Air Filter Tips

With the seemingly unlimited options of air filters, it can be quite overwhelming to select the proper air filter for your equipment. Many customers often ask, “How often should I change my air filter?” “Which is the best type of air filter for my unit?” “How do I install it properly?” “What will happen if I forget to change the air filter?” This article will address these aforementioned questions, and help you pick the right filter for your system.

What is the Air Filter’s Purpose?

The air filter’s primary role is to remove particles from the air stream and prevent them from accumulating inside of your equipment. Without the air filter or if its neglected, dirt and debris that is in the air stream will enter your equipment and impact its ability to keep you comfortable. Furthermore, it increases wear and tear on your equipment, and this causes premature breakdowns. Additionally, a fouled filter can cause your utility bills to skyrocket and lead to costly repair bills.

How Do Air Filters Work?

There are various filtering technologies but they all work to strain or trap dirt particles. Filters are rated by the size of particles that they can remove at a certain air flow and pressure drop. Some filters are one time use and disposable while others can be cleaned and reused. Despite the style we like to compare filters to changing the oil in your car — a routine but important task. Changing your air filter is key to having a reliable and efficient heating and cooling system.

How Do I Decide Which Air Filter is Best for Me?

There is a ton of marketing for filters and their capabilities. Many advertise removing certain allergies or other Indoor Air Quality pollutants. Even though these products may provide enhanced filtration, their use may be putting your system in jeopardy. The primary purpose of your filter is to protect the equipment. Often to achieve the elevated filtering capabilities as marketed, many manufacturers will sell larger oversized filters. We will describe larger filters as filter that are 2’’ in diameter and wider. These filters are not necessarily bad, but they are typically installed as an afterthought.

An hvac system is usually designed to an applicable codes and standards, most likely ACCA’s (Air Conditioning Contractors of America) Manual D. Additionally, furnaces usually come with a rating of .5’’ wc. This is the rated air pressure that furnaces or air handlers are tested to operate within. At this nominal pressure, designers have to size duct work and other items in their air distribution system. To fit modern style construction techniques, duct sizes have to be kept to a practical size in order to be accommodated by the construction members (i.e. walls and ceilings).

Oftentimes for larger filters to work correctly, duct work modifications have to be performed to accommodate the excessive pressure drop. If you select a large restricted filter for your equipment, it may exceed the airflow limits of your equipment and cause more harm than good. To illustrate, imagine trying to get water from your garden hose and then switching out the garden hose with a drinking straw. This illustration is not an exaggeration. Large restrictive filters can wreak havoc on your hvac system. Installing a large 4 or 5-inch filter (in many cases) exceeds the air flow pressure ratings on your system. The results of these filters without the proper duct modifications will include increased noise, higher energy bills, equipment short cycling, motor failure, and other costly repair bills.

Air Doctors Heating and Cooling, LLC Recommendations

To comply with most manufacturers and applicable codes and standards, the Air Doctors Heating and Cooling, LLC recommend a 1 ‘’ standard or pleated filter for your traditional HVAC systems. “Bigger is better” does not necessarily fit in this situation. Remember, your system was designed with this type of filter in mind. Any deviation without a duct medication will cause problems for your system. The filter should be changed every 30 days. A good habit is to set a reminder on your phone to remind you. Some thermostat models may also send a message or have a filter change button to help the end user remember.

Avoid using dirt loading or the changing of color as the basis to change the filter. Filters work on pressure drop, so waiting until the filter gets dirty does not benefit the system or save you money. If fact, it does the opposite and also increases noise energy bills, promotes equipment short cycling, and motor failure, and increases costly repair bills.

To install your air filter, first take a look at your equipment. There are few different arrangements for most hvac systems. Typically, there is a whole or an opening located near your equipment. This opening is generally rectangular in size, or you may have a box or enclosure located near your furnace. Your filter gets installed in this location. If the opening is a standard one-inch opening, you can install the filter by inserting it into the opening with the arrow facing towards the equipment. The arrow represents the downstream side of the filter. If you have a larger filter and a filter encloser, some will allow a standard one-inch filter. Some enclosures will not be able to accommodate the smaller filter and the encloser will have to be modified by a professional HVACR contractor. If your filters are reusable, then they can simply be washed in a utility tub, dried, and reinstalled.

Need a filter? Check out our online store. You can order a filter; have it delivered; and even have it installed! Visit our online store for more information.

Air Doctors Heating and Cooling, LLC are a fully licensed and insured heating and air conditioning company that serves most Southeast Michigan municipalities. Our staff is fully certified and pre-screened to provide our customers with a safe and satisfying experience. With over 100 years of combined industry experience, we take pride in solving all of your comfort needs. We are a family-based business that has been providing quality service to our neighbors for over 40 years. Contact us today to get started.