Evaluation of demand-controlled ventilation and enthalpy exchangers in small commercial buildings

This paper evaluates the operating cost savings and overall economics associated with these two different ventilation load reduction technologies : demand-controlled ventilation (DCV) and enthalpy exchangers. A specialized simulation tool was developed and used to perform the evaluations. For both technologies, the savings potential and economic payback are better in more extreme climates., particularly in cold climates because the ventilation load is a larger portion of the overall load. For retrofit applications, DCV with an economizer was found to give the greatest savings in utility costs for all the buildings and climates considered. Although utility cost savings were found to be less for enthalpy exchangers, they have the advantages of allowing smaller primary cooling and heating equipment for new applications and providing better indoor air quality.The operating cost savings for both DCV and enthalpy exchangers are dependent on assumptions concerning occupancy.