You don't have to sail to the North Pole to need a heater on board your boat. The advantage of heating is that it dries out and renews the air. On a boat, humidity is a recurring problem. There is nothing better than a heater to combat it.
Webasto has the solution. This equipment manufacturer meets the needs of comfort on board. It offers forced air heaters, but also water heaters, air conditioning, Isotherm refrigerators or even sunroofs for boats. This company has acquired its know-how by being one of the largest automotive suppliers.
Principle of forced-air heating
Forced-air heating consists of a burner (a small boiler) that burns diesel oil (the same as the one that powers the engine). This rear mounted boiler is connected to a through-hull with a gooseneck (pipe on the outside like an exhaust outlet) to remove the burnt gases. Air circulates through the boiler and is directed to the cabins using a built-in electric fan.
A circuit of ducts running throughout the boat directs hot air into all cabins. We understand that the closer we are to the boiler, the hotter the air will be. By limiting the distances, heat loss is reduced.
Heating adapted to small boats
Webasto has 3 models: 2 kW, 4 kW and 5.5 kW. The fuel consumption is very limited. Indeed, the largest model consumes only 0.61l/h (0.67l/h in boost mode at full power). Electricity consumption remains limited with between 1.2 and 2.4 A per hour at 12 V for the small model.
The heating is regulated by a thermostat (like at home) with the possibility of equipping a programmable controller with heating time schedules: the MultiControl.
Forced air heating will be useful in winter to dry out a boat or to keep warm in the saloon. But this system is also useful in the summer to renew the air in the boat and clean the interior.
Characteristics of Webasto forced-air heaters
| Model | Air Top 2000 STC | Air Top EVO 40 | Air Top EVO 55 |
| Heating capacity | 0.9 - 2.0 kW | 1.5 - 3.5 kW (4.0 kW*) | 1.5 - 5.0 kW (5.5 kW*) |
| Electrical Voltage | 12 V | 12 or 24 V | 12 or 24 V |
| Power consumption | 14 - 29 W | 15 - 40 W (55 W*) | 15 - 95 W (130 W*) |
| Fuel consumption | 0.12 - 0.24 l/h | 0.18 - 0.43 l/h (0.49 l/h*) | 0.18 - 0.61 l/h (0.67 l/h*) |
| Air flow rate | 93 m3/h | 140 m3/h | 220 m3/h |
| Dimensions | 311 x 120 x 121 mm | 423 x 148 x 162 mm | 423 x 148 x 162 mm |
| Weight | 2,6 kg | 5,9 kg | 5,9 kg |
* Enhanced heating power with Boost mode for 6 hours with Air Top Evo 40, or 30 minutes with Air Top Evo 55.
