Next year we will move to a new place, and probably I'll build a container kiln over there. Because electricity is quite expensive and I have a wood chipper my self, I was thinking of making a conventional kiln instead of a DH kiln. When heating on wood chips I can use the boiler for heating the house, barn and office with one boiler and buffer tanks. In that way I can get some value out of branches, flints, bark etc. When heating for multiple uses I'd think that the boiler will work more efficiently, not idling all days. And maybe in summer I could add some sun collectors to warm up the buffers.
Is there someone who has experience with heating kilns on biomass and what amount of power should I think of?
Your power will that needed for the fans, vents, water pump and what ever your boiler requires. Add their requirements together and that's it. Sorry but without more information that's all I can tell you.
For the electric power it's not too difficult to determine, but I meant the power of the boiler itself. There are compact woodchip boilers from 50 kW to >500
I am looking for used units and most of them are >100 kW but I don't know or that's too big. If i have to estimate it, I would think something between 50 and 100 kw should be enough, but I don't have any documentary to check this. The boiler shouldn't shut off too often, because every time you start overnew it produce quite some smoke etc.
Following
In Montana I plan to use a Central Boiler 760 HDX, water temp set at 190 deg
heating the following
3 bedroom house
domestic hot water
2 car garage attached to house - future work shop
Hot tub inside garage
30x60 polebarn - set at 45 deg
10x26 greenhouse - in the future
10x24 Kiln - built out of wood
I think to size the boiler, you will some details about size and purpose of areas to heat, as well as insulation, how much hot water you need. I think in a kiln, it will need most heat at start up, or longer time to temp. and of course output can be affected by the quality of the fuel, moisture ect. i would tend to error on the high size. I think of boilers in terms of BTUs. I think the KW can be converted. @GeneWengert-WoodDoc (https://forestryforum.com/board/index.php?action=profile;u=20498)
Usually, when referring to a boiler in lumber drying, we consider that the boiler will be operating over 212 F to that steam is created. Steam has much more heat or energy per length of pipe in the kiln or other heating area. Steam also can be transported more easily than hot water. Finally, a pipe at 220 F releases more heat to the surrounding air that is at 130 F than a pipe at 190 F, or cooler, as heat transfer depends on the temperature difference.
For reference, consider that air dried wood will require about 3 million BTUs into the kiln to drying 1000 Bf of lumber. Due to boiler efficiency and transportation of energy to the kiln, the boiler needs at least 25% and maybe 50% higher rating for the kilns.