What Metro Vancouver’s air quality advisory means for your building
I woke up this morning with a sore throat and a cold. As someone that suffers from allergies year around, the smoke seems to have irritated my sinuses. Looking outside, I could see that the smoke from wildfires still hasn’t dissipated. What does this mean for your building’s air quality?

What is the current air quality?
Metro Vancouver is continuing an Air Quality Advisory for Metro Vancouver and the Fraser Valley because of high concentrations of fine particulate matter due to smoke from wildfires burning in British Columbia and the western United States. Elevated levels of fine particulate matter are expected to persist until there is a change in fire or weather conditions. Smoke concentrations may vary widely across the region as winds and temperatures change, and as wildfire behaviour changes.

What is the pollutant?
Fine particulate matter, also known as PM2.5, refers to airborne solid or liquid droplets with a diameter of 2.5 micrometres (µm) or less. PM2.5 can easily penetrate indoors because of its small size.

Does my building’s air handling unit filter take out these particles?
Most likely no.  The most common filter type BC Comfort installs has an effectiveness of MERV8.  MERV means Minimum Efficiency Reporting Value which was developed by the American Society of Heating, Refrigeration and Air Conditioner Engineers – ASHRAE. MERV values vary from 1 to 16. The higher the MERV value is the value the more efficient the filter will be in trapping airborne particles.

A MERV8 filter isn’t rated to trap particles <3.0 microns.

What type of filter rating do I need to filter PM2.5 particles?
A MERV13 filter will trap these particles with a 90% or better effectiveness.  However, some smaller air handling units can’t accept MERV13 filters because they do not have sufficient motor horsepower to push air through more effective filters.

What’s the cost?
MERV 13 filters are about triple the cost of MERV8 filters.  However, this is typically just an increase from $5 to $15 per filter.  Of course, there’s also the technician and truck cost for installation.

Why aren’t higher effectiveness filters normally used?
Aside from the increased upfront cost, higher effectiveness filters need to be replaced more frequently and also use more fan energy (i.e. electricity) because they have a higher pressure drop.

Historically, air quality in Metro Vancouver has not required higher grade filters.  Typical MERV8 filters will trap pollen, dust, mold spores, cement dust and other common pollutants.  ASHRAE recommends MERV6 filters.

What should I do?
If you are concerned about the indoor air quality of your building, contact your BC Comfort service advisor.  They can provide you more information including the type of filters currently being used in your building, and whether higher effectiveness filters can be installed in your air handling units.

For more information, please contact BC Comfort.