Can anyone offer help with a draft problem?

[jtp10181]

Attached is a picture from the job. The retail previewer drew on it where the chimney was to go, and that's where it is today. Yes, I know if you look in the manual it shows a picture of a roof and we put the chimney in the "not recommended" location. Of course I was not involved until it was all installed and they have problems.

They have a Quadrafire Cumberlan Gap installed in the room right below the roof you see in the pic. I talked to the installer today and he said it meets the 2/10/3 rule but the cap is not above the peak. The roof is fairly steep and we used support brackets to hold the chimney up. The customer says they are getting smoke in the house when the wind blows from the south, but they cannot see it puffing out of the stove. They just notice the smell after its burned for a while and especially when they get up in the morning it is the worst. I put a call into them asking which side of the house the chimney was on (N,E,S or W). I am guessing the wind is blowing over the roof and right over the cap, causing a pressure pocket. Logical solution would be to just extend the chimney up higher. But how high? How high is too high? What side effects could be cause by too much exposed chimney?

I know our wood products really good but I am no expert on chimney physics. Thanks for any suggestions.

 

[stoveguy2esw]

what is the altitude above sea level (guess) also how much chimney is exposed? you are right in saying the location of the flue would have been better closer to the peak as more of the flue is located inside the structure. smoky mornings could be caused by loss of temp late in the fire causing some inversion (weakening of draft) wind comes into efect as well (steep roof , lower than peak can play in that a bit , maybe a directional cap would help. does the unit start easy and burn completely through the charge of wood? sorry lots of questions but information fuels the discussion. i'll try to help much as i can.

 

[elkimmeg]

I would extend it an additional 2' You know the 2/10/3 rule is a bare minium then there are situations like yours I have had to add height to chimneys that were code compliant
Sometimes one never knows till it is installed. It does appear a certaint wind direction comming down that roof could present issues

 

[jtp10181]

Its Wisconsin... we are near sea level I think but really I have no clue. I would have to ask the installer how much chimney exposed. I think its an 8/12 pitch so that means 80" + 24"... so about 8.6' of exposed chimney at the min of 2/10 and I doubt they went much higher than that. They were having problems with smokey starts also but they came inot the showroom and we talked for about an hour and I gave them some pointers. After that they called back a week later or so with the current problem. What do you mean by burning completely? Asking if the fire can sustain itself, or if it just dies by itself? Also, we use Simpson Duravent class A chimney, I'm not sure I have seen a directional cap in thier catalog, we do not like to mix and match parts since its not tested together.

 

[Robbie]

"especially when they get up in the morning it is the worst"

Sounds like a draft problem for sure because sometimes when the fire dies down and no longer has the heat rising to keep the draft pulling, there can be some smoke come in through the pipe seams.

Maybe a draft helper in the wall or something like that..........or their pipe is too short.

I think they need to add about 4 feet to their pipe, I bet it would make a difference, mine did a lot.


Robbie

 

[stoveguy2esw]

Its Wisconsin... we are near sea level I think but really I have no clue. I would have to ask the installer how much chimney exposed. I think its an 8/12 pitch so that means 80" + 24"... so about 8.6' of exposed chimney at the min of 2/10 and I doubt they went much higher than that. They were having problems with smokey starts also but they came inot the showroom and we talked for about an hour and I gave them some pointers. After that they called back a week later or so with the current problem. What do you mean by burning completely? Asking if the fire can sustain itself, or if it just dies by itself? Also, we use Simpson Duravent class A chimney, I'm not sure I have seen a directional cap in thier catalog, we do not like to mix and match parts since its not tested together.

directional cap would be "aftermarket" as for burning completely are they getting ash or chunks eight ands a half ft is a lot to have exposed to cold, what they may be getting is cooling of the flue before the fire has completely died, smoky start could be a bit of stack effect (tight house negative pressure) this will be magnified as the flue cools does the unit have an outside air intake connector? if so an oak kit may help. getting back to the cap the directional cap is what they call a monsoon cap or "spanish helmet" cap , i know a guy who does them , i'll look him up if i can find him and post contact , he does this type of cap , think his name is mark stevens, have to look. have had success with his caps in past with wind downdraft issues with our units i'll find his contact tonite or look it up at work next week. i'll let ya know

 

[jtp10181]

we would not use any sort of aftermarket cap so I don't need his info.

 

[Corie]

At what point would you consider it? When the stack is 32 feet tall?


That said, draft force is HIGHLY dependent on stack height. Its raised to the fourth power in the draft equation. Add four feet and see what happens.


OR how about an insulated chase around the flue?

 

[DriftWood]

Your location may be higher or lower. These are from NWS Milwaukee, WI, NOAA, National Weather Service, seven day forecast for Madison, WI. Just enter your city,state click enter.

Point Forecast: Madison, WI
43.09N -89.37W (Elev. 850 ft)



Madison, Dane County Regional-Truax Field
Lat: 43.14 Lon: -89.33 Elev: 873.031

http://www.crh.noaa.gov/forecast/MapClick.php?CityName=Madison&state=WI&site=MKX

 

[webbie]

A little height may help if it is wind-related.

Aftermarket caps such as Vacu-Stak are very popular in this type of situation and, in my opinion, provide no safety issues in such an installation.

 

[GVA]

The stove is in the room just below roofline?
So would that be about a 16' chimney total? Is this enough?

South side of house look at the satalite dish These point south

Based on the fixed windows on the side (near peak) I would say this room has cathedral ceilings.

This may not be related but in the pic there is alot of snow missing at the right side of the roof all the way up from the soffit to the peak.
Can't tell if there is a ridge vent but is it possible that the stove may be sucking the smoke through the soffits and this stove is using them as it's source of outside air?
Yes I know this pic was taken before install...
Just wondering outloud if the house was breathing right to begin with

I'm a pellet head so you may exercise the ignore function.........................Now...... :coolsmile:

 

[jtp10181]

Yeah they do have a higher ceiling. I could not tell form the other pics if it follows the roof exactly or if it has less of a pitch. I think I will do two things.

1. Figure out how tightly built their house it, possibly add an OAK.
2. Send the installer out with a 2ft, 3ft, and 4ft section and have him add whichever one will work the best without making the chimney unstable.

 

[jtp10181]

OK bringing back this thread. The installer reminded me of something very important I forgot to mention.

This house has two very large (bar sized I'm told) exhaust fans in the basemenet because they smoke down there.

Also the roof of the house (the room the stove is in) has no vapor barier, just paper faced insulation batts. The ceiling also has lots of can lights in it.

This sounds like a disaster.... still think raise chimney first. Then try Outside Air Kit?

With the exhaust fans I'm thinking maybe all it needs is some more air in the house.