The new building for the cabin trim activities will also be CO2-free. Its equipment includes a solar boiler, heat pumps and photovoltaic cells. Also, by analogy with the truck assembly plant, bright colours have been chosen for the walls and floors. Roof lights increase the incidence of natural light, while floors are surfaced with a light epoxy layer.
The new building is approximately 11,000 m² in size and contains a production zone, a pre-assembly and materials handling area and social buildings.
Solar boiler
Hot water in the building is produced using a solar boiler. Solar collectors have been placed on the roof to gather the solar energy. These achieve maximum efficiency when directed southwards at an incline of 45 degrees. The solar collectors contain a liquid that is heated by the sunlight. This liquid transfers its heat to the cold mains water in the solar boiler. In summer this boiler heats sufficient water to a comfortable temperature. In winter additional heating is needed. Business companies are also subject to legionella legislation, which means that the water leaving the boiler must be heated to at least 60°C and in the return piping to a minimum of 50°C. The additional heating in the cabin trim project will be provided by heat pumps.
Heat pumps
The heat pumps that have been chosen for the cabin trim project use the environmental heat (outside air) for space heating and for additional heating of sanitary hot water. The principle of a heat pump can be explained simply based on the way a refrigerator works. When we place a bottle of milk in the fridge, the idea is that the temperature of the milk should become and remain lower. An evaporator inside the refrigerator withdraws heat from the bottle, which cools the milk. The heat withdrawn in this way is released via the condenser grill at the back of the refrigerator. The entire process is driven by a compressor. In the case of the cabin trim plant, heat is withdrawn from the outside air by means of the heat pump, with a condenser then used to transfer the heat given off to a low temperature emission system (max. 50°C). All current heat emission systems, like radiators, convectors and underfloor heating are suitable for this. In heat pump systems the principle is: the lower the transfer temperature, the higher the heat generation yield. The energy yield of a heat pump lies between 3.5 and 4. This means that 1 kWh of incoming electricity produces at least 3.5 kWh of thermal energy.
Photovoltaic cells
In photovoltaic systems, solar cells convert the collected light directly into electricity. The electricity generated is delivered via a transformer (converting DC into AC) directly into the electricity network. The amount of energy produced by the photovoltaic cells varies with the available and incident light and the temperature of the solar cells.
K-level
The new cabin trim building has an insulation level of K45. The K-level of a building tells us how well it is insulated. The K-level is determined by the U and R values of the various wall parts and the compactness of the building. The lower the K-level, the better the building is insulated. The U-value or coefficient of heat transfer (expressed in W/m²K) tells us how much heat is lost per second and per m² at a temperature difference of 1°C between the inside and outside of the building. The lower the U-value, the better the wall insulation. The R-value or heat resistance (expressed in W/mK) expresses the heat conductivity of a material. The higher the R-value, the greater the heat conductivity.