The resistance in the duct-controlling area is small, a n d duct-removing area can achieve

the maximum of board electrostatic dust removing through unit ventilation cross-section.

• The polarized area, the duct-controlling area and back- pressure area form three-area

high-voltage electric fields, which have the functions such as killing bacterial, removing dust

and odor with high efficiency.

Performance Parameters of High-Voltage Electrostatic Air-Purifying Sterilizer

Items Performance

Index

Items Performance Index

Dust removing

efficiency and

purifying effect by

one-time pass

PM1.0 >=98.9% Bactericidal efficiency after 30

minutes from start up

>=99.92%

PM2.0 >=99.5% Purifying efficiency of Methanol

(concentration after 1 hour after

start-up)

0.03mg/m3

PM5.0 >=99.4% Purifying efficiency of TVOC 85%

PM10 0.015mg/m3 The concentration of Ozone

generated during the operation

0.005mg/m3

Bactericidal efficiency by one-

time pass

>=94.69% Continuous operating results Efficiency

decreasing <=0.1%

Equipment Resistance 30Pa

4.10 Activated Carbon Filter

Principle

Activated Carbon Chemical Filter can clean the chemical pollutants in the air, such as odorant,

ammonia, SO2, VOCs and etc., satisfying the requirements of industry condition, environment

protection and civil use. We need to know the followings before we select the model of

Activated Carbon: type of the pollutants, concentration of the pollutants, a i r temperature and

relative humidity.



Carbon filters can be used efficiently up to 40°C temperature and 70% relative humidity. In case high

efficiency pre-filtration (F7-F9) is used in applications, filters are not filled with dust particles which

allows them to continue their true function of capturing gas molecules more efficiently and for a longer

period of time.

Absorptivity of regular carbon decreases with increasing humidity, yet this is not an issue for active

carbon. Furthermore, in cases where the contact time is increased by lowering flow rate, active carbon

filters operate more efficiently. Another point which should be taken into consideration in carbon filter

selection is that they are 10-20% more adsorptive when loaded to 50% of their total capacity.

Properties

Manufactured as cylindrical cartridges, active carbon filter is used in the filtration of harmful and

malodorous gases. These filters are preferred in Air T&D air conditioning systems in cases where the

return air as well as fresh air needs to be purified for these harmful and malodorous gases.

Our company uses the Activated Carbon Casing which can be reused, having two types of the

frame: plastic and metal. Customers can entrust the professional factories to replace the Activated

Carbon (experienced users can replace the Activated Carbon by themselves), and they can reuse the

Activated Carbon after its regeneration as well. This will decrease the shipping fare of customers.

Activated Carbon Chemical Filters should be allocated before or behind the conventional filters.

The former is for protection, preventing the duct from obstructing the microporous structure of the

Activated Carbon. The latter is for pre-protection, preventing the powder of the Activated Carbon from

polluting the ventilation system.

Harmful Gases in Typical Places

Typical Harmful Gases Places Typical Harmful Gases Places

Methanol Interior Decoration,

Hospital

Odorant, VOCs Interior Decoration, Airports,

Offices

Acid Gases Paper-making, Micro-

electronics

Stink livestock farm, Slaughter House,

Sewage Treatment Plant

Alkaline Gases livestock farm, Micro-

electronics

Mercury Vapor Electroplating, Electrification

Sulphur Oxides, Nitrogen

Oxides

Micro-electronics Radioactive Gases Underground Projects, Caves,

Nuclear Power Plant

4.11 Silencer

Silencers are elements which bring noise levels to desired levels while attenuating noise within air handling

units or ventilation ducts. Sound attenuation is achieved through the porous material found within the

silencer. In Air T&D applications where low noise levels are called for, silencing units are placed in front of

and/or behind fan cells. The sound attenuation is achieved by the sound absorbent material which has been

manufactured from foam glass with a fire rating of A2. The foam glass is selected in the range of 20-50

kg/m3.

Properties

Frontal surfaces of silencers should be covered with sheet metal to prevent the air from passing directly



over the foam glass material. If the air would be passed directly over the foam glass material, very high

pressure losses will occur in the porous environment, hence on the foam glass. While silencers serve basic

their function of attenuating sound, they cause pressure losses resulting from air flow within the air

handling unit or the ventilation duct. For this reason, silencers that are placed at specific distances should

be designed to make sure their frontal surfaces that are perpendicular to air flow will lead to minimal

pressure drops, hence eliminating needless pressure losses. For this reason, frontal surfaces of silencers

have plain, triangular and curved forms. Pressure losses occurring within the silencer cell has been

examined for a simulated silencer cell selected for the experimental setup.

