2-i

CHAPTER 2. MARKET ASSESSMENT

TABLE OF CONTENTS

2.1 BACKGROUND AND DEFINITIONS.......................................................................... 2-1

2.1.1 Water-cooled and Evaporatively-cooled Air Conditioners.................................. 2-1

2.1.2 Variable Refrigerant Flow Commercial Package Air Conditioning and Heating 

Equipment............................................................................................................ 2-2

2.1.3 Computer Rooms Air Conditioners..................................................................... 2-3

2.1.4 Federal Energy Conservation Standards.............................................................. 2-5

2.1.5 ASHRAE Standard 90.1-2010 Equipment Classes and Efficiency Levels ......... 2-7

2.2 MARKET ASSESSMENT............................................................................................ 2-10

2.2.1 Trade Associations............................................................................................. 2-11

2.2.2 Manufacturers.................................................................................................... 2-11

2.2.3 Market Performance Data .................................................................................. 2-12

LIST OF TABLES

Table 2.1.1 Current Federal Energy Conservation Standards for Commercial Package Air 

Conditioning and Heating Equipment Classes with Increased or New Efficiency 

Levels in ASHRAE Standard 90.1-2010 ............................................................. 2-6

Table 2.1.2 Equipment Classes With Updated Efficiency Levels in ASHRAE Standard 90.1-

2010...................................................................................................................... 2-8

Table 2.2.1 Manufacturers of the Commercial Equipment Included in this Rulemaking ......... 2-12

Table 2.2.2 CEC Computer Room Air Conditioners Minimum Efficiency Levels................... 2-19

Table 2.2.3 Computer Room Air Conditioner Database Breakdown ........................................ 2-20

Table 2.2.4 Average SCOP for Computer Room Air Conditioners .......................................... 2-21
2-ii

LIST OF FIGURES

Figure 2.2.1 EER Histogram of Small Water-cooled Air Conditioners.................................... 2-14

Figure 2.2.2 EER Histogram of Large Water-cooled Air Conditioners.................................... 2-15

Figure 2.2.3 EER Histogram of Very Large Water-cooled Air Conditioners........................... 2-15

Figure 2.2.4 Histogram of Water-Source VRF Systems (≥135,000 Btu/h) with No Heat Recovery

............................................................................................................................ 2-18

Figure 2.2.5 Histogram of Water-Source VRF Systems (≥135,000 Btu/h) with Heat Recovery

...........................................................................................................................2-18

Figure 2.2.6 Air-Cooled Computer Room Air Conditioners (<65,000) Sensible Cooling Capacity 

Histogram........................................................................................................... 2-22

Figure 2.2.7 Air-Cooled Computer Room Air Conditioners (<65,000 Btu/h) SCOP Histogram

...........................................................................................................................2-23

Figure 2.2.8 Air-Cooled Computer Room Air Conditioners (≥65,000 Btu/h and <240,000 Btu/h) 

Sensible Cooling Capacity Histogram............................................................... 2-24

Figure 2.2.9 Air-Cooled Computer Room Air Conditioners (≥65,000 Btu/h and <240,000 Btu/h) 

SCOP Histogram................................................................................................ 2-24

Figure 2.2.10 Air-Cooled Computer Room Air Conditioners (≥240,000 Btu/h and <760,000 

Btu/h) Sensible Cooling Capacity Histogram.................................................... 2-25

Figure 2.2.11 Water-Cooled Computer Room Air Conditioner (<65,000 Btu/h) Sensible Cooling 

Capacity Histogram ........................................................................................... 2-26

Figure 2.2.12 Water-Cooled Computer Room Air Conditioner (<65,000 Btu/h) SCOP Histogram

............................................................................................................................ 2-26

Figure 2.2.13 Water-Cooled Computer Room Air Conditioner (≥65,000 Btu/h and <240,000 

Btu/h) Sensible Cooling Capacity Histogram.................................................... 2-27

Figure 2.2.14 Water-Cooled Computer Room Air Conditioner (≥65,000 Btu/h and <240,000 

Btu/h) SCOP Histogram .................................................................................... 2-27

Figure 2.2.15 Water-Cooled Computer Room Air Conditioner (≥240,000 Btu/h and <760,000 

Btu/h) Sensible Cooling Capacity Histogram.................................................... 2-28

Figure 2.2.16 Water-Cooled Computer Room Air Conditioner (<65,000 Btu/h) With a Fluid 

Economizer Sensible Cooling Capacity Histogram........................................... 2-28

Figure 2.2.17 Water-Cooled Computer Room Air Conditioner (≥65,000 Btu/h and <240,000 

Btu/h) with a Fluid Economizer Sensible Cooling Capacity Histogram........... 2-29

Figure 2.2.18 Water-Cooled Computer Room Air Conditioner (≥240,000 Btu/h and <760,000 

Btu/h) with a Fluid Economizer Sensible Cooling Capacity Histogram........... 2-30

Figure 2.2.19 Glycol-Cooled Computer Room Air Conditioner (<65,000 Btu/h) Sensible Cooling 

Capacity Histogram ........................................................................................... 2-30

Figure 2.2.20 Glycol-Cooled Computer Room Air Conditioner (<65,000 Btu/h) SCOP 

Histogram........................................................................................................... 2-31
2-iii

Figure 2.2.21 Glycol-Cooled Computer Room Air Conditioner (≥65,000 and <240,000 Btu/h) 

Sensible Cooling Capacity Histogram............................................................... 2-32

Figure 2.2.22 Glycol-Cooled Computer Room Air Conditioner (≥240,000 and <760,000 Btu/h) 

Sensible Cooling Capacity Histogram............................................................... 2-33

Figure 2.2.23 Glycol-Cooled Computer Room Air Conditioner (<65,000 Btu/h) with a Fluid 

Economizer Sensible Cooling Capacity Histogram........................................... 2-33

Figure 2.2.24 Glycol-Cooled Computer Room Air Conditioner (≥65,000 and <240,000 Btu/h) 

with a Fluid Economizer Sensible Cooling Capacity Histogram ...................... 2-34

Figure 2.2.25 Glycol-Cooled Computer Room Air Conditioner (≥240,000 and <760,000 Btu/h) 

With a Fluid Economizer Sensible Cooling Capacity Histogram ..................... 2-35
2-1

2.1 BACKGROUND AND DEFINITIONS

The American Society of Heating, Refrigeration, and Air-Conditioning Engineers 

(ASHRAE) released an updated version of the American National Standards Institute 

(ANSI)/ASHRAE/Illuminating Engineering Society of North America (IESNA) Standard 90.1 

(hereinafter referred to as ASHRAE Standard 90.1-2010) on October 29, 2010. ASHRAE 

Standard 90.1-2010 included increased efficiency levels for water-cooled and evaporativelycooled commercial package air conditioners (triggering DOE review of the minimum standards 

for these equipment classes) and created a new set of equipment classes for variable refrigerant 

flow (VRF) products (which were previously covered as small, large, and very large commercial 

package air conditioning and heating equipment) and for air conditioners and condensing units 

serving computer rooms (i.e., computer room air conditioners). ASHRAE Standard 90.1-2010 

also increased its efficiency level for certain classes of water-source VRF commercial package 

heat pumps in comparison to the existing Federal standards that would apply, thereby triggering 

DOE review of the standards for those equipment classes. 

2.1.1 Water-cooled and Evaporatively-cooled Air Conditioners

Water-cooled and evaporatively-cooled air conditioners are part of a subset of 

commercial package air conditioning and heating equipment. EPCA defines a “commercial 

package air conditioning and heating equipment” as an “air-cooled, water-cooled, evaporativelycooled, or water-source (not including ground water-source) electrically operated, unitary central 

air conditioners and central air conditioning heat pumps for commercial application.” (42 U.S.C. 

6311(8)(A)) 

Air conditioners use a refrigeration cycle to cool an indoor space by moving heat from 

the cold location to a hotter location by means of evaporating and condensing a fluid, typically a 

refrigerant. An air conditioner typically has four major components: a compressor, condensing 

coil, expansion valve, and an evaporator coil. The compressor turns the refrigerant from a low 

pressure gas into a high pressure gas, which raises the temperature of the gas. At the next step, 

the condensing coil convects the heat from the hot refrigerant, which condenses into a liquid, still 

at a high temperature and high pressure. This liquid refrigerant then goes through an expansion 

valve that lowers the refrigerant’s pressure and temperature before entering the evaporator coil. 

The evaporator coil cools the indoor air by transferring heat from the warmer indoor air to the 

low temperature refrigerant. 

Commercial-size water-cooled and evaporatively-cooled air conditioners cool 

commercial facilities and utilize water instead of ambient air (as is used in air-cooled equipment) 

to cool the condensing coil. In the case of a water-cooled air conditioner, the condensing coil is 

submerged in circulating water; whereas in the case of evaporatively-cooled air conditioner, the 
2-2

condensing coil is sprayed with water that evaporates as air passes over the coil. Both systems 

utilize the high heat capacity of water to optimize the heat transfer from the refrigerant in the 

condensing coil. Water-cooled air conditioners can be used effectively in any type of 

environment, while evaporatively-cooled air conditioners are most effective in hot-dry climate 

regions (i.e., the southwestern United States).

