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FAQs about IEQc7.1 :

ASHRAE-55 comfort criteria ask for space air speed. Is this the same as the supply air volume measured in cubic feet per minute (CFM)?


What should I do about a warehouse space?

How can thermal conditions for areas with metabolic rates outside of 1.0–1.3 be determined? (Per ASHRAE Standard 55-2004 Section 5.2.1.1, Figure 5.2.1.1 can be used for areas with metabolic rates between 1.0 and 1.3).

There are a few spaces in my project that can’t meet these requirements. Can’t I just exclude them?

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NC-2009 IEQc7.1:Thermal Comfort—Design

Can someone help the new guy? Thanks?

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C M E
Engineer
LEEDuser Basic Member
1 thumbs up

So I recently got hired, and the first thing they have me working on is getting familiar with LEED credits and completing the forms. This may sound like a dumb question, but how do I determine the Operative Temperature for Cooling and Heating? I already obtained my climate design conditions from our Load Calc program. Thanks, CE

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Lindsay Austrom
Mechanical Engineer
Stantec
LEEDuser Premium Member
18 thumbs up

Fri, 08/02/2013 - 15:22

Hi CE, Welcome to LEEDuser! Does your office have a copy of ASHRAE Standard 55? The operative temperature is clearly defined, as well as other terms and requirements for this credit. The comments on this page are also helpful, so have a read and don't be afraid to ask more questions. The operative temperature is based on the local air temperature and the mean radiant temperature (which is a function of radiant heating/cooling sources). If your spaces have a reasonably good building envelope and no radiant heating/cooling systems, you can assume that the operative temperature equals the local air temperature. See Appendix C in ASHRAE Standard 55-2010 for details.
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C M E
Engineer
LEEDuser Basic Member
1 thumbs up

Fri, 08/02/2013 - 16:48

Yeah I've read through ASHRAE 55 and Apendix C and that's what I thought. I'm just always hesitant on assuming. I appreciate the help.
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Lew Bonadies
Marketing Consultant, LEED AP O+M
BtoB Projects, LLC
LEEDuser Basic Member
9 thumbs up

Mon, 06/01/2015 - 21:14

But how do we calculate radiant temperature.? Air temperature i assume is the set point temperature of heating and cooling inside the building.?
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Lindsay Austrom
Mechanical Engineer
Stantec
LEEDuser Premium Member
18 thumbs up

Mon, 06/01/2015 - 22:35

Lew, yes the air temperature is your HVAC system setpoint. The mean radiant temperature (MRT) can be calculated from the temperatures of surrounding surfaces and their relative positions. I use the ASHRAE Thermal Comfort Tool v2 software, which includes an MRT calculator. I don't think that the free Berkeley CBE tool includes one, but someone please comment if it or any other thermal comfort software tools have an MRT calculator. If your project includes radiant heating/cooling and you need to calculate the MRT manually, the ASHRAE 2009 Handbook - Fundamentals (Chapter 9) includes MRT equations that can be used for standing or seated occupants.

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