Modern building regulations require losses to minimised when ventilation is required. The Mitsubishi SAF500E7 ventilation and heat recovery unit captures warm air leaving the building and recycles the warm air to heat the incoming air used for ventilation of the premises in winter. Likewise in summer the exhausted air can be used to cool the incoming air to the building hence saving in air conditioning costs. The Mitsubishi SAF500E7 model is suitable for medium sized premises with a 500 cubic metres per hour flow rate.