Having learned a thing or two while we installed the exhaust for the basement ventilation system, I was hopeful that I could manage the the 1st floor by myself.
When I took down the top of the main chimney with its three intact flues, we realized that we could reuse them. The idea was to have each chimney flue fitted with a ventilation exhaust.
The northernmost chimney flue accommodates the soil gas or radon removal system. The larger and southernmost flue is fitted with the ERV exhaust duct for the garden unit and 2nd floor unit. That leaves me with the center flue, which I would like to use for the 1st floor ERV exhaust.
The inside of the flue is square and measures about eight and a half by eight and a half inches.This was just large enough to fit the eight inch round exhaust duct.
I got the materials onto the roof, prepared my temporary chimney cover, assembled the ducts, connected them and sealed all seams.
Once I had 15 feet of ducts assembled, I enlisted the help of our neighbor to lower the pipe carefully into the flue. We had to add another two five-foot sections of duct in order to get all the way down to the 1st floor.
The center flue did have an original opening on the first floor, that I increased slightly to fit the 90 degree elbow at the bottom of the exhaust pointing towards the ERV location in the ventilation closet. Once that was done, I closed up the opening with bricks.
Back on the roof, I placed and sealed the exhaust cone, fitted the storm collar and installed the exhaust cap. I was pleasantly surprised by how smooth and uneventful this installation proceeded – for once!
Material choices
To date, I had used regular galvanized ducts that I purchased at the common hardware stores.
Not too long ago, I was referred to Albany Steel & Brass Corporation, a family owned business just a couple of miles north of us.
They offered a Ductmate product called Green Seam. It is a slightly heavier gauge than what I had used in the past, has a ‘Snap Lock’ technology, which makes it easier to put the pipes together, has zero VOC gaskets along the longitudinal seam and the female end of the duct, and carries a union label.
This sounds all pretty fancy. Imagine my surprise when I realized that these ducts sell literally for the same price as the ordinary and lower quality ducts you get at your home improvement stores. Guess where I purchased all my duct work this time around!
Despite the Green Seam gaskets, which are a really nice feature, I still opted to apply duct mastic at all seams. It hardly takes any time, is relatively cheap, and gives me the extra peace of mind.