Hi everyone, as promised, following is my report of the installation of our new stove and the enclosure I built around it. First, a little background: We live in central Vermont and have heated with wood since we built our log house over 34 years ago. Originally we used a Riteway stove installed on our main floor. That worked, but we had to bring in the wood every several days which took up space was messy and when we decided to have kids, we immediately knew that we'd either need to fence in the stove or move it downstairs to the basement. When I built the concrete block foundation, I framed in a small door which I thought could be used to toss in wood. So we had a regular block chimney built from the cellar up, the original was metalbestos, and moved the stove downstairs. At this point I bought and welded up a big size Freeflow and winched it down the stairs and hooked it up into the chimney. A contractor friend donated a bunch of large diameter ductwork, which I hung up to conduct the heat to the corners of the living/dining room and the back rooms. When we added on an extension out back on sauna tubes for the kids, I ran the ductwork out to them. I fully insulated the floor, and wrapped insulation around the ductwork that was exposed under the extension.
To get the heat out to the rooms, I fabricated a heavy sheet metal enclosure around the freeflow, and wrapped it and the plenum with insulation so that as much of the heat as possible would flow to the registers. Some of the ductwork was simply plated over space between floor joists. By 1979, this was how we heated the house. The Freeflow was a huge stove with a capacity to really pack a lot of wood in it. It typically burned all night although it took a lot of careful packing and cautious adjustment of the airflow. Nothing was automatic, you adjusted the air flow and that was it. Too much air, the stove would REALLY heat up. Not enough and it would smolder without really giving off heat. The ductwork worked fine for the main rooms of the house, but really did not flow horizontally enough to get out to the kids rooms, so I had to add a duct fan to help it along. That did work, but then robbed the heat for the rest of the house. Our two kids often came out to the big central register directly over the stove to dress in the morning standing on it.
Fast forward 30 years to now. Three weeks ago we had our new Dutchwest stove delivered and removed the old Freeflow, which had cracked tubes internally and smoked us out whenever we had a fire, until it heated up enough to close the cracks. I removed the enclosure and plenum in order to facilitate the installation of the new stove.
I spent the last week fabricating a new enclosure which I attached to the newly hung plenum. Originally, the plenum fed three ducts: one that led straight up to the main register over the stove, and the other two main ducts fed via huge curved elbows out of the plenum. I removed everything from the plenum, then installed the elbows inside it and hoisted the entire plenum up to the wooden frame below the main register and screwed it in place. You can look down through the register and see the two big elbows, but there is still plenty of room for the heated air to flow around the elbows and up through the register. None of this was scientific, I used the OTLAR method: Oh that looks about right.
I reconnected what was left of the elbows to the two main trunk lines using scrap from the old plenum, which did not need to be so big anymore. Finally, I created an enclosure around the stove using channeled metal roofing. It was on sale at a local hardware store because it had been stored outside for years and had a little corrosion. I drew a 4 foot square around the stove and cut each piece of roofing to a taper and leaned them against the plenum. I used 2X2" external sheet metal corner moulding to tie the edges together. The corner moulding went on the inside and was attached using self tapping screws. I cut an opening for the stove door and framed around the opening using the corner moulding. I left that open. Then I cut off the plenum about an inch below where the roofing leaned against it because the plenum otherwise would have hung down about a foot below where the roofing touched it.
The stove required short cool burns to harden up the paint without smoking too much, gradually letting the fire get hotter and hotter. That's all done now and the stove can burn as hot as necessary.
Being one of the modern airtight stoves, it is a little balky about starting. The stove door needs to be kept cracked open a little in order to supply enough air to light the kindling and main chunks of wood. But once the fire has heated up the firebox and exhaust pipe and chimney, it burns as advertized and I have to turn off some of the air flow.
How does it work? All the main building registers, including the far corner ones are flowing heat. The kids are gone now so I don't bother running the rear room duct fan. It doesn't take much wood for the stove to produce a lot of heat and the enclosure and registers are working fine. Naturally, it takes some time to get everything up to heat. I'd say that it takes about an hour before the temperature starts rising. I've enclosed a couple of pictures of the enclosure. Well, I take that back, I'm apparently unable to post the pictures as they are too large. I'll try later.
Corky Scott
To get the heat out to the rooms, I fabricated a heavy sheet metal enclosure around the freeflow, and wrapped it and the plenum with insulation so that as much of the heat as possible would flow to the registers. Some of the ductwork was simply plated over space between floor joists. By 1979, this was how we heated the house. The Freeflow was a huge stove with a capacity to really pack a lot of wood in it. It typically burned all night although it took a lot of careful packing and cautious adjustment of the airflow. Nothing was automatic, you adjusted the air flow and that was it. Too much air, the stove would REALLY heat up. Not enough and it would smolder without really giving off heat. The ductwork worked fine for the main rooms of the house, but really did not flow horizontally enough to get out to the kids rooms, so I had to add a duct fan to help it along. That did work, but then robbed the heat for the rest of the house. Our two kids often came out to the big central register directly over the stove to dress in the morning standing on it.
Fast forward 30 years to now. Three weeks ago we had our new Dutchwest stove delivered and removed the old Freeflow, which had cracked tubes internally and smoked us out whenever we had a fire, until it heated up enough to close the cracks. I removed the enclosure and plenum in order to facilitate the installation of the new stove.
I spent the last week fabricating a new enclosure which I attached to the newly hung plenum. Originally, the plenum fed three ducts: one that led straight up to the main register over the stove, and the other two main ducts fed via huge curved elbows out of the plenum. I removed everything from the plenum, then installed the elbows inside it and hoisted the entire plenum up to the wooden frame below the main register and screwed it in place. You can look down through the register and see the two big elbows, but there is still plenty of room for the heated air to flow around the elbows and up through the register. None of this was scientific, I used the OTLAR method: Oh that looks about right.
I reconnected what was left of the elbows to the two main trunk lines using scrap from the old plenum, which did not need to be so big anymore. Finally, I created an enclosure around the stove using channeled metal roofing. It was on sale at a local hardware store because it had been stored outside for years and had a little corrosion. I drew a 4 foot square around the stove and cut each piece of roofing to a taper and leaned them against the plenum. I used 2X2" external sheet metal corner moulding to tie the edges together. The corner moulding went on the inside and was attached using self tapping screws. I cut an opening for the stove door and framed around the opening using the corner moulding. I left that open. Then I cut off the plenum about an inch below where the roofing leaned against it because the plenum otherwise would have hung down about a foot below where the roofing touched it.
The stove required short cool burns to harden up the paint without smoking too much, gradually letting the fire get hotter and hotter. That's all done now and the stove can burn as hot as necessary.
Being one of the modern airtight stoves, it is a little balky about starting. The stove door needs to be kept cracked open a little in order to supply enough air to light the kindling and main chunks of wood. But once the fire has heated up the firebox and exhaust pipe and chimney, it burns as advertized and I have to turn off some of the air flow.
How does it work? All the main building registers, including the far corner ones are flowing heat. The kids are gone now so I don't bother running the rear room duct fan. It doesn't take much wood for the stove to produce a lot of heat and the enclosure and registers are working fine. Naturally, it takes some time to get everything up to heat. I'd say that it takes about an hour before the temperature starts rising. I've enclosed a couple of pictures of the enclosure. Well, I take that back, I'm apparently unable to post the pictures as they are too large. I'll try later.
Corky Scott
Seems to have served you well over the years - though I am curious, why not just get a wood furnace to install directly to your plenum?
