# first 8ft of vertical run on pellet vent pipe hot to the touch



## kserr (Dec 20, 2008)

Hi
First year with a pellet stove.  I'm burning a St. Croix EXP ,not that it matters my question is , should the first 8ft of our vent pipe be hot to the touch.  I was told that you could put your hand right on the pipe and not get burned.  We have about a 16ft vertical run, after the first 8ft the pipe is cold.  Just concerned that I'm losing valuable heat.  No problems with the stove burns great.  Never get klinkers or black soot on glass.  Any input would be great.


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## crausch (Dec 20, 2008)

I don't have a St. Croix but with my Harman my pipe is only about 110 degrees around 4' up. It's hot but you can hold you hand on it. At about 5' I go into a 90 elbow and start vertical. All the pipe feels about the same temp though. Do you have one of those stove pipe magnetic thermometers? I had one left over from my wood stove. I keep it stuck to my vent pipe about 4' up the vertical from the back of the stove. Temp seems to always stay around 105-110F. On occassion when the stove is burning hotter with higher flame, it only creeps up a few degrees.


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## kserr (Dec 20, 2008)

I'll have to get a magnetic thermometer and see what the temp. of the pipe is.  I'm guessing that its hotter than 110 because I can't keep my hand on the pipe.  I go straight out about 2ft into a tee then straight up a 4"inch pipe. Thanks for the suggestion.


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## rayttt (Dec 20, 2008)

its doublewalled pellet vent pipe? or single wall stove pipe?


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## Xena (Dec 20, 2008)

Same stove here.  I have the same set up.
Got about a 2 foot horizontal into a 4" T
then 4" vertical going 15 ft up the chimney.
I can't reach the pipe up in the chimney, but
can tell you that when my stove is cranking
I cannot hold my hand even on that cleanout T
or I'll get burned.  On the #1 settings I can 
hold it there no problem.  Don't think you have
anything to worry about there.


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## kserr (Dec 20, 2008)

Thanks I feel better now.  Love the stove, wasn't so sure at first because I bought this when I was told I couldn't get a harman and then they called me and said I could get one .  Was upset at first , but the more I read I'm glad I got my St Croix.


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## kserr (Dec 20, 2008)

rayttt said:
			
		

> its doublewalled pellet vent pipe? or single wall stove pipe?


 Its Simpson Duravent double wall with that rope stuff


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## slls (Dec 20, 2008)

My stove is direct vent, adapter and 10 inches of pipe inside. I can't hold my hand on the pipe after the adapter, a few inches away before it enters the wall, I can leave my hand on it all day. I run it on medium heat and high convection fan.


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## firewarrior820 (Dec 21, 2008)

clean your pipe


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## orangecrushcj7 (Dec 21, 2008)

firewarrior820 said:
			
		

> clean your pipe



I would actually disagree.  The ash build up in the pipe would act as an insulator and make the pipe cooler to the touch.  Though it is still a good idea to keep the pipes clean.


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## slls (Dec 21, 2008)

firewarrior820 said:
			
		

> clean your pipe



Pipe is clean, 2 feet long. Take off the turn down and look in with flash light.  I was saying how efficient my stove is, very little wasted heat.


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## firewarrior820 (Dec 21, 2008)

slls said:
			
		

> firewarrior820 said:
> 
> 
> 
> ...


my post was intended for kserr ,sorry for the confusion


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## Corie (Dec 22, 2008)

Remember that the temp. limit for exhaust gas in pellet pipe is 500 degrees above ambient. Human touch temperature is 120 degrees f so you're in good shape from a safety standpoint.......now of course from efficiency standpoint, the colder the exhaust gas the better.

-posted via iPhone


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## kserr (Dec 22, 2008)

Corie said:
			
		

> Remember that the temp. limit for exhaust gas in pellet pipe is 500 degrees above ambient. Human touch temperature is 120 degrees f so you're in good shape from a safety standpoint.......now of course from efficiency standpoint, the colder the exhaust gas the better.
> 
> -posted via iPhone


 Yes that was my only concern heat loss.  Actually on low, I can put my hand on the pipe its only on the highest setting that I can not leave my hand on the pipe.  but we never see smoke or any evidence of exhaust coming out of our pipe. Of course thats a 15ft vertical run.


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## webbie (Dec 22, 2008)

As Corie mentions, you are well within any safety spec......that is why pellet pipe has clearances to combustibles. In theory, it could get up to a temp where it would burn you instantly on touch and still be safe.

If it is hot, the good news is that it is transferring some heat into the room. The bad news is that the stove itself may not be as efficient as it can be, and those who have a short run of pipe right to the outside may be losing some heat.

It is my educated guess that many Pellet stoves in the field run at a vastly lower efficiency than claimed. Someday another series of field tests will be performed......in the last series they came out much lower than the specs. Until then, it is always good to be conservative on total (Seasonal or AFUE-TYPE) efficiency. A figure of 65-70% is probably accurate for lower-line pellet stoves, and perhaps 75% for the top of the line tuned just right.


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## MCPO (Dec 22, 2008)

Just to affirm others findings I can hold my hand on the pipe only when the stove is on #1 (lowest setting) On higher settings it gets hotter accordingly and I can only momentarily touch it.
 Common sense tells me this has to be normal.


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