Installed in the return grid of your home, air filters pre-filter dust and other particles to keep the ducts clean and extend the life of the HVAC unit's main filter. If you have a standard size return grille, you can accommodate a regular rectangular shaped air cleaner. It is recommended to have an air filter on each return grille, as long as you choose the right size and thickness. Filters will improve the air quality in your home and protect your HVAC equipment from dust, pollen, pet dander, and hair.
The return air outlet leading to the boiler or air controller for a heat pump or air conditioner must have an air filter. If your system has a large return air vent designed for a filter, you must keep a filter in it at all times, and replace it when it becomes dirty enough to prevent airflow. To ensure proper airflow, it is important to have a suitable filter on the return side of your air conditioning system. By attaching a high-quality, well-fitting filter to the return vent, you will remove particles from the air before they can enter the air conditioning system.
A good filter will keep the air handling unit, coils, and ducts clean. If the filter doesn't fit properly, it can be as bad as not having a filter. A good central air conditioning system has return ventilation in each room to precisely control the temperature of each room and maintain the same air pressure in each room. To get the right type of filters for your system, consult an HVAC expert or the manual that came with your heating and cooling system.
If you have the same problem, remember to place filters in EACH return vent to prevent dust from entering the AC coil. Air filters with a MERV rating of 13 to 16 are high-efficiency air filters that are not suitable for some standard heat pumps. However, you can buy a collapsible filter where the large one-piece filter is divided into 3-4 pieces and hinged together. The bottom line is that the air returning to your oven or air handler must have an air filter to clean the air before it causes dirt-related problems in your HVAC system.
A fiberglass filter is the cheapest option, pleated filters better trap particles in the air, while HEPA filters are capable of filtering 99.97% of all particles. In general, return air ducts are installed under stairs, in hallways, or in any large, open area of your home. Some people want to filter more dust and are thinking about putting filters in the AC return grilles. However, if you choose a filter with too high of a MERV rating, it could restrict airflow and cause long-term damage to your heat pump.
To ensure proper airflow and protect your HVAC equipment from dust and other particles, make sure to install an appropriate filter on each return grille in your home.