How Often Should I Replace My Air Filter?

Air filters are a critical piece of equipment used to protect your HVAC system, keep it running smoothly, and help with clean airflow in your home. Because it is out of sight, many homeowners neglect to replace their air filters (commonly called furnace filters) in a timely manner.

If your system is using a filter well past its prime it can cause your heating and cooling equipment to work harder than necessary. A furnace filter that has dust and dirt preventing the flow of air will cause your system to overexert itself in its efforts to achieve your set temperature. This straining of your system to produce an appropriate air temperature can cause three problems.

Problem #1

It lowers the efficiency of your system as it works harder to overcompensate and in turn increases your utility bill.

Problem #2

It could cause greater damage to your system (freezing coils, liquid slugging of your air compressor, or heat pump).

Problem #3

It reduces the clean output of air throughout your home. With the humidity levels we all experience in Hampton Roads, an unchanged air filter can be a breeding ground for bacteria and mold.

The replacement timeline for your filter depends on a couple of factors.

Factors that Impact Air Filter Replacement

What type of filter are you using?

The low-cost fiberglass filters should be changed every 30 days. The pleated air filters are a bit more expensive but can last up to 6 months. A good rule of thumb is to replace pleated filters every 90 days. If you have electrostatic or washable filters, they should be washed, dried, and re-installed once a month. The washable filters are more eco-friendly and, if cleaned and reused appropriately, can last 5 to 10 years.

Who is in the home?

If there are allergy or asthma sufferers in your home then filters should be replaced more frequently – a minimum of every 6 weeks.

If you have shedding pets such as cats or dogs in your home then filters should be replaced more frequently – a minimum of every 2 months. When the seasons change cats and dogs are more likely to have greater shedding. When winter turns to spring and when summer turns to fall are two key periods to change your filter if you have a shedding pet in the home.

Is it time yet?

Remembering to actually change your filter is one of the biggest hurdles. You can always add it to your calendar, just like all the other appointments in your life. A great trick is to write the date on the border of your filter when it is installed so that you will know at a glance how long it has been in use. If you do not have a clue as to the last time your air filter was changed, give it a quick eye test. If you see a subtle layer of dirt on the filter and the filter’s material is somewhat visible beneath then it is still fine. When it goes past that point – the layer of dust or dirt coating is covering most of your filter’s surface and the filter material is obscured, then it is time for a replacement.

Call The Experts

Consider enrolling in Smith & Keene’s Signature Service Plan to help keep an eye on the efficiency of your home’s heating and cooling equipment. And if you suspect it’s time to replace or repair your HVAC system, give us a call.