Jotul F45 Greenville Experiences

[bigealta]

Oh yeah you removed the rear shield.
Interesting test.

 

[Todd]

1.5 hours in, turned down to low.

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Here’s a similar load from last night comparing the temps from before and after the pea gravel. There seems to be quite a dip in flue temps compared to before.

 

[Todd]

34 lbs of Red Oak for this evening’s fire!

 

[Todd]

An hour in cruising at med low air.

 

[bigealta]

So sounds like the removal of the rear heat shield sheds more heat from the f45's exhaust than the added pea gravel's affect of raising firebox temp.

Actually that does not make a much sense though?

What do you think is going on there?

 

[Todd]

So sounds like the removal of the rear heat shield sheds more heat from the f45's exhaust than the added pea gravel's affect of raising firebox temp.

Actually that does not make a much sense though?

What do you think is going on there?

I had the rear heat shield and bottom heat shield off since last year. The only difference is the pea gravel in the side shields this year.

Flue temps were about 100-150 degrees higher last year. Maybe the sides are sucking more heat away from the firebox somehow? I don’t know, you’d think with no pea gravel the convection between the shields would whisk away more heat?

Stove top temps are also higher. All I’ve done this year so far is cold starts and the stove top temps are coming up faster than the flue temps now. I’ve seen 500 in 15 minutes ! It’s not the flue probe, I have three of them and they all do the same.

 

[Todd]

Here’s my first full load burn at lowest air setting. These flue temps are getting down to Blaze King territory lol.

This is an hour in. Shut her down all the way after 30 min. Plenty of secondary action going on.

 

[bigealta]

Hmmm. Hard to comprehend that higher stovetop temps co exist with colder flue temps.
I'm perplexed.

 

[Jebb]

From a unmodified F45v2 user, hitting STT of 500 from a cold start in 15 minutes is damned impressive

 

[Todd]

Hmmm. Hard to comprehend that higher stovetop temps co exist with colder flue temps.
I'm perplexed.

Well I think that’s the way it’s supposed to be? My previous wood stoves ( Keystone, Fireview and BK Princess) all were like that.

I’m just surprised my flue temps dropped this much from last year because of this mod. It must of made the heat transfer efficiency better somehow? I’ll take it, more radiant heat is better for my open floor plan and high ceilings.

 

[bigealta]

Well I think that’s the way it’s supposed to be? My previous wood stoves ( Keystone, Fireview and BK Princess) all were like that.

I’m just surprised my flue temps dropped this much from last year because of this mod. It must of made the heat transfer efficiency better somehow? I’ll take it, more radiant heat is better for my open floor plan and high ceilings.

ok so with higher stove top temps and assuming higher internal temps , the f45 is probably drawing more air thru the stove which could account for the flue temps being cooler. The fire and secondaries flames and coal heat has direct paths to the stovetop and sides.

I guess this could be a reason Why the actual exhaust is cooler?

 

[bigealta]

And / or the sides and back are running cooler than last year as they are shedding more heat at a faster rate.

So the top runs hotter while the rest of the stove runs "cooler" with a faster heat transfer.

 

[Todd]

Actually the sides are running a bit hotter and stay warmer for longer. I never really took temps off the back though.

 

[EbS-P]

Conduction moves more heat than convection.

 

[Jfior1983]

I’m about to have my f45 installed in anchorage Alaska. House is Well insulated, Triple pane windows, chalet style home with about 1600 sf. Hoping I didn’t make a mistake not getting the f55. My question is…what is “normal” operating temp? Should I have a thermometer on the stove top, or on the pipe? Pretty excited about this, since I wanted a non-cat stove and this seemed to be the best option I could find. Anyone offering tips for operation? I’m going to burn well seasoned white birch.

 

[Todd]

I’m about to have my f45 installed in anchorage Alaska. House is Well insulated, Triple pane windows, chalet style home with about 1600 sf. Hoping I didn’t make a mistake not getting the f55. My question is…what is “normal” operating temp? Should I have a thermometer on the stove top, or on the pipe? Pretty excited about this, since I wanted a non-cat stove and this seemed to be the best option I could find. Anyone offering tips for operation? I’m going to burn well seasoned white birch.

Both stove top and flue temps are good guides to what’s going on with your stove. I mostly monitor flue temps after reloading since they usually react faster than stove temps. Once I see flue temps get up to the 400 -500 range I’ll start backing down the air in stages and keep watching the temps and fire til I get the output I want. I like to keep the stove temp below 700 and mostly cruise in the 500-650 range and my internal flue temps are usually around 400-600 depending on the air setting and weather conditions affecting draft.