What Are the Causes of HVAC Condensation in Cold Weather?

November 16, 2021

Experiencing HVAC condensation in the winter could be a harmless occurrence if you heat with a heat pump or a cause for alarm if you use a combustion fuel. In either case, it's helpful to know what causes it, as well as its remedies to keep HVAC condensation from being a threat to health or home.

Heat Pumps

Heat pumps use an outdoor condenser that uses refrigerant to collect the heat in the air to warm your home. As it does so, the coils inside the outdoor unit can condense the water in the air as a natural reaction to the water vapor in the cold air hitting the warm condensing coils. If it's cold enough outside, frost may start to build on the coil.

Heat pumps use a switch stop the freezing. This switch sends the heat pump into the cooling cycle, taking heat from the indoor air to warm up the outdoor coil. Some heat pumps use the auxiliary heating strip to warm the outdoor coils. If your heat pump doesn't start to thaw, contact Aggressive Mechanical Contractors for help.

Combustion Furnaces and Boilers

One of the byproducts of burning a combustion fuel is water vapor. The gases should go up the flue or chimney, since the byproducts also include carbon monoxide (CO). If there's any obstruction or crack in the chimney or heat exchanger, the combustion gases may leak into your home instead of going up the chimney.

Make sure your CO detector batteries are working, and watch for excessive condensation on the windows. If you notice any HVAC condensation near your furnace, contact your HVAC contractor immediately, as CO is a fast-acting, deadly gas.

Condensing Furnaces

If you have a condensing furnace or boiler, you may have a leaking drainpipe. These furnaces use an additional heat exchanger to extract heat from the combustion gases. They generate waste water as a result. A cracked or leak in the drain pipe could damage your home or emit noxious gases indoors.

For more information or assistance with HVAC condensation, contact Aggressive Mechanical Contractors, providing HVAC services for Monmouth County homeowners.