Among the addenda open for public comment is addendum ch, which proposes a new set of interior lighting power densities (LPD) limits for both building area and space-by-space compliance paths. These new LPD limits stem 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 said. “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% of the 3,000 counties in the United States) 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 United States 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.

Addenda open for public comment from until Oct. 4, 2015, include the following.

• bt updates efficiency values for low-voltage dry-type transformers to be consistent with federal law.

• bx requires a modeler to use the design set point for multi-zone thermostat systems.

• bv exempts baselines with purchased cooling and heat from the reset control requirements in Appendix G.

• bw provides a baseline for lighting controls consistent with addendum bm.

• bz replaces Table 6.8.1-11 to account for the new rating conditions.

• by requires pipe insulation on the first 8 ft of branch piping.

• cb updates duct insulation requirements.

• ca modifies the fan power criteria by lowering of the motor power threshold for the fan speed control requirement.

• ce increases the minimum ERV requirements from zero to a reasonable minimum size for smaller units.

• cc replaces the definition of sidelighting effective aperture that was inadvertently deleted in 90.1-2013.

• cf adds additional requirements to section 6.1.1.3.1 for direct replacement HVAC equipment.

• ci adjusts the equations for fenestration orientation in Section 5.5.4.5 by requiring a lower solar heat gain coefficient (SHGC) for west and east facing fenestration, and by allowing the use combinations of fenestration area, exterior shading, and SHGC to demonstrate compliance.

• ck makes a change to control set point for the cooling tower to better scale with its climate, clarifies the operation of the condenser water pump as a constant volume pump, and modifies the exception for pump W/gpm for water side economizer.

• cj modifies a footnote in Appendix G for single zone variable air volume systems serving computer rooms.

• du requires water-side economizers for non-fan chilled water systems such as radiant cooling or passive chilled beam systems and for active chilled beam systems.

In addition, seven addenda are open for public comment until Oct. 19, 2015. They include the following.

• 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 Btuh. 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.