Your forced air furnace filter plays an important role in maintaining the air quality in your home. Checking and replacing the furnace air filter is one of those chores most people know they're supposed to do, but few remember.
Usually when we do home inspections in the Ottawa area, there is a clean furnace air filter in the furnace and a very dirty one sitting next to the furnace. Hmmm ...
How often do furnace air filters need to be changed?
Depending on the quality of the filter, number of people, pets and amount of dust it could be monthly or every three months (for an average home). The general rule is "If it looks dirty, it is dirty."
Another way to determine when your furnace filter needs replacing is you could install an air filter gauge (General G-99 Air Filter Gauge Kit.). The G-99 Air Filter Gage provides a visual indication of the need to replace the air filters in forced air heating and cooling systems. The gage is installed between the furnace blower and the filter where a slight vacuum exists due to the air flow resistance of the air filter.
Why should you change the furnace air filter?
A dirty filter restricts airflow through your heating system. Reduced airflow can mean uneven heating or cooling, increased fuel bills, and possibly premature failure of your furnace due to the added stress of pulling air through the dirty filter.
How to change the furnace air filter?
CAUTION: First locate the power shutoff for the furnace and turn it off before you begin.
STEP #1 - Turn the furnace power off. Usually the switch is well marked in the stairway to the basement or near the furnace. (The Emergency Shut-off tags in the photo below are provided with every ib42 Ottawa Home Inspection)
|Furnace (emergency) shut off switch
STEP #4 - Replace it as needed, but at least every three months. The rate at which they get dirty depends on the number of people, pets and amount of dust in your home.
STEP #5 - Turn the furnace power back on.
- Mark airflow direction on the duct work with a marker so that it will be easier to remember the orientation of the filter the next time.
- Mark the date on the side of the filter as a reminder of the last change.
|Furnace air flow, note arrow on filter is the same direction
|Furnace air flow, note date on filter
Furnace Filters Information and References
Some useful information about furnace filters from the EPA.
Furnace filters are rated by Minimum efficiency reporting value (MERV) and here is a chart
How to choose the right furnace filter
YouTube Video (Note: Make sure to turn the furnace power off first and then back on after!)
GOVERNMENT OF CANADA PUBLICATIONS
http://www.statcan.gc.ca/pub/16-002-x/16-002-x2012001-eng.pdf (stat on furnace changes)
CITY OF TORONTO
Indoor Air Fact sheet
AMERICAN LUNG ASSOCIATION
“Air Cleaning Devices”
ASSOCIATION OF HOME APPLIANCE MANUFACTURERS
A website on portable air filters and the ANSI / AHAM AC-1 Clean Air Delivery Rate (CADR) approach.
CALIFORNIA AIR RESOURCES BOARD
“Air Cleaner Devices for the Home: Frequently Asked Questions” An overview of considerations when purchasing a filter.
CANADA MORTGAGE AND HOUSING CORPORATION (CMHC)
“Your Furnace Filter”
Objective information on the performance of specific models, as well as general advice.
FOR INFORMATION ON ASTHMA CONTROL
www.asthma.ca and www.cmhc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_005.cfm
“Warning - Health Canada warns the public about air cleaners designed to intentionally generate ozone” This publication includes a list of affected ozone generator brands and models.
Healthy Indoors Partnership (HIP) will prepare a separate consumers’ guide to finding and buying low-emission products and services. In the meantime, we suggest the following helpful sites:
www.oikos.com and www.cmhc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_006.cfm
NATIONAL AIR FILTRATION ASSOCIATION
Provides technical guides to MERV ratings and air filtration.
Inspected by 42 Home Inspections - Kanata and Ottawa surrounding area