lost heat?

[loneeagle15]

This is my second year of burning and I wondered about it last year and did nothing about it. So this last weekend when it was -17 for the high my Mansfield was sitting at around 500 and the flue temp (stove top gauge) was around 800 (Gauge that goes through the flue) with it completely damped down am I losing way too much heat out the flue? If so what can I do about it?
Thanks

 

[meathead]

800* for an interior flue temp is a good safe/efficient range to be in. It would coorelate roughly with 400* exterior flue temps. As long as your stove is at a good operating temp, which it sounds like it is, I wouldn't be concerned with efficiency at 800* interior pipe temps. Shutting the primary down is the only step I would take, which it sounds like you have. Too much cooler and you start risking creosote build up. I say keep 'er goin' just like you are.

 

[savageactor7]

That is the million dollar question for me too...this being the 1st stove I've had without a flue damper. While our QF4300 is adequate for heating I can't help but think an inline flue damper used correctly would throw 3x the heat that the best stove blower (big gimmick imo) would. Just say'en we have over 25 years of stick time with flue dampers.

 

[struggle]

When it goes below 0 mine will draft like that as well to the point of running 800 on my probe. The only concern you might have is that when you go to brush your chimney is that it will be already clean ;-P

Mine will usually settle down around 650-700 once it goes to cruising stage and will keep secondary burn for a very long time.

Seems normal to me.

 

[begreen]

It's likely drafting stronger than you are used to due to the extreme cold and perhaps high winds? You could add a manual damper to tweak the draft if this is a common condition.

 

[Rich L]

I agree with the installing of a stovepipe damper.My Mansfield was throwing a lot of heat up the chimney until I installed the damper.Now I'm recieving a massive amount of heat.

 

[savageactor7]

^now that's what I was hoping for someone that bucked the trend of damper less flues and has first hand experience. Thank you Rich.

 

[Rich L]

^now that's what I was hoping for someone that bucked the trend of damper less flues and has first hand experience. Thank you Rich.

Your welcome,Let us know how it goes after the install.

 

[oconnor]

I think the big change for those who have burned for years is that the new stove doesn't exhaust as much air as the old pre EPA units did. The guage may show a high temp, but that doesn't correlate to the number of BTU leaving the house. A new stove only pumps between 10 to 25 cfm up the flue (source www.woodheat.org) - the old units exhausted way more. With less air leaving, the flue temp is higher (less dilution), but that doesn't correlate to lost heat. If the flue isn't hot, you won't get the draft needed, because you don't have the velocity in the flue.

I know that doesn't seem to agree with the experience that some folks have had, but it makes sense to me.

The other concern I have is that the EPA approval of the stove is based on the air being managed the way the stove was designed - when you add a key damper, you aren't running the unit the way it was designed (It wants the air to be restricted before the fire, not after, as this will affect the flow patterns in the firebox), and you won't necessarily get the clean burns that the design intends.

My 2 cents - Canadian at that, so multiply by 0.75 .

 

[Rich L]

I think the big change for those who have burned for years is that the new stove doesn't exhaust as much air as the old pre EPA units did. The guage may show a high temp, but that doesn't correlate to the number of BTU leaving the house. A new stove only pumps between 10 to 25 cfm up the flue (source www.woodheat.org) - the old units exhausted way more. With less air leaving, the flue temp is higher (less dilution), but that doesn't correlate to lost heat. If the flue isn't hot, you won't get the draft needed, because you don't have the velocity in the flue.

I know that doesn't seem to agree with the experience that some folks have had, but it makes sense to me.

The other concern I have is that the EPA approval of the stove is based on the air being managed the way the stove was designed - when you add a key damper, you aren't running the unit the way it was designed (It wants the air to be restricted before the fire, not after, as this will affect the flow patterns in the firebox), and you won't necessarily get the clean burns that the design intends.

My 2 cents - Canadian at that, so multiply by 0.75 .

I know my Woodstock manual and me thinks my Mansfield manual states in conditions of high or excessive draft a pipe damper can be used.I have a damper on both stoves with no excess creosote though my heat and heat times have increase.Hey if it doesn't work in certain situations remove it or leave it open how difficult is that.

 

[oconnor]

If the manual says go for it, then go for it. I know that a lot of manuals on EPA stoves actually say do not install a key damper.

Don't get me wrong, I'm not anti - damper. I just hope that folks install them for good reasons, vice old-times sake.

 

[Bill]

Jd how high from the top of the stove is the chimney thermometer? 800* is to high in my opinion, also try dampering the stove down faster, so it's not running away from you. If you have a big coal bed and load the stove to the gills, it takes off pretty fast.