Simulative design method for decentral air handling unit including air-to-air heat pump

Institute for Energy Efficient Buildings and Indoor Climate, RWTH Aachen University, Germany

^* Corresponding author: tobias.froehlingsdorf@eonerc.rwth-aachen.de

Abstract

Since people spend around 90 % of their daytime in buildings, the energy demand in buildings to maintain thermal comfort is remarkable. By developing a decentralized air handling unit (AHU), equipped with a R290 heat pump, it is targeted to reduce the installation time in buildings and the CO2 emissions for air conditioning. To integrate decentralized AHU with heat pumps in residential or non-residential buildings, these must be carefully designed in advance to get the highest efficiency. The development process considers a wide range of aspects, including energy demand, component design and acoustics. The simulation results in a total heating load of 1080 W. The load is distributed in 500 W of the sensible heat in the energy recovery system, 500 W through the condenser of the heat pump and 80 W through the electric air pre-heater for frost protection. After design and component selection, the decentralized AHU was built up as a demonstrator. The comparison of simulation and experiments prove the validity of virtual pre-development by showing a maximum deviation of 5 % in the heat flow of all components in heating mode by using constant efficiency models.