Chimney exit temperature quite high

[PhillyB]

I am after a bit of advice and hoping someone can help (apologies for the long story to set the scene)

I have a Lopi (Travis) Flush Wood Hybrid Large insert in my house (triple skin flue) with an exodraft RSV-009 chimney fan.

The issue i have is that i struggle to get the fire up to temperature while keeping the smoke exiting the chimney at a reasonable temperature as well. The chimney fan has a probe and often alerts me when it gets to 440F while the fire inside is already closed off 70% and the chimney fan at 15%.

When the chimney fan was installed a length of flue was removed leaving about 9 foot of flue in total (4 foot removed).

The questions i have are

• Am i running the fire too hot?
• How much would the temp drop if i add the missing length of flue back in? (temperature range outside from 60 - 24F day and night)
• Is that flue length too short?

Thanks everyone in advance.

 

[begreen]

9' of flue is too short for any modern stove. The Lopi insert requires at least 15' flue.
If the flue gases are at 250º or higher exiting the chimney that's ok.

 

[PhillyB]

9' of flue is too short for any modern stove. The Lopi insert requires at least 15' flue.
If the flue gases are at 250º or higher exiting the chimney that's ok.

I have another 4 foot section sitting in my shed, how much lower do you think the temp would drop by placing it on?

 

[bholler]

I am after a bit of advice and hoping someone can help (apologies for the long story to set the scene)

I have a Lopi (Travis) Flush Wood Hybrid Large insert in my house (triple skin flue) with an exodraft RSV-009 chimney fan.

The issue i have is that i struggle to get the fire up to temperature while keeping the smoke exiting the chimney at a reasonable temperature as well. The chimney fan has a probe and often alerts me when it gets to 440F while the fire inside is already closed off 70% and the chimney fan at 15%.

When the chimney fan was installed a length of flue was removed leaving about 9 foot of flue in total (4 foot removed).

The questions i have are

• Am i running the fire too hot?
• How much would the temp drop if i add the missing length of flue back in? (temperature range outside from 60 - 24F day and night)
• Is that flue length too short?

Thanks everyone in advance.

Why did you add the fan?

 

[PhillyB]

Why did you add the fan?

We had issues with Carbon Monoxide in the house on cooldown, had two different fireplace installers come out and have a look but they couldn't figure it out.

I got sick of the once every three weeks the alarm going off and I had the fan installed, in the process they removed one 4 foot length of chimney.

Have been struggling to get the fire to run at a reasonable stable temp without a lot of work, the fan company have said the sweet spot should be 300-400F max on chimney exit for an efficient burn.

 

[bholler]

We had issues with Carbon Monoxide in the house on cooldown, had two different fireplace installers come out and have a look but they couldn't figure it out.

I got sick of the once every three weeks the alarm going off and I had the fan installed, in the process they removed one 4 foot length of chimney.

Have been struggling to get the fire to run at a reasonable stable temp without a lot of work, the fan company have said the sweet spot should be 300-400F max on chimney exit for an efficient burn.

What did they try?

 

[PhillyB]

What did they try?

Pulled apart the fireplace and cleaned everything out, replacing the seal around the cat
Extended the chimney by the 4 foot length
Replaced the cap
Replaced the seal around the door
Told me i was running it too cold when shutting down for the night - fire temp made no difference, even left inlet full open going to bed and it still did it

 

[bholler]

Pulled apart the fireplace and cleaned everything out, replacing the seal around the cat
Extended the chimney by the 4 foot length
Replaced the cap
Replaced the seal around the door
Told me i was running it too cold when shutting down for the night - fire temp made no difference, even left inlet full open going to bed and it still did it

Did they test draft? Check for adequate makeup air?

 

[bholler]

We had issues with Carbon Monoxide in the house on cooldown, had two different fireplace installers come out and have a look but they couldn't figure it out.

I got sick of the once every three weeks the alarm going off and I had the fan installed, in the process they removed one 4 foot length of chimney.