Silencer Selection

Name Resistive Silencer Micro-perforated Silencer

Structure - Applying the galvanized steel to

form the frame.

- Using the sound absorbent material

inside and the screen board on the

surface.

Applying the galvanized steel and other steel materials.

Feature - Being able to absorb noise of

different frequencies by changing the

thickness of resistive silencer.

– The sound attenuation dose is large

and the head loss is small.

- Being able to broaden the range of silence frequency

and control the silencer with different central

frequency by changing the perforation diameters and

rate.

- The head loss is small and regenerated noise is low.

Scope of Application - The maximum air flow velocity is 10

m/s.

-Suitable for normal air-conditioning

systems.

- The maximum air flow velocity is 20 m/s.

- Suitable for clean air-conditioning systems or easily

dust-collecting cases.

Studies have shown that intake and discharge frontal surfaces of silencers should have a curved form. It has

been observed that this provides a 26% reduction in pressure losses occurring within the silencer cell.

Experimental studies have also shown that maximum sound attenuation is achieved with the silencer with

curved intake and discharge surfaces. For this reason, silencers with curved intake and discharge surfaces

are preferred in Air T&D air handling units.

Performance parameters of resistive silencer

Length of

Silencer (Modulus)

Values of noise attenuation under different Octave Band (dB)

63Hz 125Hz 250Hz 500Hz 1kHz 2kHz 4kHz 8kHz

6M 2 5 12 13 15 13 11 9

8M 3 8 18 19 22 18 13 11

12M 4 11 23 23 28 23 15 12

Performance parameters of micro-perforated silencer

Length of Silencer

(Modulus)

Values of noise attenuation under different Octave Band (dB)

63Hz 125Hz 250Hz 500Hz 1kHz 2kHz 4kHz 8kHz

6M 2 6 8 10 6 10 8 6

8M 3 8 9 12 7 12 10 8

12M 4 10 13 20 10 20 13 10



5. Electrical and Automation System

5.1 Electrical System

According to customers' different requirements, Air T&D air handling units can select multiple electrical

controlling schemes, such as traditional direct starting, star-triangle starting and variable-frequency

starting/control. The main electrical components and elements of the control cabinet are all the

international mainstream products, in order to ensure the accurate controlling and electrical safety.

The Air T&D AHU is a ready-to-install functional part with an internal cabinet for all control and safety

apparatus. Only the electrical power supply and the control signals required from superordinate control

systems need to be connected to the installation site. It is factory tested and the test report is included in

the delivery.

Air T&D can extend the controlling functions such as local/remote switch control, BA control, interlocking

between fan and fire damper, interlocking between fan and other equipment, etc.

Schematic Diagram of Direct Starting (Motor Power ≤ 11KW)



Schematic Diagram of Star-Delta Starting (Motor Power ≥ 15KW)

L1L2L3

QS

U V W

FU1

KM

KH

M3 ~

KMY

KM△

FU2

SB1

SB2

KM△

KM

KMY

KMYKT

KT KMY KM KM△

KH

Thermal relay

Circuit Breaker

Fuse

Delay Contact

AC Contactor

Stop Button

Start Button

Fan Motor

Description of Element

KH

QS

FU1-2

KT

KM

SB1

SB2

M1

Function Features:

- Fan starting and stopping controlling

- Output Power: Direct Starting for 0.25-11KW, star-triangle Starting for 15-55KW

- Indication for power, operation, and fault status

- Fire alarm interlocking device

- Circuit protection for overload, short circuit, anti-phase, loss of phase, overvoltage and under-

voltage, voltage imbalance

Variable-Frequency Starting/Control

A VFD provides adjustable speed control for single fan motor. Normally, an Air T&D AHU which has been

installed by VFD can vary the frequency within 30 to 50Hz in order to control motor rotation speed. It also

provides protection for the motor operation.

