American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

Standard 90.1Energy Standard for Buildings Except Low-Rise Residential Buildings

Presented to: October 21, 2013 ASHRAE Columbus Chapter

Agenda• 90.1-2010 – What Changed

• 90.1-2013 – What Changed

• 90.1-2016 – Items Being Considered

• Questions

Development of 90.1-2010

HVAC Equipment

• Several Changes Made to Equip Efficiency.• Process for Equipment Efficiency Upgrades.

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AHRI

90.1DOE

Notable Changes in 90.1-2010

Computer Rooms no longer exempted from standard. 2.3 The provisions of this standard do not apply to C. equipment and portions of building systems that

use energy primarily to provide for industrial, manufacturing, or commercial processes.

Computer Rooms

Economizers:

TABLE 6.5.1B Minimum Fan-Cooling Unit Size for Which an Economizer is Required for Computer Rooms

Climate Zones Cooling Capacity for Which an Economizer is Required

1a, 1b, 2a, 3a, 4a No economizer requirement2b, 5a, 6a, 7, 8 ≥135,000 Btu/h3b, 3c, 4b, 4c, 5b, 5c, 6b ≥65,000 Btu/h

Computer RoomsEconomizers (Exceptions):

j. Systems primarily serving computer rooms where:

1. the total design cooling load of all computer rooms in the building is less than 3,000,000 Btu/h and the building in which they are located is not served by a centralized chilled water plant, or

2. the room total design cooling load is less than 600,000 Btu/h and the building in which they are located is served by a centralized chilled water plant., or

3. the local water authority does not allow cooling towers, or

4. less than 600,000 Btu/h of computer room cooling equipment capacity is being added to an existing building

Computer RoomsEconomizers (Exceptions):k. Dedicated systems for computer rooms where a minimumof 75% of the design load serves:

1. those spaces classified as an essential facility2. those spaces having a mechanical cooling design of Tier IV as defined by ANSI/TIA-9423. those spaces classified under NFPA 70 Article 708 – Critical Operations Power Systems (COPS)4. those spaces where core clearing and settlement services are performed such that their failure to settle pending financial transactions could present systemic risk as described in “The Interagency Paper on Sound Practices to Strengthen the Resilience of the US Financial System, April 7, 2003”

Computer RoomsWater Economizers Design Capacity

Water economizer systems shall be capable of cooling supply air by indirect evaporation and providing up to 100% of the expected system cooling load at outdoor air temperatures of 50°F dry bulb/45°F wet bulb and below.

(Exceptions):a. Systems primarily serving computer rooms in which 100% of the expected system cooling load at 40°F dry bulb / 35°F wet bulb is met with evaporative water economizers.b. Systems primarily serving computer rooms with dry cooler water economizers which satisfy 100% of the expected system cooling load at 35°F dry bulb.

Computer RoomsTABLE 6.8.1K Air Conditioners and Condensing Units Serving

Computers Rooms

MinimumSCOP-127 EfficiencyDown flow units / Upflow unitsANSI/ASHRAE 127

Notable Changes in 90.1-2010

Energy Recovery

6.5.6.1 Exhaust Air Energy Recovery. Individual fansystems that have both a design supply air capacity of5000 cfm or greater and have a minimum outdoor air supply of 70% or greater of the design supply air quantity shall have an energy recovery system with at least 50% recovery effectiveness.

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Energy Recovery

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Notable Changes in 90.1-2010

Single Zone VAV New Requirements for chilled water and commercial package rooftop units to have 2 speed or VAV fans.

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Single Zone VAVa. Air-handling and fan-coil units with chilled-water cooling coils and supply fans with

motors greater than or equal to 5 hp shall have their supply fans controlled by two-speed motors or variable-speed drives. At cooling demands less than or equal to 50%, the supply fan controls shall be able to reduce the airflow to no greater than the larger of the following:

1.One half of the full fan speed, or

2. The volume of outdoor air required to meet the ventilationrequirements of Standard 62.1.

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Single Zone VAV

b. Effective January 1, 2012, all air-conditioning equipment and air-handling units with direct expansion cooling and a cooling capacity at AHRI conditions greater than or equal to 110,000 Btu/h that serve single zones shall have their supply fans controlled by two-speed motors or variable speed drives. At cooling demands less than or equal to 50%, the supply fan controls shall be able to reduce the airflow to no greater than the larger of the following:

1. Two-thirds of the full fan speed, or

2. The volume of outdoor air required to meet the ventilation requirements of Standard 62.1.

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Notable Changes in 90.1-2010

Lab Exhaust Fan Power (p) Fan power limits placed on laboratory exhaust fans.

