
The condensate drain is an essential part of any central air conditioning system. Having proper drainage is important for ensuring your air conditioning system works effectively and prevents air quality issues in your home. In this article, we’ll explain how the condensate drain in an AC works, why it’s so important and how to tell if your system has sufficient drainage.
Why an AC System Needs a Condensate Drain
As an air conditioning system runs, condensation naturally forms and collects on its evaporator coil. The reason is that the cold refrigerant in the coil causes the air flowing through the system to cool down so much that it reaches its dew point. That results in much of the water vapor that the air contains also getting cold enough to change from a gas into a liquid. Much more condensation will obviously form when the air is more humid since it contains much more water vapor. However, some condensation will still form even in a desert climate like Las Vegas since the air always contains some moisture. That’s why you still end up with condensation forming on a glass or soda can any time the air is much warmer than the fluid inside these containers.
This process of condensation is how air conditioning systems help to dry the air inside a building, and it is also responsible for lowering the indoor temperature. It’s also why central AC systems must have a condensate drain to capture and remove the water. As condensation forms on the evaporator coil, the water eventually starts dripping down into the drain pan below the coil. A pipe connects to the bottom of the drain pan, which then links to other pipes that carry the water away. The location where the water empties can vary depending on where the air handler is located.
Air handlers can be located in the basement, crawl space, attic or on the ground floor depending on what type of foundation the home has. In Las Vegas, it’s common for the air handler to be either in the attic or on the ground floor since many homes are built with a slab foundation and don’t have a crawl space. In this case, the drain line often runs through an exterior wall so that all the water drains out. If the air handler is in the basement, it’s common for the drain line to empty out into a nearby floor drain or directly into a plumbing drain pipe. There are also homes that use a condensate pump to pump all the water up out of the basement so that it still drains outside.
The Role Condensate Drains Play in AC Systems
Without the condensate drain, there would be no way for all the water to drain away from the system and you’d end up with lots of water leaking out of the air handler onto the floor. This results in flooding that can potentially lead to property damage. In addition to keeping floods at bay, having proper drainage is also important for helping to prevent issues with mold, mildew and bacteria in your AC system.
All the water that collects and drips off the evaporator coil should drain away quite quickly. Although the coil remains damp while the AC system is running, it also should dry out soon after the system shuts off because of the remaining moisture evaporating into the air. If either the cool stays wet or water sits in the drain pan for a prolonged period, it can easily lead to mold, mildew and bacteria growth. That’s why you’ll often notice that your AC starts putting out moldy or musty-smelling air if the water isn’t draining away properly.
Having mold and bacteria growing inside an AC system is a critical concern since these pathogens and spores will then get spread throughout the house as the system runs. This can create significant issues with indoor air quality and lead to illness or exacerbate allergies and other respiratory issues. Mold can also spread to other parts of the house and potentially lead to an infestation.
Another issue is that mold and mildew can end up clogging the condensate drain. When this happens, you’ll end up with the water backing up and eventually starting to leak out of the air handler onto the floor.
One final thing to note is that mold growth on the evaporator coil can greatly decrease the energy efficiency of your AC system. What happens is that the growth on the coil acts like an insulating layer that blocks much of the air flowing into the system from contacting the coil. This reduces how much heat the coil can capture from the air, which makes the system cool more slowly and work less efficiently.
What Issues Can Cause an AC to Start Leaking?
You can usually tell if your AC system has proper drainage just by checking to see if it’s leaking. Any time you notice water on the floor near the air handler, it indicates that either the system doesn’t have proper drainage or there is so much water draining into it that it’s overwhelmed. The latter commonly happens when an AC system freezes up and then begins to thaw. If the system runs for a prolonged period when frozen, a thick layer of ice can build up on the evaporator coil. The ice can then start melting quickly enough that it leads to water dripping into the drain pan faster than it drains away, resulting in the pan filling up to where it begins overflowing.
You’ll always be able to tell quite quickly if your AC is frozen since it will result in hot air flowing out of your vents. If this situation occurs, you should turn your AC off to prevent any damage from occurring. It’s also a good idea to put towels on the ground around the air handler in case water starts leaking out so that you can hopefully avoid any water damage.
If your AC is working properly and you notice water leaking out of the air handler, it’s a sign that it doesn’t have proper drainage. The most common reason this will happen is due to a clog. However, it can also indicate that there is a crack or loose joint in the condensate lines.
Another possibility is that there is a crack or hole in the drain pan. Sometimes you can just have a professional apply a patch to stop the pan from leaking, but a large crack or hole will usually require the pan to be replaced. Unfortunately, replacing the pan isn’t always possible since sometimes it is welded directly to the evaporator coil. In this case, your only choice will be to just replace the coil and pan together.
With more than 25 years of professional experience, Polar Air & Heating, Inc. is the company to trust if you need any residential or commercial HVAC service in the Las Vegas area. We offer expert air conditioning and heating repairs, and our team is also ready to help with your maintenance and installation needs. Contact us today if you need to schedule a service appointment or if you have any questions.
