Ventilation strategies for low-energy buildings involving air purification and energy recovery -Climate, energy, comfort and indoor air quality aspects

In many climate zones, low energy buildings will not be able to utilize natural ventilation at all times. Hence, low-energy mechanical comfort systems will still be required. For green buildings there are design objectives well above minimum standards for comfort and indoor air quality (IAQ) that are meant to improve occupant productivity. The latter can make meeting low-energy requirements even more challenging. To meet these sometimesconflicting requirements, the principles of concurrent engineering may be applied to support design charettes. Candidate solutions should include: (1) reducing the amount of outside air while producing an equivalent clean air delivery rate (CADR) using purification technologies, and/or (2) using an energy recovery ventilator (ERV) on the remaining outside air coupled with a smart economizer operating strategy. Simulation results are presented that support these strategies by addressing the cost of conditioning ventilation air and dependence of contaminant levels on the amount of ventilation.