6.5.3.1 Fan System Power Limitation

Exception:c. Fans exhausting air from fume hoods. Note: If thisexception is taken, no related exhaust side creditsshall be taken from Table 6.5.3.1.1B and the FumeHood Exhaust Exception Deduction must be takenfrom Table 6.5.3.1.1B.

Laboratory Exhaust Fans

Notable Changes in 90.1-2010 Fume Hood Exhaust Modifications made to fume hood exhaust requirements

6.5.7.2 Fume Hoods. Buildings with fume hood systemshaving a total exhaust rate greater than 15,000 cfm shall include at least one of the following features:a. VAV hood exhaust and room supply systems capable of reducing exhaust and makeup air volume to 50% or less of design values.b. Direct makeup (auxiliary) air supply equal to at least 75% of the exhaust rate, heated no warmer than 2°F below room setpoint, cooled to no cooler than 3°F above room setpoint, no humidification added, and no simultaneous heating and cooling used for dehumidification control.c. Heat recovery systems to precondition makeup air from fume hood exhaust in accordance with Section 6.5.6.1, Exhaust Air Energy Recovery, without using any exception.

Fume Hood Exhaust

6.5.7.2 Laboratory Exhaust Systems. Buildings withlaboratory exhaust systems having a total exhaust rate greaterthan 5000 cfm shall include at least one of the following features:

a. VAV laboratory exhaust and room supply system capable of reducing exhaust and makeup air flow rates and/or incorporate a heat recovery system to precondition makeup air from laboratory exhaust that shall meet the following:

A + B×(E/M) ≥50%

Where:

A = Percentage that the exhaust and makeup air flow rates can be reduced from design conditions.

B = Percentage sensible recovery effectiveness.E = Exhaust airflow rate through the heat recovery device at design conditionsM = Makeup air flow rate of the system at design conditions.

Notable Changes in 90.1-2010

Kitchen exhaust hoods (ax) Worked with TC to properly characterize exhaust hoods and makeup air for kitchens. Many years of improper language that encouraged designs that wasted energy.

6.5.7.1 Kitchen Hoods. Individual kitchen exhausthoods larger than 5000 cfm shall be provided with makeup airsized for at least 50% of exhaust air volume that is

a. unheated or heated to no more than 60°F andb. uncooled or cooled without the use of mechanical cooling

Kitchen Exhaust

6.5.7.1.1 Replacement air introduced directly into thehood cavity of kitchen exhaust hoods shall not exceed 10% ofthe hood exhaust airflow rate.

Kitchen Exhaust

6.5.7.1.2 Conditioned supply air delivered to any space with a kitchen hood shall not exceed the greater of:

a. the supply flow required to meet the space heating or cooling load

b. the hood exhaust flow minus the available transfer air from adjacent spaces. Available transfer air is that portion of outdoor ventilation air not required to satisfy other exhaust needs, such as restrooms, and not required to maintain pressurization of adjacent spaces

Kitchen Exhaust

6.5.7.1.3 If a kitchen/dining facility has a total kitchen hood exhaust airflow rate greater than 5,000 cfm then each hood shall have an exhaust rate that complies with Table 6.5.7.1.3. If a single hood, or hood section, is installed over appliances with different duty ratings, then the maximum allowable flow rate for the hood or hood section shall not exceed the Table 6.5.7.1.3 values for the highest appliance duty rating under the hood or hood section. Refer to ASHRAE Standard 154 for definitions of hood type, appliance duty, and net exhaust flow rate.

Exception: At least 75% of all the replacement air is transfer air that would otherwise be exhausted.

