My experience with Chinese diesel heaters is one of trial and error mixed with educated guesswork. I wanted to be able to keep my 38’ travel trailer warm a -30 degrees Fahrenheit. Since I rebuilt the trailer with this in mind I insulated the walls and ceiling at r10 and the floor at r14 using polyiso insulation. This compares to the theoretical r3.5 the trailer came with. I chose to use diesel heaters primarily because the lp furnace we used on our other similar size camper could not keep up with the cold once the temperatures dipped into the teens mostly because the tanks would get cold and not supply enough propane to the furnace. Secondly the diesel heaters are small enough to fit in the limited space we had available. Third since at least two diesel heaters are required to meet the heat demands of the size of my travel trailer at -30 and one will work down to 10 degrees the redundancy of two heaters is helpful as only one will be absolutely needed for most of the heating season in addition the lp furnace is still available in an emergency. Fourth the electrical power consumption of the diesel heater is considerably less than the lp furnace.
Our definition of comfortable is temperatures in the upper 60s with usable hot and cold water.
The first thing was to figure out how much heat I would need to supply the trailer. Time for google.
A quick check of a btu calculator shows a minimum requirement of 42000 btu to accomplish this feat.
Unfortunately each heater maxes out at a 5.5k heat input. That’s about 18,000 btu per heater 36,000 btu total. Obviously no heater is 100 percent efficient so I won’t actually get 36000 btu of heat. Fortunately the calculator that I used is designed for calculating the installation of a wood burning stove so I can assume that the actual btu output required for my space is closer to 34000 btu. That’s close enough for me to go ahead with the experiment. I installed 2 5k diesel heaters and before I insulated the floor I ran 300’ of 3/8 pex pipe throughout the floor to see if I could capture the lost heat from the exhaust and return it to the floor to keep the tanks from freezing and make the floor warm. I installed the heaters. I found that into the teens a single heater was sufficient but at that temperature two heaters actually used less fuel apparently the efficiency of these heaters drops the hotter they are fired. So I figured I had close to enough btu output to keep the trailer “warm” at -30 but how am I going to keep my water tanks and pipes from freezing below the floor. My idea is to use exhaust heat recovery to pipe warmed water throughout the floor and around the holding tanks. According to you tube channel “David Mcluckie “ he has concluded by experiment that a coolant heat recovery system can extract between 500 to 800 k of heat. That’s potentially more than a conventional electric space heater at almost 5500 btu. I used 2 egr coolers originally designed for the 6.0 liter ford powestroke engine as my heat exchangers and a small 12v hot water pump attached to a overflow tank in order to circulate the coolant through the 3/8 pipe I had previously installed. The installation was full of challenges but the end result was that I was able to keep the inside of the camper at 64 degrees at -31. We can live with that.
Our definition of comfortable is temperatures in the upper 60s with usable hot and cold water.
The first thing was to figure out how much heat I would need to supply the trailer. Time for google.
A quick check of a btu calculator shows a minimum requirement of 42000 btu to accomplish this feat.
Unfortunately each heater maxes out at a 5.5k heat input. That’s about 18,000 btu per heater 36,000 btu total. Obviously no heater is 100 percent efficient so I won’t actually get 36000 btu of heat. Fortunately the calculator that I used is designed for calculating the installation of a wood burning stove so I can assume that the actual btu output required for my space is closer to 34000 btu. That’s close enough for me to go ahead with the experiment. I installed 2 5k diesel heaters and before I insulated the floor I ran 300’ of 3/8 pex pipe throughout the floor to see if I could capture the lost heat from the exhaust and return it to the floor to keep the tanks from freezing and make the floor warm. I installed the heaters. I found that into the teens a single heater was sufficient but at that temperature two heaters actually used less fuel apparently the efficiency of these heaters drops the hotter they are fired. So I figured I had close to enough btu output to keep the trailer “warm” at -30 but how am I going to keep my water tanks and pipes from freezing below the floor. My idea is to use exhaust heat recovery to pipe warmed water throughout the floor and around the holding tanks. According to you tube channel “David Mcluckie “ he has concluded by experiment that a coolant heat recovery system can extract between 500 to 800 k of heat. That’s potentially more than a conventional electric space heater at almost 5500 btu. I used 2 egr coolers originally designed for the 6.0 liter ford powestroke engine as my heat exchangers and a small 12v hot water pump attached to a overflow tank in order to circulate the coolant through the 3/8 pipe I had previously installed. The installation was full of challenges but the end result was that I was able to keep the inside of the camper at 64 degrees at -31. We can live with that.