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#1 Posted : 27 May 2007 18:48:00(UTC)
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Posted By Jonathan Gray
Recent complaints from office staff re temperatures have raised a few 'problems'.

I know that the recommended comfortable temp range is about 16C-30C, however, this office contains quite a bit of electricial equipment and a proposed change would introduce one more body and more equipment. At present the average temp, (high-low, measured over 24hrs for 2 weeks), is coming out at 32C. {This is despite the fact that windows and doors are open to allow air flow}. Has anyone come across a formula for calculating the heat contributed by a human body or for calculating the heat that may be produced by office equipment. For example computer terminals, monitors etc. The office is running 24hrs with staff working a 12hr rotating shift. Water is provided as are electricial fans.

Thanks

JG

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#2 Posted : 27 May 2007 22:14:00(UTC)
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Posted By Chris Packham
As far as human metabolic rates are concerned, there is a useful table in Occupational Health by Harrington, Gill, Aw and Gardiner (ISBN 0-632-04832-8) which, I believe, should be on any health and safety practitioner's bookshelf.

You will find the table of metabolic rates vs. activity on page 156 (or contact me direct).

With equipment, just look at the wattage of the actual equipment and assume that all power input is converted into heat. This may not be strictly correct, but is in general a good rule of thumb.

Chris
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#3 Posted : 28 May 2007 07:58:00(UTC)
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Posted By Adrian Watson
Jonathan,

Try a good HVAC book they will give the formulae for heat output from electrical equipment and for heat output from a person.

An acceptable temperature range for a ppd 10% is an air temperature of 20 C +/-2.5 C for a person wearing a light suit doing office work; a temperature gradient of 1.5 C from floor to head; with air movement of 0.15 m/s and no draughts; a relative humidity of 50%; and no radiant sources.

Regards Adrian
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#4 Posted : 28 May 2007 13:53:00(UTC)
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Posted By Ron Hunter
The best I can remember from my College days (1973-76), Environmental Engineering classes was 60 watts per person. As for the electrical equipment, you can effectively assume that the rating plate figure (or volts * amps) is all given out as heat (watts).
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#5 Posted : 29 May 2007 09:21:00(UTC)
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Posted By Jonathan Gray
Many thanks for the info and reccomendations everyone, a great help.
I'm off to update my reference libary.
Thanks again.

John.
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