Can I Run My AC Without a Filter?

Smiling Four Seasons HVAC technician replacing an air filter

What happens if you run your AC without a filter?

Can I run my AC without a filter? We hear this question from customers, and the answer is yes and no. While running your AC without a filter for a few hours is okay, much longer could potentially damage your AC system.

We understand that life happens. You can’t always rush to the store to get a new filter. It may seem like running your system with a dirty filter is worse than running it without one for a day or two, but that’s not necessarily true.

If you’re routinely changing your filters every 1-3 months, a day or two past the change date won’t harm your system. On the other hand, running your system for months with no filter could cause the following to occur:

  • Decreased air quality
  • Frozen evaporator coils
  • Increased energy bills
  • Damaged compressor
  • Poor indoor cooling comfort

Let’s look at each of these issues in a bit more depth to understand the importance of using an AC filter.


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Decreased Air Quality

Without an air filter, pollutants can enter your home.

Your air filter is the frontline defense against pollen, dust, mold spores, pet dander, VOCs, and other pollutants entering your home. The filter traps these particles as the AC pushes conditioned air throughout your home. Changing the air filter removes toxins that could have impacted your health and home comfort.

So, when you operate your AC without a filter, those particles can enter your home, decrease your home comfort, and aggravate health conditions like asthma and allergies.

Frozen Evaporator Coils

Your evaporator coil can freeze over without an air filter.

Your filter does more than protect the air you breathe. It also protects one of the most important components of your AC system: the evaporator coil.

The filter removes dust and other small particles that would otherwise cake the evaporator coil. When blocked by dust and grime, the evaporator coil cannot do its job and absorb heat from your indoor air. Because the coil is full of a cold chemical agent, it freezes over if a thick layer of dirt prevents warm air from touching it.

A frozen evaporator coil leaves you needing emergency AC repairs because your AC system will not be able to function. Replacing your filter is always more affordable than repairing an evaporator coil.

Increased Energy Bills

You may pay more in utility bills if you run your AC without a filter.

Energy efficiency is important to consider when it comes to system maintenance. Greater efficiency means reduced consumption of energy. Reduced energy consumption means lower electric bills.

The same logic applies in reverse. A less efficient air conditioner requires much more energy and quickly increases your bills. That’s what happens when you remove the filter from your AC unit. Your system must work harder to remove warm air from your home and push out cooled air. A system working harder also means more wear and tear, leading to a potential replacement.

Next up, we’ll look at some of the damage you can do to integral parts of your AC when running it without a filter long-term.

Damaged Compressor

Your compressor could get damaged when you run your AC without a filter.

If you continue running your AC without a filter, you can also damage other system components. Your AC’s parts lean on one another for support and assistance to do their jobs. When you compromise one part, the entire system suffers.

The compressor is one of the most important components of an AC system. It pumps refrigerant through the system, allowing it to absorb heat from your indoor air and transport it outdoors. Without a functional compressor and evaporator coil, your AC will not run.

Do you remember what happens to your coil when running an AC without a filter? It freezes over, reducing its effectiveness and indirectly impacting the compressor. The longer the coil stays frozen, the more damage you do to the compressor.

Eventually, you will need to replace the compressor to restore your system to proper working order. That’s one of the more expensive AC repairs in Portland, and it may mean going without AC for a short time while our NATE-certified technicians make those repairs.

Poor Indoor Cooling Comfort

You may notice a decrease in home comfort when running your AC without a filter.

The first sign of trouble you may encounter when running your AC without a filter is the air from your vents is less cold than expected. Perhaps it starts coming out in short bursts instead of a continuous flow. Your home starts to warm up as your system struggles to produce enough cool air to meet the temperature set on your thermostat.

Many problems can occur when you run your AC without a filter for too long. A frozen coil and struggling compressor will inhibit your system’s ability to cool your home properly. As indoor comfort starts to deteriorate, it’s time to put a filter into your AC system. When replaced in time, your system will correct itself and resume normal operations.

If you run the system without a filter for too long, you will probably need to call Four Seasons for a prompt AC repair in Portland. A frozen coil and compromised compressor are problems only a well-trained HVAC technician can fix.


Need Assistance with Your AC Filter? Call Four Seasons for Reliable AC Repair in Portland

Contact Four Seasons for an AC tune-up and efficient air filter replacement.

During an AC tune-up, our friendly and knowledgeable technicians can help you upgrade your filter to maximize your home’s air quality. We also provide professional central AC repairs and installations with fair, upfront pricing and convenient scheduling options.

Call Four Seasons today at 503-538-1950 or click below to experience 5-star cooling service!

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