Wood stove heat reclaiming unit

[Frank S]

For an industrial application I would want to design my heating unit to be at the minimum a tri fuel unit IE gas Oil & organic such as wood pellets or chips. with forced air combustion automatic ash removal the unit would also have an exhaust gas re-combustion chamber with massive thermal mass forced air convection I imagine that I would construct the combustion chamber out of Inconel or the modern equivalent with integral boiler tubes for radiant circulation heating.
There are many secondary heat sources associated in a machine / fabrication facility such as the heat from welding or from the electric motors running the machines.
Vent hoods over welding stations should be able to serve a secondary purpose. They are primarily thought of as a means to removing the fumes but they can also provide a significant amount of passive heating which can easily become passively active by the addition of small thermally powered fans.
Cooling a facility can be more problematic than heating but the total thermal mass helps there as well.

[Toolmaker51]

The only stoves I've run across are small, some had water jackets.
My fervent hope is low-pressure water in iron radiators will be satisfactory. Natural gas and a secondary combustible fuel, to avoid petroleum if possible. I've collected a couple thousand pounds of iron radiators; estimating the surface area of them in comparison to a very large local house [~10,000 sq. ft.]. They'll be on shelves above the floor, near ceiling height. My 6500 sq. ft and 16' flat ceiling need 375k. It will be drywall, with blown insulation. The joists are 8" so at least R19+, windows are glass blocks, so it's sealed decently.
I don't have cooling other than large shop fans. The loading doors are on 3 sides, summer's tolerable.

[Frank S]

placing them high up off the floor near the ceiling id going to be great providing that is where you are working wearing your anti gravity boots.
Sorry thermal dynamics 101 heat rises.
the other side of that coin is having them at floor level they are the most in the way objects in the world. Impossible to keep an area clean around them and if they are near any machine that generates swarf they act like huge chip collection repositories.
Ideally using long finned tubes placed about 3 ft off the floor and having a shelf over them works best
Using the cast iron radiators if they were mounted at about 8 ft high from the floor with a bright surfaced deflector behind and above them and smallish muffin type fans https://www.amazon.com/Achla-Designs.../dp/B001FXVJ1U
behind them or better yet under them forcing a low volume air flow up and around them, the deflector which would be behind and above , plus if louvers were horizontally mounted in front these would direct the air flow down and out.
Heated air almost needs to be moved by convection for best results but a gentle push greatly aids the areas to be covered. drawing the colder air upwards to the radiators will help a lot as well.
Anything that can be done to move the cold stagnant air near the floor to force it to be absorbed with the heated air also helps

[Frank S]

I had all but forgotten about this thread as with many I have started only reminded of it just today by someone thanking me for a post in it.
Let me make an update while the heat reclaiming chamber I made functioned admirably the first winter I used it I later removed it for reasons of difficulty in cleaning of the many passage ways. the cleaning plate I had in it really needed some modifications but as the unit was welded up solid the only way to do this would have been to cut it open make the mods then weld it back up.
However with a hot enough fire the soot would not form on the surfaces and previously deposited soot would eventually be expelled this was hardly possible to do in my house as even on the days that winter that dropped into the single digits due to the amount of reclaimed useable heat available we never were able to build a large extremely hot fire for long enough periods of time or often enough to maintain a decent enough draw velocity which would pull the flames fare enough into the chamber to help with the cleaning. Smaller fires were more than sufeincent to heat nearly the entire 1850 sq ft of the house while not making the living room so unbearably hot. on one day where the temps did not rise above the mid teens we actually had many of the windows and the kitchen door open for a good part of the day because the heater had brought the living room temp to over 100°f and the kitchen to 90°f. For that reason and reasons that it wasn't very aesthetically pleasing
The following winter after removing the chamber I placed about 300 lbs. of ceramic tiles on the top of the stove to serve as thermal mass I still have to watch how large of a fire I build in the thing and not even think about building a fire in the mornings if the outside temps are going to rise into the 50s or better the thermal mass will still radiate enough heat to last until the outside warms up.
I saved the chamber to eventually install in my more than 6000 sq ft work shop but the heater I plan to construct to go under it may possibly be a tri fuel IE wood, oil, or propane