Cold air coming in at stove connector?

[pcampbell]

I had a blower door test done and the efficiency expert pointed out that tons of air is coming out where the stove hooks up to the double stove pipe. Where my fingers are in the picture. Is this normal?

I understand that the Selkirk DSP adapter has 1/2" of air space between inner and outer pipes at the bottom to allow for variations in flue sizes but should this air space be continuous with the rest of the chimney? I.e., it's not separated from the rest of the airspace inside of the adapter?

Here is the piece I believe that is used:
http://www.amazon.com/Selkirk-266210-Stove-Pipe-Adapter/dp/B000JTK2N2

 

[bholler]

Yes that is supposed to be there that is how double wall pipe works. But i am not sure where the outside air would be getting in. can you show pics of the rest of the setup?

 

[pcampbell]

Here are a few more pictures.

 

[realstihl]

When they did the test it put negative air pressure in the house. Your adapter is leaking air and not sealed to the stove. Mine was so bad I had to use 3/8 door gasket to make the connection. I don't like DSP at all for this and other reasons.

 

[bholler]

When they did the test it put negative air pressure in the house. Your adapter is leaking air and not sealed to the stove. Mine was so bad I had to use 3/8 door gasket to make the connection. I don't like DSP at all for this and other reasons.

That has nothing to do with single wall or double wall it is either the stove pipe or the collar is the wrong size if you needed 3/8" gasket to make the inner wall fit tight. But honestly stove pipe joints are not sealed and don't need to be so when you put a blower door in you will get some air out of those joints. But in real life it really wont make much of any difference at all

 

[realstihl]

That has nothing to do with single wall or double wall it is either the stove pipe or the collar is the wrong size if you needed 3/8" gasket to make the inner wall fit tight. But honestly stove pipe joints are not sealed and don't need to be so when you put a blower door in you will get some air out of those joints. But in real life it really wont make much of any difference at all

Sorry, but that's not true. Too many leaks equal weakened draft.

 

[Woody Stover]

Too many leaks equal weakened draft.

If all your pipe is made by the same company, it should all fit pretty tight, and air leakage will be minimal. I haven't dealt with double-wall, though. Not sure what is going on with the OP's leak....

 

[mitchell721]

Do you need the adapter. When I installed my stove I had the same thing but took it out as long as the regular pipe goes over your flue outlet with the inside pipe on the inside so creosote is contained. Then you don't need it. I seem to recall reading that it was for recessed stove flue outlets or something like that. If I'm wrong someone will correct me

 

[mitchell721]

May be required to adapt some stove flue outlets to Double Wall Stove Pipe.
From the sellkirk catalog

 

[bholler]

Sorry, but that's not true. Too many leaks equal weakened draft.

very true but simply because it leaks when the house is depressurized does not mean it is an issue at all

 

[dh1989]

My double wall pipe was leaking in the same spot. I did a smoke test holding a lit match near the flue collar with the stove running and it drew the smoke in. I bought some Rutland door gasket and wrapped it Around and tucked it in. No more leak.

 

[mellow]

Isn't the air supposed to be flowing through the pipe, that is what acts as an insulator to help keep temps down for reduced clearance.

Just learned something, new:

There are two general types of double-wall flue pipes: sealed and vented. A sealed double-wall flue pipe is effective at retaining the heat in the flue gases because the air space between the inner liner and outer shell acts as an insulator.

A sealed double-wall pipe is a good choice to maximize draft and minimize creosote deposits. Use sealed double-wall pipes if the assembly must be long or if the appliance is expected to produce low flue gas temperatures. The system to the left uses a sealed double wall telescopic length between the stove and chimney.

A vented double-wall pipe allows cooling air to pass between the inner and outer layers. Where the flue pipe assembly is short and straight, a vented double-wall pipe can be acceptable. However, vented pipe is not a good choice for longer flue pipe assemblies or for appliances that are expected to produce low flue gas temperatures.

http://www.woodheat.org/flue-pipe-installation.html

 

[pcampbell]

It *looks* correct to me. The ribbed part of the DSP adapter fits inside of the flue output , so I don't think the stove-> DSP is actually leaking.
I think the outer wall of the DSP is allowing cold air seep down

Yes it was most noticeable when we had the blower door test going - but on a windy day I could feel cold air getting pushed down and out the bottom too.

Maybe this is just how it is designed. I'm assuming I should not try to fill the holes with any kind of sealant.