Willis Carrier originally developed what we now know as air conditioning, back in 1902. His objective was to help a friend who owned a printing business. Excessive humidity was causing problems with the printing paper. A system was installed that removed humidity from the air. Another result of this new machine was that it also caused the air to become cooler. This is exciting stuff, isn’t it?

Yet another by-product of air conditioning is water. This water, known as condensation, is collected on the cooling coil during the air conditioning cycle. The amount of water depends on many factors – including the amount of humidity in the air. The water then drips into a condensate drain pan, then into a drainpipe that takes the water to a drain, or to the ground. The drain pans are usually made from metal, or plastic.

In a properly installed and maintained system, this process usually works for years without any trouble. However, there are several instances when water from condensation can become a real problem.

This is sometimes the case when the cooling coil is located in the attic, above a ceiling. To prevent problems, local building codes are very specific as to how the drain lines are to be installed. In fact, they require that two independent drain lines be connected to the drain pan. This is required in case the first drain, or primary, ever becomes plugged, or inoperable for any reason, the overflow will go into the secondary drain line, and avoid having the water come through your ceiling.

The primary drain, under normal circumstances, usually handles all of the condensation. The condensate drain line must be slopped so that the water can flow downhill. This drain line must terminate either at ground level, into the earth, or be directed to a sewer line. The other drain line, or secondary, is required to terminate above a window, door, or walkway, where the homeowner would notice the water dripping, and call their service company. A condensate pump can also be used if a proper slope cannot be achieved. The pump is about the size of a shoebox. It will hold the water, and when full, ‘push’ the water, even uphill, through a tube to the sewer drain or another pipe to the ground.

If the installation had been done properly, this drain system is very reliable. Most problems occur on installations where the primary and secondary drain lines have been connected together. In this scenario, if either line were to become plugged, the water will have nowhere else to go but down – through your ceiling. This is an indication that a permit was not obtained, or an inspector would have ordered a correction.

Problems can also happen if the drain is not sloped properly. This can be from a poor installation, or if the pipe was not supported properly and starts to sag, which will trap the water.

Due to a variety of factors, including age, metal drain pans can rust and eventually leak. If this happens, it is usually best to replace the cooling coil – not replace the drain pan.

For even more detailed information about cooling coils, humidity, and condensation join us at our next Homeowners Workshop. All questions will be addressed, so bring your list. There is no cost, so bring your friends, neighbors and relatives. If you are interested in attending, call (818) 886-2600 to make a reservation. Join us for a couple of hours and you’ll take home some useful information.

Jim Berry was a heating and air conditioning service technician prior to becoming a Sales Consultant for Kahn Air Conditioning. Kahn hosts free monthly workshops to help homeowners learn more about heating and cooling systems. For questions regarding heating or air conditioning, send an e-mail to Jim at jberry@kahnair.com

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