Quick draft question

[sw18x]

How much will a leaky door gasket increase draft reading on a manometer? I'm measuring draft from a port in the flue, my reading came out quite a bit higher than I expected. However, the dealer replaced a gasket for me recently on a warranty deal and there's a small gap between the ends of the gasket (more like a depression where the ends taper down). I know the door isn't quite sealing right here because on a cold start I had some smoke spillage, I quick shut and latched the door, and the smoke visibly came out this gap. For reference, my draft was reading over .010 in/wc and I'm looking for .05. I have a 3 ft section of pipe I recently added that I can remove, but hesitate to do so if the door gasket is giving me a high reading.

Thanks.

 

[bholler]

How much will a leaky door gasket increase draft reading on a manometer? I'm measuring draft from a port in the flue, my reading came out quite a bit higher than I expected. However, the dealer replaced a gasket for me recently on a warranty deal and there's a small gap between the ends of the gasket (more like a depression where the ends taper down). I know the door isn't quite sealing right here because on a cold start I had some smoke spillage, I quick shut and latched the door, and the smoke visibly came out this gap. For reference, my draft was reading over .010 in/wc and I'm looking for .05. I have a 3 ft section of pipe I recently added that I can remove, but hesitate to do so if the door gasket is giving me a high reading.

Thanks.

If anything it would reduce your reading.

 

[brenndatomu]

If anything it would reduce your reading.

A large leak would...but in my experience, a small leak raises the draft because it keeps the fire hotter and the flue warmer.

 

[sw18x]

So apart from the increase in temperature, the air flow through that leak should have negligible results on my draft reading, right?

 

[bholler]

A large leak would...but in my experience, a small leak raises the draft because it keeps the fire hotter and the flue warmer.

Yeah you may be right. But either way I doubt it will make much difference if testing is being done while running wide open air like you should

 

[maple1]

Did you by chance get a decimal point in the wrong place in one of those numbers?

 

[maple1]

Also, simply for control of the stove sakes, I think I would get all leaks fixed no matter what the draft readings were.

 

[sw18x]

Also, this my first time measuring draft with a digital manometer. Its breezy out today and i just checked again, readings were all over from mid .06s up to .014. Is it normal for wind conditions to have that much impact on the reading?

 

[maple1]

Also, this my first time measuring draft with a digital manometer. Its breezy out today and i just checked again, readings were all over from mid .06s up to .014. Is it normal for wind conditions to have that much impact on the reading?

Yes very normal.

 

[Bad LP]

Also, this my first time measuring draft with a digital manometer. Its breezy out today and i just checked again, readings were all over from mid .06s up to .014. Is it normal for wind conditions to have that much impact on the reading?

Yes, wind will change the readings.

 

[bholler]

So apart from the increase in temperature, the air flow through that leak should have negligible results on my draft reading, right?

The air flow through the leak would reduce your reading. The increase in temp caused by that would increase it. Just adjust the latch or replace the gasket.

 

[sw18x]

Thanks maple1. It's a new stove and dealer/manufacturer are currently engaged trying to problem solve another issue. Thats why i decided to measure draft myself to rule out low draft as a cause. The new gasket was part of their solution but hasn't worked out so far. Having draft data will hopefully speed up this process, but I agree that the gasket probably needs to be addressed for performance sake.

 

[bholler]

Also, this my first time measuring draft with a digital manometer. Its breezy out today and i just checked again, readings were all over from mid .06s up to .014. Is it normal for wind conditions to have that much impact on the reading?

I am assuming you readings are negative as they should be. If so you have things backwards. A draft of .06 is much stronger than .014.

 

[sw18x]

No, double checked my decimals, also measured in kpa and converted to double check my numbers.

 

[sw18x]

OK you got me. I double checked my decimals but not my typing. That's. 06 to .14

 

[bholler]

OK you got me. I double checked my decimals but not my typing. That's. 06 to .14

Ok .14 is really high. How tall is your chimney what stove etc?

 

[sw18x]

24ft with the new section. I did things backwards and added 3 ft last weekend thinking I might have low draft. Including my 2 45s and 2ft horizontal the manufacturer recommendation was 21 feet for my install so I thought I might have been at the lower limits of draft. Turns out I was wrong.

The .14 reading was momentary, mostly getting .07s .08s then for an instant it will jump up before settling back below (or should I say above since it's negative pressure) .010.

Yesterday before the wind picked up my readings were more like .05 to .07.