Kitchen Exhaust

6.5.7.1.4 If a kitchen/dining facility has a total kitchen hood exhaust airflow rate greater than 5,000 cfm then it shall have one of the following:

a. At least 50% of all replacement air is transfer air that would otherwise be exhausted.

b. Demand ventilation system(s) on at least 75% of the exhaust air. Such systems shall be capable of at least 50% reduction in exhaust and replacement air system airflow rates, including controls necessary to modulate airflow in response to appliance operation and to maintain full capture and containment of smoke, effluent and combustion products during cooking and idle.

c. Listed energy recovery devices with a sensible heat recovery effectiveness of not less than 40% on at least 50% of the total exhaust airflow.

Notable Changes in 90.1-2010

Garage ventilation Reduce airflow if not required to reduce fan energy and heating energy.

Garage Ventilation

6.4.3.4.5 Enclosed Parking Garage Ventilation.Enclosed parking garage ventilation systems shall automatically detect contaminant levels and stage fans or modulate fan airflow rates to 50% or less of design capacity provided acceptable contaminant levels are maintained.

Exceptions:a. Garages less than 30,000 ft2 with ventilation systems that do not utilize

mechanical cooling or mechanical heatingb. Garages that have a garage area to ventilation system motor nameplate

hp ratio that exceeds 1500 ft2/hp and do not utilize mechanical cooling or mechanical heating.

c. Where not permitted by the authority having jurisdiction.

90.1-2013 What Changed

90.1-2013 Notable ActivitiesEnvelope 1. Significant increase to insulation values (bb)

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Columbus, Ohio Fairbanks, Alaska

Roof Insulation (ab. deck) R-20 R-20

Metal Framed Wall R-13 + R7.5 c.i. R-13 + R7.5 c.i.

90.1-2010 Standard

Columbus, Ohio Fairbanks, Alaska

Roof Insulation (ab. deck) R-30 R-35

Metal Framed Wall R-13 + R10 c.i. R-13 + R18.8 c.i.

Addendum to 90.1-2010

Economizer/Humidification SystemNot really a new requirement but clarified applications where hydronic cooling and humidification are utilized to maintain dewpoints above 35F, that a water economizer shall be utilized if an economizer is required.

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VAV Static Pressure Sensor Location (s)Located such that set point no greater than 1.2” wg or shall have automatic reset controls based on damper position (reset logic shall have alarm provisions for rogue zones with manualdisable)

DDC Requirements (aa)Most new buildings and renovations to existing systems

currently with DDC

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Escalators & Moving Walkways (b)When not conveying passengers shall operate at minimum speed per ASME A17.1

• Fan Efficiency (u)

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Minimum FEG = 67Per AMCA 205

Exceptions:-single or multiple fans 5 hp or less.-Part of a system with a 3rd party certification or covered by another efficiency standard (i.e. part of pkg equip)

Cooling Tower Flow Turndown (af)1. Previously the standard required towers with motors 7.5 hp and larger to be

at least 2 speed. This addendum requires that for multi-tower installations that utilizes VFDs that the towers not be staged, but rather control all fans at the same speed.

2. Multiple Tower installations with multiple pumps (in parallel) shall be able to reduce flow to 50% of the design flow rate (really a mfgr reqt)

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Small Motor Efficiency (aj)Motors 1/12 hp to less than 1 hp shall be ECM or minimum 70% efficient. Also shall have means to adjust motor speed for balancing or remote control. Targets cooling applications (fan coils and fan powered boxes), though have exception when fan is for heating only

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Hydronic Variable Flow(ak)(90.1-2016)Requires variable flow on all heating and chilled water systems if there are 3 or more control valves. No longer a hp exemption. Also requires water temperature reset (chilled and htg water based on valve position unless using valve position to comply with variable flow requirement).

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Boiler System Design Input (Btu/h) Minimum Turndown Ratio (am) **≥ 1,000,000 and less than or equal to 5,000,000 (3 to

1)> 5,000,000 and less than or equal to 10,000,000 (4 to 1)> 10,000,000 (5 to 1)

Requires the use of multiple single stage boilers or the use of modulating boilers.

