Residential Ventilation Unit with Thermoelectric Heat Exchanger for Control of Supply Air Temperature
The aim of the project is to develop and verify a residential ventilation unit that allows year-round control of the supply air temperature without the necessary support of cooling and heating systems. The main result is a functional sample of a residential ventilation unit, which predominantly uses the technology of a future prototype.
The current solution is a compact residential ventilation unit with a low height for easy installation, for example on a toilet. The highest air flow is 150 m3/h. Within the project, many variants of the active heat exchanger solution and the overall configuration of the ventilation unit were designed and tested.
It uses a pair of heat exchangers to ensure its function. The first is a highly efficient heat recovery exchanger, the second is an active exchanger using thermoelectric modules. With this exchanger, the unit provides heating and cooling of the ventilation air.
The resulting solution uses a counter-current arrangement using aluminium exchangers, which suitably distributes the heat flow from the individual modules and creates an increased heat exchange surface for heating and cooling the air.
At the same time, a power supply controller for thermoelectric modules is being developed, which is key to achieving high efficiency over the entire operating range. With correct control, the unit reaches an increase in supply air temperature 10 K above the extract air temperature in winter mode. In summer mode, the outdoor air temperature is reduced by up to 9 K. The EER of the entire ventilation unit during cooling is 0.6 to 2.3.