Anderson,
I was checking this out recently I don't believe temperature or humidity setpoints are regulated by ASHRAE 90.1 during occupied periods. I think they primarily limit this through ASHRAE 55 regarding thermal comfort. Of course ASHRAE standard 55 is often not mandatory but it is certainly good practice. It goes without saying that several space types such as hospitals and labs have special temperature and humidity requirements that are industry-specific.
Scott P. West, P.E., LEED AP BD+C, BEAP, BEMP
Indeed, ASHRAE 55 is he relevant standard for thermal comfort; however... While ASHRAE 90.1 does not specify min and max for the temperature setpoints be during occupied hours, it does include requirements for separation of the heating and cooling setpoints to provide an adequate deadband.
[IES]
Timothy Moore
Two things:
1. For the affected climate zones, the wording of the cited section requires controls that allow for setback temperatures in a range large enough to include those temperatures... not those temperatures specifically. To paraphrase, the controls must allow for a heating setback temperature setpoint anywhere between the occupied heating setpoint and down to 55F (or lower). Likewise there must be a cooling setback range to include anything between the occupied cooling setpoint and up to 90F (or higher). The prescriptive requirement is for a minimum range of control, not to define what those setback temperatures actually are.
2. I agree with Scott: 90.1 does not prescriptively mandate temperature setpoints (for setback or occupied hours). If you are doing an Appendix G based model, it does require baseline and proposed models to have matching inputs in this regard, however.
So in sum, I'd concur both your design (occupied) and setback temperatures should be determined in accordance with your mechanical design load calculations, which in turn should consider and be informed by owner/climate/industry-specific space conditioning requirements with respect to occupied and unoccupied states.
Regards,
NICK CATON, P.E.
Hi Anderson,
a few years ago I did some research on thermal comfort and deadbands. In my
PhD, first chapter you can find that. It is also published in Applied
Energy, but the chapter is more elaborate.
http://hdl.handle.net/1979/2651
Leen Peeters
Scott, Nick, Leen and Moore,
Thanks for your feedback. Now I have lots of sources to investigate a bit
more.
Thanks Leen for sharing your PhD research. I?ll have a look at it.
My conclusion so far is that there aren?t specific temperature values for
this situation. It?s basically a matter of design.
Regards,
Anderson Letti
2013/12/2 Timothy Moore