There are many efficiency standards around the world. Below are a select few that are more highly promoted/enforced
ASHRAE Standard 90.1
ASHRAE Standard 90.1 generally establishes the efficiency standards for commercial equipment (e.g. CRACs) and forms the basis for DOE efficiency standards for that equipment. State and local jurisdictions may adopt ASHRAE Standard 90.1 efficiency standards in their building codes (refer to http://bcapcodes.org/code-status/commercial/ for the current version each state has adopted). ASHRAE Standard 90.1 is a consensus based standard established by industry experts including members from AHRI and DOE.
ASHRAE 90.1-2010 and ASHRAE 90.1-2013
ASHRAE 90.1-2010 and ASHRAE 90.1-2013 minimum efficiency levels are listed below for air-conditioners and condensing units serving computer rooms. Efficiencies are shown in units of Sensible Coefficient of Performance (SCOP) in accordance with ASHRAE 127-2007 for Upflow and Downflow units.
ASHRAE 90.1-2016 minimum efficiency levels are listed below for air-conditioners and condensing units serving computer rooms. Efficiencies are shown in units of Net Sensible Coefficient of Performance (NSenCOP) in accordance with AHRI 1360-2016 for Down-Flow Unit, Up-Flow Unit - Ducted, Up-Flow Unit – Non-ducted, and Horizontal-Flow Unit Standard Models.
ASHRAE 90.1-2019 minimum efficiency levels are listed below for air conditioners and condensing units serving computer rooms. Efficiencies are shown in units of Net Sensible Coefficient of Performance (NSenCOP) in accordance with AHRI 1360-2017 for floor mount units (down-flow unit, up-flow unit - ducted, up-flow unit – non-ducted, and horizontal-flow unit standard models) and ceiling mount units (ducted and non-ducted).
Ceiling Mount Units
ASHRAE Standard 90.4
ASHRAE Standard 90.4-2016
ASHRAE 90.4-2016 is a performance-based standard that looks at the overall design of a data center and establishes maximum mechanical (MLC) and electrical (ELC) requirements which include the CRACs and CRAHs. There are 2 different compliance paths that can be used to show compliance, one that is based on the design condition calculations and the second that is based on the annualized operation calculations. This standard is currently (as of Summer 2020) in review by regulatory bodies for consideration in future regulations.
ASHRAE Standard 90.4-2019
ASHRAE 90.4-2019 is a performance-based standard that looks at the overall design of a data center and establishes maximum mechanical (MLC) and electrical (ELC) requirements, which include the CRACs and CRAHs. The 2019 version of the standard eliminated the design condition calculations therefore the MLC is now based only on the annualized operation calculations. The maximum MLC values were reduced in this version of the standard.
United States Federal Department of Energy (DOE):
DOE has regulated the energy efficiency of CRACs since 2012. In the Code of Federal Regulations (CFR), DOE defines a CRAC as “a basic model of commercial package air-conditioning and heating equipment (packaged or split) that is: Used in computer rooms, data processing rooms, or other information technology cooling applications; rated for sensible coefficient of performance (SCOP) and tested in accordance with 10 CFR 431.96, and is not a covered consumer product under 42 U.S.C. 6291(1)-(2) and 6292. A computer room air conditioner may be provided with, or have as available options, an integrated humidifier, temperature, and/or humidity control of the supplied air, and reheating function.” CFR 431.92.
Effective July 1, 2015, DOE requires manufacturers to certify the sensible cooling capacity and SCOP efficiency of up-flow or down-flow, floor mounted, direct expansion (DX) CRAC cooling products, and to post certified ratings on the DOE public database (Compliance Certification Management System (CCMS)). The listings for CRAC products are under “Air Conditioners and Heat Pumps—Computer Room Air Conditioners.”
The required federal minimum efficiencies for these specific products are shown in the table below (10 CFR 431.97 – Table 7).
Products NOT Regulated by DOE:
According to guidance documents issued by DOE, the products listed below are covered equipment but don’t have to meet minimum energy conservation standards. DOE does not define minimum efficiencies for the following CRAC products. Because manufacturers do not certify the efficiency of these products to DOE, they are not listed on the CCMS.
- Chilled water computer room air-handler (CRAH) products (products that use cold chilled water to cool the air)
- Horizontal flow floor mounted CRAC products (most often applied between server racks) — DOE Guidance
- Ceiling mounted CRAC products — DOE Guidance
DOE Compliance Monitoring and Implications:
If the product is an up-flow or down-flow, floor mounted, direct expansion (DX) CRAC cooling product as defined by DOE, it is the responsibility of the manufacturer to list the product on the CCMS in order to sell the product in the U.S. and its territories.
