Is it possible that a climate could be benign enough that RH sensors would be redundant or unnecessary, and a project would still gain IEQ 2.3 compliance with temperature monitoring alone?
In our situation of moderate humidity and temperatures we rarely control for RH (except with museums, libraries, or with chilled beam applications, for example). We monitor temperature very frequently and control it very well. If we had logs of interior RH that demonstrate we usually have comfortable conditions the "natural way," (without controlling it in AHU's) could we get the point without installing all the RH sensors and energy consuming equipment?
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Samantha Harrell
LEED Project Reviewer certificate holder115 thumbs up
March 27, 2012 - 12:48 pm
I suggest you reference LEED Interpretation 5484 in your submittal. This LI has not yet been considered for EBOM 2009 projects, so the reviewer may determine that it is applicable to your project. The LI states that "if it can be proven that maximum humidity levels will not be exceeded based on the local climate, then the humidity monitoring requirement will be waived. To demonstrate compliance, provide climate data that shows peak outdoor humidity levels will not be problematic for indoor comfort as defined by in ASHRAE Standard 55, and/or provide a summary of the psychrometric analysis (without contribution of air cooling) accompanied by a narrative."
Allen Doyle
Sustainability ManagerUniversity California Davis
4 thumbs up
March 27, 2012 - 2:53 pm
Thanks, Samantha,
We await the response to LI 5484.
As you might expect, we only measure RH where we control it, so we may need to deploy loggers.
Alternatively we can calculate indoor RH from outdoor RH. Here is a site or calculator that will do the above:
http://www.lenntech.com/calculators/humidity/relative-humidity.htm
I'm looking for:
1) the equation to plug into a spreadsheet
2) what percent excursions from comfort standards would be allowed?
3) Finding worst case situations:
high indoor RH: High outdoor temp and RH
Low indoor RH: Low outdoor temp and RH
4) A NOAA or weather site that would list both T and RH at the same time.