The First Facility Management Blog

A proposed addendum to ASHRAE’s energy standard will allow for increased energy savings by modifying envelope requirements to allow the use of more daylight-friendly skylight materials in certain climate zones and require photocontrols with certain skylights.

The current wording of the standard limits the use of high solar heat gain coefficient (SHGC) plastic skylights that transmit high levels of light in climate zones 1 through 3. This restricts one of the potentially most energy efficient ways to use skylighting, according to Eric Richman, chair of the 90.1 lighting subcommittee.

The proposed addendum would provide an exemption to the SHGC requirements when high-diffusion skylights are used in conjunction with a multi-level photocontrol system. Photocontrol systems regulate lighting and save energy by reducing the artificial lighting in buildings when natural lighting reaches a useful level.

“One result of this change will be to allow for more flexibility in designing skylight systems for energy savings and facility enhancement,” says Richman. “The requirement for lighting controls when daylight is available will create electricity energy savings while reducing inner cooling loads.”

Other proposed addenda to ANSI/ASHRAE/IESNA Standard 90.1-2007 include:
• Addendum a, which will clarify that the current cooling tower requirements in the standard apply to open circuit cooling towers only, as the standard is now written.
• Addendum b, which now references Standard 62.1-2004 for minimum ventilation requirements rather than a specific section of the standard. This addendum also provides an exception that allows a regulating body to require more stringent ventilation rates for specific types of facilities when the safety of the occupants is a major design factor that is more important than complying with the fan power limitation requirements.
• Addendum c, which would add vivarium to the list of spaces that require specific humidity levels to satisfy process needs in section 6.5.2.3
• Addenda e, which would modify energy recovery requirements by expanding them to cover the use of energy recovery by weather zone and for outside air percentages equal to or greater than 30%.