Currently I am working on laboratory building and pursuing points for EAc1 Optimize Energy Performance. During the design phase, my team and mechanical consultant made an attempt at energy modeling and came out with a similar result. However, when the energy modeler for NYSERDA funding did theirs, it came much less than what we had anticipated. After several discussions, we found out that NYSERDA modeler didn’t count for possible saving for low infiltration rate because ASHRAE 90.1 2007 Appendix G does not allow performance credit for infiltration reduction. So if we want to purse obtaining additional points for ‘infiltration reduction’, I would probably need to do ‘exceptional calculation method’.

I was wondering if anybody have any experience on this one and offer some advice. One possible steps we discussed were;

1) Establish the baseline leakage to be modeled in the baseline simulation, based on typical construction practice, field studies, etc.
2) Measure actual leakage of completed building (use blower door or some other technique).
3) Develop and document approach (including simulation assumptions) to estimate energy savings. In a lab building there is significant mechanical ventilation 24/7, so we’d need to think through how to translate infiltration reduction into energy savings in this setting. In general, infiltration is often turned off/minimized in the simulation when mechanical ventilation is on, which obviously reduces / cancels out any savings that may be realized due to air tightening of a lab building.

But this just seems too much and not sure if we would obtain points doing this. Also this credit falls under ‘design’ submission, so testing part just doesn’t make sense to me.