How much and where should an air conditioning unit drip?
All room air conditioners drip — or at least they should. However, drips in the wrong place or the wrong volume of dripping water may be a sign of a problem with the air conditioner. Find out how much air conditioner leaking water is normal, and when it signals trouble.
Why air conditioners drip
As the name suggests, air conditioners do more than simply cool your home. They help condition the indoor air and increase comfort by reducing humidity. The air conditioner’s cooling coil or evaporator absorbs moisture from the room. The airborne water vapor cools into liquid form and then collects on cold surfaces in the air conditioning unit, similar to the condensation that collects on an iced drink.
How much air conditioners drip
The volume of air conditioner dripping condensation varies widely depending on current humidity levels and temperature, as well as several details regarding the size, efficiency and installation of the air conditioner.
On a summer day in a hot, humid climate, you can easily find each window A/C unit leaking up to two gallons of water per day, while central air conditioning systems may drip 20 gallons daily. Keep in mind that this water can be diverted for reuse in landscape irrigation. On the other hand, air conditioner condensation should not be collected for drinking water because of the risk of lead exposure and other contaminants.
Where air conditioners drip
The condensed water should leak from the back of the air conditioner unit whenever the unit is running. The water drips from the cooling coil into channels that should be angled toward the back of the unit. Some of the water is used to cool heating coils in the machine, but most will drip out of the unit.
If an air conditioner is not dripping, it may not properly be doing its job of dehumidifying the room. If A/C is leaking water from locations other than the back of the unit, you may have another type of problem.
Troubleshooting air conditioner dripping
Perhaps the most common issue with air conditioner condensation is water dripping out the front of the unit, caused by installation errors. Such drips can ruin furniture or flooring, and may lead to mold concerns. The back of the air conditioner should be slightly lower than the front to encourage proper drainage.
Water dripping from the sides or front of the air conditioner might also be caused by air leaks. If the air conditioner is not properly sealed in place, hot outside air could turn into dripping condensation when it hits the cool air conditioning surfaces. You may need to caulk and insulate around the air conditioner to reduce such condensation. This will also boost efficiency and could reduce energy bills.
If the water freezes into ice rather than dripping out, the air conditioner likely needs servicing. If there is no water dripping out, the drains may be blocked, which also means you should call for professional HVAC service.
Updated December 7, 2017.