Top 5 HVAC Problems Caused by a Dirty Air Filter: 2023 Homeowners Guide

Top 5 HVAC Problems Caused by a Dirty Air Filter

It’s a simple problem to fix, but it causes the most common issues with all types of air conditioning, not just those with central air conditioning. 

Your heating and cooling system is an expensive and fundamental part of keeping your home comfortable.

Still, many homeowners fail to maintain their HVAC system adequately (the same applies to heat pumps).

The air filter is your first line of defense in maintaining an effective and efficient HVAC system that keeps you and your family comfortable and healthy.

But what happens when dirty air filters start to cause problems? 

Keep reading to learn more about the top 5 dirty air filter symptoms and how they can quickly damage your HVAC system, health and back pocket. 

❌ No.1 – Higher Energy Bills

a man burning money on his energy bill

Your HVAC system works by circulating conditioned air around your home.

So the performance of your blower fan can significantly impact your home’s energy consumption.

The harder your fan has to work to move air in and out of your ductwork, the higher your utility bills will be. According to the Dept of Energy, clogged air filters can contribute up to 15% more energy usage

These inefficiencies caused by a clogged air filter increase exponentially until you replace a bad air filter with a new one.

❌ No. 2 – Frozen Evaporator Coils

frozen evaporator coil

The cooling process works by soaking up heat from the air that flows across the evaporator coil.

Your cooling system then takes that heat and transfers it outside to the condenser, where it dumps that heat into the surrounding air.

If your evaporator coil does not have adequate airflow, it cannot remove heat as designed.

This will cause the temperature on the coil to drop below freezing.

Ice will start to form from the moisture in the air and accumulate on your coil.

Dust and dirt also have the unfortunate side effect of finding their way to a damp evaporator coil will exponentially cause a build-up of moisture leading to a frozen coil. 

Also, the dust and dirt that has accumulated on an evaporator coil will exponentially cause a frozen coil as the moisture makes it easier for contaminants to stick to the coil. 

This can be a serious and expensive issue if not treated correctly.

If you suspect you have frozen cooling coils, then check out this guide:

❌ No. 3 – Reduced Airflow

HVAC blower motor

As mentioned above, dirty air filters force blower fans to work harder to keep the air flowing through your home and HVAC system.

If your air filter becomes clogged with dirt, dust, debris, pet dander etc., it can be increasingly difficult for your fan to achieve the desired temperature during the summer cooling season.

This can also lead to hot and cold spots in your home due to reduced airflow.

It could also cause your AC blower motor to fail, which is an expensive fix versus regularly replacing a 10-dollar air filter.

Just saying…

❌ No. 4 – Lower Indoor Air Quality

girl sneezing doe to poor indoor air quality

A dirty air filter can significantly contribute to contaminated air in your home.

This is particularly dangerous for people with chronic allergies, asthma or other respiratory conditions.

A clogged air filter not only lowers the airflow and reduces the amount of air being filtered, but it can also cause many contaminants to be recirculated back into your ductwork and your home.

This can lead to mold, mildew and bacteria growing in your HVAC system. 

This is especially true if you have pets that shed or you live in a dry, dusty area.

If you want to know more about air filters and their effect on your home’s indoor air quality, check out the air filter guide below. 

⭐ PRO TIP: Not all filters are created equal. It’s possible to buy the wrong one for your system and cause even bigger problems, so be sure to read our air filter guide. 

❌ No. 5 – HVAC System Failure

Heat Pump Installation

All of the problems listed above, if not treated, can lead to the most expensive pain of them all, the total failure of your heating and cooling system.

Any one of the above problems can lead to a catastrophic failure.

For example, damaged evaporator coils can cost more than half the amount of a replacement air conditioning system.

If your AC is already close to its use-by date, it may be better and cheaper to replace the entire system in the long run. 

Spending 10 – 20 dollars every few months sounds like a good trade-off.

As HVAC technicians, we see many expensive replacements that could have been avoided with proper attention and your air filter is the first step in the process.

⭐ Thoughts on Dirty Air Filter Symptoms

Woman holding pleated air filter

Air filter replacements are a cheap and easy way to avoid all the above points.

Your heating and cooling system is an efficient piece of equipment designed to keep you either cool in summer or warm in winter. If the whole system cannot work as designed, you will have problems. 

We are advocates of a good maintenance schedule to ensure your system is always ready to work, even on the most extreme days.

Given your investment in your HVAC system, it makes sense to ensure you check your air filter every month and replace it every one to three months, depending on your circumstances.

All of this can be done with a simple visual inspection of your filter each month.

So don’t wait until a clogged air filter ruins your day when you need your HVAC system the most. Instead, replace that dirty air filter regularly. 

⭐ Finally!

Phyxter Approved Logo on Service Truck

To learn more about air filters and how to improve dirty air in your home, check out our handy guide on air filters and how to pick the right one for your home: 

If you live in the North or Central Okanagan area, call Phyxter Home Services.

We are experienced heating and cooling experts and pride ourselves on providing the best customer service to our local communities. 

So don’t wait until clogged air filters cause more significant, expensive issues; change that air filter today!

Dealing with other common HVAC problems?

Check out: Top 18 Common AC Problems and Solutions and Homeowners Guide to Furnace Repair: 16 Most Common Problems & Solutions

Russell Jones

Russell, a native Australian and VP of Operations at Phyxter Home Services, is also part-owner of Vernon Air Conditioning, Plumbing, and Electrical Services. When he's not busy with work projects and renovations, Russell enjoys putting his vast knowledge of home improvement to good use by sharing his tips and tricks.

About our blog

Phyxter (pronounced Fix-ter) is a national home services brand specializing in Residential HVAC, Electrical and Plumbing solutions.

Phyxter is laser-focused on writing the best articles and guides to empower homeowners to get the best out of their homes.

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