2.1.2 Variable Refrigerant Flow Commercial Package Air Conditioning and Heating 

Equipment

Variable refrigerant flow systems are a subset of commercial package air conditioning 

and heating equipment that is newly defined in ASHRAE 90.1-2010. VRF systems are most 

commonly used in hotels, schools, and office buildings where different zones have different 

heating and cooling load requirements depending on occupancy and time of day. VRF systems 

typically have one outdoor condensing unit that is connected to multiple indoor evaporator coils, 

as opposed to the single indoor evaporator coil typically found in conventional air conditioners 

and heat pumps. Each evaporator coil in a VRF system can be individually controlled, and VRF 

systems are capable of monitoring and adjusting the refrigerant flow to each evaporator to meet 

the requirements of heating and cooling loads in specific zones. Some VRF heat pumps have a 

heat recovery option, which allows the system to move heat between zones within a building via 

a third refrigerant line that connects indoor evaporator coils. The heat recovery feature allows a 

zone requiring heat to be warmed using the heat extracted from a zone requiring cooling, and 

vice versa. However, if all zones need to be heated at the same time, then the heat would need to 

be provided by other means (e.g. the reverse refrigeration cycle).

Water-source VRF systems utilize a condensing unit that transfers heat to or from 

circulating water depending on whether the system is in cooling or heating mode. These systems 

allow the condensing unit of the system to be placed indoors, such as in a mechanical closet or a 

basement. Having the condensing unit indoors decreases the amount of refrigerant piping to the 

individual evaporator coils, which is especially useful for equipment installed in high rise office 

buildings.

Neither EPCA nor DOE’s regulations in the Code of Federal Regulations (CFR) define 

variable refrigerant flow systems. ASHRAE Standard 90.1-2010 defines a variable refrigerant 

flow system as “an engineered direct expansion (DX) multi-split system incorporating at least 

one variable capacity compressor distributing refrigerant through a piping network to multiple 

indoor fan coil units each capable of individual zone temperature control, through integral zone 

temperature control devices and common communications network. Variable refrigerant flow 

utilizes three or more steps of control on common, interconnecting piping.” AHRI Standard 

1230-2010, the ASHRAE Standard 90.1-2010 test procedure for this equipment, uses the term

“variable refrigerant flow multi-split system” and defines it as “a split system air-conditioner or 
2-3

heat pump incorporating a single refrigerant circuit, with one or more outdoor units, at least one 

variable speed compressor or an alternative compressor combination for varying the capacity of 

the system by three or more steps, multiple indoor fan coils units, each of which is individually 

metered and individually controlled by a proprietary control device and common 

communications network. The system shall be capable of operating as an air conditioner or a 

heat pump. Variable refrigerant flow implies three or more steps of control on common, interconnecting piping.” AHRI Standard 1230 and ASHRAE Standard 90.1-2010 uses the term

“multi split” to distinguish them from “mini split,” the indoor units of which can only be 

controlled by one thermostat. Since DOE believes that it is important to distinguish VRF

systems as multi-split systems, DOE proposed to formulate definitions for this equipment class

based on the definitions above. DOE defines “variable refrigerant flow multi-split air 

conditioner” and “variable refrigerant flow multi-split heat pump” in section V.A of the NOPR. 

The definitions DOE proposes clearly delineate VRF air conditioners and heat pumps as a subcategory of commercial package air conditioning and heating equipment and are structured in 

such a way to ensure that there are no overlaps with any other covered equipment class. The 

definition also incorporates all of the unique features of this equipment, such as the individuallycontrolled indoor units and an integral control device for monitoring the system. There is also a 

subcategory of VRF heat pumps that have “heat recovery,” which DOE also defines in section 

V.A of the NOPR. 

2.1.3 Computer Rooms Air Conditioners

“Air conditioners and condensing units serving computer rooms” is a new equipment 

class established in ASHRAE Standard 90.1-2010. ASHRAE Standard 90.1-2010 modified its 

scope to cover air conditioning equipment used for process cooling and specified the efficiency 

metric for this equipment class as sensible coefficient of performance (SCOP) as measured by 

ASHRAE 127-2007, Method of Testing for Rating Computer and Data Processing Room 

Unitary Air Conditioners. Because of this expansion of scope, DOE tentatively concluded that it 

has the authority to regulate and set standards for this equipment. Thus, DOE must define 

computer room air conditioners so that this equipment class would be clearly differentiated from 

other commercial packaged air conditioners and heat pumps. ASHRAE Standard 90.1-2010 does 

not contain a definition for “air conditioners and condensing units serving computer rooms,” but 

does define a “computer room” as “a room whose primary function is to house equipment for the 

processing and storage of electronic data and that had a design electronic data equipment power 

density exceeding 20 watts/ft2 of conditioned floor area.” ASHRAE 127-2007 defines a 

“computer and data processing room (CDPR) unitary air conditioner” as a system “consisting of 

one or more factory-made assemblies, which include a direct expansion evaporator or chilledwater cooling coil, an air-moving device, and air-filtering devices. The air conditioner may 

include a compressor, condenser, humidifier, or reheating function. Where direct expansion 

equipment is provided in more than one assembly and the separate are to be used together, the 
2-4

requirements of rating outlined in this standard are based upon the use of matched assemblies. 

The functions of a CDPR air conditioner, either alone or in combination with a cooling and 

heating plant, are to provide air filtration, circulation, cooling, reheating, and humidity control.”

Neither of these definitions gives any unique physical characteristics that could differentiate 

computer room air conditioners from other commercial packaged unitary air conditioners. 

Computer room air conditioners operate in the same manner as other commercial 

packaged unitary air conditioners in that they provide space conditioning by means of a direct 

expansion system. However, cooling computer rooms, server rooms, and data centers presents 

unique challenges because these areas contain valuable equipment that are sensitive to small 

changes in temperature and humidity. Too much humidity can lead to water condensing on 

electronic components, and too little humidity may cause static discharges. Computer equipment 

are also constantly producing dynamic, high density heating loads, which means that the air 

conditioning also would need to be running constantly and needs to be able to cool any “hot 

spots.” Server rooms and data centers are typically located in the center of buildings away from 

windows and often have limited floor space, which limits the size and positioning of the air 

conditioner and causes issues related to removing the heat from the computer room.

Because of these challenges computer room air conditioners have different design 

requirements than standard air conditioners, even though they use the same process and 

components as conventional air conditioners (i.e., a refrigeration cycle with a compressor, 

condensing coil, expansion valve, and evaporator coil). Computer room air conditioners have to

maintain the temperature in a narrow range and maintain a specific relative humidity (usually 

between 40 and 55 percent); so in addition to cooling, these equipment have to be capable of 

both humidifying and dehumidifying the air. These air conditioners are often called “precision 

air conditioners” because of this control requirement. These units can be installed in various 

configurations, including floor mounted, ceiling mounted, or portable units for moving around 

the room. The condensing units can be cooled by air, water, or a glycol-water mixture. However, 

even though humidity control is an essential feature for conditioning computer rooms, humidity 

control is typically an optional feature for computer room air conditioners since most of the 

system is custom built for a specific application.

Because DOE is not aware of any physical features unique to computer room air 

conditioners and because computer room air conditioners are typically described by their 

application, DOE is proposing a definition for computer room air conditioners based on how the 

equipment is marketed for use and which test standard is used to rate its performance. For the 

NOPR DOE has proposed to define “computer room air conditioner” as “a unit of commercial 

package air conditioning and heating equipment that is advertised, marketed, and/or sold 

specifically for use in computer rooms, data processing rooms, or other precision cooling 

applications, and is rated for performance using ASHRAE Standard 127, (incorporated by 
2-5

reference, see §431.95). Such equipment may not be marketed or advertised as equipment for 

any other space conditioning applications, and may not be rated for performance using AHRI 

Standard 210/240 or AHRI Standard 340/360.” DOE used this definition when compiling its 

database of computer room air conditioners described in section 2.2 of this chapter.

2.1.4 Federal Energy Conservation Standards

On January 12, 2001, DOE published in the Federal Register a final rule promulgating 

the current standards for 5 equipment classes of small (i.e., cooling capacity <135,000 Btu/h) and 

large (i.e., cooling capacity ≥135,000 Btu/h and <240,000 Btu/h) water-cooled and 

evaporatively-cooled air conditioners. 66 FR 3336. This final rule adopted the efficiency levels 

set by ASHRAE Standard 90.1-1999. On July 22, 2009, DOE published in the Federal Register

a final rule setting the standards for very large water-cooled and evaporatively-cooled equipment 

with a cooling capacity ≥240,000 and <760,000 Btu/h. 74 FR 36312. In the July 2009 final rule, 

DOE adopted the efficiency levels for these products as specified in ASHRAE Standard 90.1-

2007. 

