Furnace Filters


A simple part of this large component of your home is critical, yet largely forgotten because for most homeowners it is one of those “out of sight, out of mind” types of home maintenance.

What is a furnace filter?
When you run your heat and air conditioning, the air passes through your filter which is designed to trap debris and dirt from contaminating your furnace and circulating into your ductwork and home. Filters come in different sizes, filtration levels, and can be installed in more than one location.

What happens when if I don’t replace the filter?
When the filter becomes too dirty:

  • Poor air quality. Dirt and debris will bypass a dirty/blocked filter and circulate through your system into the home and your family will be breathing that dirty air. This dirty air can aggravate those with respiratory issues such as asthma.
  • Comfort. The amount of air volume to your home is restricted, resulting in reduced comfort (heat and cool air).
  • Higher energy bills. The air handler has to work harder to push air through the dirty filter which increases your monthly heating and cooling bills.
  • System breakdowns. Increases the chances of overheating and/or other breakdown because the system is working harder.
  • Dirty components. Dirt and debris can, and will, bypass a dirty/blocked filter and cause dirt buildup on the interior components of your system such as coils, burners, control panels, etc. This buildup can result in your system malfunctioning and/or being damaged and/or shutting down.
  • Cracked heat exchanger. When the furnace does not receive enough air due to a dirty/blocked filter, the extra strain on the system can cause the heat exchanger to overheat and even crack. This is not a cheap repair.

How often should I replace my filter?
The answer varies based on the size of the home, number of people who live in the home, number of pets, how often the system is run, carpet vs hardwood, etc.

We recommend:

  1. Install a new filter with the date written on the visible edge.
  2. Check the filter every 30 days and replace as needed.

What kind of filter should I get?
Our discussions with HVAC technicians is that the filters with very high MERV ratings do capture more dirt and debris, but also get dirty faster. This means you will need to change your filter more often.

The general industry standard is that – MERV 5 – 8 is good, and 9 – 12 is better.

This simple home maintenance is often overlooked and can cause hundreds – even thousands – of dollars of damage.

We also recommend an annual preventive maintenance of your system by a qualified and licensed HVAC technician.

Can’t do it yourself?
Contact our trusted vendor under “HVAC”