We have a hotel development project in China seeking for the LEED-NC v2009 certification. We are now facing a problem of setting the baseline case for the energy model.
The project floor area is larger than 60,000 ft² and consists of a commercial podium and a hotel tower. Since the hotel is defined as residential spaces and its heating source is fossil fuel, we have chosen “System 1- Packaged Terminal Air Conditioner (PTAC)” as the baseline HVAC system for the whole development including hotel tower and commercial podium. However, the commercial podium is a non-residential space consuming more energy than that of the residential space. It is unfair to simulate the whole development in PTAC baseline, as the energy saving in commercial spaces will be insignificant.
It is stated on Page G-23 of ASHRAE 90.1-2007 User’s Manual that ”If a building has both residential and non-residential spaces with their total conditioned floor area both greater than 20,000 ft², for instance a residential tower with retail and restaurants at the base, then the HVAC system type is determined separately for the residential and non-residential portions.” Apparently, we can separate the development into two portions –the residential portion for the hotel tower and the non-residential portion for the commercial podium, and set different baselines for each option.
Our Question is: Is separated baselines for residential and non-residential portions acceptable for LEED-NC/ LEED-CS v2009 EAp2/ c1 submission? Is there any successful case that we can refer to?
Thank you.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
April 13, 2011 - 8:27 am
Yes. You are simply following the exception listed in Appendix G3.1.1.1(a). Cite this section to the reviewer to explain why you are using two baseline systems. This aspect of the baseline model is pretty clear cut and you would not need to cite any other case to justify its use.
The grey area here is related to how you treat the hotel corridors and other non-guest room areas on each floor. Our interpretation is as follows - while the hotel guest rooms are residential, the corridors and other spaces on each floor are not considered residential and should be modeled with the baseline system used in the commercial podium.