| Diesel | 2–8 kW | Approximately 70–250 m³/h of warm air, depending on fan speed and heater design | About 0.10–0.85 L/h | 12 V or 24 V DC | Cars, vans, motorhomes, trucks, buses, and construction equipment | High energy density; suitable for long operating periods; fuel is widely available for diesel vehicles | Produces combustion exhaust; requires a correctly routed exhaust outlet and intake system; diesel can gel in severe cold |
| Gasoline | 2–5 kW | Approximately 70–180 m³/h of warm air, depending on the selected output level | About 0.10–0.65 L/h | 12 V or 24 V DC | Passenger vehicles, SUVs, vans, and smaller recreational vehicles | Good cold-start performance; compact systems can provide strong heat for small and medium cabins | Highly flammable fuel; requires careful installation, ventilation, and exhaust routing; not suitable for diesel-only fuel systems |
| LPG or Propane | 2–6 kW | Approximately 80–220 m³/h of warm air, depending on the heater and fan setting | About 0.15–0.50 kg/h | 12 V or 24 V DC for controls and the fan | Motorhomes, caravans, service vehicles, and vehicles with approved LPG storage systems | Clean-burning compared with many liquid fuels; practical for vehicles already equipped with LPG cylinders | Requires a certified regulator, gas lines, ventilation, and leak protection; cylinder capacity affects operating time |
| Electric Resistance | 0.5–2 kW from a 12/24 V vehicle electrical system; higher outputs generally require shore power | Approximately 25–100 m³/h, depending on electrical input and fan design | 500–2,000 W electrical input | 12 V, 24 V, or 120/230 V AC | Small cabins, windscreen demisting, short-duration preheating, or vehicles connected to shore power | No combustion exhaust; simple operation; low maintenance; useful where fuel installation is not practical | High current demand on 12/24 V systems; can rapidly drain a battery; limited heating capacity when disconnected from mains power |