The proposed project is intended to appraise and then investigate the performance of new non-ozone depleting refrigerants and their required compatible lubricating oils. It will utilise computational skills and experimental equipment using expertise developed in a recent collaborative project. This will allow manufacturers to make use of new refrigerant materials that are being introduced to comply with environmental legislation. For the refrigerant side, testing will be performed initially on a single tube heat exchanger for various combinations of refrigerants lubricating oils and materials. Successful combinations will be used in simulated full scale heat exchangers and assessed in scaled laboratory tests. Computer modelling of practical heat exchanger performance will be undertaken for the combinations under test. Heat exchanger air side, air flow, and heat transfer performance will be modelled for typical practical applications and tested experimentally. The final project stage will be to verify research results and computer models by test verification in finished products.