Mould is one of the most common issues found in homes during winter. It can damage surfaces, create unpleasant odours and contribute to health issues such as asthma, allergies and other respiratory conditions.
Many people believe that simply heating a home will prevent mould, while others think opening windows is enough. The reality is that heating and ventilation work together, and one is far less effective without the other.
Why does mould appear?
Everyday activities such as showering, cooking, drying clothes and even breathing add moisture to the air inside your home. When this warm, moist air comes into contact with colder surfaces such as windows, walls and ceilings, condensation forms. If that moisture remains, mould can begin to grow.
Heating alone is not enough
Turning on a heat pump warms the air inside your home, but it won’t remove all moisture. Effective moisture control requires both heating and ventilation. Without ventilation, that moisture remains trapped indoors. As temperatures drop, the moisture settles back onto cold surfaces as condensation, creating the perfect environment for mould growth.
Ventilation alone is not enough
Opening windows helps remove moisture, but a cold home can still experience condensation. When walls, ceilings and windows remain cold, moisture in the air can quickly settle on those surfaces. This is why homes that are ventilated but not adequately heated can still experience dampness and mould problems during winter.
The best solution: Heating and ventilation together
A warm, well-ventilated home is far less likely to develop mould.
Heating helps keep surfaces warmer and reduces condensation. Ventilation removes excess moisture before it can settle on walls, ceilings and windows. Used together, they create a healthier, drier and more comfortable home.
Simple habits that make a difference
• Open windows and doors for a short period each day to allow fresh air to circulate
• Use bathroom extraction fans during and after showers
• Use rangehoods whenever cooking
• Dry clothes outdoors whenever possible
• Keep furniture slightly away from external walls to improve airflow
• Clean heat pump filters and extraction fans regularly
• Use the heating provided to help maintain a comfortable indoor temperature during winter.
Try “Flash Ventilation”
Rather than leaving a window slightly open all day, try opening several windows and doors fully for a few minutes each morning. This quickly replaces damp indoor air with fresh air while helping the home retain much of the warmth stored in walls, floors and furnishings.
Watch out for hidden cold spots
Mould often appears first behind large furniture, inside wardrobes, around window frames and in corners of rooms where air circulation is limited. Keeping these areas clear and allowing air to move freely can help prevent moisture build-up and mould growth.
A healthier home can also cost less to heat
Moist air is harder to heat than dry air. By reducing indoor moisture through good ventilation, your heating system can operate more efficiently, helping your home feel warmer and potentially reducing winter energy costs.Back