While we need to seal our homes properly to reduce wasteful loss of heating and cooling, we still need good ventilation. Breathing fresh air is necessary to good health, so if our homes are not properly ventilated our health could easily be adversely affected.
Poor ventilation can cause a build up of allergens, mould and smoke- if you are a smoker or have a smoky fireplace. These and many other allergens can build up and cause respiratory problems for those who suffer from hayfever or asthma. Many people are allergic to dust mites that thrive in a humid climate, so proper ventilation is necessary to eliminate these pests.