Whether you live in an area that is prone to drought or you simply care about the environment, consider tapping into your home's central air conditioning unit to get water for your garden. This is called condensate recovery. Here's what you need to know and how to build a condensate recovery system for a garden irrigation or sprinkler system.
Condensate created by your air conditioning unit
Residential-sized central air conditioners can produce 5 gallons of water per day in dry climates and 20 gallons of condensate each day in humid climates. That's a lot of water that can be used to water your garden, especially during droughts when using water for gardens can result in fines. Condensation is moisture from the air and is similar to distilled water because it has very little, if any, mineral content.
A central air conditioner draws in warm air and cools it over evaporator coils, which results in the formation of condensate. From there, the condensate collects in a drain pain, which gets released into a sump pump pit or sewer drain when a float device activates a switch when the drain pan is nearly full.
Components of a condensate recovery system
A condensate recovery system consists of the following components:
Condensate recovery—You'll need to redirect the drain pipe from the air conditioner to go to a special recovery system instead of the current set-up. The condensate will collect in the recovery system until it is needed by the irrigation system in your garden. The recovery system consists of a container to hold the condensate from the air conditioner, a water treatment unit, and an additional unit for the treated water. Of course, the two containers and piping need to be appropriately sized, so you may want to contact a professional for their expertise.
Water treatment—Using a water treatment unit is ideal so any microorganisms and bacteria can be removed from the condensate. This is particularly important if your garden contains vegetables and/or your children and family pets spend any time in your garden or the areas that surround it. The size of the water treatment system should depend on the amount of humidity your region is prone to get. That way, you can be sure the water treatment system can keep up with the demand of condensate that needs to be treated.
Underground holding tank—Depending on the size of your garden and the humidity levels in your region, you may want to consider installing an underground holding tank near your garden to hold the water after it has been treated. Keep in mind, however, that this water shouldn't sit too long or it could become stagnant and have a horrible odor. To reduce this risk, install a pump in the holding tank to circulate the water. Also, consider perforations near the top of the tank to allow water to escape from the tank when the water in the tank reaches a certain level.
Irrigation or sprinkler system—Decide between installing an irrigation system or a sprinkler system as either will work for your needs. Since the water will be treated beforehand and if there's no risk of stagnation, there will be no concern of the water being unsafe for your garden, children, and pets. However, if you do not install a pump in the holding tank to reduce the risks of stagnation, you may want to go with an underground irrigation system, instead, which consists of perforated pipes installed underneath your garden. Of course, if your garden has already been planted and is established, it would be a better idea to go with a sprinkler system for the least disruption to your garden.
Speak with your HVAC technician, a plumber, or a water treatment specialist for more information about installing a condensate recovery system for your specific needs.