Manufacturers who are non-compliant are subject to federal financial penalties and potential suspension of sales (see CFR 429.114 and CFR 429.120).
U.S. State and Local Codes
State and local jurisdictions may establish building codes for new construction. For commercial equipment these codes may not be more stringent than the DOE requirements. However, for new construction, states may adopt ASHRAE 90.1 Standards before DOE makes updates to reflect the latest ASHRAE 90.1 requirements.
California Energy Commission (CEC):
The California Energy Commission (CEC) has regulated the energy efficiency of CRACs since 1988. Similar to the U.S. federal CCMS database, CEC requires that up-flow or down-flow, floor mounted, direct expansion (DX) CRAC cooling products have sensible cooling capacity and SCOP efficiency certified by the manufacturer on the CEC Modernized Appliance Efficiency Database System (MAEDBS) in order to be eligible for sale in California.
Because federal regulations regarding energy efficiency of CRACs preempt differing state law, the CEC in general follows the definitions and requirements of the DOE for these products. SeeCEC Title 20 — 2019 CCR § 1602 which, for example, uses the federal definition of CRAC. The minimum efficiencies for these products in California are set by the federal requirements noted above (see CEC Title 20, Tables C-7). In addition, chilled water computer room air-handler, horizontal flow floor mounted and ceiling mounted products do not have minimum efficiencies and are not required to be listed on the MAEDBS pursuant to DOE Guidance on horizontal flow units and DOE Guidance on ceiling mounted units.
However, note that CEC also defines minimum efficiencies for evaporatively-cooled products (see CEC Title 20, Tables C-11). AHRI believes these requirements are preempted under 42 U.S.C. § 6316 and California does not have the authority to establish separate standards for these products.
The requirements regarding energy efficiency minimums should not be confused with Title 24 – Building Energy Efficiency Program, which covers the overall efficient design of a building. As a basic requirement of Title 24, an appliance (in our case a CRAC) must meet the minimum energy conservation listed in Title 20 and must be listed in the CEC MAEDBS. In addition, Title 24 stipulates certain options, such-as electric reheat, that cannot be used and certain options, such as an economizer, that may be required.
Ontario, Canada Ministry of Energy (OME):
The Ontario Ministry of Energy (OME) regulates the energy efficiency of CRACs manufactured on or after July 1, 2016, with the following requirements (see Ontario Regulation 404/12, Section 10), which in general follow the DOE standards:
- Testing standard: DOE 10 Code of Federal Regulations Part 431, Subpart F, §431.96 Uniform test method for the measurement of energy efficiency of commercial air conditioners and heat pumps, as it read on the date the particular appliance or product is manufactured.
- Scope of application: a factory-made unitary electrically operated air conditioner designed for use in computer rooms, data processing rooms, or other information technology cooling applications, that is air- or water-cooled, a downflow or upflow unit, and where the functions of the air conditioner either alone or in combination with a cooling unit and heating plant are to provide air filtration, circulation, cooling, reheating, and humidity control. Glycol-cooled air conditioners are included.
- Prescribed efficiency standard or requirement: DOE 10 Code of Federal Regulations Part 431, Subpart F, §431.97 Energy efficiency standards and their compliance dates, as it read on the date the particular appliance or product is manufactured.
OME Compliance Monitoring and Implications:
OME requires that the energy performance of CRAC units be verified by a recognized verification agency such as AHRI. There is not currently an Ontario database and users should look to CCMS for certified ratings.
Saudi Standards, Metrology and Quality Organization (SASO–2874)
In November 2016, SASO published proposed minimum efficiency performance standards (MEPs) for large capacity air-conditioners including unitary air-conditioners, condensing units, chillers, absorption chillers, electrically operated variable-refrigerant-flow (VRF) air-conditioner systems, and close control air-conditioners and condensing units serving computer rooms. MEPs for close control air conditioners and condensing units serving computer rooms match those shown in ASHRAE 90.1 – 2016.
These requirements became effective June 2017, followed by an enforcement date October 2017. All regulated products exported to Saudi Arabia must be registered into SASO’s online platform called SABER, which houses all associated compliance documentation. AHRI Certified products are compliant with SASO 2874 through a “Path A” compliance method (Section 6.2 Path A – Product using the AHRI certification program). This method includes supplying an AHRI certificate declaring that the applicable equipment is operable at 52°C (125.6°F) as part of its SABER registration. DCOM equipment manufacturers exporting to Saudi Arabia that do not have AHRI-certified equipment must comply through the “Path B” compliance method (Section 6.3 Path B – Product using test report as evidence of the declared performances) and submit equipment test reports from an accredited laboratory as part of their registration into SABER.