What Size Diesel Heater Do I Need? 2KW vs 8KW Sizing Guide
If you are asking what size diesel heater do I need, you are already ahead of most winter campers. A heater that is too small never catches up on a 10-degree night, and one that is too big cycles on and off, wastes fuel and dries out the air. The good news: for most people the choice comes down to two sizes, 2KW and 8KW.
Quick Sizing Chart: 2KW vs 8KW
| Space | Typical size | Pick |
|---|---|---|
| Truck bed tent, 2-person tent | Up to about 100 sq ft | 2KW |
| Ice shack, hunting blind, truck cab | Up to about 120 sq ft | 2KW |
| Cargo van, camper van, small boat cabin | About 100-200 sq ft, poorly insulated | 8KW |
| RV, travel trailer, one-car garage | About 200-400 sq ft | 8KW |
Three Things That Change the Answer
1. How cold it gets
A 2KW unit is plenty for a tent at 35 degrees. Below 15 degrees, or with wind, step up to 8KW so you are not running flat out all night.
2. Insulation
Bare metal vans lose heat fast. If your van has no insulation yet, size up. A well-insulated small camper can often get by with less.
3. How fast you want it warm
An 8KW heater on a low setting warms a van in minutes and then idles quietly. A 2KW heater is slower to warm up but sips fuel.
Our Picks by Situation
Best for tents, truck beds and blinds: 2KW
The VEVOR 2KW Diesel Heater, 12V/24V All in One Diesel Air Heater, with Bluetooth APP Control, Remote Control and Display Screen, CO Alarm, Fast Heating Portable Diesel Heater for Vehicles and Outdoors has app and remote control plus a built-in CO alarm, which matters most in small enclosed spaces.
Best for vans and RVs on a budget: 8KW
The VEVOR Diesel Air Heater, 8 kW DC12-24V, Fast Heating Diesel Parking Heater with Remote Control and Square Color Digital Display, Low Noise, Voice Announcement, for RV, Truck, Camper, Boat and Trailer has a color display and voice prompts, so it is easy to set and forget.
Best for camo fans and hunting trucks: 8KW
The VEVOR 8KW Diesel Heater, 12V/24V All in One Diesel Air Heater, Bluetooth APP Control, Remote Control and Display Screen, CO Alarm, Fast Heating Horizontal Portable Diesel Heater for Vehicles, Garage sits horizontally, fits under a bench or in a truck bed, and adds Bluetooth control.
Gear That Makes Winter Camping Easier
- Sleep off the ground in a VEVOR Truck Bed Tent, 5.5'-6' Pickup Truck Tent with Rain Layer and Carry Bag, Waterproof PU2000mm Double Layer Truck Tent for Camping, Accommodate 2-3 Person, for Camping Traveling Outdoor Activities so your heater only has to warm a small space.
- Keep food and drinks organized in a VEVOR Insulated Portable Cooler, 52 qt, Holds 50 Cans, Ice Retention Hard Cooler with Heavy Duty Handle, Ice Chest Lunch Box for Camping, Beach, Picnic, Travel, Outdoor, Keeps Cool for up to 6 Days. In winter it keeps things from freezing as much as it keeps them cold.
See every size side by side in our Diesel Heaters collection, or read Diesel Heater vs Propane Heater if you are still deciding on fuel.
Who This Is For
Truck campers, van owners, RV travelers, hunters and anyone heating a small space this winter who wants to buy the right size the first time.
Frequently Asked Questions
Is 8KW too much for a van?
No. Most 8KW units run on low settings in a van and only use full power to warm up quickly or on very cold nights.
Can a 2KW heater heat an RV?
Only a small, well-insulated one in mild weather. For most RVs and travel trailers, 8KW is the better choice.
Does a bigger heater use more fuel?
Fuel use depends on the setting, not just the size. An 8KW heater on low uses roughly the same fuel as a 2KW heater on high.
The Bottom Line
Small space and mild cold: 2KW. Vans, RVs, garages or real winter: 8KW. Pick yours before the next cold front and test it at home first.