As noted previously, variable refrigerant flow systems are new classes of equipment in 

ASHRAE Standard 90.1-2010. However, these equipment classes are currently covered under 

the more broad Federal equipment classes of commercial package air conditioning and heating 

equipment. ASHRAE Standard 90.1-2010 set the efficiency levels for all classes of VRF systems 

equal to the existing Federal energy conservation standards for commercial package air 

conditioning and heating equipment, except for the equipment class of water-source VRF heat 

pumps with a cooling capacity <17,000 Btu/h. Therefore, with the exception of water-source 

VRF heat pumps with a cooling capacity <17,000 Btu/h, DOE was not required to perform an 

analysis of those equipment classes. In addition, ASHRAE Standard 90.1-2010 includes 

efficiency levels for water-source VRF heat pumps with cooling capacity ≥135,000 Btu/h, which 

are not currently regulated by Federal energy conservation standards. The current Federal energy 

conservation standard for water-source heat pumps with a cooling capacity <135,000 Btu/h was 

set by the January 2001 final rule, which adopted the ASHRAE Standard 90.1-1999 levels. 66 

FR 3336. The Energy Policy Act of 2005 (EPACT 2005) set the current Federal standard for the 

other classes of commercial package air conditioners and heating equipment with the exception 

of air-cooled heat pumps with a cooling capacity less than 65,000 Btu/h, which were included in 

EISA 2007. 

Table 2.1.1 shows the current Federal energy conservation levels for equipment classes 

where ASHRAE Standard 90.1-2010 increased the efficiency levels in comparison to the Federal 

levels. 
2-6

Table 2.1.1 Current Federal Energy Conservation Standards for Commercial Package Air 

Conditioning and Heating Equipment Classes with Increased or New Efficiency Levels in 

ASHRAE Standard 90.1-2010

Equipment Type Cooling Capacity Subcategory Federal Standard

Small Commercial 

Package Air Conditioning 

Equipment, Water-cooled 

and Evaporatively-cooled 

≥65,000 Btu/h and 

<135,000 Btu/h

Electric Resistance or no 

heating

11.5 EER

All other 11.3 EER

Large Commercial 

Package Air Conditioning 

and Heating Equipment, 

Water-cooled and 

Evaporatively-cooled 

≥135,000 Btu/h and 

<240,000 Btu/h

Electric Resistance or no 

heating

11.0 EER

All other 11.0 EER

Very Large Commercial 

Package Air Conditioning 

and Heating Equipment, 

Water-cooled and 

Evaporatively-cooled 

≥240,000 Btu/h and 

<760,000 Btu/h

Electric Resistance or no 

heating

11.0 EER

All other 10.8 EER

Small Commercial 

Package Air Conditioning 

and Heating Equipment, 

Water-source*

<17,000 Btu/h HP 11.2 EER

4.2 COP

Large Commercial 

Package Air Conditioning 

and Heating Equipment, 

Water-source*

>135,000 Btu/h HP None

Air-cooled Computer 

Room Air Conditioners

<65,000 Btu/h Downflow None

Upflow None

≥65,000 Btu/h and 

<240,000 Btu/h

Downflow None

Upflow None

≥240,000 Btu/h and 

<760,000 Btu/h

Downflow None

Upflow None

Water-cooled Computer 

Room Air Conditioners

<65,000 Btu/h Downflow None

Upflow None

≥65,000 Btu/h and 

<240,000 Btu/h

Downflow None

Upflow None

≥240,000 Btu/h and 

<760,000 Btu/h

Downflow None

Upflow None

Water-cooled Computer 

Room Air Conditioners 

with a Fluid Economizer

<65,000 Btu/h Downflow None

Upflow None

≥65,000 Btu/h and 

<240,000 Btu/h

Downflow None

Upflow None

≥240,000 Btu/h and 

<760,000 Btu/h

Downflow None

Upflow None

Glycol-cooled Computer 

Room Air Conditioners

<65,000 Btu/h Downflow None

Upflow None

≥65,000 Btu/h and 

<240,000 Btu/h

Downflow None

Upflow None

≥240,000 Btu/h and 

<760,000 Btu/h

Downflow None

Upflow None

Glycol-cooled Computer 

Room Air Conditioners 

with a Fluid Economizer

<65,000 Btu/h Downflow None

Upflow None

≥65,000 Btu/h and 

<240,000 Btu/h

Downflow None

Upflow None
2-7

≥240,000 Btu/h and 

<760,000 Btu/h

Downflow None

Upflow None

* This equipment class includes VRF systems, for which ASHRAE Standard 90.1-2010 updated its standard levels.

2.1.5 ASHRAE Standard 90.1-2010 Equipment Classes and Efficiency Levels

The previous version of ASHRAE Standard 90.1 (ASHRAE Standard 90.1-2007) 

specified the efficiency levels for water-cooled and evaporatively-cooled air conditioners as a 

single equipment class including both types of equipment. In ASHRAE Standard 90.1-2010, 

ASHRAE specified different efficiency levels for water-cooled air conditioners and 

evaporatively-cooled air conditioners, while retaining the same cooling capacity ranges: <65,000 

Btu/h, ≥65,000 and <135,000 Btu/h, ≥135,000 and <240,000 Btu/h, and ≥240,000 and <760,000 

Btu/h.

a ASHRAE Standard 90.1-2010 further divides these products based on whether they have 

electric resistance/no heating or any other kind of heating.

ASHRAE Standard 90.1-2010 also created new equipment classes for VRF systems. 

ASHRAE divides air-cooled VRF systems into 4 size categories: <65,000 Btu/h, ≥65,000 and 

<135,000 Btu/h, ≥135,000 and <240,000 Btu/h, and ≥240,000 and < 760,000 Btu/h.a

 ASHRAE 

90.1-2010 also divides water-source VRF systems into 3 size categories, <65,000 Btu/h, ≥65,000 

and <135,000 Btu/h, and ≥135,000 and <760,000 Btu/h.a

 For both air-cooled and water-source 

VRF systems, ASHRAE also further divides those equipment classes with a cooling capacity 

greater than 65,000 Btu/h based on whether or not a heat recovery system is present. ASHRAE

Standard 90.1-2010 raised the efficiency level above the Federal standard for VRF heat pumps

with a cooling capacity <17,000 Btu/h and VRF heat pumps with a cooling capacity ≥135,000 

Btu/h (for which no Federal standard exists). 

ASHRAE also created new equipment classes for air conditioners and condensing units 

serving computer rooms. ASHRAE first divides air conditioners and condensing units serving 

computer rooms into 5 classes depending on cooling mechanism: air-cooled, water-cooled, 

water-cooled with a fluid economizer, glycol-cooled (rated at 40% propylene glycol), and glycolcooled with a fluid economizer. ASHRAE further divides these classes into 3 size categories 

(<65,000 Btu/h, ≥65,000 and <240,000 Btu/h, and ≥240,000 Btu/h) and orientation (upflow and 

downflow) to make up a total of 30 unique efficiency levels for this equipment class. 

Table 2.1.2 below shows the ASHRAE Standard 90.1-2010 efficiency level for the 

updated equipment classes along with the currently applicable Federal minimum efficiency 

standards for comparison.

 a ASHRAE Standard 90.1 does not specify an upper limit on the cooling capacity for the largest capacity equipment 

class (i.e., ≥240,000 Btu/h). However, EPCA limits the size of very large commercial package air conditioning and 

heating equipment to cooling capacities below 760,000 Btu/h.
2-8

Table 2.1.2 Equipment Classes With Updated Efficiency Levels in ASHRAE Standard 

90.1-2010

ASHRAE Equipment 

Type

Cooling 

Capacity Subcategories

ASHRAE 

Standard 

90.1-2010

Federal Minimum 

Energy 

Conservation 

Standards

Water-cooled Air 

Conditioner

≥65,000 and 

<135,000Btu/h

Electric 

Resistance or 

No Heating 

Split System 

and Single 

Package

12.1 EER

(as of 

6/1/11)

11.5 EER

All Others

Split System 

and Single 

Package

11.9 EER

(as of 

6/1/11)

11.3 EER

≥135,000 and 

<240,000Btu/h

Electric 

Resistance or

No Heating

Split System 

and Single 

Package

12.5 EER

(as of 

6/1/11) 11.0 EER

All Others

Split System 

and Single 

Package

12.3 EER

(as of 

6/1/11)

≥240,000 and 

<760,000Btu/h

Electric 

Resistance or 

No Heating

Split System 

and Single 

Package

12.4 EER

(as of 

6/1/11)

11.0 EER 

All Others

Split System 

and Single 

Package

12.2 EER

(as of 

6/1/11)

10.8 EER

Evaporatively-cooled 

Air Conditioner

≥65,000 and 

<135,000Btu/h

Electric 

Resistance or 

No Heating

Split System 

and Single 

Package

12.1 EER

(as of 

6/1/11)

11.5 EER

All Others

Split System 

and Single 

Package

11.9 EER

(as of 

6/1/11)

11.3 EER

≥135,000 and 

<240,000Btu/h

Electric 

Resistance or 

No Heating

Split System 

and Single 

Package

12.0 EER

(as of 

6/1/11) 11.0 EER

All Others

Split System 

and Single 

Package

11.8 EER

(as of 

6/1/11)