U V W

M23 ~

M13 ~

Disp

lay

VFD

1U

Fire contact

Heat Elimination Fan

Fan

L1 L2 L3L N PE

U1

1V

11

W1

1

U1

2V

12

W1

2

U1

1

V1

1

W1

1

U1

0

V1

0

W1

0

R S T U V W G

X1

COM

TA

TC

K1

FU1 U11

KM11

N

9

10

11

12

XT11

N

QF11

Terminal

Miniature Circuit Breaker

Fan Motor

Transducer

Cooling Machine

Auxiliary Contractor with Time

Fuse

Description of Electrical Element

XT11

QF11

M1

1U

K1

KM11

FU1

Notes for Variable-Frequency Starting/Control:



- If using variable frequency motor, implement the controlling with the dotted-line part above,

and the power is 3/N/PE AC 380/220V 50HZ;

- If using the normal motor, no need the controlling of the dotted-line part, and the power is

3/N/PE AC 380/220V 50HZ;

- All alarms are inter-locking with Fire control.

Electrical Cabinet

• Installation Position: can be installed on the wall beside the units;

• Suggesting that the distance between the installation position and fan is less than 3m,

height (based on the operation plane) is greater than 1.4-1.5m.

• If the wire connecting distance is greater than 3m, the wire connection needs to be done by

customers themselves.

• The routing on site and the materials of duct should be done by customers themselves.

5.2 Automation System

All Air T&D handling units come equipped with Air T&D BSTAR software and controller mounted in a control

cabinet inside the unit. The controller is accessed by opening the external control cabinet door with an

emergency stop button. In order for the unit to run using the BSTAR controller and default controls program,

the VFD selector switch must be in “remote” mode.

The unit control program can be accessed using a computer with the Air T&D DAQ tool software and the

unit-mounted standalone display. The standalone display is mounted in a sealed cabinet on the front of the

unit next to the external disconnect. The operator display touch screen is an intuitive operator interface for

monitoring and changing building control functions. With the operator display you can:

• Choose specific chilled water flow within specified range.

• Choose specific air flow within specified range.

• Monitor space temperature, air flow, filter status, etc.

• Identify and troubleshoot problems.

• View and reset controller alarms.

Field elements

Type Elements Function and properties

Actuator

Motorized Flow

Control Valves

- Two-way: It is used to adjust the flow rate of the water entering the system

proportionally or On/Off controlled.

- Three-way: Allows the water coming from the system and the boiler to mix and

determines the ratio of mixture.

Damper Motors

- Normal: Air flow is used to control the control dampers in heating-cooling and

ventilation systems.

- Spring return: Air flow that has a safety function in heating-cooling and ventilation

systems is used to control the control dampers (e.g. freeze protection, smoke control,

hygiene).



Sensor

Heat Sensors

- Duct type: It is used to measure the temperature in ventilation ducts.

- Room type: It is used to measure the indoor temperature in Heating-Cooling-

Ventilation systems.

- Outdoor type: It is used to measure the outside temperature.

- Freeze-free thermostat: It is used to protect the heating coils in the heating-cooling-

ventilation systems against the risk of freezing.

Humidity Sensors

- Duct type humidity sensor: It is used to measure the indo- or humidity and

temperature in Heating-Cooling-Ventilation systems.

- Room type humidity sensor: It is used to measure the indoor humidity and

temperature in Heating-Cooling Ventilation systems.

Pressure Sensor

- Differential pressure switch: It is used to sense the dirtiness of the air filters and

determine whether the fans are operating properly or receiving "belt breakage”

warning.

- Differential pressure sensor: It is mainly used to adjust flow rates of the fans and

monitor the filter dirtiness in a sensitive way.

Controllers

Two types of controller were designed by Air T&D to control central air-conditioning and air handling system,

i.e., Universal Controller and Terminal Controller. Optoelectronic isolation technology is adapted here to

the controller for accurate data acquisition and stable operation. The controllers provided the various data

collection ports to satisfy all the central air-conditioning systems. The advantages of the controller are as

follow:

- Using ARM chips, with more powerful real-time processing capabilities

- A more powerful processor, and more analog/digital I/O port

- Complex logic arithmetic function

- A friendly human-computer interface

- Simple, easy networking with RS-485

- Low-power design, no heat sink

U13 (Universal controller) L13A (Terminal controller)

BSTAR Software

BSTAR, provided by Air T&D, is a unique project development platform and management system for building

automation, which integrates abundant functions such as monitoring, control, optimization, fault detection

and diagnosis (FDD), and energy management (EMS) for HVAC systems. Inheriting the following advantages,

this platform and its tools bring effective BMS design and facility operation, and will make the buildings



more energy-efficient and eco-friendly.

