Doubling the efficiency of your woodstove.

[Wallybear]

Most people do not know this, but if you have a direct air intake to your stove from out side you can double the efficiency of your stove.

The stove itself will not be anymore efficient, but the drawing of cold air through the cracks in your home will be all but eliminated.

When you fire up a stove and the exhaust is vented outside through your chimney you are creating a vacuum that needs to be filled. This fresh air that your stove is using comes from the room it is in. That air needs to be replaced and is drawn in from outside through the cracks in the walls and around doors, windows and such. This cold air now has to be heated up and so your wood stove is constantly fighting against itself. It is heating the room and at the same time it is drawing cold air into the home.

What needs to be done is to pipe intake air directly into your wood stove from outside. This will give it the air it needs without drawing it through your home and defeating the purpose. A 3" pipe is considered adequate for most wood stoves. You will need to cut a hole in the back or side of your stove and weld a nipple on for connecting to. I like to also put a damper system into that nipple for intake control. A stainless flex hose clamped on to the nipple works really well for running it outside. Make sure that you have all the heat isolation precautions set up in your wall. The last house I was in I ran it through the floor behind the stove and drew my air from under the house.

 

[THEFAN]

I like it. I wil have to keep this in mind. hmm

 

[dacjohns]

Sounds good but I would use caution before doing this. Modifying your stove could couse problems with your insurance.

 

[Wannabefree]

I am sooo doing this next year! My insurance company doesn't care

 

[Marianne]

Wallybear, you answered a question I have had for some time - the size of the pipe. Although 3" sounds big, you're probably correct. I saw one on tv, the guy just ran the pipe under his woodburner through the floor and outside. He said by putting it underneath, you never felt any cold drafts from it. Looked flush, and he put a plug in the pipe during the non-burning season. The pipe size was never mentioned, but I was guessing it was 2".

We have a wood stove and a wood burning furnace. For the furnace burn air, we were going to run 2" pipe through the wall, put a tall extension on the outside, top it with hardware cloth and a short extension on the one next to the furnace. Kind of like a U shape, with one leg being taller. The outer part of the furnace doesn't get hot like the wood stove, especially where we were going to put it, so I was thinking of using PVC or just galvanized. It won't be in an area that could catch on fire
The wood burning furnace unit is up on concrete blocks. I thought we'd run the PVC on the floor against the side of the blocks. The shorter leg of the PVC 'U" would come up just to that height and angle over towards the ash door. I usually have that cracked for better draft.
I was hoping by having the U shape, it would create a bit of a cold air plug at the bottom to stop some of the cold air from coming in during the night after the wood burns down and the furnace is no longer running.
I'm going to check where we could install the burn air intake pipe for our woodstove today. Thanks for posting!