Insulating and heating my workshop with a diesel heater

I mentioned this in some weekly posts, but wanted to write a dedicated one so I have a place to link to in the future.

Working out in my 10’x14′ workshop on a cold day in January and shivering, I resolved to finally put in some heat.

My first idea was a tiny top-loading wood stove that I could burn offcut chunks in. I priced out some options, but it ultimately had three big downsides:

They take a while to heat up and cool down. I can’t just go out there and work for an hour, I need to start the fire an hour before, keep an eye on it, feed it while I work, and make sure it burns out before I go back in the house.

They are expensive! The cheapest one I could find new was $350, and the quality was iffy. Good ones were over $1000 and made for sailboats. Used ones are hard to come by, too.

They take up valuable floor space. This matters in a tiny shed.

When I was chatting with my Dad about it, he asked,

“Have you considered a diesel heater?”

I hadn’t, mostly because I had never heard of one. I knew I didn’t want a loud, smelly forced air propane heater, and that is that I thought a diesel heater was, but I was totally wrong. They are small, quiet, and fuel efficient. People often use them in RVs, ice fishing huts, hunting cabins, and garages.

We settled on a Silvel 8KW, 12V version, which my parents gifted to me for my birthday. To power it we used a 120V -> 12V converter.

In order to make a heater worthwhile, I needed to insulate. It had bare studs with plywood paneling on the outside.

I went with double reflective insulation because it is cheaper and easier to install than fiberglass (less itchy too!) and less messy than spray foam. It won’t keep the space conditioned all the time (not a good choice for a house), but it will work long enough to keep the space heated while I’m working out there.

I used the 16″ width for between the rafters and 48″ on the inside of the roof. I put up about half of it myself and Dad helped with the other half over President’s Day weekend.

Once we got the insulation hung, we installed the heater. We opted to install it outside to reduce the noise, save space, make exhausting it easier, and not have to worry about filtering out dust from the air intake. We piped the hot air in through the wall.

I set up a French cleat shelf outside on the back of the shed under my kayak storage overhang to keep it out of the rain. Air intake and exhaust go through a hole in the bottom of the shelf. We used a hole saw to cut a hole big enough for the pipe to go through, ran wires for power, and secured everything in place.

The heater works great! It runs for about 14 hours on a gallon of diesel, give or take depending on which level you run it on. (It has levels 1-10).

After running for ~3 hours on level 10, it got the cold shed up from 36F to 70F. Incredible.

A month later I’m still very happy with it. Working in a warm workshop makes a huge difference. Even after I turn the heater off, the shed holds heat in for a while as long as the door is closed. I tried to seal as many gaps around things like the door as I could with weather strip.

Up next: A post about building and installing the work bench, and a post about the french cleat tool storage.