Solar Evaporative Fan Coil Unit

The purpose of any engineering project is to anticipate a need and meet that need through prediction analysis and design. Over 70% of the nation’s energy is consumed by building infrastructure such as HVAC systems, electrical, etc. HVAC systems use boilers to generate hot water or steam to heat buildings and evaporative chillers to provide air conditioning, much like the central plant on campus. The project included the construction of a solar collector that will heat water to 140F in order to run it through a heat exchanger that can have air passed over it. An evaporative chiller was also designed to harness the latent heat of vaporization to chill a heat exchanger that can then have water passed through it. The circulation pump and any temperature sensors will be powered by a photovoltaic array so that no electricity is needed to power the device. The air from the ducted fan can then be passed over this heat exchanger in order to generate hot air for a room, and the same for the cold air with cold water. Testing will consider input and output water temperature, as well as input and output air temperature in order to compare the changes and develop a value for efficiency. Initial testing has found that 140F heating water can provide enough load in a heat exchanger to provide 85F leaving air temperature. Water that has been cooled to 40F by the evaporative chiller can provide a leaving air temperature of 55F.https://digitalcommons.cwu.edu/cwu_met/1014/thumbnail.jp