Properly working heating and cooling systems are integral aspects of a comfortable home or workplace, especially during summer. One malfunction can leave you sweltering in the heat and make your home unbearable. When temperatures start to cliumb outside, the last thing you want is to find your portable air conditioner knocked out by a simple malfunction. The good news is that not every malfunction is a disaster. Though some require professional help, a great many can be resolved on your own, without the need for a technician. Before you spend any money on repairs, take some time to see if any of these simple fixes are enough to get your portable AC up and running again.
My AC Isn't Providing Enough Cooling
Portable air conditioners are ideal for cooling small areas, such as bedrooms or living rooms, or for providing supplemental cooling in places central AC systems can't reach. Because they're small units, the two primary reasons for inadequate cooling are incorrect sizing and extreme ambient temperatures.
The size of an air conditioner refers to its cooling power, not its physical proportions. Portable ACs are sized according to their BTU ratings, and if your portable AC has the wrong BTU rating for the size of the room you're trying to cool, its efficiency will be affected. A unit with too many BUTs will cause the unit to cycle off too quickly, while a unit with too few won't be powerful enough to affect the ambient temperature. To find out whether your portable air conditioner is the right size for the room it's in, measure the length and width of the room. If your room is oddly shaped, try breaking it up into smaller shapes like squares and triangles. Calculate the area of a triangle my multiplying the base by the height and dividing in two. Once you've calculated the area, consult our portable air conditioner sizing guide to see what size air conditioner will work best in that space. If you're on the cusp of two different sizes, always choose the bigger one. It's okay to have a little more BTU than you need, just so long as it's close to the correct size.
On the other hand, if the ambient temperature is too high, it can also cause insufficient cooling. As portable AC units release cool air out into the room, they vent hot air from the compressor outside. This constant venting causes a pressure imbalance that pulls in warm air from the other areas, including adjoining rooms and the outdoors. Normally, if the room is properly sealed and all the doors and windows are closed, the air coming is never enough to overwhelm the portable AC unit. If there's a leak, or if the outside temperature is extremely high, the air conditioner may not be able to generate enough cold air to cool the room. Sunlight can also heat a room faster than your portable air conditioner can cool it. If temperature keeps rising, check for leaks and close the blinds. It may be enough to swing things the other way.
My Portable AC Won't Start
My Portable Air Conditioner Stops Operating On Its Own
Check to make sure the timer is not on, as an active timer can cause the unit to cease operation. Also, if the ambient temperature in your room is lower than the set temperature, this may cause your portable air conditioner to shut off. To remedy this, shut the unit down and wait for the room temperature to rise before turning the unit back on again.
No Air Comes Out of the Air Conditioner
There are many reasons for lack of air flow. The most common cause is a clogged filter. Remove the grill in the back of the unit and clean any excess dust off the filter with a brush or a vacuum, then rinse if off with some running water. Also check for clogs in the evaporator or condenser coils, which you can see in the top compartment of the AC unit after you remove the grill and filters. If you spot any, remove them with your vacuum hose attachment.
The second reason your portable air conditioner may not be venting air is frost on the cooling coils, also known as the evaporator coils. This happens when the low temperatures around the coils cause water to condense. If the water doesn't drain properly, it can build up and freeze around the coils, hampering air flow. To check the coils the same as above. Remove the back grill and the filters and inspect the top compartment. If you see any frost, turn the unit off and let it defrost. Once the ice has melted, normal operation should resume. Read our article on automatic defrosting and frozen AC coils to learn more.
The third reason may be the compressor has overheated. Check the hose and window unit to make sure they're still venting air properly. If the portable AC is unable can't vent the heat generated by the compressor, it will build up inside the unit and cause the compressor to shut down. Straighten the hose, remove any blockages, and position the unit further away from the window. If it's too close, the hose can sag restrict air flow (visit our venting FAQ to learn more). Let the unit cool for 15-30 minutes and then turn it back on. Normal operation should resume.
If it doesn't, it's time to call a qualified professional. The problem may be a malfunctioning fan motor, a low refrigerant charge, a refrigerant leak, or a blown compressor. Do not attempt to repair these issues yourself. Contact a local repair man or, if your unit's under warranty, contact the manufacturer for help.