This project developed and prototyped a new CSIRO-developed solar air conditioning technology, which was designed to provide high efficiency, low carbon heating and cooling for Australian commercial buildings.
Report extract
This project developed and prototyped a new CSIRO-developed solar air conditioning technology, designed to provide high efficiency, low carbon heating and cooling for Australian commercial buildings. The novel technology has been specifically designed to operate using high temperatures to enable high efficiency operation. This increases the amount of cooling that can be achieved from the collected solar heat or, conversely, a smaller field can be used to provide the same cooling. This potentially represents a significant cost improvement as collector fields are typically a major component of the overall project costs.
This project aimed to verify the technical viability of the high temperature, solar heat driven two stage desiccant air conditioning system. The commercial partner (Stockland group) hosted a demonstration system at the Stockland Wendouree shopping centre in Ballarat, Victoria. A solar collector field and heat storage system was installed by NEP Solar incorporating solar heat collection with parabolic trough collectors, and heat storage in a thermal oil tank.
The chosen air conditioning design consists of two desiccant wheels to provide maximum dehumidification of the process air. A closed loop, solar heat driven, high temperature regeneration air stream is used for moisture removal from one wheel. The other wheel does not use any external heat. Heat cascaded from the high temperature wheel is used for regeneration of the low temperature wheel. As a result of the closed loop regeneration and heat cascading design, the unit is expected to provide higher thermal Coefficient of Performance (COP) compared with a single stage desiccant air conditioning system. This enables a smaller solar field to be used for the same cooling capacity, or alternatively, more cooling can be provided from a given size field.