To address the need to provide a vitally important supply of fresh air and wet room extraction for the home occupants we installed whole house mechanical ventilation and extraction systems which incorporated heat recovery. These systems work using a centralised ducting system to blow fresh filtered air to each of the rooms in the home and extract moisture and stale air from each of the wet rooms and the kitchen. Both the supplied fresh air and extracted stale air pass through a heat exchange unit where the stale air leaving the home passes its heat on to colder incoming fresh air to warm it up before entering the rooms. This heat exchange makes the system very energy efficient and it results in about 90% of the heat, which would have been lost to the atmosphere, being recovered and returned to assist with the heating demand of the home. The supply and extract air is moved using 2 small fans that normally cost less than €15 per year to run.