We are going through the third party reviewer portion of the credit and have one final hiccup. A garage type space is heated and conditioned with an energy recovery unit with gas heating. The baseline system is modeled with a constant volume rooftop unit with an ERV wheel, same as the proposed, but gas heating and DX cooling.
The reviewer is now stating that since the baseline system has cooling, then the proposed (built by now) building needs cooling. ASHRAE 90.1-1999 is the design guide line and section 11.4.3(d) was quoted as stating this is the design criteria. My version of ASHRAE 90.1-1999 states, "Minimum outdoor air ventilation rates shall be the same for both the budget building design and the proposed building. Heat recovery shall be modeled for the budget building design in accordance with 6.3.6.1."
My question is does any one agree with the reviewer regarding the cooling requirement? If the inspector is correct, where do I find this in ASHRAE 90.1 as I cannot find it? Are there different versions of ASHRAE 90.1-1999?
Lorne Mlotek
BASc., LEED AP BD+C, O+MLeadingGREEN Training and Consulting Inc, Viridis EC LLC
25 thumbs up
June 3, 2013 - 3:30 pm
If I understand the issue correctly, I partially agree with the 3rd party reviewer. The baseline and proposed must be consistent, IE if you're cooling the space with DX in your baseline, it must be cooled by X system in your proposed building. However, if you are strictly heating the garage type space with the ERV and not providing any cooling, I believe the fix is pretty simple. Separate the garage space from the building and only model the space to be heating with a cooling load equal to zero. Clearly, if the building is already constructed, this space does not need to be cooled as I assume it is operating fine. If you strictly alter your base building to eliminate the cooling element it will lower your modeled electricity savings but should satisfy the 3rd party's demands.
If I understand the issue is more one of consistency between base and proposed buildings rather than an additional cooling system.