Help with Exhaust/Stove Setup

[bltjudge]

My family and I moved into a house that had two pellet stoves and electric baseboard heat as a backup. Our stove upstairs seems extremely inefficient and needs to be cleaned 2-3 times a week. I believe it has something to do with how the exhaust is set up as a draft can be felt coming into the house from outside. It is currently using 3" piping.

It is a Witfield WP4 Quest. (Manual)
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Inside View

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Outside View
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I am thinking I have to basically run the vent all the way above the roof, about 10' up from where it comes out of the house, a similar situation can be seen on page 18 of the manual.

Or like this?

I had a few questions:
- Recommendations on the kind of piping, ends, or elbows I should use, the manual says "PL"
- Any other setups that should be considered?
- I saw the manual said something about the fresh air tube going outside on page 16, is this necessary?

 

[DneprDave]

Your stove is direct vented, this is a perfectly acceptable way of venting a pellet stove. My workshop pellet stove is vented that way and it works great..
It sounds like the stove needs a thorough cleaning. It's internal passages are probably full of ash. You could take the stove apart and vacuum the combustion fan and convection fans as well as the exhaust passages. Or, you can do the leaf blower trick, remove the outside vent cap and adapt the suction side of an electric leaf blower to the end of the exhaust vent, leave the pellet stove's door open for maximum air flow and turn on the leaf blower. It will suck all the trapped ash out of the inside of the stove. Keep the leaf blower running until you no longer see ash coming out.

I preform the leaf blower trick after every ton of pellets I burn. I only have to vacuum out the combustion space once a week if I keep the hidden parts of the stove clean.

The fresh air tube going outside is called an Outside Air Kit or OAK, as the lazier typists on this board call it, it will allow the stove to draw outside air in for combustion and reduces drafts inside the house as well as improve the efficiency of the stove.

 

[bltjudge]

The leaf blower trick seems like it should work in keeping the system a little cleaner. I have taken the entire thing apart several times now and cleaned it with my air compressor and ash vac so I know that isn't contributing to the air being sucked into the system through the exhaust.

Guessing the first thing would be to run an outside air kit to see if that would help.

Beyond that running 6-9' of vertical pipe to raise the outlet should help eliminate the draft also right?

 

[DneprDave]

A vertical run would help when there is a power outage and the combustion blower stops, it would draw the smoke out of the stove, but that is all it would do. I wouldn't waste time and money putting in a vertical vent.

If your combustion blower is working properly, you shouldn't be pulling any air back through your exhaust vent.

 

[CleanFire]

I believe it has something to do with how the exhaust is set up as a draft can be felt coming into the house from outside.

What kind of a draft do you feel, cold air from the thimble plate, or warm air?

 

[bltjudge]

Thanks for the information.

Only when the stove is off do we feel the cold air drafting in through the stove vents.

The stove itself definitely overpowers this draft and blows air out during operation, at no point does the draft overpower the stove blower fan.

 

[CleanFire]

If the usual prevailing wind is blowing against that side of the house, a short section (4-6 feet) of outside vertical pipe may help to lessen the cold air spill you feel and improve draft when heating / improve efficiency. (Like pic 2 in your first post.)

Agree w/ DneprDave, I wouldn't go crazy with a through-roof vent though, (if it was me) I'd just try tweaking the current setup.

 

[bltjudge]

Wind is kind of all over but it doesn't blow directly against that side of the house.

I wasn't planning on doing anything crazy, if a 6' vertical shoot would help then I would consider doing that but not much more.

 

[Ricks]

I have a quest it is a very good stove. If the stove needs to be cleaned every two or three days something is wrong. There are two exhaust passages that are very hard to clean. And there is no direct access to them. As you face the stove on the top left and right sides of the heat exchange tubes are two rectangular openings. They both lead down to the bottom of the firebox. The left one travels across the bottom joins up with the right one then exits out the right side of the stove through the exhaust blower..

The best way to clean these passages is using the leaf blower.

When I do this with my stove I can run it for a week or more before I need to clean it.

Good luck

Rick.......

 

[CleanFire]

I would try the leaf blower cleaning suggested by Dave and Rick, before investing in modifying the vent setup.