Horizontal Diesel Heater for Trailers

Why Trailers Benefit from Diesel Heat

A trailer has no running engine to tap for heat, and relying on electric hook-up leaves you exposed at unpowered sites. A horizontal diesel heater solves both problems by burning diesel stored in a small tank to warm the cabin, whether you are parked at a remote campground or a roadside rest stop. The flat housing fits neatly against a trailer frame or inside a storage bench.

Suitable Trailer Types

The heater suits caravans, travel trailers, toy haulers, horse trailers, and enclosed work trailers. In living trailers it keeps sleeping and dining areas comfortable, while in horse and cargo trailers it prevents freeze damage and warms the space for people working through cold days.

Mounting in a Trailer

Mount the unit low on a rigid bracket near the floor, away from wheel spray and baggage. Run the exhaust through the floor or side wall with a downward loop, and route the warm-air duct up into the cabin. Ensure the heater is accessible for filter changes and that the control switch sits within easy reach of the door.

Heating the Living Space

Use insulated ducting to carry warm air to the bedroom, dinette, or wash area. A single outlet near the center of the trailer often balances heat well, while larger trailers benefit from two ducts. Closing off unused rooms helps the heater reach target temperature faster.

Power When Parked

The heater draws only a small amount of 12 volt power, so a modest battery or solar setup can support overnight heating. Keep the battery charged and the heater on a thermostat to avoid draining it by morning.

Cold-Weather Reliability

Diesel heaters are built to start and run in low temperatures, making them ideal for winter camping and frost protection. Let the heater complete its cool-down cycle before cutting power to protect the glow plug and combustion chamber.

References

Karjalainen, P., Nikka, M., Olin, M., Martikainen, S., Rostedt, A., Arffman, A., & Mikkonen, S. (2021). Fuel-operated auxiliary heaters are a major additional source of vehicular particulate emissions in cold regions. Atmosphere, 12, 1105.

Miklnek, L., & Gotfrd, O. (2014). Study of exhaust emissions reduction of a diesel fuel operated heater during transient mode of operation. Czech Technical University in Prague.

Zietsman, J., Johnson, J., Ramani, T., Farzaneh, R., Rodgers, M., Samoylov, A., Xu, Y., & Moore, A. (2015). Effectiveness of idle reduction technologies in reducing driver exposure to diesel emissions. Transportation Research Record: Journal of the Transportation Research Board.