What’s the connection between HVAC vs. plumbing in a typical residence? After all, the HVAC system primarily circulates heated or cooled air, while plumbing moves water. Actually, plumbing’s a factor in both air conditioning and furnace operation, depending on the size, type, and efficiency of a specific unit. Here are some ways the interaction of HVAC vs. plumbing occurs. 

Why It’s Called Air “Conditioning”

Air conditioning involves more than just cooling air. Extracting water vapor from indoor air is also an important function.

  • The process begins at the evaporator coil as warm, moist indoor air passes through frigid coil passages. Water vapor in the air condenses into liquid condensate.
  • Condensate collects in the drip pan beneath the unit. On a humid summer day, a central AC may produce as much as 20 gallons of liquid condensate. 
  • Condensate water continuously flows out of the pan through a drain tube into the household drain system. 

What Can Go Wrong?

Blockage in the condensate drain system quickly leads to an overflowing drip pan. Expensive indoor water damage can occur rapidly. Clogs in the drip pan or drain pipe are frequently caused by algae or mold formation. Service by a qualified professional HVAC technician includes cleaning the drip pan and blowing out the drain tube to restore proper flow. To prevent recurrence, biocide tablets are installed in the drip pan to inhibit algae and mold. 

Why Furnaces Make Water

High-efficiency modulating furnaces include a second stage where extra heat is extracted by condensing water vapor that’s present in exhaust gases. Condensate collects in a drip pan, then passes through a trap into a drain line that usually terminates outside the house.

What Can Go Wrong?

A furnace drain blockage typically triggers a sensor that shuts down the furnace until the problem is resolved. Due to safety issues, clogs in the furnace drain system require a certified technician to clear the obstruction, then reset the furnace to operate again.

Ask the pros at Mowery Heating, Cooling, and Plumbing for more facts about HVAC vs. plumbing issues.