≥240,000 and 

<760,000Btu/h

Electric 

Resistance or 

No Heating

Split System 

and Single 

Package

11.9 EER

(as of 

6/1/11)

11.0 EER

All Others

Split System 

and Single 

Package

12.2 EER *

(as of 

6/1/11)

10.8 EER
2-9

ASHRAE Equipment 

Type

Cooling 

Capacity Subcategories

ASHRAE 

Standard 

90.1-2010

Federal Minimum 

Energy 

Conservation 

Standards

Variable Refrigerant 

Flow, Water-source

<17,000 Btu/h All heating 

types

Multi-split 

system

12.0 EER 

4.2 COP

11.2 EER

4.2 COP

Multi-split 

system with 

Heat 

Recovery

11.8 EER

4.2 COP

11.2 EER

4.2 COP

≥135,000 Btu/h All heating 

types

Multi-split 

system

10.0 EER

3.9 COP

None Multi-split 

system with 

Heat 

Recovery

9.8 EER

3.9 COP

Air Conditioners 

Serving Computer 

Rooms, Air-cooled

<65,000 Btu/h -

Downflow 2.20 SCOP

None

Upflow 2.09 SCOP

≥65,000 Btu/h 

and <240,000 

Btu/h

-

Downflow 2.10 SCOP

Upflow 1.99 SCOP

≥240,000 Btu/h -

Downflow 1.90 SCOP

Upflow 1.79 SCOP

Air Conditioners 

Serving Computer 

Rooms, Water-cooled

<65,000 Btu/h -

Downflow 2.60 SCOP

None

Upflow 2.49 SCOP

≥65,000 Btu/h 

and <240,000 

Btu/h

-

Downflow 2.50 SCOP

Upflow 2.39 SCOP

≥240,000 Btu/h -

Downflow 2.40 SCOP

Upflow 2.29 SCOP

Air Conditioners 

Serving Computer 

Rooms, Water-cooled 

with Fluid Economizer

<65,000 Btu/h -

Downflow 2.55 SCOP

None

Upflow 2.44 SCOP

≥65,000 Btu/h 

and <240,000 

Btu/h

-

Downflow 2.45 SCOP

Upflow 2.34 SCOP

≥240,000 Btu/h -

Downflow 2.35 SCOP

Upflow 2.24 SCOP
2-10

ASHRAE Equipment 

Type

Cooling 

Capacity Subcategories

ASHRAE 

Standard 

90.1-2010

Federal Minimum 

Energy 

Conservation 

Standards

Air Conditioners 

Serving Computer 

Rooms, Glycol-cooled

<65,000 Btu/h -

Downflow 2.50 SCOP

None

Upflow 2.39 SCOP

≥65,000 Btu/h 

and <240,000 

Btu/h

-

Downflow 2.15 SCOP

Upflow 2.04 SCOP

≥240,000 Btu/h -

Downflow 2.10 SCOP

Upflow 1.99 SCOP

Air Conditioners 

Serving Computer 

Rooms, Glycol-cooled 

with Fluid Economizer

<65,000 Btu/h -

Downflow 2.45 SCOP

None

Upflow 2.34 SCOP

≥65,000 Btu/h 

and <240,000 

Btu/h

-

Downflow 2.10 SCOP

Upflow 1.99 SCOP

≥240,000 Btu/h -

Downflow 2.05 SCOP

Upflow 1.94 SCOP

*Given the historical approach of the ASHRAE committee to setting efficiency levels with for commercial air 

conditioning and heating equipment, this efficiency level appears to be a mistake in ASHRAE Standard 90.1-2010.

DOE believes the intended level is 11.7 EER, and an addendum to lower the value to 11.7 EER is currently being 

considered by ASHRAE. Accordingly, DOE considered the value 11.7 EER as the ASHRAE Standard 90.1-2010 

efficiency level in its potential energy savings analysis.

ASHRAE Standard 90.1-2010 raised the efficiency level in comparison to the current 

Federal minimum energy conservation standards for six water-cooled air conditioner equipment 

classes, six evaporatively-cooled air conditioner equipment classes, and one water-source VRF 

heat pump equipment classes. In addition, ASHRAE Standard 90.1-2010 created efficiency 

levels for one water-source VRF heat pump equipment class and for thirty classes of air 

conditioners serving computer rooms that were not previously covered by DOE’s regulations. 

DOE assessed the current market and performed a potential energy savings analysis for each 

equipment class where DOE found models on the market. The market assessment is described in 

the sections immediately below.

2.2 MARKET ASSESSMENT

The following market assessment identifies the manufacturer trade associations and 

domestic and international manufacturers of commercial water-cooled and evaporatively-cooled 

air conditioners, VRF systems, and computer room air conditioners. The market assessment also 
2-11

summarizes the relevant market performance data for each equipment class where such data was 

available. 

2.2.1 Trade Associations

DOE researched various trade groups who represent manufacturers, distributors, and 

installers of the various types of equipment being analyzed this rulemaking. The AirConditioning, Heating, and Refrigeration Institute (AHRI) is one of the largest trade associations

for manufacturers of space heating and cooling equipment, representing over 90% of the 

residential and commercial air-conditioning, space-heating, water-heating, and commercial 

refrigeration equipment manufactured in the US.

1 AHRI also develops and publishes test 

procedures standards for residential and commercial heating, ventilation, and air conditioning 

(HVAC) equipment and coordinates with the International Organization for Standardization 

(ISO) to help harmonize the US standards with international standards, if feasible. AHRI also 

maintains the AHRI Directory of Certified Product Performance that lists all the products and 

equipment that have been certified by AHRI. Water-cooled air conditioners can be found in the 

commercial unitary large equipment directory, and VRF systems can be found in the VRF multisplit air conditioning and heat pump equipment directory. There are no evaporatively-cooled air 

conditioners or computer room air conditioners listed in the AHRI directory.

Heating, Airconditioning & Refrigeration Distributors International (HARDI) is a trade 

association that represents over 450 wholesale heating, ventilation, air conditioning, and 

refrigeration (HVACR) companies plus over 300 manufacturing associates and nearly 140 

manufacturing representatives. HARDI estimates that 80% of the revenue of HVACR systems 

goes through its members.

2

Air Conditioning Contractors of America (ACCA) is another trade association whose 

members include over 4,000 contractors and 60,000 professionals. ACCA provides contractors 

technical, legal, and market resources, helping to promote good practices and to keep buildings 

safe, clean, and affordable.

3

2.2.2 Manufacturers

DOE reviewed the efficiency data for water-cooled and evaporatively-cooled air 

conditioners currently on the market by examining the AHRI Directory of Certified Product 

Performance4 and the California Energy Commission (CEC) Appliance Efficiency Database.5 To 

supplement the data in the AHRI and CEC databases, DOE gathered additional information from 

the websites of individual manufacturers of that equipment. For VRF systems DOE used the 

AHRI Directory of Certified Product Performance for VRF systems and gathered data from 
2-12

manufacturers’ websites for this equipment. DOE gathered data on computer room air 

conditioners from the CEC database and from manufacturers’ websites.

DOE identified eight manufacturers of water-cooled air conditioners, three manufacturers 

of evaporatively-cooled air conditioners, three manufactures of water-source variable refrigerant 

flow heat pumps, and five manufacturers of computer room air conditioners. The manufacturers 

for each equipment class are listed in Table 2.2.1.

Table 2.2.1 Manufacturers of the Commercial Equipment Included in this Rulemaking

Water-Cooled Air 

Conditioner 

Manufacturers

Evaporatively-Cooled 

Air Conditioner 

Manufacturers

Water-Source Variable 

Refrigerant Flow 

System Manufacturers

Computer Room Air 

Conditioners

Aaon, Inc. Aaon, Inc. Daikin American Power Conversion

Allied Thermal Systems Trane Inc. LG Electronics U.S.A., 

Inc.

CompuAire

Carrier Corp. York International 

Corp.

Mitsubishi Electric & 

Electronics USA, Inc.

Data Aire, Inc.

Lennox International Liebert

Engineered Air Stulz Air Technology 

Systems

Thermoplus Air, Inc.

Trane Inc.

York International Corp.

2.2.3 Market Performance Data

For each equipment class analyzed, DOE began by gathering market data to characterize 

the efficiency and performance of models currently on the market. As noted earlier, DOE 

gathered information from the AHRI Directory of Certified Product Performance, as well as the 

CEC Appliance Efficiency Database. DOE also examined individual manufacturer’s websites 

and product literature to compile a complete database of models for each equipment class.

For the analysis, DOE only examined the equipment classes for which ASHRAE 

Standard 90.1-2010 increased its efficiency levels: water-cooled and evaporatively-cooled air 

conditioner equipment classes with cooling capacities greater than or equal to 65,000 Btu/h, 

water-source VRF heat pumps with a cooling capacity <17,000 Btu/h, water-source VRF 

systems with a cooling capacity ≥135,000 Btu/h, and computer room air conditioners. .

