At this time of year, our attention is drawn to the colder weather ahead and it’s natural to think more about heating and not cooling. But, during fall, it’s natural to think about summer, the vacations taken, and how our homes withstood the hot temperatures. This is especially true when it comes to HVAC systems which are complex and expensive to replace. The air filter is one of the most overlooked components in an HVAC system because it’s simple, inexpensive, and easy to replace with no special skills or tools. In this article, we will explain the purpose of the air filter and six common problems that may affect the HVAC system throughout the year.
What is an Air Filter?
An air filter is widely understood to be a mechanical device that removes contaminants from the air to improve the indoor air quality (IAQ). This is only partially correct, a standard air filter can remove some particulates that degrade IAQ, but that is not the primary purpose. An air filter in the air conditioner or furnace is needed to remove dirt, dust, and other particles that can damage sensitive components in the HVAC system, All the pollutants that you may see on the surface of a dirty air filter can degrade the performance, lifespan and energy efficiency of your HVAC system. Although there are air filters that can significantly improve the IAQ such as High Efficiency Particulate Air (HEPA) these are not compatible with all systems. If you are interested in IAQ improvements, contact your local heating and cooling specialist for expert help and advice.
6 Clogged Air Filter Problems
The HVAC system relies on a steady supply of air to keep the home comfortable and run at optimal efficiency. If the air filter is clogged, here are six problems that you may encounter:
1. Degraded Cooling Capabilities
The AC system doesn’t cool the home; it removes heat, and this indirectly makes the home feel cooler. This may seem like a trivial distinction, but it’s important when you understand how the system works and how it can go wrong. To make the home feel cool, the air conditioning runs air across an evaporator coil which is cold. The blower fan draws in fresh air, and if this is impeded by a clogged air filter, there is less air to make the home cooler. The blower wheel will work harder to compensate, but the cooling will feel uneven and inconsistent, and these can lead to hot and cold spots.
2. A Frozen Evaporator Coil
Insufficient air running over the evaporator coil causes another problem, ice on the surfaces. The refrigerant that circulates through the home to gather the heat for release outdoors cannot warm up sufficiently. This causes the moisture to freeze, which degrades the performance, and the risk of damage is increased. In extreme cases, sheets of ice may even form inside the air handler unit!
3. Burnt Out Motors
The removal of dirty and dusty air from the inside of the HVAC system is essential for smooth operations. If the internal motors are coated with dirt and grime, they are prone to burnout. The air filter can become heavily clogged, and regular changes are essential. If the airflow is degraded, this will change the air pressure, and the dust that’s present in the system will move around, which raises the risk of motor burnout. In extreme cases, a pleated filter may even be sucked into the blower fan, which can lead to an expensive repair bill. If the motors are under this type of pressure, you may notice strange noises and/or a burning odor emanating from the air vents.
4. Poor Indoor Air Quality (IAQ)
Although we’ve shown that the primary purpose of the air filter is the removal of contaminants, there are some IAQ benefits for your home. A look at a clogged air filter will reveal the quantity of dust, dirt, pet dander, and other contaminants that have been removed from the air. But, if the air filter is not cleaned, the dust may slip around the filter due to air pressure, and the IAQ will be lowered. You may even notice that there is more dust in your home, and frequent vacuuming may not solve the problem. As the IAQ degrades, the first people to notice will be those with asthma, allergies, and pre-existing respiratory diseases. Opening a window to bring fresh air into the home will help, but the air filter must be cleaned to make a real difference.
5. Cut Off Power
During normal operations, the AC system should run smoothly with no power surges or outages. If you notice that the air conditioner is turning on abruptly, it’s time to check the electrical panel for a tripped circuit breaker. Why? The additional strain placed on the system by a clogged air filter will cause the blower fan to work harder. In an attempt to compensate for the lack of airflow, the blower fan may cause a power surge.
6. Increased Electrical Bills
We’ve mentioned overworked components a few times during the course of this article. But, when the system has to work harder, it will consume more energy for no appreciable gain. The blower motor works hard under normal operating conditions, and it consumes the most power in the HVAC system. So, it should come as no surprise that this motor will work even harder when the air filter is clogged. This will lead to dramatic rises in energy bills that are easily avoided.
A clogged HVAC air filter can cause a lot of problems in the home that are easily avoided. The owner’s manual for your HVAC system will detail how and when an air filter change should occur. The air filter change frequency may be increased if you have pets in your home because pet hair is a major cause of filter clogging. When you install a fresh air filter, make sure that it’s the correct size; you’ll see the details on the filter rim. If you can’t remember when you changed the air filter, do it now and make a note of the next filter change date.
If you want to schedule a tune-up for your HVAC system, contact your local heating and cooling specialist today.