Alde water heating for motorhomes: the miracle boiler from Sweden
Alde Rask was a true tinkerer and inventor. The Swede conducted research in many areas from the 1940s. He developed trailer accessories, electric brakes, circulation pumps – and also a caravan.
Today the name Alde stands for one thing above all: water heaters. In contrast to the German market leader Truma, the Swedes do not rely on warm air as a heat transfer medium, which selectively heats the room through air nozzles at various points in the vehicle. The Alde heating works according to purely physical principles.
Heat exchanger particularly sustainable
Due to the complex structure, the Alde heating is not suitable for retrofitting; it must be ordered when purchasing the motorhome. The biggest disadvantage of the system is its weight. Speaking of which, the price is also important.
Depending on the equipment, a water heater costs from 3700 euros. Anyone who only travels south for a few weeks a year will not want to invest that. But in motorhomes that are used all year round, this investment is always worthwhile.
The heat exchanger is particularly sustainable because it uses the heat from the engine to heat the interior. More than 60 national and international manufacturers offer the Swedish heaters as standard or at extra cost. The production of the Alde systems has always taken place on the site of the former workshop from the 1940s.
90 percent of all heaters produced in Färlöv are exported. From a small village in southern Sweden out into the wide world to the USA and South Korea. Because not only the Scandinavians appreciate the feel-good warmth.
A robot does the welding
The heart of the system is the heating chamber. This is later in a cylindrical shape. Welding is required to connect the sheet metal ends. This first work step is one of the few in production that is performed by a robot.
Employees put the bent sheet into the machine, which then welds both ends firmly and neatly together. The use of this machine has several advantages: increased production, occupational safety and a reduction in error tolerance.
Leak testing and assembly
After each welding step, the components are placed in a water bath. This checks whether the weld seam is tight. Leaks must not occur in the closed water system. Only when no bubbles appear does production continue.
The heating boiler, which is also round and welded, is now mounted around the heating chamber and both are firmly connected to the base and lid. Later, the heat spreads from the inside to the outside, heating the water in the heating boiler and the glycolic liquid that flows through the convectors, underfloor heating pipes and towel warmers.
Control board and electrics
After installing the heating rods and burner, the control board is installed, as well as the wiring and connection of the electrical system. The circuit board later controls all the electronics of the heating system. The combustion chamber itself has both a gas burner and at least two electric heating rods.
The customer later operates all heating functions via the control panel or the special Alde app and can decide whether to heat with gas, electricity or a combination of both.
Final inspection on the test bench
Although each individual step has already been checked during the entire production process, a comprehensive final check of the entire heating system is carried out at the end.
Experienced employees check the electronics, functionality and tightness of each individual heater on a standardized test bench. Only when everything is in order here is the system sent to manufacturers in Scandinavia and the rest of the world.
The finished water heater
The cylindrical heating unit, together with the water heater and insulation material, is in the rectangular metal housing. But the heating unit is only a part of the heating system.
Extreme test in our own cold chamber
Every heater can only be as good as it is installed in the vehicle. That is why well-known manufacturers and Alde constantly test together in the company’s own cold chamber under extreme conditions.
First, each test candidate is equipped with sensors throughout the vehicle and then exposed to 24-hour cooling. After the prescribed time, the heating-up phase takes place and the heat distribution is checked.