Can an Air Filter be Too Thick?

Learn what happens when an air filter is too thick for your HVAC system and how you can avoid costly problems by using the right size.

Can an Air Filter be Too Thick?

When it comes to air filters, it's important to get the right one for your system. If the filter is too thick, it can get dirty quickly and make your air conditioning unit work harder than necessary. On the other hand, if the filter is too thin, it won't be able to capture enough particles and debris. The general best practice is to use the thickest possible air filter to achieve maximum efficiency.

The thickness of the air filter depends on the configurations of your system. A good benchmark to follow when considering MERV ratings is that if they are more than 13, the pleats will most likely be too thick for the filter. But never try to force an air filter to fit in a space it's not designed for. If the filter is too dense, the heater or air conditioner may have to run longer to counteract increased air resistance.

A filter that is too small allows contaminants to accumulate on critical components, which impairs performance. The right filter will improve your health and comfort without causing utility bills to rise. MERV 11 to 13 are high-efficiency filters that come in a variety of configurations. These filters can remove particles as small as 0.3 microns and other debris such as microorganisms and bacteria. Most air filters are 1 inch thick, but some systems can accommodate filters 2 to 5 inches thick.

In our tests, we found that the thicker the filter, the better it works and the longer the replacement intervals. For example, a 13 MERV filter has a thickness of 1 inch. The 4-inch thick air filter has a definite advantage over the filter 1 in terms of longevity, airflow and maximum filtering potential. If you put several 1-inch filters together, it's similar to putting 5 coffee filters together and trying to brew a cup of coffee, it just doesn't work. Poorly fitting one-inch filters where air passes around the frame (even causing the frame to bend and deform) is very common.

If you try to use a 4-inch thick air filter for a system that is made for a 1-inch thick filter, the efficiency will actually be worse. A clean, well-adjusted filter avoids a number of costly problems and will keep your oven running at its optimum capacity. Deeper pleated filters allow dirt to spread over a larger surface area, reducing pressure drop and allowing filter replacement less frequently without significantly affecting system performance. If you want a powerful MERV air filter that can improve your health and comfort without causing utility bills to rise, look for a home air filtration solution that can meet your needs. Some of these steps include keeping a house clean and ventilated to reduce dust and pollen that will pass through the filter. When too dense a filter is used in an HVAC system that doesn't require that degree of resistance, it can restrict necessary airflow and make your oven work harder. Filters that reduce airflow force components such as the fan, motor and electrical components to work overtime. If a filter looks dirty with accumulated dust, it is far beyond the point of a profitable exchange.

Leaving the air filter in the ducts too long can cause dust and particles to accumulate and overload the filter. In conclusion, getting an air filter with pleats that are too thick can make your air conditioning unit work harder than necessary and increase heating and cooling costs. It's important to use the right size of air filter for your system in order to achieve maximum efficiency and avoid costly problems.