Every air conditioner requires a filter with a particular Minimum Efficiency Reporting Value (MERV) rating. Knowing that the highest rating is 16, some people buy the highest-rated filter.
The most immediate impact of not using a filter in your AC is a decline in air quality. Without a filter, contaminants like dust, dander, pollen, and other particles that would normally be trapped are now free to circulate in your home.
If you can't find an air filter near your HVAC unit, then you may have to look in your return vent. Because HVAC units are often set up in a more difficult to access area, the filters are sometimes placed here for better accessibility.
Changing the filters in a return vent
The air filter is typically located at the point where the return duct enters the air handler. Larger houses often have more than one HVAC system. Each system will typically have at least one air filter.
If your home has a forced air heating or cooling system, then it has at least one air filter. This filter's job is to remove airborne particles and debris from the air inside of your home. By regularly replacing your air filters, you can enjoy a healthier, more comfortable indoor environment for your entire family.
Running your AC for any time without an air filter is not recommended due to the permanent damage it can cause to the HVAC system. Dirt and dust that is normally absorbed by the filter can make its way into the AC system and wreak havoc on the mechanical components, often leading to expensive repairs.
If you have a basement, the air handler is likely there. Otherwise, it may be in your attic, a utility room (or closet), crawl space, or in your attached garage. Air filter locations vary by HVAC system, equipment locations, and duct configuration.
Motor and Compressor Malfunctions
Your filter should be stopping dirt, pet hair, and other particulates from ever reaching these parts of your system. When your filter fails to do this or isn't in place, the motor and compressor get dirty and eventually fail to work properly.
Most HVAC systems come with furnace filters, so many homeowners are well-acquainted with them. Because return air filters are less common, it may be useful to review the differences between the two types.
What Problems Can Arise from Running My AC Without a Filter? As mentioned previously, running your air conditioner without a filter can lead to severe problems. It could lead to decreased comfort and permanent damage to your HVAC system, which may result in hefty repair bills.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
At the very least, your commercial air filters should be changed at least once every three or four months. If your commercial HVAC system is in a factory, restaurant, auto body shop, or other building with heavy machinery and a lot of dust or debris, it should be changed more frequently.
How Often Do I Need to Change Out My Air Filter? Generally, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days, or 3 months. That can change based on where your home is located (ex. dusty, dry climates), if you have any pets, and the age of your system and equipment.
A clogged air filter can cause more harm than good. During the day, your AC should cycle on and off, but a dirty air filter can make those cycles more frequent than they should be. Cycling is not only noisy, but it also wastes energy.
The dust and debris getting into the air conditioner will affect the condensate drainage system that removes the moisture from the system. The drain in the condensate pan will become clogged, leading to build-up of water that will leak from the AC and promote mold and mildew growth inside the system.
However, we strongly recommend you don't run your furnace without a filter for any length of time. With air constantly moving through your furnace and your home, dust and debris can quickly build up, even in a matter of minutes. When this level of buildup happens, your furnace can malfunction.
While air recirculation mode is activated, air filtration activities continue as normal. Instead of filtering fresh intake air, the system filters the recirculated air in the same manner. However, it's important to note, that when the system is activated there is less fresh air being drawn into the car.
Most people assume just one, but now you're probably asking yourself, “Does my HVAC have two air filters?” If so, we have the answer for you! Every HVAC system has at least one air filter. These can be made of various types of materials, though they serve the same purpose.
Tip: If you're looking to replace your outside AC unit filter, the filter location varies depending on the unit. However, it can usually be found along the air conditioner return duct.
It may be difficult to locate on some HVAC systems, but you can usually find the air filter in the return air duct. Or, in layman's terms, that big metal grate on your wall, floor, ceiling, or utility closet door. Return air ducts can be just about anywhere.
If you've ever asked the question "how do I find my air conditioner filter," you've come to the right place. Typically, AC filters will either be located in return ducts or inside the air handler in your attic or basement.
Most homes across the U.S. have forced air systems and in newer homes there will be cold air return vents placed at both the ceiling and the floor of many rooms. Having two air return vents allows you to seasonally control which air is returning to the HVAC system. In older homes, this may not be an option.