Energy and water recovery using air-handling unit condensate from laboratory HVAC systems

This paper examines ways to reduce energy and water consumption in laboratory HVAC systems. The data add to existing research into reduced potable water consumption derived from air handling unit (AHU) condensate. It also explores and validates the potential for energy recovery. The literature shows that hot, humid climates can be ideal for AHU condensate to be leveraged as a source for pre-cooling and dehumidifying. The findings also reveal locations best suited for its application, because condensate generation is greatest when pre-cooling and dehumidification are needed most. Psychrometric relationships are used to predict condensate generation based upon ambient meteorological conditions. Since laboratories require high volumes of 100% outside air, data show they are the perfect candidates to reuse relatively pure, cold condensate. This study analyzes AHU condensate utilization for both energy and water recovery modes; evaporative pre-cooling for sensible energy recovery, and condensate as a source for cooling tower make-up water. An optimization scheme is presented that maximizes energy and water savings based on outside air enthalpy, condensation generation, and energy recovery mode.