When Should I Change My Air Conditioner's Air Filter at Home?

February 26, 2015

Sometimes we’re asked what is the most important thing that London area homeowner's can do to ensure efficient functionality of their air conditioning and heating system between their seasonal tune-ups? It's a simple question with a simple answer; remember to change the heating and air conditioning air filter. Replacing furnace and return air filters is extremely important to the proper performance of your HVAC system, not to mention your home's air quality. Research suggests that indoor air pollution is one of the top five environmental health risks? You probably don’t consider it as you sit and watch TV, but this is the air you breathe day and night. Changing the air filters is not a tough thing to do for most London homeowners, but there are usually two obstacles to actually completing this job:

  1. Knowing just how often to replace your furnace or air conditioner filter.
  2. Changing them when you’re suppose to.

When To Change Your Air Filters

Most filters have a recommended guideline on the box or plastic. It may instruct "Lasts up to 3 months" or "Change filter every 90 days". Look around at the store and you should see that some are meant to only last one month, while other manufacturers (like Honeywell) have released media air cleaners with filters meant to be exchanged once every 6-12 months. The standard seems to be once every few months for most higher quality filters, but we have a rule of thumb that we tell our customers to go by. If it's dirty, change it! A dirty air filter can exacerbate or cause damage to pricey components, like your compressor, so it's best to change it out more often than neglect it. If you want to listen to the manufacturer's recommended limit, we suggest scribbling the date on the filter when you swap it out, and adding a reminder for yourself in your phone or on a calendar. Also be aware that your filter manufacturer may have a different recommendation from your HVAC unit manufacturer.

Choosing how often to change your air filters hinges on several factors:

  • Which air filter your system requires
  • The entire air quality of your London area home
  • Pets – Dogs, cats, etc.
  • Occupancy of the home
  • How much construction is taking place in the neighborhood around your home

For your standard 1"-3" air filters, the OEM specs basically tell you to change them bi-monthly, which is really a great rule of thumb. Still, generalities may not be suitable for your specific needs. If you have to endure light to moderate allergies, you might require an upgraded air filter or change them even more often than OEM specifications. On the other hand, if you're in a less populated area, own a less occupied home (like a vacation home) or an area with few automobiles and trucks, changing your air filter every 12-months may be quite sufficient. Why should you factor in your pets? They have a tendency to shed, which can clog your air filter in no time, just like a vacuum. Of course, the air filter is just doing its job by containing pet hair and dander, but tremendously dirty filters can cause diminished HVAC performance.

In summary:

  • Seldom used home or single occupant homes without pets or allergies: Change 6-12 months
  • Common suburban home without pets: Change every 90 days
  • Got a cat or dog: Change every 60 days
  • Several pets or have allergies: Change every 30-45 days

How To Remember To Change Your Air Conditioner's Air Filters

It's simple; sign up for the Service Experts Email Club. This is a convenient way to get money-saving discounts and other helpful information on your smartphone, tablet or desktop. Plus, your email subscription preferences let’s you set a reminder to change your London area home's air filter every 30, 60, 90, 120 or 365 days, or a specific date of your choice.

How to replace your return air filter

Most of us know how to replace the air filter in their system, but some homes have another filter in the return ductwork. Whether you have one or not is dependent on what your unit's manufacturer recommends. Your unit is made to handle a set amount of pressure in your home sweet home, and the more filters you have the harder the blower motor works, which can reduce the lifespan of your system if it isn't designed for it. Learning whether you have a return filter and replacing it is a piece of cake:

  1. Go to your return air vents.
  2. Some covers have screws and some have tabs. Unscrew or pull tabs to take off the wall.
  3. Check for a filter. If one is inside, pull it out and write down the size.
  4. Verify the filter type is the one recommended by the manufacturer.
  5. If filter is dirty, replace with the manufacturer's recommended filter of the same size and type.
Amazing as it may seem, filters can really affect your home's airflow, which is why we recommend checking in with the manufacturer. A more expensive HEPA filter that is designed to catch tinier dust will restrict airflow more than a cheaper filter. With restricted airflow comes more pressure on your system, so you should verify that your HVAC system was engineered to handle it. Otherwise, you might experience uneven heating and cooling efficiency in your home, and system parts may die off much faster than otherwise.