Committee on the Environment

  • 1.  Is thermal comfort a discussion during design?

    Posted 04-16-2014 10:13 AM
    This message has been cross posted to the following Discussion Forums: 2030 Commitment and Committee on the Environment .
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    One of the main reasons we build buildings is to keep its occupants comfortable. Most complaints in a building come from lack of thermal comfort.

    How often do architects discuss thermal comfort with the client? or within the team?

    In commercial buildings, I have found that if you start your design with this basic question, then there is an opportunity for expanding the thermal comfort to conserve energy.

    Here are some simple and practical tips regarding expanding thermal comfort.
    https://prem-sundharam.squarespace.com/blog/2014/4/15/expanding-thermal-comfort

    There are lot of different thermal comfort models - this one is the most standard from ASHRAE. What are your experiences with thermal comfort discussions?





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    Premnath Sundharam AIA
    Senior Associate
    DLR Group, Inc.
    Phoenix AZ
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  • 2.  RE:Is thermal comfort a discussion during design?

    Posted 04-17-2014 07:35 PM
    It would also be good to include Mean Radiant Temperature when discussing thermal comfort for humans.  The body relates to MRT about 40% greater than it does to air temperature.  MRT is more comfortable and healthy than blowing air at people to warm or cool them.  Air is a good insulator and not a good conductor of temperatures.

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    Edward Cazayoux FAIA
    Principal/architect
    EnvironMental Design
    Breaux Bridge LA
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  • 3.  RE:Is thermal comfort a discussion during design?

    Posted 04-25-2014 02:12 PM

    Thermal comfort research identifies six primary factors that affect thermal comfort - all six of these should be included in any conversation about thermal comfort. Air temperature and humidity are the two factors that typically come to mind first, and they are the factors controlled by an air conditioning system. However, radiant temperature, air velocity, metabolic rate and clothing insulation are all just as important to consider in a design. In certain spaces, such as a private school with uniform dress code, clothing insulation and metabolic rates will be fixed values, so you must use the other four factors to offset high clothing insulation and set metabolic rates to create a comfortable environment for occupants. In settings like traditional office spaces, it is more efficient to adjust the least energy intensive means of providing thermal comfort, such as adding or removing an outer layer of clothing and adjusting air velocity to achieve acceptable levels of thermal comfort.

    I'd recommend checking out the Center for the Built Environment's free online comfort tool, which allows you to alter each of the six primary thermal comfort factors and determine design set points that result in acceptable thermal comfort per ASHRAE Standard 55. The thermal comfort tool can be found here: http://smap.cbe.berkeley.edu/comforttool.  Acceptable levels of comfort are generally a Predicted Mean Vote (PMV) between 0.5 and -0.5 and Predicted Percent Dissatisfied (PPD) less than 10%.


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    Christian Taber
    Research Engineer
    Big Ass Fans
    Lexington KY
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    Original Message