Regd. Baseline Systems to be used for Buildings with both Cooling & Heating as per ASHRAE 90.1 2010

Hi Marcus, Thankyou for the reply.  I would request further clarifications on the process loads in exceptions which is asked to differ by 31.2 W/m2 or more from average of other spaces served by the system for System 3 or System 4 to be applicable.   Is this process load talking about equipment power density EPD (W/m2) or the peak cooling loads observed in various zones after cooling load simulation?

Hi Marcus, thanks for the clarification.  I have 2 things to clarify here now: 1. It is said the thermal loads should differ by 31.2 W/m2 or more from the average of other spaces served by system. What is this average considered as peak cooling load differs for each and every zone 2. I would further like to understand whether the applicability of this exception for additional baseline system types of 3 and 4 (based on thermal loads) depends on the particular functionality of the whole building. Like for example, in hospitals and commercial towers,the baseline exception gets applicable to zones like Electrical/ELV/UPS battery rooms based on the peak cooling loads differing from average of 31.2 W/m2. Am  I interpreting it correctly now?   Would appreciate your suggestion on the above 2 points and thanks in advance.

Hi Marcus, What I meant by the first point "It is said the thermal loads should differ by 31.2 W/m2 or more from the average of other spaces served by system. What is this average considered as peak cooling load differs for each and every zone" is whether the applicability of the exception for baseline systems 3 or 4 depends upon peak cooling loads in these smaller zones differ by 31.2 W/m2 or more from rest of the bigger space(based on functionality of building)? Is that what ASHRAE 90.1 trying to say?

Hi Marcus, I would like to raise a point here. 1. So, we are first asked to segregate the spaces based on functionality and larger area. For example, in a commercial space like mall, we have these machine rooms like UPS/electrical/ELV battery rooms, which occupy a small proportion of area in the whole mall space and hence the exception apply to these rooms. 2. Now secondly, we find the average of peak thermal loads for these rooms. Then find whether the peak thermal loads for each of these rooms differ by 10 btu/hr/sqft from average peak thermal load. Am I right now in interpreting this exception? Thankyou in advance.

Got it. Appreciate your explanation.