Using the AHRI and CEC directories as a starting point and augmenting the data with 

information from manufacturer websites, DOE compiled a database of water-cooled air 

conditioner models with efficiency data available and separated them into the appropriate

equipment classes based on cooling capacity: small (i.e., <135,000 Btu/h), large (i.e., ≥135,000 

Btu/h and <240,000 Btu/h), and very large (i.e., ≥240,000 Btu/h and <760,000 Btu/h). DOE 

found no evaporatively-cooled air conditioners in the AHRI and CEC directories but found a few 
2-13

evaporatively-cooled air conditioners from manufacturers’ websites. DOE compiled a database 

of evaporatively-cooled air conditioner models with efficiency data available and found no 

models that fall into the small and large equipment classes. Accordingly, all evaporativelycooled models identified were in the very large equipment class. Therefore, DOE did not 

perform a potential energy savings analysis for the NODA for small and large evaporativelycooled air conditioners and is not analyzing them as part of this NOPR analysis; however, DOE

did analyze small (≥65,000), large, and very large water-cooled air conditioners and very large 

evaporatively-cooled air conditioners as part of the potential energy savings analysis for the 

NODA and for this NOPR.

For the NODA, DOE used manufacturers’ websites to compile a database of watersource VRF heat pumps with a cooling capacity <17,000 Btu/h and water-source VRF heat 

pumps with a cooling capacity ≥135,000 Btu/h. However, after the NODA was published, AHRI 

released a VRF multi-split air conditioning and heat pump database as part of their Directory of 

Certified Product Performance. Thus, for the NOPR market assessment DOE used the AHRI 

database and supplemented that database with models found from manufacturer’s websites that 

were not in the AHRI database. DOE found no water-source VRF heat pumps with a cooling 

capacity <17,000 Btu/h on the market, but it did find water-source VRF heat pumps with a 

cooling capacity ≥135,000 Btu/h. Therefore, DOE did not perform a potential energy savings 

analysis for the NODA for water-source VRF heat pumps with a cooling capacity <17,000 Btu/h 

and did not analyze them for this NOPR (as explained in the NOPR), but it did perform a 

potential energy savings analysis for water-source VRF heat pumps with a cooling capacity 

≥135,000 Btu/h.

Lastly, for computer room air conditioners, DOE compiled a database of available 

models using information from the CEC directory and from manufacturers’ websites. AHRI does 

not have a database for computer room air conditioners in their Directory of Certified Product 

Performance. DOE then divided the computer room air conditioner models into 30 equipment 

classes, by net sensible cooling capacity (<65,000 Btu/h, ≥65,000 Btu/h and <240,000 Btu/h, and 

≥240,000 Btu/h), by cooling type (air-cooled, water-cooled, water-cooled with a fluid 

economizer, glycol-cooled, and glycol-cooled with a fluid economizer), and by orientation (i.e., 

whether it is upflow or downflow). DOE used this database as the starting point for its analysis 

of computer room air conditioners. 

2.2.3.1 Water-Cooled Air Conditioners

Small Water-cooled Air Conditioners. Small water-cooled air conditioners have a 

cooling capacity greater than or equal to 65,000 Btu/h and less than 135,000 Btu/h and have their 

condensing coil completely submerged in water. Small water-cooled air conditioners are part of 

the water-cooled and evaporatively-cooled air conditioners equipment class, whose Federal 

energy conservation standard is 11.5 EER for systems with electric resistance or no heating and 
2-14

11.3 EER for systems that use any other type of heating (66 FR 3336; 10 CFR 431.97). 

ASHRAE Standard 90.1-2010 changes the efficiency rating to 12.1 for systems with electric 

resistance or no heating and 11.9 for systems that use any other type of heating. DOE analyzed 

the distribution of energy efficiency ratios (EERs) for these products as well as the minimum, 

maximum, and average cooling input capacities and EER values. The average EER value for this 

equipment class is 13.9. Of the models identified by DOE, two (13 percent of the total models) 

have EERs rated below the ASHRAE Standard 90.1-2010 levels. 

Figure 2.2.1 EER Histogram of Small Water-cooled Air Conditioners

Large Water-cooled Air Conditioners. Large water-cooled air conditioners have a 

cooling capacity greater than or equal to 135,000 Btu/h and less than 240,000 Btu/h and have 

their condensing coil completely submerged in water. Large water-cooled air conditioners are 

part of the water-cooled and evaporatively-cooled air conditioners equipment class, whose 

Federal energy conservation standard is 11.0 EER regardless of what kind of heating is used (66 

FR 3336; 10 CFR 431.97). ASHRAE Standard 90.1-2010 changes the efficiency rating to 12.5 

for systems with electric resistance or no heating and 12.3 for systems that use any other type of 

heating. DOE analyzed the distribution of efficiencies for these products. The average EER for 

these units was 13.1. DOE identified 6 models (43 percent of the total models in this equipment 

class) that would fall below the ASHRAE Standard 90.1-2010 levels for this equipment class.

0

1

2

3

4

Number of Models

EER
2-15

Figure 2.2.2 EER Histogram of Large Water-cooled Air Conditioners

Very Large Water-cooled Air Conditioners. Very large water-cooled air conditioners 

have a cooling capacity greater than or equal to 240,000 Btu/h and less than 760,000 Btu/h, and 

have their condensing coil completely submerged in water. Very large water-cooled air 

conditioners are part of the water-cooled and evaporatively-cooled air conditioners equipment 

class, whose Federal energy conservation standard is 11.0 EER for units with electric resistance 

or no heating and 10.8 for units with all other kinds of heating (74 FR 36312; 10 CFR 431.97).

ASHRAE Standard 90.1-2010 changes the efficiency rating to 12.5 for systems with electric 

resistance or no heating and 12.3 for systems that use any other type of heating. DOE analyzed 

the distribution of efficiencies for these products. The average EER rating for these units is 13.0. 

DOE identified 12 models (34 percent of the total models identified) that would fall below the 

ASHRAE Standard 90.1-2010 efficiency level for this equipment class.

Figure 2.2.3 EER Histogram of Very Large Water-cooled Air Conditioners

0

1

2

3

4

Number of Models

EER

0

1

2

3

4

5

Number of Models

EER
2-16

2.2.3.2 Evaporatively-Cooled Air Conditioners

Small Evaporatively-cooled Air Conditioners. Small evaporatively-cooled air 

conditioners have a cooling capacity greater than or equal to 65,000 Btu/h and less than 135,000 

Btu/h. Small evaporatively-cooled air conditioners are covered as part of the water-cooled and 

evaporatively-cooled air conditioners equipment class, whose Federal energy conservation 

standard is 11.5 EER for systems with electric resistance or no heating and 11.3 EER for systems 

that use any other type of heating (66 FR 3336; 10 CFR 431.97). ASHRAE Standard 90.1-2010 

changes the efficiency rating to 12.1 EER for systems with electric resistance or no heating and 

11.9 EER for systems that use any other type of heating. DOE surveyed the AHRI database and 

manufacturers’ websites to find small evaporatively-cooled air conditioners with cooling 

capacities greater than or equal to 65,000 Btu/h and less than 135,000 Btu/h and did not find any 

on the market.

Large Evaporatively-cooled Air Conditioners. Large evaporatively-cooled air 

conditioners have a cooling capacity greater than or equal to 135,000 Btu/h and less than 

240,000 Btu/h. Large evaporatively-cooled air conditioners are covered as part of the watercooled and evaporatively-cooled air conditioners equipment class, whose Federal energy 

conservation standard is 11.0 EER regardless of what type of heating is used (66 FR 3336; 10 

CFR 431.97). ASHRAE Standard 90.1-2010 changes the efficiency rating to 12.0 EER for 

systems with electric resistance or no heating and 11.8 EER for systems that use any other type 

of heating. DOE surveyed the AHRI database and manufacturers’ websites to find large 

evaporatively-cooled air conditioners with cooling capacities greater than or equal to 135,000 

Btu/h and less than 240,000 Btu/h and did not find any on the market.

Very Large Evaporatively-cooled Air Conditioners. Very large evaporatively-cooled air 

conditioners have an input capacity greater than or equal to 240,000 Btu/h and less than 760,000 

Btu/h. Very large evaporatively-cooled air conditioners are covered as part of the water-cooled 

and evaporatively-cooled air conditioners equipment class, whose Federal energy conservation 

standard is 11.0 EER for systems with electric resistance or no heating and 10.8 EER for systems 

that use any other type of heating (74 FR 36312; 10 CFR 431.97). ASHRAE Standard 90.1-2010 

changes the efficiency rating to 12.0 EER for systems with electric resistance or no heating and 

11.8 EER for systems that use any other type of heating. During the market research, DOE 

identified several models from manufacturers that would be classified as very large 

evaporatively-cooled air conditioners. However, the efficiency rating for these models was not 

readily available, and DOE was unable to obtain it. For the energy use analysis, DOE used the 

same efficiency distribution as the air-cooled equipment class. For more detail on the energy use 

analysis see chapter 4.
2-17

2.2.3.3 Variable Refrigerant Flow Water-source Heat Pumps

Water-source VRF Heat Pumps with a Cooling Capacity less than 17,000 Btu/h.

