Hitzer Furnace 82

That is very true. It does say duct board has a 250 degree rating and that's what the hitzer manual calls for, but im not sure now.

xandrew245x wrote:That is very true. It does say duct board has a 250 degree rating and that's what the hitzer manual calls for, but im not sure now.

Call Hitzer or your local hvac dealer,either one should be able to clear this issue up for you.
You might just want to rip out all that existing duct work & install the proper duct,keep the lessor rated stuff in a corner so when you move you can just switch all the duct work again,easy.

If you call HITZER--260-589-8536, ask for Dean. Even though it states you would be OK in the manual--this should put your mind at ease.

i agree with windy and fred call hitzer they will and do take there time and knowledge to help you and will be good to go !!! very good folks to deal with ,period !!

I will call hitzer later today. I talked to the insurance and they said they will just come out and inspect it when done, as long as it's within specs of the manual I will be fine, he said it's really no big deal.

I can't remove the existing duct, it's enclosed in drywall because my basement is finished.

I had a set up with a similar stove/furnace, but with all metal duct work, and what was in the manual for that particular model was with a power failure to remove the blower cabinet side door (where air filters were) and allow gravity heat to move the air away from enclosed heat exchanger during while the power was out.

But, I must also state the the duct work was built to the stove/furnace mfg'r specs and was oversized very much by/compared to normal non-solid fuel duct standards.
My take off plenums were 24"x24" into a tee that was 8"x24" split in two directions. If memory serves me right...furnace was hand-fed solid fuel rated ~80,000 btu/hr.

This is were the OP may get into trouble...undersized ducts, by hand-fed non-solid fuel standards, and having non-metallic ducts to boot.

Much as I like living on the edge, this scares me.

BTW: Oh, might be worth mentioning...a stoker doesn't have the same issues described above due to the inability to continue to feed raw coal and having the small amount of coal burning on the grate that would quickly self extinguish for lack of (electricity) any combustion fan air.

Maybe Corrosionman could give you a temp reading on the supply side of his 82FA. Or anyone else with an 82FA.

Duct board....we are talking about that foil faced cardboard, right?

I realize furnace supply set ups are different & far better than a pipe coming off the top of my mag stoker... but the high temp of the air coming off mine would keep me from using duct board on the supply side of any solid fuel furnace. I use metal duct & have a 1" air gap between it and the drywall ceiling and I'd be nervous without that gap for the first 10' or so across the ceiling.

I'm using ductboard similar to this: http://www.bing.com/images/search?q=duct+board&view=detailv2 ... ajaxhist=0
I got mine free, and I've never had a problem. I've had quite a few power outages over the years. I've also hit the 250 degree high limit on the fan switch once or twice. This stuff is my main trunkline and my oil furnace is tied into it also.

I helped a friend of mine install a hot blast last year, now his main trunk was metal but the rest was flex. We took some reading of temp coming off the unit and even under a really hot burn with wood I think the max temp was maybe 200.

If corrosion could give me a temp reading that would be awesome.

There would be about 10' of metal duct before its tied into the duct board.

On page 1 & page 2,you were quite concerned about keeping this project insurable.
Now some members are offering options as to how you can cheat on the required specs for duct work
Minimum & maximum are on opposite ends of the scale
Measuring someones duct temp's under normal conditions does not change the safe working limits required.
Maybe the manufacturers & code folks are thinking of the WHAT IF possibility of a handfed furnace during a power outage & no one home to shut down the draft
Obviously some of us are forgetting what would happen under that condition
The heat will crawl up the ductwork
The ductwork will handle the extra heat...
IF duct work of proper spec's has been installed.

This is why im going to call hitzer Direct and see what they say.

Not to be argumentative, but the furnace he is getting is oversized for his house, he will be at just over idle to keep his house warm. A power outage doesn't automatically mean his furnace will reach meltdown temps. The air coming off the furnace wil get hotter without the blower, of course, but to reach 250 under his conditions is very slim.

With my house and setup, I have to run my furnace pretty hot to keep it warm in here, thus the need to close mine down some if the power goes out.

For him to replace all the ductwork in a finished basement would be cost prohibitive, just as a boiler is cost prohibitive for him.

I have state Farm insurance.

In the hitzer manual it doesn't say anything at all about duct clearences, just says a temp rating.

Funny part is some of my hot water baseboard lines are tight against wood, you can even see where it has burned th wood a bit, but the house is still here. I know those pipe get hot

How far is the rise from the top of the Hitzer furnace to the ductwork? Mine is 20 inches and I have metal in that section.

The bottom of my duct work is 78" off the floor the hitzer is 48" to top, so it could be as much as 30".