The ideal relative humidity for both health and comfort is about 30–50%. These levels may differ in winter months.
Causes Of High Humidity With Air Conditioning Units:
- Oversized System – An oversized AC system does a poor job of controlling both temperature and humidity. That’s because the powerful compressor turns on and off too frequently, so the system never runs long enough to remove moisture from the air.
- Single Speed – When the unit can only run at one speed, it turns on and runs full blast until the air reaches set temperature. Then it turns off until the temperature once again goes above the thermostat threshold. That often means the unit doesn’t run consistently enough to remove humidity.
- Negative Air Pressure – Negative air pressure results in too much air being vented from your ducts. When you have negative pressure, the air tries to balance itself by drawing in more outside air any way that it can, which can be bad if the outdoor humidity is high.
- Leaving The AC Fan On – This can accidentally blow the moisture your AC has removed back into the space before it has a chance to drain away.
- Old Unit – As your air conditioner ages, parts wear, and it may not run as efficiently as it used to. That tendency is increased when the system hasn’t been regularly maintained.