Fundamental Investigation of Direct Contact Heat Exchange for Application in HVAC Systems: A Case Study

An air conditioning system based on a direct contact heat and mass transfer process between water and air may offer benefits such as increased energy efficiency, temperature and humidity control, and improved indoor air quality. To investigate the feasibility of this type of technology, a numeric model is used to study the heat and mass transfer between a single droplet and moist air to gain fundamental insight into the heat and mass transfer process. Further, preliminary experiments are performed in a low speed temperature and humidity controlled wind tunnel to validate some of the models findings, e.g. the effect of droplet size on heat and mass transfer. A case study is presented to investigate how such a system would operate in a hot, dry climate as well as a hot and humid climate.