Innovation for our own ends
Lasers need cooling, people need warmth: When PRIMES constructed its annex in 2012, the aim was to achieve maximum sustainability, and to that end we employed the latest technology for energy efficiency, with cisterns, solar system and concrete core activation. The result was an energy concept that was an all round winner, using the waste heat of the lasers, for example, for heating purposes and stockpiling cold water in a cistern. A building of 1,000 square metres of usable space, which requires (almost) no heating and no air-conditioning, is the result. A superb effort on the part of engineers. Environmental friendly and efficient.
Generating cooling for the lasers
For the strongly varying cooling requirements of the PRIMES lasers two water tanks were sunk into the ground outside the building. Each water tank stores 25 cubic metres of cold water.
If heat is needed for building heating, the heat pump takes it from the cistern and makes it available to the heating circuit. The heat pump itself only has a heating power of 14 kW. Due to the long running time during the heating period, however, enough cold water is generated that for short periods cooling capacities up to far in excess of 100 kW are available. In summer, the heat pump releases its heat via heat exchangers to the outside air.
Heating and cooling of the building
All heating and cooling occurs through concrete core activation of the ceilings. This method, which is also called concrete core temperature control, uses the capacity of the ceilings and/or walls of a building to store thermal energy and uses it to heat or cool rooms.
Water pipes were buried in the concrete of the ceilings at intervals of around 15 cm, which can heat or cool the concrete by means of the water flowing through. In winter, the circulating water is heated up to 23 C with the heat pump. This obviates the need for room-based heating control. If the water tanks were not be able to supply sufficient heat in periods of low outside temperatures, the gas heating provides additional heat. Per heating season, on average 20,000 kWh of waste heat can be recovered.
In summer the water of the concrete core activation is cooled back down via the tank water. In this way, pleasant room temperatures are achieved even without expensive and energy intensive climate control.
Heating and cooling of the building
Thanks to the southern orientation of the room and the installation of a saw-tooth-roof it was possible to install a solar power system of 51 kWp. Of the 50,000 kWh generated, PRIMES requires around 35,000 for its own use.
Impressive result
Through the combination of heating and cooling in conjunction with heat recovery via large buffer storage, energy consumption has been massively reduced. And as a pleasant side-effect, it was also possible to reduce investment in the cooling plant: instead of installing 100 kW cooling power operating all the lasers, only 12 kW of cooling power were installed.