I got the pics on the boiler, its a real beast! I talked with a friend who does hvac on the side and he said it would probably be too big for the garage and house. I did also end up talking with my cousin who said he could get me a smaller wood furnace (not boiler) for free! So, it looks like I'll be taking advantage of that. Perhaps it can even be modified to heat some water for the house.

I still really like the idea of some sort of boiler system.

That way, both the boiler and solar panels could heat a common fluid for heating the garage.

Gasifiers are easy to use as boilers.

Some wood stoves aren't hard to hook a liquid heat exchanger on. It depends on their size, shape, and design.

The other advantage of a gasifier I forgot to mention is that they don't smoke. That's an advantage if you have a neighbor downwind from you who you don't want to send wood smoke to.

Daox, if you have solar hot water panels to Collect heat for the garage, how do you want to RELEASE that heat in your garage?

I think your garage is on an uninsulated concrete slab, right?

My dad has a big back room "shop" off the back of his garage. In that area, he laid down foam flat on the concrete and put a plywood floor over the top of that. It is amazing how much warmer it is in that area.

You could do the same thing but put down PEX tubing and have a hydronic floor garage!

I never finished the build on this (yet ) but I have a non-condensing boiler as when I replaced my boiler a couple of years ago for layout reasons I had to go floor mounted and all the condensing boilers were wall mounted. If you hold your hand above the flue outside the house the amount of heat venting to the outside is a lot (even with a condensing boiler it would be considerable.) SO I built a heat exchanger with a shroud to channel the boiler exhaust flow (outside the house so as not to impede the exhaust fumes) through a heat exchanger coil and got very hot water out . I have only just completed a pipe run under the floor space right through the house to the garage on the other side of the house to the boiler so am pretty well set to complete this project ).Still have to install a pump, wind a new acid resistant heat exchanger coil and connect the whole shebang to a radiator I have installed in the garage.

A potential problem is the condensate is acidic and I have yet to wind a new heat exchanger in PVC covered copper to replace my original coil (which has lasted so far ). I got a lot of other projects and got lazy last winter and used a fan heater in the garage. Looking at my winter electricity bill last year I think I must shortly complete this project or go bankrupt.

Anyway having tested the o/p of my initial coiled heat-exchanger I'm pretty convinced this will work ok and give me a garage/workshop heated for free. If any of you guys with a boiler feel the heat going out with the flue gases you might be tempted to go the same way. Even if you don't heat the garage with it you will still have a lot of "free" heat to use anyway you want. I felt very gratified when I saw recently that in the UK we can now buy a commercial version of this system .

Sounds like a great idea Big Al. It would be very cool if you could start a new thread about this and post up some pictures! :)

Well, me and Ben Nelson picked up some solar hot water panels that will likely be my source of heat for the garage in the winter. Check out the link below for more info:

http://ecorenovator.org/forum/solar-...nels-free.html

I just priced out some propane and propane accessories.

$180 spent at Tractor Supply gets me a 2.6kW (9000BTU/hr) indoor-rated propane heater, a 20lb tank, a CO detector, and 20lbs of propane. $220 for the same thing with 5kW instead.

It would take about $200 in fiberglass to insulate my garage to R13. Whether or not I decide to insulate, I will need to seal the garage, as it's very well ventilated right now. In fact, I should probably start by sealing the garage and seeing how much geothermal heating rises up from my garage's compacted gravel floor.

2.6kW is probably not enough. IF I were able to seal up the garage 100% (not going to happen), 2.6kW running 24/7 is just enough to hold my garage 32°F warmer than the air outside. That's probably not warm enough to really work outside.

There is the electric option, but a 15A circuit can only pass 1.8kW, which isn't enough to heat more than just a person in the garage.

Sounds like the $40 additional for the 5kw system would be money well spent.

32F warmer than outside is probably fine IMO. Once it becomes winter, 40 degrees even feels like summer.

Hmm, make that $130/$170, since I can use the 20lb tank off my dad's propane grill. That should give me 20hrs run time on the larger unit. The larger unit will also be more efficient, by virtue of getting things up to temperature quicker so I don't spend as much time preheating the garage. Ambient +32F might be sufficient, but the 2.6kW unit would take forever to get there, and that's with a number of generous assumptions, including my garage being R3. Obviously adding R13 on top of that would cut steady state fuel use to one fifth.

Too bad I don't need another project right now, because this would be a good one.