Excellent user interface, configurable assembles and competitive integrations. These increase

staff productivity, improve plant reliability and life, and save time/money during maintenance.

Dedicated and High-valued function modules. Auto-tuning control, FDD, and energy efficiency

analysis and optimization fill the gap between industry and academy.

Flexible and Extensive. Modular and structured framework facilitates function extensions, and

makes it easy to integrate with/into other BMS by the self-defined or third-party plugins.

Using this powerful tool software, customers can design basic controls and some advanced functions for

Air T&D air handling units:

• Temperature control

• Frequency converter operation for constant air flow or duct pressure

• On-demand control

• Heating and cooling shunts

• CO2-compension of fans

• Control of different types of heat exchanger

• Energy measurement

• Control of extra fans

• Control of temperature zones

• Communication via BACnet, or Modbus

• Monitoring via a C/S or B/S interface

The following is a sample HMI drawing for an air handling unit designed with BSTAR.



6. Installation and Maintenance

6.1 Installation of Air Handling Unit

Rigging and Installation Procedure

1) The chassis of AHU is allocated by forks and lifting holes. There should be a protection pad

between the lifting rope and the unit preventing from the abrasion of the unit panel when

conveying the units, which may affect the performance and installation accuracy of AHU.

Lifting ropes should be kept away all water pipes and air duct interfaces outside the unit

during the AHU lifting process.

2) The unit should be installed on smooth concrete base (or channel steel base) which should

be 200-250mm higher than machinery hall floor. The length and width of the concrete

floor should be 200mm longer than the exterior frame of the unit, and there should be

floor drains around. The length and width of the steel channel beam should be the same as

the exterior frame of the unit, and there should have drains. The steel channel beam

should be prepared by customers themselves.

3) There should be sufficient space (not less than 1m) around the AHU for the installation,

operation, daily inspection and maintenance, especially for the piping, wiring and service

besides AHU doors.

4) When assembling AHU on the site, all the functional sections should be sealed by sealing

strips and clamped by the clamping equipment from the inside of unit and bottom dock,

preventing from air leakage. The joints can be coated with sealant if necessary.

5) After assembling all the parts as a whole, the inside sundries should be cleaned out.

Connecting the external pipe to the inlet and outlet pipes of the unit after the external

pipe being cleaned out, preventing coil pipes from blocking.

6) Installing the valves and joints on the outside of the AHU for the inlet and outlet pipes.

However, the weights of the valves, pipes and equipment which are connecting to the

outside of the unit cannot be bear by the AHU itself.

7) The motor should be connected to the power supply with the protection devices, and the

unit casing should be grounded. Reduced Voltage Starting Mode should be taken into

consideration for the motor which is greater than 15kW.

8) Condensation water pipe of the cooling coil should be installed with water blocks in order

to ensure the fluent water drainage. The water blocks should be prepared by customers

themselves.

Recommendation for installation

• Air handling unit is mounted over a leveled building site (foundation or construction). The

site should be sized for the specific camera.

• The weights of the air duct and water pipes which are connecting to the unit cannot be bear

by AHU itself.

• Sections are mounted one to another with sealing rubber between them. Connection

between them is made with bolt connection.

• When connect the air handling unit to duct system, flexible connections should be used



to prevent transmissions of noise and vibration.

• The supplying pipes for heating and cooling units should not prevent the unit

maintenance. It is advisable to connect them through flexible pipe-connections.

• The indicated directions of inlet and outlet of water sections and counter -flow between

water and air must be observed.

• When connecting the coils to the heat exchanger, please be careful to prevent from

damaging the copper pipes.

• As for the coils which share the same pipes, they need to be heat-insulated and dew-

insulated, and they should be allocated with drain pipes as well.

• To prevention of freezing of water coil unit is recommended at the inlet section (fresh air)

to mount multiple leaf damper equipped with spring return actuator. Cooling coil and

Heating coil should be protected for anti-freezing in winter.

• Must be ensured siphon, placed before condensation line is connected to the building

installation.

• For heat exchanging coils which use the cooling and hot water as medium, the bottom side is

the water inlet and the top side the water outlet. The result should be opposite if using the

vapor as the medium. Furthermore, if using the vapor as the medium, there should be a

valve for draining of condensate water in the outside pipes, and releasing vapor should

be after the accomplishment of condensate water draining.

• The design pressure for the coils is 1.6MPa.

