Does Insulation Make Condensation Worse

Does Insulation Make Condensation Worse

By Ruth MacEachern

Product Manager

Modern houses are designed to be more energy efficient than ever before, with high quality insulation in roofs and walls to prevent heat loss and flush fitting windows and doors that prevent draughts.

Unfortunately, these improvements in energy efficiency also make properties almost airtight, which means that without effective ventilation, humidity levels can build up quickly which increases the risk of condensation as well as allowing indoor air pollution such as allergens and Volatile Organic Compounds to concentrate to the point where the air quality falls.

How does insulation affect condensation

Condensation is formed when air temperature falls below the dew point, and the air can no longer hold as much water vapour. When this happens – usually when the air meets a cool surface such as a windowpane or a wall, the water vapour is deposited as liquid – condensation. If untreated, condensation can soak into porous surfaces such as wood and plaster where it will form damp patches that damage the fabric of the building and allow mould to grow.

Insulation has both positive and negative effects on the formation of condensation in a home.

A well-insulated home will retain its heat more consistently, which means that there are smaller swings in temperature during the day and night. This, coupled with interior walls that are protected from the cold outside means that there is less opportunity for air to come into contact with surfaces where condensation can form.

The downside of a well-insulated house is that the flow of air in and out of the building is reduced. This means that the humidity levels can rise higher than they would in an environment where air is exchanged more readily. Higher levels of humidity mean that the dew point of water can be higher than it might be otherwise, and that condensation can form at a higher temperature.

Reducing Condensation in a Well Insulated Home

Controlled ventilation is the most effective way of preventing condensation.

Whole house ventilation such as the EnviroVent Atmos Positive Input Ventilation System (PIV) works by drawing in fresh filtered air from outside to displace the humid air from indoors. This works in conjunction with extractor fans in key rooms such as bathrooms and kitchens where the majority of moisture is added to the air.

Learn More about Positive Input Ventilation Systems >>

Find out More

If you are suffering from condensation in your home and are worried about the risk of damp or mould, EnviroVent can help. Simply enter your postcode into the box below to find a local ventilation specialist. We can visit your home to conduct a free home survey that will identify the causes of condensation in your home and provide advice about the best way to deal with it.