Variable ventilation airflow rate in dwellings - costs and benefits

Ventilation systems with variable airflow rates (VAV) can be used to decrease the amount ofenergy used to heat and cool the supply air and move the supply and exhaust air. Additionally,the occupancy detection system can work together with the heating and cooling system anddecrease other energy uses by changing the indoor climate demands when building is not occupied. However, a VAV system has higher installation and maintenance costs than a system with constant airflow rate (CAV). This paper gives examples of energy use and life cycle costs (LCC) for different ventilation systems in dwellings. The LCC was calculated with a computer program for LCC calculations of indoor climate systems, ProLive. The occupancy level of a building is one of the most important parameters regarding the energy use calculations of VAV systems. The results show that it can be beneficial with variable airflow rate in dwellings from an LCC perspective.