Water-source VRF heat pumps with a cooling capacity less than 17,000 Btu/h are covered as part 

of the small commercial package air conditioning and heating equipment class, which has a 

Federal energy conservation standard of 11.2 EER and 4.2 COP. ASHRAE Standard 90.1-2010 

changed the efficiency rating for water-source VRF systems with a cooling capacity less than 

17,000 Btu/h to 12.0 EER and 4.2 COP for those systems with no heat recovery technology and 

to 11.8 EER and 4.2 COP for those systems with heat recovery technology. DOE surveyed the 

AHRI database and VRF manufacturers’ websites to find VRF water-source heat pumps with 

cooling capacities below 17,000 Btu/h and did not find any on the market.

Water-source VRF Heat Pumps with a Cooling Capacity Greater than or Equal to 

135,000 Btu/h. Water-source VRF heat pumps with a cooling capacity greater than or equal to 

135,000 Btu/h currently do not have a Federal energy conservation standard. ASHRAE Standard 

90.1-2010 set new efficiency levels for those systems with a cooling capacity greater than or 

equal to 135,000 Btu/h at 10.0 EER and 3.9 COP for systems without heat recovery devices and 

9.8 EER and 3.9 COP for systems with heat recovery devices. From the AHRI directory and 

manufacturers’ websites, DOE found 106 models with no heat recovery option and 58 models 

with a heat recovery add-on for a total of 164 unique units. The AHRI directory gave EER 

information as tested by AHRI 1230-2010: Performance Rating of Variable Refrigerant Flow 

(VRF) Multi-Split Air-Conditioning and Heat Pump Equipment, which is the test procedure as 

listed in ASHRAE Standard 90.1-2010 for this equipment. However, manufacturers’ websites 

did not release any EER data as tested by AHRI 1230-2010, so DOE used only the models in the 

AHRI directory for EER information (a total of 98 units). For water-source VRF heat pumps 

with a cooling capacity greater than or equal to 135,000 Btu/h, the average EER is 11.3 for units 

without a heat recovery system and 11.4 for units with a heat recovery system. A histogram of 

EER for this equipment class is shown in Figure 2.4 and Figure 2.5. 
2-18

Figure 2.2.4 Histogram of Water-Source VRF Systems (≥135,000 Btu/h) with No Heat 

Recovery

Figure 2.2.5 Histogram of Water-Source VRF Systems (≥135,000 Btu/h) with Heat 

Recovery 

0

1

2

3

4

5

6

7

8

9

10

10.310.510.710.911.111.311.511.711.912.112.312.512.712.913.113.313.513.713.914.114.314.5

Number of Models

EER

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

10.310.510.710.911.111.311.511.711.912.112.312.512.712.913.113.313.513.713.914.114.314.5

Number of Models

EER
2-19

2.2.3.4 Computer Room Air Conditioners

Prior to ASHRAE Standard 90.1-2010, computer room air conditioners were not 

considered covered equipment under EPCA, so there are currently no Federal energy 

conservation standards for these equipment. However, as explained in the NODA, ASHRAE 

Standard 90.1-2010 expanded the scope of ASHRAE Standard 90.1 to include these products, 

which DOE interpreted as also expanding its authority under EPCA. (See section II.C of the 

notice of data availability (NODA).b) As a result of the lack of existing Federal standards (and as 

a result, lack of reporting requirements), manufacturers are not required to report the efficiency 

of their equipment; and several manufacturers do not report efficiency information. However, the 

CEC regulates the minimum efficiency of computer room air conditioners, requiring units 

installed in the state of California to be tested using ASHRAE 127-2001 and meet a minimum 

EER rating as listed in Table 2.2.2.

Table 2.2.2 CEC Computer Room Air Conditioners Minimum Efficiency Levels

CEC Equipment Type Cooling Capacity (Btu/h) Minimum Efficiency Level

(ASHRAE 127-2001 EER)

Air-cooled computer room air 

conditioners

< 65,000 11.0 EER

≥ 65,000 and < 135,000 10.4 EER

≥ 135,000 and < 240,000 10.2 EER

Water-cooled, Glycol-cooled, 

and Evaporatively-cooled 

Computer Air Conditioners

< 65,000 11.1 EER

≥ 65,000 and < 135,000 10.5 EER

≥ 135,000 and < 240,000 10.0 EER

As noted previously, the CEC maintains a directory of “computer room air conditioners” 

in its appliance efficiency database. DOE searched the CEC database for computer room air 

conditioners and supplemented that data with information from literature found on manufacturer 

websites. In total, DOE found 1364 models computer room air conditioners, many of which are 

variations of the same base model. For example, a given model could have the same basic 

design and construction, but with multiple optional features, such as optional upflow or 

downflow configuration, and the option of adding a fluid economizer; thus from this single 

model, 4 different variations are possible, each variation with its own efficiency characteristics 

and each falling into a separate equipment class. From the 5 manufacturers identified, DOE 

found 22 model lines of computer room air conditioners, consisting of 120 base models and 1244

models that were optional variations of those models to make up the 1364 models in its database.

DOE presents the models included in its database broken up by equipment class in Table 2.5.

 b

 On May 5, 2011, DOE published a Notice of Data Availability and request for public comment in the Federal 

Register as a preliminary step pursuant to EPCA’s requirements for DOE to consider amended energy conservation 

standards for certain commercial equipment covered by ASHRAE Standard 90.1. 76 FR 25622.
2-20

Table 2.2.3 Computer Room Air Conditioner Database Breakdown

Equipment Class Size Category Number of 

Upflow Units

Number of 

Downflow Units

Air-Cooled

<65,000 Btu/h 63 140

≥65,000 Btu/h and <240,000 Btu/h 99 126

>240,000 Btu/h 13 11

Water-Cooled

<65,000 Btu/h 31 68

≥65,000 Btu/h and <240,000 Btu/h 56 71

>240,000 Btu/h 12 10

Water-Cooled with a 

Fluid Economizer

<65,000 Btu/h 17 44

≥65,000 Btu/h and <240,000 Btu/h 47 58

>240,000 Btu/h 4 4

Glycol Cooled

<65,000 Btu/h 28 63

≥65,000 Btu/h and <240,000 Btu/h 57 71

>240,000 Btu/h 10 8

Glycol Cooled with a 

Fluid Economizer

<65,000 Btu/h 32 60

≥65,000 Btu/h and <240,000 Btu/h 66 79

>240,000 Btu/h 9 7

DOE found efficiency information for three of the five computer room air conditioner 

manufacturers. The CEC database included EER information for two manufacturers, and one 

manufacturer included EER information in its product literature. In all cases the EER 

information was measured according to the procedures in ASHRAE 127-2001. However, DOE 

notes that ASHRAE Standard 90.1-2010 adopts an updated version of ASHRAE Standard 127 

(i.e., ASHRAE Standard 127-2007), which changes the efficiency metric from EER to SCOP. In 

addition, the standard rating conditions were changed between the 2001 and 2007 editions of the 

ASHRAE 127 test procedure, which adds to the difficulty of obtaining information about product 

efficiency as rated using the new SCOP rating metric. A footnote to Table D1 in Appendix D of 

ASHRAE 127-2007 contains a “rule-of-thumb” formula listed in equation 1 below that 

approximates the SCOP value using the old EER rating. 

Eq. 2.1

DOE found EER information for 208 models in its database (15.2% of the database) and 

used this rule of thumb conversion to convert this EER data into SCOP data. The rule of thumb 

converts EER into SCOP by multiplying the EER at the old rating condition (71.6°F dry-bulb 

(DB) return temperature and 50% relative humidity (RH)) with the sensible heat ratioc (SHR) at 

 c Sensible heat ratio (SHR) is the ratio of a unit’s sensible cooling capacity divided by the total (i.e., sensible and 

latent) cooling capacity.
2-21

the new rating condition (75°F DB return temperature and 45% RH) and dividing by 3.5. For the 

units in the CEC database, DOE found the SHR at the new rating condition in the manufacturer’s 

product literature. For units where DOE obtained EER data from manufacturer literature, SHR 

information was only available at the old rating condition. To approximate the SHR at the new 

rating condition, DOE increased the sensible cooling capacity at the old rating condition by 8.9% 

(the average percent increase in sensible cooling capacity from the old rating condition to the 

new rating condition for the rest of the models in the database) and increased the total cooling 

capacity at the old rating condition by 3.3% (the average percent increase in total cooling 

capacity from the old rating condition to the new rating condition for the rest of the models in the 

database). DOE used these new sensible and total cooling capacities to estimate the SHR at the 

new rating condition for these units. Thus, DOE was able to calculate estimated SCOP values for 

all of the units for which it had EER information.

