If your home feels more humid than usual, you may want to get your air conditioning system inspected.
Split-system units with an indoor coil and an outdoor coil are designed to dehumidify indoor spaces. The
blower will push warm air over the indoor coil. As the air cools, condensation will form. The indoor coil
will essentially absorb both heat and moisture from the air, thus cooling and dehumidifying your home.
The following problems, however, may interfere with the dehumidification process.
Only the Fan Is Running
Your air conditioning system must be running in order for it to dehumidify your home. If only the fan is
running, it won’t be able to remove heat and moisture from the air. Check your thermostat to see if the
fan is set to ON or AUTO. The ON setting will allow the fan to run continuously, whereas the AUTO
setting will only allow the fan to run when your air conditioning system is running.
Dirty Evaporator Coil
A dirty evaporator coil may prevent your air conditioning system from dehumidifying your home.
Located near the furnace or air handler, the evaporator coil is the indoor coil. It contains a series of
hollow tubes that carry refrigerant.
As a heat exchanger, the evaporator coil must be clean to perform its job. If it’s coated in dust, dirt and
other forms of debris, it won’t be able to absorb heat from the air. And if it can’t absorb heat, it won’t
be able to effectively dehumidify your home. You should check the evaporator coil to determine
whether dirt and debris is to blame for your air conditioning system’s poor dehumidification.
AC System Is Too Big
You might be surprised to learn that the size of your air conditioning system can affect its
dehumidification process. If your air conditioning system is too big for your home, it may struggle to
dehumidify your home. An oversized system will quickly cool your home. These short cycles may fail to
offer a sufficient amount of time for dehumidification.
Clogged Condensate Drain
A clogged condensate drain can interfere with your air conditioning system’s dehumidification process.
Below the evaporator coil is a pan connected to a drain. As water vapor condenses on the evaporator
coil, it will drip into this pan. At the base of the pan is the condensate drain, which runs to your home’s
Condensate drains can become clogged. As water travels through them, they’ll provide a breeding
ground for mildew. Mildew will grow inside of the condensate drain while subsequently restricting the
flow of water.