Why is My Air Conditioner Not Dehumidifying?

August 26, 2013

Your air conditioner ran long and hard all summer to keep you comfortable, but all of the sudden it’s still cool in your house but it’s also MUGGY…

A Quick Lesson on Humidity

We are sensitive to humid air because the human body uses evaporative cooling as the primary mechanism to regulate temperature.  When it’s humid, the rate at which the perspiration evaporates on the skin is slower making us feel warmer.
 
Air conditioning equipment usually reduces the humidity by circulating the humid air over a cold evaporator coil which condenses the water vapor from the air and then sends the water down the drain.

Possible Causes of an AC System that is Not Dehumidifying

Inadequate refrigerant charge – if your system is leaking refrigerant it will not properly dehumidify the air
 
Oversized System – If you’re AC is too large for your home it will cool the air at such a fast rate that the air does not spend enough time moving over the evaporator coil to be dehumidified.  Once your thermostat is satisfied, it shuts off the cooling because desired temperature has been reached, but there will still be too much water vapor in the air to be comfortable.
 
Transitional Months – The temperature during these months varies from 90 degrees one day to 60’s the next, therefore your air conditioner might not be running long enough on a regular basis to dry out the air.  These are typically the months when we receive a lot of phone calls from clients concerned that the air conditioner might not be working.
 
Dirty Filters or Coils – Even if you had your air conditioner serviced at the beginning of the season, it may need to be cleaned again, and always change your filter on a regular basis.
 
September is usually one of those months where we start getting a wide range of temperatures.  If you are not comfortable at the “normal” temperature setting and the air conditioner hasn’t been running much, you can try reducing the setting on the thermostat one degree lower at a time until you are back in your comfort zone.  
 
If you would like more information on humidity control for your home, just give the experts at Santa Fe Air Conditioning a call.