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Computer Room PUE (ap) 6.6 Alternative Compliance Path

Climate Zone PUE a

1A 1.612A 1.493A 1.414A 1.365A 1.366A 1.34

1B 1.532B 1.453B 1.424B 1.385B 1.336B 1.33

3C 1.394C 1.385C 1.36

7 ≤ 1.328 ≤ 1.30

PUE=Total Power ÷ Total IT Power

6.5.3.2.1 Fan Airflow Control (aq) ** Each cooling system listed in table 6.5.3.2.1 shall be designed to vary the indoor fan airflow as a function of load and shall comply with the following requirements.

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Cooling System Type Fan Motor Size Mechanical

Cooling

Capacity

Effective Date

DX Cooling any ≥110,000 Btu/h 1/1/2012

≥75,000 Btu/h 1/1/2014

≥65,000 Btu/h 1/1/2016

Chilled Water and

Evaporative cooling

≥5 HP Any 1/1/2010

≥1/4 HP Any 1/1/2014

Table 6.5.3.2.1 Effective Dates for Fan Control

Humidification and Preheat (as)Requires humidifiers tubes to be provided with R-0.5 value insulation and restricts preheat coils from generating heat when AHU in mechanical cooling or economizer operation.

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Steam Humidifier

Face and bypassPreheat coil

Door Switches (ba) (started as window switches)Doors (including doors more than 50% glass) require switches to disable or setup/setback cooling/heating to 90F/55F. Exclusions for door with automatic closers, loading dock doors.

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90.1 Definition-Doors that are more than 50% glass are considered fenestration.

Service Water Heater Efficiency (bo) **Gas hot water systems over 1,000,000 btuh (total bldg) input require minimum 90% thermal efficiency (i.e. condensing style water heaters or heat pump water heaters).

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High Efficiency Condensing Style

Standard Efficiency

Exemption: Individual gas water heaters less than100,000 btuh input.

Commercial Refrigeration (bq)3 Addendums passes in for 2013 standard, with the first 2 primarily restating current federal requirements. This addendum added additional requirements.

•Refrigerated display cases with automatic lighting controls.•Temperature based defrost termination (in addition to time based).•Anti-sweat heater controls (based on ambient dewpoint)•Condensers with variable fan speed control.•Crankcase heaters shut-off on compressor run.

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Demand Control Ventilation (bs)Increased stringency from 40p/1000 sq.ft. to 25p/1000 sq.ft.

• Occupancies that would be included that are not included now (based on Standard 62.1 default densities) would be:– Classrooms; Music/dance class; Conference lobbies; Office Reception;

Museum; Mall commons; Gym; and health club. Daycare; computer labs; and break rooms.

• Exempt occupancies would be: Correctional cells; Daycare sickrooms; Science labs; Barber; beauty & nail salons; and bowling alley seating.

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Energy Recovery (bt)

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Zone

% Outdoor Air at Full Design Airflow Rate

≥10% and

<20%

≥20% and

<30%

≥30% and

<40%

≥40% and

<50%

≥50% and

<60%

≥60% and

<70%

≥70% and

<80%

≥80%  

Design Supply Fan Airflow Rate (cfm)

3B, 3C, 4B, 4C, 5BNR NR NR NR NR NR NR NR

 

1B, 2B,5CNR NR NR NR ≥26000 ≥12000 ≥5000 ≥4000

 

6B≥28000 ≥26500 ≥11000 ≥5500 ≥4500 ≥3500 ≥2500 ≥1500

 

1A, 2A, 3A, 4A, 5A, 6A ≥26000 ≥16000 ≥5500 ≥4500 ≥3500 ≥2000 ≥1000 ≥0

 

7,8≥4500 ≥4000 ≥2500 ≥1000 ≥0 ≥0 ≥0 ≥0

 

Table 6.5.6.1a Energy Recovery Requirement (ventilation systems operating <8000 hr/yr)

24x7 Energy Recovery (cy)

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Zone

% Outdoor Air at Full Design Airflow Rate

≥10% and

<20%

≥20% and

<30%

≥30% and

<40%

≥40% and

<50%

≥50% and

<60%

≥60% and

<70%

≥70% and

<80%

≥80%  

Design Supply Fan Airflow Rate (cfm)

3C NR NR NR NR NR NR NR NR 

1B, 2B, 3B, 4C, 5C NR ≥19500 ≥9000 ≥5000 ≥4000 ≥3000 ≥1500 >0

 

1A, 2A, 3A, 4B, 5B ≥2500 ≥2000 ≥1000 ≥500 >0 >0 >0 >0

 

4A, 5A, 6A, 6B, 7, 8 >0 >0 >0 >0 >0 >0 >0 >0

 

Table 6.5.6.1b Energy Recovery Requirement (ventilation systems operating ≥8000 hrs/yr)

Vestibule Heat (ca)Deactivate heat above 45F outside and limit heating to 60F.

