The filter
What is ZenGUARD™?
A standard MERV 9A pleated furnace filter with a patented, graphene-based ZenGUARD™ coating, developed by Zentek in Guelph, Ontario. It fits the furnace you already have.
Is it HEPA?
No. ZenGUARD™ enhances the filtration you already have. It isn’t HEPA, and it doesn’t claim HEPA-level filtration.
What does the coating do?
In independent lab testing with the MS2 bacteriophage surrogate, the coated filter removed 42% of infectious aerosols, against 16% for the same filter untreated. Every figure we publish names how it was measured.
Does it restrict airflow?
National Research Council of Canada testing showed no measurable impact to airflow. ZenGUARD™ filters have not been tested in homes.
How is it tested?
It meets ASHRAE Standard 52.2, is validated by the National Research Council of Canada, and is covered in three peer-reviewed ASHRAE publications.
Sizing and fit
How do I find my size?
It’s printed on the frame of the filter you have now: width × height × depth, in inches. Order by that size.
Why is my filter smaller than the label says?
Filters are sold by nominal size. A 20 × 25 × 1 measures about 19½ × 24½ × ¾ in, so it slides into the slot.
Will it fit my furnace?
If your furnace takes a standard 1, 2 or 4 inch filter, yes. Fit depends on the size, not the furnace brand.
What if my size isn’t listed?
We make custom sizes to order. Contact us with the size printed on your frame.
Changing it
How often do I change it?
Every 90 days for most homes. Every 60 days with pets or allergies, and every 30 days for smoke, smog or respiratory concerns.
Which way does it go in?
Point the airflow arrow on the frame toward the furnace. Air flows from the return duct, through the filter, into the furnace.
How will I remember?
Write the change-by date on the frame with the carbon pencil in the box. Scan the QR code on the box and we’ll email you when it’s time for your next filter.
Orders and plan
Where do you ship?
Within Canada. Shipping is free on every order.
How long does delivery take?
Orders ship in 1–2 business days and usually arrive in 2–7 business days. Delivery is free anywhere in Canada; remote and northern addresses can take a little longer.
Can I return or exchange an order?
Yes. Unopened filters can be exchanged or returned free within 30 days, so a wrong size is easy to fix. Unopened mask boxes can be returned within 30 days; opened boxes can’t, for hygiene.
How does the plan work?
Choose a subscription for your change schedule: every 90, 60 or 30 days. Your next pack ships at 10% off, just before you need it: on the 90-day schedule, every 6 months for a pack of two or every 12 months for a pack of four. Skip, change your size or schedule, or cancel anytime.
Why packs of two or four?
On the standard 90-day schedule, a pack of two covers six months and a pack of four covers a year. Changing more often? Pick the bigger pack, or subscribe and we’ll send them as you need them.
Business
Do you offer volume pricing?
Yes. Tiers start at 10 cases a year. A case is 12 facility filters or 10 boxes of masks.
Can I get samples?
Yes. Samples ship free. Request them on the For business page.
Do you have test reports?
Yes. Full reports are available to procurement, facilities and IPAC teams on request.