An energy recovery ventilator, or an ERV, is a mechanical device that assists in transferring the heat and moisture level of air being introduced into the building and the outgoing air. Energy recovery ventilators are applied in HVAC systems, and they may be either wall-mounted or ducted. Energy recovery ventilators assist in heating cold outdoor air during winter and cooling warm outdoor air during summer. This thus means that the energy consumed during conditioning is low, and thus there will be low energy consumption and reduced electricity bills. Another key role of the energy recovery ventilator in domestic use is that it is able to control moisture.