DOE found that for units available optionally in downflow and upflow orientation only a 

single EER value was specified and the orientation in which the value was obtained was not 

specified. DOE assumed that the reported EER was tested in the downflow orientation unless the 

unit was only available in the upflow orientation because the EER value as tested in the 

downflow configuration would be higher than if the same unit was tested in the upflow

configuration. If a unit was available in both downflow and upflow orientations, DOE assumed 

that the upflow model would have a lower EER and SCOP due to the effects of additional static 

pressure that the blower must overcome. In order to calculate the upflow SCOP, DOE reduced 

the corresponding downflow model’s SCOP by 0.11, which is the reduction in ASHRAE 

Standard 90.1-2010 between the downflow and upflow equipment classes. The average SCOP

for each equipment class is shown below in Table 2.2.4. For some equipment classes, DOE could 

not find any efficiency information from the CEC database or manufacturers’ websites. Those 

equipment classes are shown as a blank in Table 2.2.4.

Table 2.2.4 Average SCOP for Computer Room Air Conditioners

Equipment Class Size Category Average Upflow 

SCOP

Average Downflow 

SCOP

Air-Cooled

<65,000 Btu/h 2.49 2.61

≥65,000 Btu/h and <240,000 Btu/h 2.64 2.64

>240,000 Btu/h - 2.25

Water-Cooled

<65,000 Btu/h 2.76 2.90

≥65,000 Btu/h and <240,000 Btu/h 2.76 2.78

>240,000 Btu/h - 2.45

Water-Cooled with a 

Fluid Economizer

<65,000 Btu/h - -

≥65,000 Btu/h and <240,000 Btu/h - -

>240,000 Btu/h - -

Glycol Cooled

<65,000 Btu/h 2.66 2.71

≥65,000 Btu/h and <240,000 Btu/h - 2.62

>240,000 Btu/h - 2.49

Glycol Cooled with a <65,000 Btu/h - 2.43
2-22

Fluid Economizer ≥65,000 Btu/h and <240,000 Btu/h - 2.48

>240,000 Btu/h - 2.38

The following sections report for each equipment class the total number of models that 

DOE found on the market, the number of models for which DOE was able to obtain efficiency 

information, and information about the performance characteristics (such as the sensible cooling 

capacity and SCOP) of computer room air conditioners on the market.

Air-cooled Computer Room Air Conditioners with a Cooling Capacity less than 65,000 

Btu/h. ASHRAE Standard 90.1-2010 set the efficiency level at 2.2 SCOP for air-cooled 

computer room air conditioners with a cooling capacity less than 65,000 Btu/h. DOE found 203 

total models in this class and 44 models with efficiency information (18 upflow models and 26 

downflow models). The average sensible cooling capacity for this class is 34,848 Btu/h, and the 

average SCOP is 2.56. Figure 2.2.6 shows a histogram of the sensible cooling capacities, and 

Figure 2.2.7 shows a histogram of SCOP of the models on the market.

Figure 2.2.6 Air-Cooled Computer Room Air Conditioners (<65,000) Sensible Cooling 

Capacity Histogram

0

5

10

15

20

25

30

Number of Models

Sensible Cooling Capacity (Btu/h)
2-23

Figure 2.2.7 Air-Cooled Computer Room Air Conditioners (<65,000 Btu/h) SCOP 

Histogram 

Air-cooled Computer Room Air Conditioners with a Cooling Capacity Greater than or 

Equal to 65,000 Btu/h and less than 240,000 Btu/h. ASHRAE Standard 90.1-2010 set the 

efficiency level at 2.1 SCOP for air-cooled computer room air conditioners with a cooling 

capacity greater than or equal to 65,000 Btu/h and less than 240,000 Btu/h. DOE found 225 total 

models in this class and 51 models with efficiency information (21 upflow models and 30

downflow models). The average sensible cooling capacity for this class is 126,671 Btu/h, and the 

average SCOP is 2.64. Figure 2.2.8 shows a histogram of the sensible cooling capacities, and 

Figure 2.2.9 shows a histogram of SCOP of the models on the market.

0

1

2

3

4

5

6

7

8

Number of Models

SCOP
2-24

Figure 2.2.8 Air-Cooled Computer Room Air Conditioners (≥65,000 Btu/h and <240,000 

Btu/h) Sensible Cooling Capacity Histogram

Figure 2.2.9 Air-Cooled Computer Room Air Conditioners (≥65,000 Btu/h and <240,000 

Btu/h) SCOP Histogram

Air-cooled Computer Room Air Conditioners with a Cooling Capacity Greater than or 

Equal to 240,000 Btu/h and less than 760,000 Btu/h. ASHRAE Standard 90.1-2010 set the 

efficiency level at 1.9 SCOP for air-cooled computer room air conditioners with a cooling 

capacity greater than or equal to 240,000 Btu/h and less than 760,000 Btu/h. DOE found 24 total 

models in this class and 1 model with efficiency information (only a downflow model with a

0

5

10

15

20

25

30

Number of Models

Sensible Cooling Capacity (Btu/h)

0

1

2

3

4

5

6

7

Number of Models

SCOP
2-25

2.25 SCOP). The average sensible cooling capacity for this class is 286,015 Btu/h. Figure 2.2.10

shows a histogram of the sensible cooling capacities.

Figure 2.2.10 Air-Cooled Computer Room Air Conditioners (≥240,000 Btu/h and <760,000 

Btu/h) Sensible Cooling Capacity Histogram

Water-cooled Computer Room Air Conditioners with a Cooling Capacity less than 

65,000 Btu/h. ASHRAE Standard 90.1-2010 set the efficiency level at 2.6 SCOP for watercooled computer room air conditioners with a cooling capacity less than 65,000 Btu/h. DOE 

found 99 total models in this class and 39 models with efficiency information (14 upflow models 

and 25 downflow models). The average sensible cooling capacity for this class is 36,071 Btu/h, 

and the average SCOP is 2.85. Figure 2.2.11 shows a histogram of the sensible cooling 

capacities, and Figure 2.2.12 shows a histogram of SCOP of the models on the market.

0

2

4

6

8

10

12

14

Number of Models

Sensible Cooling Capacity (Btu/h)
2-26

Figure 2.2.11 Water-Cooled Computer Room Air Conditioner (<65,000 Btu/h) Sensible 

Cooling Capacity Histogram

Figure 2.2.12 Water-Cooled Computer Room Air Conditioner (<65,000 Btu/h) SCOP 

Histogram 

Water-cooled Computer Room Air Conditioners with a Cooling Capacity Greater than 

or Equal to 65,000 Btu/h and less than 240,000 Btu/h. ASHRAE Standard 90.1-2010 set the 

efficiency level at 2.5 SCOP for water-cooled computer room air conditioners with a cooling 

capacity greater than or equal to 65,000 Btu/h and less than 240,000 Btu/h. DOE found 127 total 

models in this class and 50 models with efficiency information (20 upflow models and 30

downflow models). The average sensible cooling capacity for this class is 134,398 Btu/h, and the 

0

2

4

6

8

10

12

14

Number of Models

Sensible Cooling Capacity (Btu/h)

0

1

2

3

4

5

6

7

8

9

Number of Models

SCOP
2-27

average SCOP is 2.77. Figure 2.2.13 shows a histogram of the sensible cooling capacities, and 

Figure 2.2.14 shows a histogram of SCOP of the models on the market.

Figure 2.2.13 Water-Cooled Computer Room Air Conditioner (≥65,000 Btu/h and <240,000 

Btu/h) Sensible Cooling Capacity Histogram

Figure 2.2.14 Water-Cooled Computer Room Air Conditioner (≥65,000 Btu/h and <240,000 

Btu/h) SCOP Histogram

Water-cooled Computer Room Air Conditioners with a Cooling Capacity Greater than 

or Equal to 240,000 Btu/h and less than 760,000 Btu/h. ASHRAE Standard 90.1-2010 set the 

efficiency level at 2.4 SCOP for water-cooled computer room air conditioners with a cooling 

0

2

4

6

8

10

12

14

Number of Models

Sensible Cooling Capacity (Btu/h)

0

1

2

3

4

5

6

Number of Models

SCOP
2-28

capacity greater than or equal to 240,000 Btu/h and less than 760,000 Btu/h. DOE found 22 total 

models in this class and 1 model with efficiency information (only a downflow model with a 

2.45 SCOP). The average sensible cooling capacity for this class is 292,245 Btu/h. Figure 2.2.15

shows a histogram of the sensible cooling capacities.

Figure 2.2.15 Water-Cooled Computer Room Air Conditioner (≥240,000 Btu/h and 

<760,000 Btu/h) Sensible Cooling Capacity Histogram

Water-cooled Computer Room Air Conditioners with a Fluid Economizer with a 

Cooling Capacity less than 65,000 Btu/h. ASHRAE Standard 90.1-2010 set the efficiency level 

at 2.55 SCOP for water-cooled computer room air conditioners with a fluid economizer with a 

cooling capacity less than 65,000 Btu/h. DOE found 61 total models in this class and no models 

with efficiency information. The average sensible cooling capacity for this class is 37,301 Btu/h.

Figure 2.2.16 shows a histogram of the sensible cooling capacities.

