This project goes over the build of an inexpensive garage heater using a DIY outdoor barrel stove with a heat exchanger. This outdoor setup is safe because you don’t want the stove inside the garage to catch fire if you are working with any flammable gas. We use a 30-gallon drum for the stove. The access doors and legs are purchased from the local store.
STEP 1 : MAKING THE HEAT EXCHANGER
The heat exchanger is made out of a four-inch steel pipe. We take a couple of 4-foot pipes and weld them together using another small pipe. This pipe goes inside the firebox and connects to the chimney pipes. The pipe should be thick enough that it can withstand the heat of the fire without sagging or bending. This pipe heat exchanger adds positive pressure.
STEP 2: CONNECTING THE CHIMNEY TO THE BARREL
Removable hatches are made on one side of the stoves to connect the 2 four-inch aluminum flex chimney pipes from the outside barrel to the garage.
STEP 3 : INSTALLING A BLOWER FAN
Inside the garage, we place a 4-inch exhaust fan blower that sucks the colder air from the floor and blows it through one of the flex chimney pipes into the stove. The blower is actually a hydroponics duct exhaust fan purchased from eBay.
The cold air gets pushed into the stove and moves through the heat exchanger steel pipe, gets heated, and then moves out through the second chimney flex pipe and back into the garage. The hot air from the stove moves into the garage through the second pipe.
STEP 4 : ADDING A DRIP FED WASTE OIL SYSTEM
In order to get more hot air, we also add a drip-fed waste oil system to the outdoor stove. The oil gets dripped slowly from a tank into a frying pan on top of the stove. You can add cotton rags and let it drip into there and it just keeps burning like a wick. The combination of both wood and waste oil produces better fire. If the stove gets too hot, you can turn off the oil or use oil only to maintain the temperature. You can put an insulated shack around the stove to minimize heat loss.
Image Credits : Ron Stickle