Development of a gas driven zeolite-water adsorption heat pump for multi-family homes

In this contribution we show recent developments of a gas adsorption heat pump with the working pair zeolite-water. A functional prototype with about 40 kW nominal heating capacity for a 55/45°C heating system has been designed, built and tested at conditions that represent a typical small-to-medium sized multi-family home in Germany which has undergone an average retrofit. It is shown that exhaust air from a centralized ventilation system can be an attractive low-temperature (LT) source for this thermally driven heat pump, since it can provide a source temperature >5°C over the full heating season, and under typical operation conditions of the heat pump it only needs about 2-4 kW of LT source power, reaching a Seasonal Gas Utilization Efficiency (SGUE) of about 1.2. A typical compression heat pump would need >10 kW LT source power to provide the same heating capacity, which is not possible to provide from ventilation exhaust air.