This is long but may foster some good discussions. Read at your own peril :)
I had a colleague ask me today if we had any information about exactly how much more efficient a few HVAC systems are compared to each other. His project is in pre-SD phase and the design team and owner are trying to come to a decision on which HVAC system type they should use in design. Usually we address this by giving qualitative comparisons ("good, better, best") but this owner was looking for some hard numbers. They want to know that
Client management of expectations is our usual approach to head off situations like these. The answer this owner is looking for is extremely subjective and depends on countless factors (usage, climate zone, building geometry, materials, controls, etc.) It's not really possible to distill a specific and correct answer to such a complex question. Also with it being so early in the design process, nearly all the variables are still up in the air!
So from a "best practices" perspective I want to pose the following questions to the community.
- How do you all handle situations like these at your practice?
- Would you typically conduct an energy model in this situation even at this early stage?
- What if modeling wasn't in the fee?
- Are there online or NREL tools/resources that I'm not aware of that would be useful here?
- What studies, research or reference guides to you turn to in these situations?
Thanks all! I hope we can get some good discussions going.
Cheers!
