ATLANTA - Energy use in buildings could drop with a proposed change to Standard 90.1 regulating ventilation and cab lighting in elevators, announced the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Proposed addendum df to ANSI/ASHRAE/IESNA Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings, takes a first step in addressing inefficiency of ventilation fans and cab lighting, both of which often operate 24/7, regardless of load or occupancy, said ASHRAE. The addendum is one of 12 proposed addenda to the standard currently out for public comment.
The American Council for an Energy-Efficient Economy (ACEEE) and the European E4 Committee estimate elevator energy use to be in the range of 2 to 5 percent of total building electric consumption. Proposed addendum df would require cab lighting systems to have efficacy of not less than 35 lumens per watt; that cab ventilation fans for elevators without air conditioning shall not consume over 0.7 W*s/L at maximum speed; and that when stopped and unoccupied with doors closed for over 15 minutes, cab interior lighting and ventilation shall be de-energized until required for operation.
“Two to 5 percent of building energy consumption is significant; beginning to realize those savings using this addendum is an important step,” said Drake Erbe, chair of the 90.1 mechanical subcommittee.
Also open for public review is proposed addendum di, which sets requirements for parking garage ventilation. In 1999, the standard required garage ventilation fan systems with a total design capacity greater than 30,000 cfm to have either an automatic control capable of staging fans or modeling fan volume or an automatic control capable of shutting off fans or reducing fan volume when the garage is not in use.
The 2007 ASHRAE Handbook, HVAC Applications, recommends “if permitted by local codes, the ventilation airflow rate should be varied to conserve energy.” The proposed flow rates and concentrations in the addendum are from the International Mechanical Code requirements.
“The energy savings depends on the hours of operations and the use profile of the garage,” Erbe said. “In garages that have morning and afternoon peaks and low usage during the day, the Handbook documents savings of 60 percent of fan power.”
Below is a listing of proposed addenda to 90.1 currently open for review.
Open until May 9:
• 90.1 ck allows for more flexibility in meeting ventilation requirements by referencing the Standard 62.1 definition of system ventilation efficiency and not the variables used in the Standard 62.1 multiple-spaces equation.
• 90.1 db provides an exception for certain systems serving laboratory spaces from the design airflow rate requirement in Appendix G. In addition, it clarifies that the system fan power shall have the same proportion as in the proposed design.
• 90.1 de splits the “generic lobby” from common elevator lobbies in the lighting power density (LPD) tables with adjusted LPDs to reflect specific space needs for elevator and non-elevator lobby spaces. In addition, this removes the fitness center audience seating from the LPD table.
• 90.1 df takes a first step in addressing ventilation and cab lighting in elevators regardless of occupancy.
• 90.1 dg adds a definition for the term “field-fabricated fenestration” used in section 188.8.131.52, consistent with an official interpretation approved by the Standard 90.1 committee and similar language in California’s Title 24.
• 90.1 dh clarifies the credit for on-site renewable energy and site recovered energy in Section 11 and Appendix G.
• 90.1 di sets requirements for parking garage ventilation.
• 90.1 dk adds clarity and instruction to the users of Appendix C, the envelope trade off option, for new skylighting and daylighting requirements that were added in addendum al, bc, and bn.
• 90.1 dl gives instruction to the users of Appendix C, the envelope trade off option on how to model the base envelope design and the proposed envelope design on how to comply with the cool roof provisions of Section 5.
• 90.1 do attempts to clearly establish the goals and requirements of the lighting system to ensure that owners are provided all the information necessary to best use and maintain the lighting systems.
Open until May 24:
• 90.1 dj limits the fan energy allowance for energy recovery devices to values that approximate the results of the economic analysis performed for the previously approved addendum e, with some allowance to permit adequate pressure drop for products near the minimum recovery effectiveness of 50 percent. A separate allowance is also created for coil runaround loop systems.
• 90.1 dn shows changes in Appendix G relative to addendum cj (warehouses) to 90.1-2007.
The proposed addenda are available for comment only during their public review period. To read the addenda or to comment, visit www.ashrae.org/publicreviews.
If no comments are received on these addenda, they likely will be incorporated into the 2010 version of the standard slated to be published this fall. If comments are received, the substance and volume of those comments will determine whether they are incorporated into the 2010 standard.
May 5, 2010: Addendum to Standard 90.1 to Regulate Ventilation and Cab Lighting in Elevators
May 5, 2010