Importance of Draining Condensate

Payne 90% furnaceCondensation occurs when warm air goes across a cold surfaces. For example, when warm humid air in your kitchen comes in contact with a cold glass of ice water, the moisture in the warm air, currently in a vapor state called humidity, it condenses into a liquid state.

The process of condensation happens in HVAC in many ways as well.

Use an air conditioner for example. It has condensation in two places. One place is in the outdoor coil, called the condenser. It’s enclosed, so you cannot see the process, but the same thing as the cold glass example happens. Hot refrigerant from the compressor starts in a gas state goes into and through a coil and is cooled by the outdoor air, so it goes in as a gas and comes out as liquid. 

The second place you have condensation in an A/C system is with the indoor evaporator coil. Through the normal principals of air-conditioning the evaporator coil is cold, so when the warm return air goes across the evaporator coil it condenses in the same manner as the cold glass of water. 

Here’s the issue: you need to get rid of the condensation, or you will have a big mess. As most people know water and electricity do not mix. This condensation can corrode your indoor equipment and cause damage to your property. Please follow your installation instruction for proper drainage, and contact the B-Y Customer Assurance team with any questions.. 

Another piece of equipment with condensation is a 90% furnace. 90% furnaces have two heat exchangers, a primary and a secondary. The secondary is also called a condensing heat exchanger. As the term might indicate, it cools the warmer combustion air from the primary to the point it condenses.    

A 100,000 BTU furnace running consistently for an hour under the right conditions can create up to one gallon of water. Once again you need to get rid of the water. Please follow the installation instruction for a proper drain. 

Check out a previous B-Y Tech Tip called Condensate Drainage in Gas Furnace for excellent information on proper drainage, but don’t forget about the furnace installation instructions.  Your instructions are specific to your unit. 

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