This AUTOTERM Air 4D diesel air heater with marine kit is an independent, engine-independent heating system for cabins and other enclosed spaces in boats, yachts, and vehicles. This 24 V version delivers up to 4 kW of heating power and 168 m³ of hot air per hour. It is recommended for boats of 10–12 m in Mediterranean climates and 8–10 m in Nordic climates.
The heating power is adjustable from 1.0 to 4.0 kW, while the airflow can be adjusted from 70 to 168 m³/h. The electrical power consumption is 10–56 W. The heater uses diesel according to EN 590 or HVO100 according to EN 15940 and has a fuel consumption of 0.12–0.514 l/hour. A separate metering pump delivers fuel from the vessel's main tank or an auxiliary tank. The integrated altitude function supports operation up to 4,200 m above sea level.
The heater measures 402 × 157 × 188 mm and weighs 5.5 kg. The kit includes a fuel metering pump, fuel pump cable with connector, air intake pipe with silencer, 1.8 m control panel cable, Ø24 mm heat insulation, exhaust silencer with mounting kit, 1 m exhaust pipe, 1.5 m nylon fuel line, and AT0001 mounting bracket. The bracket is made of 3 mm AISI 316 stainless steel and measures 250 × 143 × 10 mm. Control panel is not included.
The heater must be installed on a flat, dry, and protected surface with the cable side facing right or upwards. There must be at least 50 mm of free space at the hot air intake and 150 mm at the outlet. A Ø90 mm air distribution system can be used together with the Air 4D adapters P5313 and P2423. The first meter of hot air ducting must be routed as straight as possible, and system components must be able to withstand up to 130 °C. Combustion air must not be drawn from living areas, engine compartments, or luggage compartments, and at least 20 cm of space is recommended between the air intake and the exhaust outlet.
Integrated sensors and safety functions automatically interrupt operation in case of, among other things, overheating, excessively high hot air temperature, sensor errors, repeated failed start attempts, or supply voltage below 20 V or above 30 V. The temperature can be regulated with a compatible Simple Control, OLED, or Comfort Control panel. Manual control, remote control, or modem control depend on the installed control equipment. Supplying fresh outside air can reduce humidity, while recirculating cabin air provides faster heating without air exchange.
The product is type-approved according to UNECE R10 and UNECE R122. An annual inspection should include electrical connections, fuel lines, exhaust, air intake, and hot air ducts. Outside the heating season, 20 minutes of operation at full power once a month is recommended. During longer storage, the heater can be disconnected from the battery to avoid the standby consumption of 30–40 mA.
Supplementary products
Analog control panel: item no. 50.251.11
Digital control panel: item no. 50.251.01
5 m extension cable for control panel: item no. 50.251.12
Air distribution kit with three Ø90 mm outlets: item no. 50.254.63
Air distribution kit with four Ø90 mm outlets: item no. 50.254.64
Ø24 mm exhaust adapters: item no. 50.255.01, 50.255.02 and 50.255.03
Key featuresDiesel-powered air heater for boat and vehicle
24 V DC and up to 4 kW heating power
Adjustable airflow of 70–168 m³/h
Fuel consumption of 0.12–0.514 l/hour
Recommended for boats of 8–12 m depending on climate
Automatic fault monitoring and safety shutdown
AT0001 mounting bracket in 3 mm AISI 316 stainless steel
Type-approved according to UNECE R10 and UNECE R122