Figure 2.2.16 Water-Cooled Computer Room Air Conditioner (<65,000 Btu/h) With a 

Fluid Economizer Sensible Cooling Capacity Histogram

0

1

2

3

4

5

6

7

8

Number of Models

Sensible Cooling Capacity (Btu/h)

0

1

2

3

4

5

6

7

8

9

Number of Models

Sensible Cooling Capacity (Btu/h)
2-29

Water-cooled Computer Room Air Conditioners with a Fluid Economizer with a 

Cooling Capacity Greater than or Equal to 65,000 Btu/h and less than 240,000 Btu/h.

ASHRAE Standard 90.1-2010 set the efficiency level at 2.45 SCOP for water-cooled computer 

room air conditioners with a fluid economizer with a cooling capacity greater than or equal to 

65,000 Btu/h and less than 240,000 Btu/h. DOE found 105 total models in this class and no

models with efficiency information. The average sensible cooling capacity for this class is 

129,602 Btu/h. Figure 2.2.17 shows a histogram of the sensible cooling capacities.

Figure 2.2.17 Water-Cooled Computer Room Air Conditioner (≥65,000 Btu/h and <240,000 

Btu/h) with a Fluid Economizer Sensible Cooling Capacity Histogram

Water-cooled Computer Room Air Conditioners with a Fluid Economizer with a 

Cooling Capacity Greater than or Equal to 240,000 Btu/h and less than 760,000 Btu/h.

ASHRAE Standard 90.1-2010 set the efficiency level at 2.35 SCOP for water-cooled computer 

room air conditioners with a fluid economizer with a cooling capacity greater than or equal to 

240,000 Btu/h and less than 760,000 Btu/h. DOE found 8 total models in this class and no 

models with efficiency information. The average sensible cooling capacity for this class is 

285,063 Btu/h. Figure 2.2.18 shows a histogram of the sensible cooling capacities.

0

2

4

6

8

10

12

14

Number of Models

Sensible Cooling Capacity (Btu/h)
2-30

Figure 2.2.18 Water-Cooled Computer Room Air Conditioner (≥240,000 Btu/h and 

<760,000 Btu/h) with a Fluid Economizer Sensible Cooling Capacity Histogram

Glycol-cooled Computer Room Air Conditioners with a Cooling Capacity less than 

65,000 Btu/h. ASHRAE Standard 90.1-2010 set the efficiency level at 2.5 SCOP for glycolcooled computer room air conditioners with a cooling capacity less than 65,000 Btu/h. DOE 

found 91 total models in this class and 9 models with efficiency information (4 upflow models 

and 5 downflow models). The average sensible cooling capacity for this class is 35,425 Btu/h, 

and the average SCOP is 2.66. Figure 2.2.19 shows a histogram of the sensible cooling

capacities, and Figure 2.2.20 shows a histogram of SCOP of the models on the market.

Figure 2.2.19 Glycol-Cooled Computer Room Air Conditioner (<65,000 Btu/h) Sensible 

Cooling Capacity Histogram

0

1

2

3

4

5

6

7

Number of Models

Sensible Cooling Capacity (Btu/h)

0

2

4

6

8

10

12

14

Number of Models

Sensible Cooling Capacity (Btu/h)
2-31

Figure 2.2.20 Glycol-Cooled Computer Room Air Conditioner (<65,000 Btu/h) SCOP 

Histogram

Glycol-cooled Computer Room Air Conditioners with a Cooling Capacity Greater than 

or Equal to 65,000 Btu/h and less than 240,000 Btu/h. ASHRAE Standard 90.1-2010 set the 

efficiency level at 2.15 SCOP for glycol-cooled computer room air conditioners with a cooling 

capacity greater than or equal to 65,000 Btu/h and less than 240,000 Btu/h. DOE found 128 total 

models in this class and 5 models with efficiency information (only downflow models with 

SCOPs of 2.47, 2.55, 2.65, 2.68, and 2.74). The average sensible cooling capacity for this class is 

129,309 Btu/h, and the average SCOP is 2.62. Figure 2.2.21 shows a histogram of the sensible 

cooling capacities.

0

0.5

1

1.5

2

2.5

Number of Models

SCOP
2-32

Figure 2.2.21 Glycol-Cooled Computer Room Air Conditioner (≥65,000 and <240,000 

Btu/h) Sensible Cooling Capacity Histogram

Glycol-cooled Computer Room Air Conditioners with a Cooling Capacity Greater than 

or Equal to 240,000 Btu/h and less than 760,000 Btu/h. ASHRAE Standard 90.1-2010 set the 

efficiency level at 2.1 SCOP for glycol-cooled computer room air conditioners with a cooling 

capacity greater than or equal to 240,000 Btu/h and less than 760,000 Btu/h. DOE found 18 total 

models in this class and 1 model with efficiency information (only a downflow model with a 

2.49 SCOP). The average sensible cooling capacity for this class is 285,480 Btu/h. Figure 2.2.22

shows a histogram of the sensible cooling capacities.

0

5

10

15

20

25

Number of Models

Sensible Cooling Capacity (Btu/h)
2-33

Figure 2.2.22 Glycol-Cooled Computer Room Air Conditioner (≥240,000 and <760,000 

Btu/h) Sensible Cooling Capacity Histogram

Glycol-cooled Computer Room Air Conditioners with a Fluid Economizer with a 

Cooling Capacity less than 65,000 Btu/h. ASHRAE Standard 90.1-2010 set the efficiency level 

at 2.45 SCOP for glycol-cooled computer room air conditioners with a fluid economizer with a 

cooling capacity less than 65,000 Btu/h. DOE found 92 total models in this class and 1 model

with efficiency information (only a downflow model with a 2.43 SCOP). The average sensible 

cooling capacity for this class is 37,147 Btu/h. Figure 2.2.23 shows a histogram of the sensible 

cooling capacities.

Figure 2.2.23 Glycol-Cooled Computer Room Air Conditioner (<65,000 Btu/h) with a Fluid 

Economizer Sensible Cooling Capacity Histogram

0

1

2

3

4

5

6

7

8

9

Number of Models

Sensible Cooling Capacity (Btu/h)

0

2

4

6

8

10

12

14

16

18

Number of Models

Sensible Cooling Capacity (Btu/h)
2-34

Glycol-cooled Computer Room Air Conditioners with a Fluid Economizer with a 

Cooling Capacity Greater than or Equal to 65,000 Btu/h and less than 240,000 Btu/h.

ASHRAE Standard 90.1-2010 set the efficiency level at 2.1 SCOP for glycol-cooled computer 

room air conditioners with a fluid economizer with a cooling capacity greater than or equal to 

65,000 Btu/h and less than 240,000 Btu/h. DOE found 145 total models in this class and 5

models with efficiency information (only downflow models with SCOPs of 2.26, 2.45, 2.53, 

2.56, and 2.62). The average sensible cooling capacity for this class is 129,380 Btu/h, and the 

average SCOP is 2.48. Figure 2.2.24 shows a histogram of the sensible cooling capacities.

Figure 2.2.24 Glycol-Cooled Computer Room Air Conditioner (≥65,000 and <240,000 

Btu/h) with a Fluid Economizer Sensible Cooling Capacity Histogram

Glycol-cooled Computer Room Air Conditioners with a Fluid Economizer with a 

Cooling Capacity Greater than or Equal to 240,000 Btu/h and less than 760,000 Btu/h.

ASHRAE Standard 90.1-2010 set the efficiency level at 2.05 SCOP for glycol-cooled computer 

room air conditioners with a fluid economizer with a cooling capacity greater than or equal to 

240,000 Btu/h and less than 760,000 Btu/h. DOE found 16 total models in this class and 1 model

with efficiency information (only a downflow model with a 2.38 SCOP). The average sensible 

cooling capacity for this class is 293,554 Btu/h. Figure 2.2.25 shows a histogram of the sensible 

cooling capacities.

0

2

4

6

8

10

12

14

16

18

Number of Models

Sensible Cooling Capacity (Btu/h)
2-35

Figure 2.2.25 Glycol-Cooled Computer Room Air Conditioner (≥240,000 and <760,000 

Btu/h) With a Fluid Economizer Sensible Cooling Capacity Histogram

0

1

2

3

4

5

6

7

8

9

10

Number of Models

Sensible Cooling Capacity (Btu/h)
2-36

REFERENCES

1 Air-Conditioning, Heating, and Refrigeration Institute Website. About Us. 2011. (Last 

accessed April 28,2011.) <www.ahrinet.org/about+us.aspx>

2 Heating, Airconditioning & Refrigeration Distributors International Website. About 

HARDI. 2011. (Last accessed April 28,2011.) 

<www.hardinet.org/aws/HARDI/pt/sp/about>

3 Air Conditioning Contractors of America Website. About ACCA. 2011. (Last accessed 

April 28,2011.) <www.acca.org/acca>

4 AHRI Directory. Directory of Certified Product Performance. 2011. (Last accessed 

April 28,2011.) <www.ahridirectory.org>

5 California Energy Commission Website. Appliance Efficiecy Database. 2011. (Last 

accessed April 28,2011.) <www.appliances.energy.ca.gov/QuickSearch.aspx>