the joy of old houses and previous owners
 

I was looking into the easiest way to get the heat from my woodstove into the cold air return on my furnace yesterday. When the stove is going that one room gets cooking but it takes hours to get the heat upstairs and then the outside bedrooms don't really get much gain.

Last winter I used the furnace fan to push the air around and it helped but the outside rooms were still cold. Even when the furnace heat was turned on some rooms didn't really heat up.

So yesterday I decided to take a look at a strange vent on the roof above the woodstove. I had originally thought it was a straight pass through to the floor above but since that's illegal they had blocked the vent upstairs and repaired the floor. I did however notice a bit of a breeze when the furnace fan was on so I was perplexed.

Here's the hole for the vent
https://lh6.googleusercontent.com/-z...0/IMG_5236.JPG

and here's what I found
https://lh6.googleusercontent.com/-R...0/IMG_5235.JPG

My guess is there was originally another vent somewhere in that room that they disconnected when they put up the roof. Getting in there to fix this is almost impossible from that side. I'll hit it at the main connection and disconnect it there. Hopefully that will help in getting some air to the outside bedrooms...

my plans to get the heat from the stove to the cold air return involve pulling the air through those bricks with holes into the cold air return is is just on the far side of that wall. I've got a bit of work getting some ducting through to the back side but it's nothing major.

Wait...... What? I think I'm missing something here. What is that? Previous duct work from the furnace to the room with the stove?

This is nuts. 99.9% of the houses out there are really blasphemous in how poorly they are air sealed and how impossible it is to air seal them.

Nice find! And good timing, you'll get it ready for winter.

Maybe the previous owners vented the hot air to the attic/outdoors when the woodstove made it too warm in the room?;)

that is an outlet from the heatpump putting hot/cold air into the space between the downstairs ceiling and the upstairs floor. They cut a hole in the downstairs ceiling by the woodstove I'm assuming to let some of that hot/cold air out...

It attaches to the main hot duct about 3' from the furnace then runs maybe 2' to the end you see in the picture. The end is roughly 3' from that hole in the roof.


I spent a lot of time in the attic looking for air leaks and strange ducting before I put R40 on top of everything so I don't think there is any ducting from basement to attic going on but who knows. I did find that they had done a drop down ceiling over the bath tub that dropped roughly 12". They then put 6" of insulation in it so the top 6" of the walls beside the drop down had 1/2" of drywall between inside and attic air. whoops... No wonder the bedroom right there was so cold in winter. a 6'x6" strip of wall right near the ceiling with zero insulation to outside... That was at least an easy fix. I filled it with fiberglass batts and then went over the entire area with the R40. I also put up a little flag to remind me when crawling up there that there is 3' of insulation so don't just fall in ;)

getting access to this pipe is turning out to be harder then I originally thought. While brainstorming ideas on how to deal with this I had a thought.

What if I install an inline duct fan like this
Home Hardware - FAN, BOOSTER DUCT 5"
onto the end of that pipe. and have it blowing air back towards the main trunkline. then add a bit more pipe and have it draw air through that hole in the roof?

Any idea if one of these fans can pull air from the room by the woodstove and push it far enough to reach the bedrooms in this manner? I know it's not going to overpower the furnace when it is running and that's just fine.

One of those fans by the wood stove, and one of those fans for each room you are trying to get the heat to would work wonders I think. You could try just the first one, then add the room fans if you are not getting adequate results.

I started on this plan but discovered that it's a 6" not a 5" duct and it is really really hard to reach. My wife has declared whoever broke it a moron and I get to do whatever to fix it so long as the kids bedrooms end up warm.

the closet on the far side now has it's days numbered before it's a victim of the demolition.

OOOOOhhhh. Sounds like the bad work: Drywall.

Sorry about your journey ahead.
Congratulations on wife approval! That can be harder to get than a winning lottery ticket!

Today I started pulling down the paneling on the roof around the closet hoping to get in from that side. It was just too tight and too far to reach due to another takeoff in the line being right there. The broken one goes out of the top of the main line, this other one goes right out the side in the same spot.

So I decided to pull off the side line and sure enough when I finally got it out getting access to the top line was easy. I decided the best fix for this was to just pull that take off out and patch up the main line. After the patch was screwed and taped into place I hooked the side line up and ran upstairs for some totally non scientific flow testing.

The first good sign was dust started flying out of a bunch of the vents. The furnace had ran just the day before but it now had more velocity to get the dust going. As I went around checking all of the upstairs had an obvious increase in flow. The biggest improvement was the master bedroom and the middle bedroom.

Also for the first time I can now start using the vents to control the temperature in rooms by closing them up a bit. Before if the vent wasn't wide open it got almost no air.


Since the roof is all open in this area I've got a new plan on getting woodstove heat to the bedrooms. I'll use that hole in the roof and run a line over to the cold air return on the far side. I just need a couple of 90's and a bit more 5".

I'm not sure if it's ever possible to have something completely working correctly.

Last night I decided I don't need both vents in the kitchen open so I closed the vent that was blowing hot air at the fridge (who the &^*% designed this?) sure enough as soon as the vent closed hot air started pouring out from the pot drawer right above the vent. I'm assuming the ducting is pressurizing the space under the drawer and the vent isn't actually attached to the ducting just to the kickboard... I think I can get to this one from the basement in the pantry under the stairs if I can't get to it from the top by removing the drawers.