Updated: Nov 30, 2020
The need for a better heat source came while stuck in Fairbanks Alaska with a broken rear axle. With snow in the forecast, sleeping in a ground tent and winter closing in we decided to try and build a little DIY diesel heater.
Our only heat source (outside of a camp fire) leading up to this point had been a small Mr Heater Little Buddy. While it had enough BTUs for our small roof top tent there were a few disadvantages. The physical design of the heater was very top heavy and it was always trying to tip over. Even the slightest tip or movement shuts off the heater as a precaution so even small movements while we were sleeping often turned off the heater. Also with just a small Coleman style 1lb propane tank the heater only had a run time a little over 5hrs which wouldn't last though some of our coldest nights on the road. However the worst disadvantage to propane heating is the build up of condensation inside our roof top tent. When we would awake the next morning it looked as if a sprinkler had gone off inside our tent. Not good especially on damp rainy days.
Enter the cheap Chinese Diesel heater. Often referred to as Parking Heaters they are small diesel engines that efficiently heat small to medium spaces . A few years ago it seems the manufacturers in China decided to start producing these heaters for about a 10th of the cost of say a Espar or Webasto! At about $100 on Amazon or eBay it's hard to beat. They produce a very hot and dry heat and are more than enough for our roof top tent. The heater is also very efficient with fuel. Ours uses about a gallon of fuel for every 24hrs of heating, sometime less if we have it at the lowest setting.
The thing is they come in a very DIY form. You have to figure out where to mount the heater and how to run the ducting, exhaust, fuel, electrical and so on. Below is a photo of the heater out of the box getting ready to be placed in a weather proof tool box we can mount on our rear bumper.
The heater has an intake and exhaust manifold along with a small fuel port that pokes out the bottom of the heater. A metal plate is provided that sandwiches the heater to a flat surface and also allows for safe heat dissipation near the hot parts of the heater.
Here is the heater mounted in a nice weather sealed tool box. A simple rectangle cut out of the plastic and bolts tightened up we're on our way to having a heater in a box.
Next was to cut a hole on either side of the tool box to allow for the input and output ducting. On the left of the box outside air is sucked in it goes though the heater, warms up and then exits the heater on the right. The flush mounted air intake is included but I was somewhat stumped on how were going to get the hot air into our tent. After going to Home Depot a couple times I found a pretty neat dryer vent coupling. It flush mounts to the tool box and allows us to connect and disconnect a standard dryer hose really easily (hard to see in the last picture). In the second picture above you will noticed the fuel filter and fuel pump. The fuel pump makes a fairly loud ticking noise so a rubber isolated bracket is included to help keep it more quite. I also replaced the included inline fuel filter as it was made very poorly and leaked. Both are connected together with fuel line. We can now put the fuel line into a temporary diesel tank and see if this thing works.
Pardon the mess! Here is heater on the tailgate starting up for the first time. You'll see the included shiny articulated exhaust pipe and a black hose connected to an air filter. After learning how to prime the pump the heater started right up every time.
After running it for a few hours on the tail gate making sure we weren't going to burn down the forest we set up the heater on our stool and piped in the ducting to the tent. This all happened just in time for the first snow fall. Literally set up the heater as the first snow flakes started to fall. Good timing! We ran it for about 24hrs straight to see how everything went and make sure nothing over heated. It really heats up the tent quickly and again such great warm heat. As you can see the snow is melting off the tent. Successful DIY project complete and no more freezing faces while trying to sleep.
Look for a follow up post showing more about how it connects to power and how much fuel and power it uses. Stay tuned.