It’s likely one of your biggest fears as a homeowner — you get home from a long day at work, open the door... and walk into what feels like a sauna. Your gut instinct may be to crank your AC up to get things cool and comfortable. However, the problem may not be the temperature setting — instead, it could be your cooling system itself.

It’s not uncommon for air conditioners to underperform, especially when the heat of summer is at its worst. Fortunately, there are many things the average homeowner can do to prevent the cooling system from not running as efficiently as possible.

Cause #1: Air conditioner is leaking refrigerant.

The refrigerant in your cooling system is responsible for absorbing heat and, simultaneously providing cool air as it cycles through the compressor and evaporator inside of the unit. If your air conditioner has a low refrigerant charge, then it won’t be able to effectively cool your family’s home. This loss in refrigerant is often due to the AC not being maintained properly, or it may have reached the end of its usable life.

If you’ve noticed moisture around the base of your condenser (the outdoor part of your AC), it could be an indication that you have a refrigerant leak.

If you suspect this is the problem with your air conditioner, give a professional cooling technician a call. Refrigerant issues are best handled by experts since trying to fix this type of problem on your own could be dangerous. Exposure to refrigerant could cause lung problems, or irritation to your eyes, esophagus and stomach.

Cause #2: Your air filter is dirty.

Many homeowners don’t realize that they need to replace their filter in the spring and summer as well as during the fall and winter. Often, the air filter is installed as part of a home’s heating system, so many people mistakenly believe that they only need to swap the filter out during the colder months of the year.

However, the same motor that blows hot air in the winter is what circulates cold air in the summer. You need to replace the air filter at least once a month, perhaps more often if you have smokers or pets in your home. The filter is responsible for catching airborne materials, such as dirt, dust, pet hair, dander, mold spores and so on. All air passing through your home’s vents first passes through this filter. If the filter is clogged with dust, air can’t easily pass through. This can cause extra strain on your cooling system and may lead to premature wear and tear on its internal components.

Additionally, a dirty filter could jeopardize your home’s indoor air quality. This could cause serious health problems for anyone in your family who may suffer from respiratory issues or allergies.

Cause #3: Your AC isn’t properly maintained.

Cooling technicians recommend having your air conditioner inspected and cleaned by a professional every year. Unfortunately, many homeowners neglect to schedule an appointment for their air conditioner if it seems to be running fine. Many underlying AC problems can be caught by a trained technician and dealt with before they lead to an untimely breakdown of the unit.

Routine tune-ups are also important since the technician inspecting the unit will make sure that everything is working as efficiently as possible to keep your home cool. The technician will clean all working components so there isn’t a build-up of dirt and dust inside the unit. He or she will also check to be sure that the unit is operating safely.

Cause #4: Your ducts are dirty.

Schedule a duct cleaning appointment for your home every few years. During the appointment, a professional will thoroughly clean your ducts to be sure they aren’t blocked or clogged with dirt and dust. Dirty air ducts restrict air flow from your AC to the rest of your home, and when this happens, your unit has to work overtime to try and keep up with the temperature you’ve set.

Additionally, the duct expert will make sure that you don’t have any holes or cracks that could cause conditioned air from your AC to leak out and not make it through the vents in your family’s home to help keep your living space cool and comfortable.

Cause #5: Your AC isn’t the right size for your home.

If you have an air conditioner that’s too small for your home’s cooling needs, it’ll run nearly constantly to try and keep things comfortable. And on the other hand, if your air conditioner is too large for your family’s needs, it may suffer from a problem known as “short-cycling,” where the system cycles on and off excessively throughout the day. This doesn’t just cause problems for the system and lead to premature wear and tear, but it could also be costing you a fortune on your monthly energy bills.

If you suspect this is the problem in your home, contact a cooling professional. He or she will be able to determine if your unit is the proper size for your home’s needs. Also, if you’re considering AC replacement, work with an expert to be sure you have the right-sized air conditioner installed.