Hello,

An office building is aiming LEED certification, but 14% energy saving is a problem...

The designer proposed bringing internal heat load out by increased amount of outside air (e.g. 3 times that of normal OA ventilation rate) in certain period of spring, say, from March 1 to May 30. During this period, the chiller does not operate, so the energy can be saved. Does anyone know if it is an acceptable practice that complies with ASHRAE 90.1-2004? It is indicated that "Measures that may warrant use of different schedules include...natural ventilation, demand control ventilation, ..." However, the unmet load hours must be within 300 hr and the baseline and proposed shall be within 50. This seems a fairly common bullding operation practice, that the temperature and humidity within space is allowed to vary within a wider range. If so, how to define "unmet load hours"...?

If this is acceptable for LEED, could anyone kindly give me some guideline on how to do the modeling in eQuest?

Many thanks,

Rick, PE, LEED AP