Skip to content
Home » Why has my portable AC failed?

Why has my portable AC failed?

There’s nothing worse than your AC breaking on a hot day. If your portable air conditioner has suddenly stopped working, we’re here to help! Here’s a quick rundown of what may be wrong with your portable AC. 

Why portable AC failed?

There are a lot of reasons why your portable AC has failed, including issues with power, airflow, dust build-up, and water tank leaks. Here are some of the most common problems that can cause your portable AC to fail:

  • Exhaust tube blockage: A blockage or kinking in the exhaust tube will prevent heat from escaping and cause a drop-off in performance.
  • Power problems: Using an incorrect voltage power source can cause either underperformance or damage to your portable AC’s electrical components. 
  • Water tank leaks: Water from condensation is stored in your portable AC’s condensate trap. Empty it regularly to avoid mold and damage to components.
  • Dirty filters/coils: As dust and dirt build up on your portable air conditioner’s coils and filters, its performance will fall significantly. Some units will shut off after they detect this kind of fall in performance.
  • Incorrect sizing: Using a portable air conditioner that isn’t strong enough for the size of the room you’re trying to cool will likely stop your unit from cooling the space effectively. 
  • Refrigerant leaks: Refrigerant is the chemical that moves around your portable air conditioner to carry heat out of your apartment. A refrigerant leak will drop the pressure in the refrigerant coils and may stop your unit from working.
  • Compressor malfunctions: The compressor is the most essential component in your portable AC. It moves the refrigerant through the evaporator and condenser coils and helps maintain a difference in pressure between the two. A malfunction will stop your portable AC from working. 

Exhaust tube blockage

Your portable AC generates excess heat and needs a way to get rid of it. Portable air conditioners use an exhaust tube – usually routed out a window – to blow hot air outside. 

A kink or blockage in the exhaust tube can cause a build-up of pressure and hot air in your portable air conditioner, causing a drop in cooling efficiency. 

It’s normally pretty easy to tell if your portable AC has a blockage in its exhaust tube. You should be able to see bends in the tube or hear noises coming from the tube. In either case, remove the blockage or kink to restore performance.

Power problems

One major source of problems for portable AC is a mismatched power supply. Your portable AC will need a specific voltage in order to function properly and this may be different from the supply available at your chosen outlet.

If your portable AC doesn’t get a high enough voltage, then it may operate slower with less power than it needs or might not work at all. Too high a voltage can cause damage to your portable AC’s electrical components. 

Water tank leaks

Your portable AC produces water as it cools your apartment. When humid air comes into contact with the evaporative coil, the temperature drop causes water vapor to turn into water droplets.

This water accumulates in your portable AC’s condensate trap. If the trap overflows, water will start to collect in the body of your portable AC and this can lead to water damage and the build-up of mold.

Prevent condensate tank leaks by emptying your portable AC’s water trap regularly. How often you need to do this will depend on the local humidity. The more humid the air is, the more water the process of air conditioning will generate. 

Dirty filters/coils

A build-up of grime and dust on your portable AC’s filters and coils will hinder its efficiency and can lead to system failure. A dirty filter will block airflow and reduce the amount of cold air your portable AC can produce. Dirty coils will create a barrier between your AC’s cooling element and the air it’s supposed to be cooling, reducing its efficiency. 

Luckily, this is a very easy problem to solve. Just open up your portable AC (after shutting it off!) and clean the filters and coils regularly.

Incorrect sizing 

One reason why your portable AC may fail to keep your room cool or may shut off is if your unit is the wrong size for the space you’re conditioning. A portable air conditioner that’s too weak will fail to keep the room cold enough and a unit that’s too powerful may keep shutting off as it hits the target temperature.

You can determine the correct portable air conditioner size for your property by checking the BTU capacity of the unit against the size of your property. Here’s a rough guide to how many BTUs of output you need for a given space:

  • 100 to 150 sq. ft.: 5,000 BTUs
  • 150 to 250 sq. ft.: 6,000 BTUs
  • 250 to 300 sq. ft.: 7,000 BTUs
  • 300 to 350 sq. ft.: 8,000 BTUs
  • 350 to 400 sq. ft.: 9,000 BTUs
  • 400 to 450 sq. ft.: 10,000 BTUs
  • 450 to 550 sq. ft.: 12,000 BTUs
  • 550 to 700 sq. ft.: 14,000 BTUs

The above sizings are not set in stone. A hotter environment means you should opt for a slightly more powerful portable AC. Also, consider how well insulated your home is. 

Refrigerant Leak

Your portable air conditioner works by circulating refrigerant between the hot and cold components of the portable AC. The role of refrigerant is to carry heat out of your home. 

A leak means that pressure in the refrigerant pipes may fall too low to effectively cool your home. Refrigerant may damage other components if a leak is allowed to persist over tie. 

Compressor malfunction

A faulty compressor may be the cause of your portable AC’s failure. The compressor is responsible for controlling the refrigerant’s density and circulating refrigerant around your portable AC system.

Try to eliminate other possibilities before you assume that your compressor has malfunctioned. The compressor is your portable AC’s most essential component and a broken compressor basically means you have to replace the entire system.