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“Vestibules are installed to reduce infiltration into the building. The benefit of a vestibule during the heating season is negated if the vestibule is heated to the heating set point of the adjacent space. At the same time, tempering of vestibule air is needed to avoid ice formation.”

VAV Dual Maximum (ck)Elimination of 30% minimum reheat for DDC boxes, requires reduction to 20% of maximum supply air at deadband, then heat to maximum supply air (20F above space temperature), then a maximum of 50% of air can be reheated.

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Water Economizer Sizing Reqts Comp Rms (de)

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Zone

Evaporative Water Economizer

Dry Cooler Water

Economizer

Dry-Bulb (°F)

Wet-Bulb (°F)

Dry-Bulb (°F)

1 A NR NR1 B NR NR2 A 40.0 35.0 30.02 B 35.0 30.0 30.03 A 40.0 35.0 25.03 B 30.0 25.0 25.03 C 30.0 25.0 30.04 A 40.0 35.0 25.04 B 30.0 25.0 25.04 C 30.0 25.0 25.05 A 40.0 35.0 20.05 B 30.0 25.0 20.05 C 30.0 25.0 25.06 A 35.0 30.0 20.06 B 30.0 25.0 20.07   30.0 25.0 20.08   30.0 25.0 20.0

Table 6.5.1.2.1 Water Economizer Sizing Dry-Bulb and Wet-Bulb Requirements for Computer Rooms

90.1-2010:Evap Water Econ at 40F db/ 35F wb Drycoolers 35F db.

Humidity Control (di)Restricts the use of fossil fuels or electric for humidification above 30% RH. Recognizes some exceptions such as museums and hospitals or accreditation standards.

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90.1-2016Items Being Considered

• Elevator Efficiency (cw)• Computer Room Definition (cs) + 90.4• Expanded Water Economizer Reqts (du)• Evaporative Precoolers for Pkg Air Cooled • Heat Pumps/VRF + Prescriptive Reqts• Bldg Energy Recovery Ventilator Reqt

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• Fan and Pump Efficiency (DOE)• Occupant Based HVAC Controls (62.1) **• Enhanced Demand Control Ventilation• Air Cooled vs Water Cooled• Heat Recovery from Condenser Heat **

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• Advanced Energy Standards (AES) Initiatives– Hydronics working group– RTU working group

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Chiller Water “System” Example

Cooling Tower

Condenser

Evaporator

Condenser Water Pump

Compressor

Air Handler

Chilled Water Pump

Conditioned Space

Current 550/590 Chiller Standard and Certification focusASHRAE 90.1 Full and part load efficiency

ASHRAE 90.1 fan power requirement, no approach requirement and ignore water use

No focus on condenser water pumping power other than a pipe sizing requirement

No focus on chilled water pumping power other than pipe sizing

No focus on duct pressure drop and very little on applied fan power

Very little focus on the effective air distribution

Do not address multiple chillers and towers although most are applied that way

No integration of economizers, exhaust fans, ERV and IAQ

OutsideAir

Regulations No regulations

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Packaged Ducted Rooftop “System” Example

Packaged Rooftop

Conditioned Space

Rating of the rooftop EER and IEER with part of the fan power is covered by AHRI 340/360 but we do not certify the full operating map

Only part of the duct work pressure drop included in the ratings

No annualized performance for heating

Demand ventilation not reflected in ratings

ERV/Rooftop CEF can be used for full load, but not part load and annualized

Power Exhaust not included in ratings

Very little focus on the effective air distribution

On VAV units reheat not reflected in ratings

Economizer and outside air not reflected in ratings