Harman Accentra air intake tube o.d.?

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3650

Minister of Fire
May 8, 2011
924
midwest
I think I’ll add an oak. I’d like to get the parts on hand before I start. I can’t get a measurement due to the stove location and I don’t want to pull it out until I have the parts in hand. If anyone has a precise outside diameter of that tube it would be a big help. I can get a hand on it I just can’t get the calipers or tape to it. Thanks.
 
I'm betting 2 inches, but to be certain, arm your hand with a piece of cardboard with a 2" circle cut in the center and see or "feel" if it slips on loose or tight or even if not. A piece or aluminum or thin luan would work too.

You could cut a circle 2" OD, and one 1-7/8" .... drill a smaller 1/2" hole as a finger hold point, try each like "no go" vs "go" guage set.

You could hold the 2" one between a thumb and two fingers and place it at the pipe end and "feel" the edges too.

If you can't get to the open end but justy the sides of the pipe, make a "C" shape with 2" between the ends, like a fixed caliper ... try it on for "feel".

Just ideas.
 
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Good idea. Thanks
 
I just ran outside air top my P43 and I used the 3" kit since it is a basement install and kind of a longer run. The 3" flex slipped right over the stove intake. I did have to trim out my shield metal cover. It was set up for 2.5 " od pipe
 
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I managed to get a pair of long od spring calipers behind it and into the hole. I was doing it blind laying on top of the stove so I’m not sure how accurate it was but I got 2-3/4” od.
 
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I managed to get a pair of long od spring calipers behind it and into the hole. I was doing it blind laying on top of the stove so I’m not sure how accurate it was but I got 2-3/4” od.
That would be real close. The manual says to use 2.5" od tubing. I used 3" od flex which is a little over 2.75"id and fit real nicely over the nipple
 
Harman used to recommend,and sell 3" for this. Don't know if they still do. 3" will easily crush down with a hose clamp, and does not have to be perfect air tight anyway. Do not "crush" too much or deform at inlet, you could cause the flap to stick, causing other problems.
Also, 3" is a standard dryer vent size, easy to use dryer duct for long runs.
 
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I can’t go through the wall due to the fact my house is 120 year old split face block. These blocks are ridiculously hard to get through and would exit on my front porch anyway. Not ideal.

I’ve got to come out, down 90* , through the floor, over 90*, twenty five foot run, through an opening then up about four feet. I’m trying to piece it all together from assorted parts. I’ll probably make an adapter to the stove out of some round stock on my lathe. I can’t find anything that looked like it would work. Buying the kit will only add to the cost and wouldn’t get me anywhere near where I need to exit the house.

My chimney has an enormous draft. I put a mag on the stove and couldn’t get anywhere near the optimal setting even with the draft adjustment turned all the way down. There’s a lot of heat going up the chimney. The pipe is always much hotter than it should be and the top of the stove is lukewarm. My fire always looks like a flame blower. I’m thinking about reducing this intake run down to 2” to try and bring the draft down. If I do use a three inch I may need to add some way to dampen the intake to control the draft. This isn’t really the right way to do this but I hate all that heat going up the chimney. Strange that Harman doesn’t use a draft plate on the exhaust.
 
Yeh that might work. Thanks
 
Interesting. Rare for a Harman to have too much draft. What kind of chimney is it going into? Did you run a chimney liner?
From the distance you are going, I was going to recommend at least 3" ,preferably 4" most of the way.
 
14’ of 3” pellet vent straight up through the roof.
I used a Chinese made digital mag gauge to set it. Perhaps it wasn’t accurate. However the pipe gets too hot to leave a hand on with the damper dial adjusted all the way down and the flames are still really moving fast
 
"pipe gets too hot to leave a hand on"
Well that is normal,
Flames in a Harman are normally quite active, except when starting up, shutting down, or going in between.
How about when in manual mode, so fire does not go out, and flame should go up then down, depending on if heat is being called for.
 
Well it’s been a few years since I’ve really paid attention to the pellet stove because I’ve been burning coal so I guess I don’t really recall what’s what. My coal stove is a base heater and it’s so efficient at heat transfer I could hold my hand on the pipe quite long. I’ll have to relearn som pellet stove stuff I reckon.

Normally I always ran it in manual mode because the igniter went out. This is the first time I’ve run it in auto and it seems to behave the same as manual as far as I can remember. My house loses heat so fast the stove doesn’t shut off in auto.
 
Well it sounds like whenever it is on, it is running full blast. A Harman combustion blower changes speed depending on the conditions of the controls, programming and the t/stat/setting, and exhaust probe.
Kinda sounds like you need a bigger stove.
If your house is that leaky, not sure outside air to stove will help you much, or be worth it.
 
Well it sounds like whenever it is on, it is running full blast. A Harman combustion blower changes speed depending on the conditions of the controls, programming and the t/stat/setting, and exhaust probe.
Kinda sounds like you need a bigger stove.
If your house is that leaky, not sure outside air to stove will help you much, or be worth it.
I think it will. I have an enviro omega in the other end of house and it has an oak. When I run it the house draft is reduced significantly. It’s worth trying at least as long as I can keep the cost of the experiment down. I don’t want to throw a lot of money at it only to find out it was wasted effort.

The Harman does slow down in auto it just hasn’t shut itself down to the point it has to re-ignite.
 
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Interesting. Rare for a Harman to have too much draft. What kind of chimney is it going into? Did you run a chimney liner?
From the distance you are going, I was going to recommend at least 3" ,preferably 4" most of the way.
Exactly. Use 4" up to near where you need to come up through the floor then reduce to 3" thru floor and into stove. Use the semi ridgid flex. It slide right over the air inlet. No need to get that precise with a lathe.
 
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