Changes Regarding Lighting and Climate Zones Proposed for ASHRAE/IES Energy Standard

Changes regarding lighting and climate zones are being proposed to the energy standard published by ASHRAE and the Illuminating Engineering Society (IES).

Addenda to ANSI/ASHRAE/IES Standard 90.1-2013, Energy Standard for Buildings Except Low-Rise Residential Buildings, are open for public comment.

Among the addenda open for public comment is addendum ch, which proposes a new set of interior lighting power densities (LPD) limits for building area and space by space compliance paths. These new LPD limits stems from inclusion of light-emitting diode (LED) technology into the space type models that are used to determine appropriate LPD limits for compliance with the standard, according to Eric Richman, chair of the standard’s lighting subcommittee.

These LPD limits (watts per square foot) are calculated using IES formulas that relate lighting energy use to lighting quantity based on the application of appropriate lighting technologies into individual space models. These models incorporate efficient cost-effective lighting technology, appropriate light loss factors and current design practice that incorporate quality design elements.

The new LPD values are generally lower by sometimes small to often significant amounts. The magnitude of the change is based primarily on the amount of LED technology incorporated into the model.

“These proposed changes have been under consideration within the 90.1 Lighting Subcommittee for several years,” Richman says. “Inclusion of LEDs were seriously considered for the 2013 version of the standard. However, at the time the changes needed to be processed (late 2012), the cost of LEDs was still relatively high and the variety and depth of available products was not deemed sufficient to incorporate into a mandatory code. We understand that LED technology continues to improve and become even more cost-effective such that by the time these new requirements are required for building projects, their effectiveness and viability on code compliance will be even easier.”

Also open for public comment is addendum br, which was developed in response to the publication of ANSI/ASHRAE Standard 169-2013, Climatic Data for Building Design Standards. Standard 169 includes more-recent weather data (resulting in changes in climate zone assignments for some locations, including approximately 10 percent of the 3,000 counties in the U.S.) and the creation of a new Climate Zone 0. The proposed addendum adds requirements for mechanical provisions.

Under addendum w, which is expected to be published in 90.1-2016, Standard 169 is referenced for climatic data (though a new Reference Standard Reproduction Annex in Standard 90.1 includes extracts from Standard 169). Addendum w proposed criteria for Climate Zone 0 in Standard 90.1 for envelope provisions. Addendum br covers criteria for Climate Zone 0 of Section 6 (HVAC), and for the mechanical systems portions Appendix C and G.

Generally, the new Climate Zone 0 is the hotter portion of the previous Climate Zone 1, which was the warmest climate zone. Cities in Climate Zone 0 include Mumbai (Bombay), Jakarta and Abu Dhabi. There are no cities in the U.S. in Climate Zone 0; Miami and the islands of Hawaii are in Climate Zone 1. The separation of Climate Zones 0 and 1 allows separate criteria for Standard 90.1 to be developed that are more specific to the hotter regions of Climate Zone 0.

Seven addenda are open for public comment until Oct. 19, 2015. They are:

• ai includes revisions to the fenestration criteria including U-factors and SHGC in certain climate zones.
• br was developed in response to the update of Standard 169-2013, Climatic Data for Building Design Standards.
• bs updates the EER values for water-source variable refrigerant flow products above 65,000 Btu/h. The proposal also establishes for the first time minimum IEER values for this product class.
• cd establishes for the first time a product class for dedicated outdoor air systems.
• cg modifies the exterior LPD for building exteriors.
• ch modifies the LPD for both space by space and building area methods by including LED technology into the lighting systems.
• cl relocates Table 7.8 for minimum efficiency requirements for residential water heaters and pool heaters to an informative appendix.