Design of a Heat Pump Assisted Solar Thermal System

This paper outlines the design of an active solar t hermal loop system that will be integrated with an air source heat pump hot water heater to provide highly efficient h eating of a water/propylene glycol mixture. This sy stem design uses solar energy when available, but reverts to th e heat pump at night or during cloudy weather. This new design will be used for hydronic heating in the Applied En ergy Laboratory, a teaching laboratory at Purdue Un iversity, but it is more generally applicable for a residential s cale system that could be used for both hydronic he ating and hot water production. This combined system should provide efficient heating at a fraction of the operating costs of competing electric, gas, or even heat pump water he aters. The initial cost of installing a similar sys tem is currently relatively high, but it should be noted that the de sign is still in the prototype stage. The price sho uld reduce dramatically when the system is commercialized. There are multiple applications where the production o f heated fluid by a combined solar/heat pump hydronic system can be much more attractive than conventional heat ing methods. Construction and implementation of this pr oposed design will take place summer of 2014 and data collection will be pursued afterwards.