Tradeoffs between low energy use and good air quality are unavoidable when designing or operating most types of HVAC systems. Dual Fan, Dual Duct (DFDD) is a high quality system that can offer both good air quality and low energy use at low cost.
These benefits are achieved by use of high air change rates to flush pollutants, elinination of reheat to save energy and use of cost-effective design techniques made feasible by the system’s special characteristics.