Mammoth Product Training

© 2004 Venmar CES Inc.© 2006 CES Group - Confidential

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Mammoth Product Training

Evaporative Condensing


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EVAPORATIVE CONDENSING

What is it?


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Condensers

Water Cooled Air Cooled

Evap Condensed


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The Power of Evaporation

The Thermodynamic Properties of Water at Saturation

Latent heat of vaporization = 1036 btu/lb H2O

Water changing state from liquid to gas at 100f absorbs 1036 btu/lb


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Evaporative Cooling Vs Evaporative Condensing


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Evaporative Cooling Vs Evaporative Condensing

Both systems use evaporation of water to cool.

Evap cooling --- cools room air. Evap Condensing ---cools refrigerant gas, no

moisture is added to the space.


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EVAPORATIVE CONDENSING

How it works.


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How it Works:Water Spray on Condenser Coil


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Why Evaporative Condensing?

20% to 30% less compressor KW consumed than air cooled condensing

Less Air over coil, therefore quieter than air cooled condensing

Less coil required so less space on roof for equipment than air cooled.


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ASHRAE Systems and Equipment Handbook

“In comparison with an air-cooled condenser, an evaporative condenser requires less coil surface and airflow to reject the same heat, or alternatively, greater operating efficiencies can be achieved by operating at a lower condensing temperature”


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“Also, evaporative condensers typically provide lower condensing temperatures than the cooling tower/water-cooled condenser because the heat and mass transfer steps (between the refrigerant and the cooling water and between the water and ambient air) are more efficiently combined in a single piece of equipment”


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“Evaporative condensers reduce the water pumping and chemical treatment requirements associated with cooling tower/refrigerant condenser systems”


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“Evaporative condensers are, therefore, the most compact for a given capacity”


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How It Works Condensing temperature becomes a function

of the ambient wet bulb temp The wet bulb depression under the dry bulb

temperature, typically 15 to 30 degrees, leads to lower condensing temps than with air-cooled condensing

Design condensing temperatures range from 90 to 105 degrees


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ARI - WB = 75

88 F

SCT = 95 to 105 F

SET = 45 F


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Corresponding Pressure for R-134A Condensing Temp of 130F = 200psig

Corresponding Pressure for R-134A Condensing Temp of 1050 = 125psig

Evaporative Condenser

Air-cooled Condenser


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Reduced Connected kW

Typical 100 TonAir Cooled Condenser

168 Operating Amps 100 kW

Typical 100 Ton Evap Cooled Condenser

136 Operating Amps 76.0 kW

Wire Size

# 350 MCMWire Size

# 2/0


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Water Consumption

Evaporated water of 1.6 gph/ton Nominal bleed rate of ½ evaporation rate Total water consumption of 2.4 gph/ton


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Where Can Evaporative Condensing be Used?

Base design is for 75 degree wet bulb temperatures

Only a few locations have up to a 81 degree design wet bulb

Can be used anywhere cooling towers are used

Appropriately applied everywhere


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Advantages over Air Cooled Packages

Better Acoustics▼ Because evap condensers move less air than air

cooled units they typically are quieter.▼ In many areas Lot line noise is becoming a real

issue. Greater Compressor Life

▼ Evap Condensing Compressors work at lower pressures compared to Compressors applied to Air Cooled Condensers and therefore should last longer


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Advantages over Air Cooled Packages

Typically a Smaller Footprint▼ Because evap condensers move less air than air

cooled units they typically are smaller.


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Lower amp draw▼ With lower amperage required, evap condensing can

be used for applications with limited existing power supply

Evap Condensing - Benefits:


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Lower Operating Cost 30-40% less compressor kW consumed than

air-cooled condensing Can compete favorably with centrifugal chilled

water systems Reduced kW is the result of lower condensing

temperatures


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Evaporative CondenserConstruction Details

Ease of Serviceability Corrosion Resistance Long Life Reliability Quiet Operation Pleasing Aesthetics

Desirable Design Desirable Design Features:Features:


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Evaporative Condenser Construction

Draw Through Design.

Stainless Steel Housings and Sump.

Prime Copper Tube Bundle.


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To prevent the possibility of water getting into the building, use a continuously welded stainless steel pan under the sump



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Utilize a fully welded, double sloped stainless steel sump



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Interlocking stainless panels with no fasteners on the inside



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Stainless coil supports



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Stainless and ABS tube sheets



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Evap condenser coil in the sump



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Evaporative Condenser Construction Details

Spray Tree Assembly


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Moisture Eliminator


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Evaporative CondenserConstruction Details Direct Drive Condenser Fans

All Stainless Steel Mounting Frame


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Condenser Top Hinges Up


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Direct Drive Fans


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Easy Access to Components


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Designed for Serviceability


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All Stainless Steel and Non-Corrosive


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Full Access to Condenser Coil


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Spray Nozzles Visible for Inspection


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Spray Nozzles


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Spray Nozzles


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Pump suction strainer easily removable without tools


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Latest design enhancements– Ultraline evap condensers now available up to 350 tons– Penthouse up to 600 tons in a single sump– Sump basin is double-sloped to be self-draining– All water-side components made of non-corrosive materials -

even fan venturis are stainless steel– Condensers fans hinged for easy service access– Basin inlet opens up easily for complete access– Air and water flow increased for even greater efficiency



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Water Treatment


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Water Treatment Objectives

CONTROL and BALANCE of WATER CHEMISTRY to MINIMIZE:

▼ CORROSION▼ SCALE▼ BIOFOULING▼ USE of WATER

and to MAXIMIZE:▼ HEAT TRANSFER


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Chemical Treatment

Inhibitor- reduces scale and corrosion Biocide- alternate between two to prevents

biological contamination Chemical pumps- inject chemical into sump Controller- monitors water and activates

chemical pumps and bleed


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Chemical Water Treatment


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Effective Chemical Water Treatment

Maintain desired cycles of concentration Maintain prescribed biocide feed Maintain prescribed scale and corrosion

inhibitor feed Periodically monitor the system

In 4 Easy Steps!


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Scale Control

Increase water flow rates Increase coil surface area Limit dissolved solids (cycles of

concentration) Scale inhibitors keep minerals in solution Scale conditioners form transportable clumps

instead of hard deposits


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Corrosion Control

Corrosion-proof materials Limit dissolved solids (cycles of concentration) Chemical inhibitors interfere with corrosion

mechanism pH


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“All evaporative condensers should be treated to restrict biological growth”


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Oxidizing Biocides

Chlorine Bromine Ozone Iodine


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Nonoxidizing Biocides

Mehtylene bis(thiocyanate) (MBT) Decyl thioethanamine (DTEA) Tetrakis(hydroxymethyl)phosphonium sulfate Dibromo-nitrilopropionamide (DBNPA)


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Nonchemical Methods

Scale control▼ Magnetic and Electromagnetic cause minerals to

precipitate into particles that can be removed by blowdown or flushing

Biological control▼ Ozone▼ UV light


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Solids Management:Sources Sump Debris

♦ Inorganic: dust, dirt, sand

♦ Organic: leaves, pollen, grass

♦ Dolphin “powder”


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Solution: Basin Sweeping

Reduces cleaning routines by 5x Controls solids build-up in tower basin


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Centrifugal Action Separator


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Separator


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Dedicated Pump


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Purge Filter (Optional)


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HydroBoosters: Pattern of Influence


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HydroBoosters: Installation Issues

Submergence: Only 2-3 inches required


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Sweeper in Mammoth Sump


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THANK YOU

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