Have been struggling to get the fire to run at a reasonable stable temp without a lot of work, the fan company have said the sweet spot should be 300-400F max on chimney exit for an efficient burn.

The most efficient burn would be about 250 at the chimney exit

 

[PhillyB]

Did they test draft? Check for adequate makeup air?

They did not check outside lighting a small fire with the door open, i assumed that was for draft.

 

[PhillyB]

The most efficient burn would be about 250 at the chimney exit

250 fahrenheit just to confirm?
Would i see much temp drop on smoke exiting the chimney by placing the 4 foot section back in?

Also really appreciate the help!!

 

[bholler]

250 fahrenheit just to confirm?
Would i see much temp drop on smoke exiting the chimney by placing the 4 foot section back in?

Also really appreciate the help!!

If you keep the fan no you won't see much of any drop

 

[bholler]

They did not check outside lighting a small fire with the door open, i assumed that was for draft.

I am talking about measuring draft with an instrument. They absolutely should have done that to set up the fan at the very least

 

[PhillyB]

I am talking about measuring draft with an instrument. They absolutely should have done that to set up the fan at the very least

Yeah that didn't happen,
I just went back through my emails and they did however do calculations for the fireplace, included a section of it below: (there is 4 pages in total.

So i guess i am just doing it wrong

 

[trailrated]

I'm of no help, but if I have to add a bunch of gizmos and technology just to burn wood, then I'll just push a button on the thermostat and burn my oil/heat hump. Screw all that mess. Give me a basic wood stove, throw wood in and burn it.

 

[bholler]

Yeah that didn't happen,
I just went back through my emails and they did however do calculations for the fireplace, included a section of it below: (there is 4 pages in total.

So i guess i am just doing it wrong

View attachment 311049

Theoretical draft means nothing. They need to actually test pressures in the chimney and in the home to figure out the problem.

 

[PhillyB]

I'm of no help, but if I have to add a bunch of gizmos and technology just to burn wood, then I'll just push a button on the thermostat and burn my oil/heat hump. Screw all that mess. Give me a basic wood stove, throw wood in and burn it.

every fire i have had in the past has been just that, only got the fan because i couldnt solve the monoxide issue

 

[PhillyB]

Theoretical draft means nothing. They need to actually test pressures in the chimney and in the home to figure out the problem.

Yeah that was never done.

Tried the only two installers in the area.

So screwed i guess

 

[PhillyB]

Would turning the fan up to a higher speed make any difference, like opening a door to cool down a fire that is too hot?

 

[bholler]

Would turning the fan up to a higher speed make any difference, like opening a door to cool down a fire that is too hot?

No that would most likely reduce efficiency and increase temps

 

[TomMcDonald]

What's the purpose of a triple skin flue with an insert? Or is it a zero clearance installation?

 

[PhillyB]

What's the purpose of a triple skin flue with an insert? Or is it a zero clearance installation?

Sorry for slow reply,
Yep a zero clearance installation, open to any suggestions.

 

[bholler]

Sorry for slow reply,
Yep a zero clearance installation, open to any suggestions.

I know nothing about the codes in Australia but here generally insert installs in zero clearance fireplaces don't meet code. Do you have a liner running from the insert through the old fireplace flue

 

[PhillyB]

I know nothing about the codes in Australia but here generally insert installs in zero clearance fireplaces don't meet code. Do you have a liner running from the insert through the old fireplace flue

Here they have a zero clearance box that the fireplace sits in, and the 10" pipe fits into, then has to be triple skin flue until it goes outside.

Mine is only double skin once it leaves the colorbond tin roof.

 

[bholler]

Here they have a zero clearance box that the fireplace sits in, and the 10" pipe fits into, then has to be triple skin flue until it goes outside.

Mine is only double skin once it leaves the colorbond tin roof.

Ok but is there a 6" inner liner connected directly to the stove and running all the way to the top of the chimney?