Humidity Issue
Humidity Issue
(OP)
I have a 7000 sg ft office building with a 20 ton cooling, 360 MBH heating RTU. RTU has an economizer and it is bringing in 1,635 cfm for O/A. Air distribution is to a VVT system. After a week of data logging recordings average a temp of 72F and an RH of 24%. Location is southern ohio and the system is maybe 5 years old.
Can anyone help or point me in the right direction to solving this issue, at a loss right now.
Thanks
Can anyone help or point me in the right direction to solving this issue, at a loss right now.
Thanks





RE: Humidity Issue
knowledge is power
RE: Humidity Issue
The occupancy was?
Averages are nice, but is the average representative?
RE: Humidity Issue
outside conditions were mid 20's F during data collection time. the high temp in the building was 75 and low was 68. Occupied time was set on 72 F. RH high was 25% and low 23%. it was pretty consistent.
RE: Humidity Issue
RE: Humidity Issue
RE: Humidity Issue
http://www.meloairinc.com
RE: Humidity Issue
I worked for a company that designed and sold humidity sensors, in Memphis TN. Winter humidity in the building on cold days <25°F averaged 15% RH. It would dip down to 12°F or so if the outdoor temperature got below 5°F.
Same in most of the buildings -- schools, churches, office buildings, retail stores, almost everything except hospitals. You just don't find humdifiers south of the 37th parallel. People don't usually complain, because they have experienced it in the winter all their lives. The designers hide behind the "usual standard of care in the community" principle. Of course, I guess you could consider the people who bring giant-size bottles of skin lotion to work are complaining silently.
Best to you,
Goober Dave
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RE: Humidity Issue
RE: Humidity Issue
RE: Humidity Issue
RE: Humidity Issue
The University of Minnesota developed a chart for corresponding indoor humidity ratio to outdoor temperature, assuming an indoor temperature of 70F and residential style construction. I will try to paste it here. They don't guarantee no condensation, this is just a guideline.
Based on a 70ºF interior room temperature, engineering studies established the following guidelines:
Outside Temperature Inside Humidity
20º to 40ºF Not over 40%
10º to 20ºF Not over 35%
0º to 10ºF Not over 30%
-10º to 0ºF Not over 25%
-20º to –10ºF Not over 20%
-20ºF or below Not over 15%
RE: Humidity Issue
Humidifiers are maintenance nightmares and some
stupid peopleoccupants may just set them high and the you have mold all over.