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Mobile heating units supported research work at the Lucerne University of Applied Sciences and Arts

Three mobile electric heating units from the Swiss rental specialist Hotmobil were used in research work by the Lucerne University of Applied Sciences and Arts on the subject of "Comfort in public buses in extreme cold".

On behalf of the Association of Public Transportation (VöV), the Institute for Building Technology and Energy of the Lucerne University of Applied Sciences and Arts carried out comfort measurements on two public transport buses. The measurements were used to investigate the interior climate and the control behavior of the air conditioning systems with defined door opening cycles at different outside air temperatures from -10 C to 35 C using the most realistic line operation possible. The focus of the project was to provide valuable guidance to carriers for future vehicle procurements.

The measurements were carried out by the research team in the SBB climate chamber in Olten. For this purpose, the two buses were placed in the climate chamber at ambient temperatures ranging from minus 10 C to 35 C temperature, analogous to daily driving with the engines running. Since the waste heat from the engines is not sufficient to heat the passenger compartment at cold outside temperatures, the missing heating energy was supplemented with three external mobile electric heating units of the HOTBOY type, which were connected to the heating system via mobile connection hoses. The mobile electric heating units, each with an output of 36 kW, are easy to handle thanks to the mobile transport frame, and since no exhaust gases are produced, they can be installed directly in the building. The water in the heating circuit of the bus was filled with glycol to prevent the pipes and components from freezing. Since the HOTBOY units were integrated into the existing heating circuit without system separation, the HOTBOY units had to be filled with the same antifreeze. In total, the research lasted one week. 

"The use of the mobile electric heating units ran smoothly and fulfilled exactly our intended purpose in this series of investigations," commented Franz Sidler, research associate at the Lucerne University of Applied Sciences and Arts and project manager of these measurements.

Hotmobil, which specializes in the rental of mobile energy centers and is based in Thayngen in the canton of Schaffhausen, delivered the mobile electric heating units of the HOTBOY type by freight forwarder and also organized their collection after the test series was completed. "We always offer our customers all-round service and take care of all the details. If the customer is satisfied at the end of the day, we're even happier!" said Richelene Frey, who is responsible for Hotmobil sales in Switzerland, summing up the research mission of the Lucerne University of Applied Sciences and Arts.

Image source: Lucerne University