1326947a_ur_home___GreenNav_s_Open_Blog__Simple_way_to_reduce
[0] Ventilation losses [Typical losses] 20% [Simple way to reduce] 
Keeping your house ventilation is key to good health, however ventilation due to poorly fitted doors and windows may cause drafts. These should be sealed
Insulation in your home | GreenNav's Open Blog
Simple way to reduce