• To make a repair or maintenance of the unit, enough space in front of it must be ensured.

• The size of doors and entry of the technical room should be considered with the overall

dimensions of the installed sections when mounted, repaired or maintained.

Unit Model B1 (mm) B1 (mm) B2 (mm) B3 (mm)

Minimum free area to access to

the technical room

B4 (mm) H2 (mm) H3 (mm)

AHU 06XX 1350 800 1100 1650 900 1900 1400

AHU 09XX 1600 800 1100 1900 900 1900 1650

AHU 12XX 1850 900 1150 2150 900 1900 1900

AHU 16XX 2100 900 1250 2400 1000 1900 2150

AHU 20XX 2360 900 1350 2700 1100 1900 2400



AHU 24XX 2360 900 1500 2700 1200 1950 2650

AHU 30XX 2360 900 1650 2700 1300 1950 -

AHU 36XX 2360 900 1850 2700 1500 1950 -

AHU 45XX 2360 900 2200 2700 1800 2250 -

Note:

- B1 – maintenance and cleaning of air filters

- B2 – repair and replacement of fan

- B3 – repair and replacement of heat exchangers

- B4 – minimum width of the door of technical room

- H2 – height when fan or coil is repaired

- H3 – minimum height when heat exchanger is repaired

- Air T&D reserves the right to modify the provided data, subject to product development and

advanced experiments.

6.2 Usage and Maintenance

Guideline

1) Power supply for unit motor is 380V/ 50Hz three-phase voltage supply. Please check the fan

before start up, make sure the fan operates normally, and the fan impellers should not strike

with the fan casing. All electrical and mechanical equipment must be checked by professional

technicians before operation. The rotation direction of fan impeller must be correct; the unit

could be powered up after inspection without abnormalities found.

2) When the unit has multi-functions, user should consider the interlocking interaction

requirements among functional sections. For example, electric heater section should be turned

on after the fan is operating, while the electric heater should be turned off before the fan is turn

off.

3) System adjustment should be done before fan operation. For example, when the unit has no

load, the air supply must be cut off at 3/4 position to ensure the motor is operated under the

rated current so as to avoid motor overheating. Air inlet damper and Air Supply damper should

not be tightened under operation to avoid AHU deformation under high pressure. Set interlock

between damper and motor switcher if necessary.

4) Water filter should be installed on coil pipes to avoid pipe jam; the filter should be cleaned

periodically. The chilled water and spray water should be pretreated to clean and soften.

5) The conditions of filter dust deposition should be checked regularly; the filter is needed to be

cleaned or replaced when the resistance reaches the set point. Take out the filter and pad it, and

use compressed air to reversely blow the filter. Wash the filter with detergent, air-dry it before

reuse. Cleaning and replacement process should be done with caution to avoid damages;

inspection on tightness between filter and its frame must be done. Filters made by non-woven

fabrics should be replaced and avoid reuse.

6) Check belt elasticity and tear/wear conditions regularly. User could adjust the screw under the

motor to reset the slipping belt to correct position. Belt should be replaced under severe tear

and wear. Motor bearing and fan bearing should be inspected and refuel regularly to improve

operation efficiency and extend service lifetime.

7) Entire cleanness for air handling unit should be done after 1-2 years operation. The inner surface



of coper pipe should be cleaned by chemical solutions to remove incrustation scale. Meanwhile,

user should use water or compressed air to clean heat exchange fins.

8) When AHU does not work during winter time, water should be discharged from the coil; when

the unit is running during winter time, please ensure continuous water flow within the coil, and

close primary air supply damper to avoid frost damage of the coil.

9) Modular AHU must be controlled under professional technicians. There should have strict

systems of responsibility and operation instruction. The management should be provided for

daily equipment operation and maintenance.

Note

Please refer to the user manual for more details for installation, use and maintenance.

The AHU models, parameters and specifications of Air T&D might be changed without prior notifications

since the products will be continuously modified and improved. Thank you for your understanding!

Air T&D Pte Ltd

Address: 86 Phoenix Garden, Phoenix Heights, Singapore 668336

Phone: 0065-67906538

Fax: 0065-67933318

E-mail: [email protected]

www.airtd.com.sg

mailto:[email protected]

Documents

Modular Air Handling Units - airtd.com.sg · PDF fileAbout air handling units The air handling unit (AHU) is one of the most essential and critical units to be considered when designing