I live in an ICF home. We have an HRV system and A/C. However the humidity is 68%. How do I get rid of the humidity?
We live in central Illinois where the humidity can be high. We just moved into our home in April so we are new at this.
From what I have read am I right in assuming the only way to control this humidity is by using a dehumidifier? If so should i use a free standing one in the house or one that is installed on my HV system. How often should i be running the HRV system?
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There are several possible causes of the high indoor humidity you are experiencing: a leaky envelope (unlikely), an oversized air conditioner (possible), overventilation (possible), or lingering construction moisture (probable).
It's also possible that everything about your house is normal, and you simply need a dehumidifier.
1. Do you know if your home has been tested with a blower door? Do you know the results?
2. Do you know if your HVAC contractor performed a Manual J cooling load calculation to help size your air conditioner?
3. Has your HRV been commissioned? Have you been instructed about how to operate your HRV to be sure that you aren't ventilating your house at a rate that exceeds ASHRAE 62.2 requirements?
Assuming that you know that your home's envelope is relatively tight, and that your AC unit was properly sized, and that you aren't running your HRV for too many hours a day, you should go out and buy a $300 stand-alone dehumidifier and use it. Remember not to leave your windows and doors open while you are dehumidifying.
Next summer, you may not need to run the dehumidifier, since the amount of lingering construction moisture will be less.