A packaged heating, ventilation, and air conditioning (HVAC) system is an integrated piece of mechanical equipment that provides all three mechanical functions for a space. Packaged roof top units (RTUs), which are the baseline technology assessed in this study, are the predominant method of building conditioning in California. It is estimated that 75% of commercial building floor area in California is conditioned with packaged systems . The emerging technology assessed in this study is the Seeley Climate Wizard (CW) Hybrid, which is a packaged RTU that integrates a heat pump with an indirect-direct evaporative cooling (IDEC) system that is designed as a direct replacement for a traditional RTU. This project evaluates the Climate Wizard (CW) Hybrid, manufactured by Seeley International, in a field study and compares its performance to a baseline packaged RTU.
The CW Hybrid combines an indirect-direct evaporative cooling (IDEC) system with a heat pump, which results in the energy saving benefits of evaporative cooling with the capabilities of a heat pump. The IDEC system portion of the CW Hybrid operates with 100% outdoor air filtered by MERV 13 filters on the inlet. The system operates using both indirect and direct cooling in series by passing the air through an indirect evaporative heat exchanger followed by direct evaporative media. The resulting supply air is below the wet bulb temperature of the ambient air, meaning that comfort can be maintained in buildings in dry climates like California using significantly less electricity than compressor-based air conditioners. The single-speed heat pump side of the system can provide either heating or cooling based on the position of the reversing valve. The supply air on the heat pump is recirculated from the room and filtered with a MERV 13 filter.