Using process heat for indoor heating

SERO GmbH premises

In the new production and administration building, a two-pipe system with heat recovery ensures that heat energy is transferred within the building as needed. (Copyright: Mitsubishi Electric)

Industrial manufacturing processes generate waste heat that often goes unused and is simply released into the environment. The company SERO GmbH manufactures electronic assemblies and equips printed circuit boards. Its new building uses process heat generated from the first-floor production facility to heat the offices above. This is made possible by smart building technology and a simultaneous heating and cooling system with heat recovery, supplemented by a ventilation system that uses external air conditioners and heat exchanger coils to precondition fresh air.

Most of the production heat is drawn off using a VRF R2 system from Mitsubishi Electric. Each of the two stories is cooled by ten 4-way ceiling cassette air conditioners. Each interior unit has a cooling capacity of 10 kW, while four exterior units with different capacity levels are installed on the roof of the production facility.

Administrative offices heated entirely by waste heat

The phase separation of the coolant used between interior and exterior devices is carried out in two central refrigerant distributors (BC controllers). These BC controllers transfer surplus thermal energy to one of six water heat exchanger units as needed. The heat exchanger units then transfer the thermal energy from the coolant to the heating circuit water before it is transported to a buffer tank. The thermal energy is used for the underfloor heating system in the offices. The ceiling cassettes in the offices, like those in the production facility, are integrated into the R2 system and support the heat recovery process as well as reducing energy costs. They cool the rooms in summer but can also provide some heating as needed.

“We didn’t need to use any fossil-fuel-based heat generators at all in the new build. The thermal output from the production facility is enough to heat all of the administrative offices, including the reception, the showroom and a meeting room,” explains Gary Metzger, managing director of Metzger Kälte-Klimatechnik GmbH. In summer, the surplus heat is drawn off in a controlled process.

The heat recovery system cuts the company’s energy bills and has saved it from having to invest in a conventional heat generation system. The building’s cost-efficient energy set-up is supported by a ventilation system. The supply air is preconditioned by the heat exchanger coils inside four split air conditioners with an optimized heat pump function from Mitsubishi. The ventilation system, too, offers the advantage of meeting both heating and cooling needs with a single, highly efficient technology. (SP)

For more information, please visit the website of Mitsubishi Electric