New Filters for Fresh Air Ventilator (HRV)

So, I don’t usually run my home’s fresh air ventilator, so maintaining it is not #1 on my to-do list. So, even though the filters are supposed to be cleaned out every few months, and the heat recovery core cleaned annually, this is the first time I’ve serviced it since we built the home in 2009. The unit is a Venmar Constructo 1.5.

Needless to say, it was a mess. One of the two filters had degraded to the point it was unusable, and the other wasn’t far behind. New filters cost ~$35 each, but I thought I could do better, both in terms of cost and quality. So, I took a trip to the local big box store and bought a one-size-fits-most washable filter (link here) and got to work.

Step One: Remove old filter from frame. Try not to destroy it so you can trace around it on the new filter.

Step Two: Cut new filter to matching size and work it into the frame. It helps to pry the long edges of the frame open just a bit.

Step Three: Press the frame closed on the new filter.

This was as far as I planned to go, but the filter seemed a bit flimsy and felt like it would separate from the frame next time I washed it. So I added another step.

Step Four: Cut plastic grid to appropriate size and attach to each side of filter with plastic cable ties. I had to use some wire here, because I didn’t have any small ties on hand. Wire will most likely rust away, so that’ll get replaced as soon as I get to the store. See the photos below for more details.

Other photos:

The original filter was a coarse, open foam:

The new filter has coarse and fine filtration layers sandwiched between a screen material:

The wire ties that hold the pieces of plastic framing together: