Reducing condensation

Lifestyle can be the dominant factor in condensation. This can be seen where a change of tenancy results in condensation problems when before there were none.

Households vary in size and make-up, and habits vary concerning cooking, washing and heating. Overcrowding means much more moisture is produced by metabolism alone. Income levels of households vary, and some households suffer fuel poverty when they simply cannot afford to heat their homes enough. Or they use heating regimes that they think are economical but which in fact are not; for example, having the central heating switch on and off intermittently. In fact a low continuous background level of heating when it is cold helps keep surface temperatures above dew point.

Moisture is generated in the home from cooking, breathing, washing and heating. It may also be generated by building defects, building design and materials used in construction, where penetrating damp, moisture from below ground, plumbing leaks, etc. may feature. Any moisture that is generated disperses to other parts of the house or to the outside by diffusion or by air circulation. Air circulation can be caused by wind pressure differentials or by thermal currents.

Air circulation by air movement can carry greater quantities of moisture than that dispersed by diffusion alone. Opening internal and external doors and windows affects how moisture moves around a house. Design and layout of the building influences patterns of moisture movement. The key aim is either to extract moisture at source soon after it has been generated or to duct moisture out of the building via dedicated pipes and ducts from appliances, e.g. ducts from clothes driers.

How can occupiers reduce condensation produced in the home?

1. Temperature levels.

• Programme central heating to maintain a continuous, low background level of heating to all habitable space when it is cold.
• Organise the servicing of central heating installations to improve their efficiency (simple bleeding of radiators significantly increases their heat output).
• Remove clothes from radiators to improve their heat output.

2. Ventilation rates.

• Open windows immediately after baths or showers to help remove moisture-laden air. Also keep the bathroom door shut.
• Remove temporary coverings or blocking off at ventilation grilles, air bricks and vents.
• Use extraction fans to expel moisture-laden air from the room where it is generated.
• Reduce clutter of possessions, personal effects and furnishings to enable improved air circulation.
• Draw curtains fully back to reduce the blockage of ventilation pathways to openable window sashes or trickle vents.

3. Moisture available.

• Reduce steam generation by careful filling of baths and basins.
• Carry out less boiling of foods, or simply use pan lids effectively to reduce steam generation.
• Keep bathroom or kitchen doors shut until moisture-laden air has been expelled.
• Reduce the use of gas or paraffin portable heaters that produce moisture.
• Mop up condensate on window cills, etc.
• Dry clothes in a room that can be suitably ventilated and shut the room door.
• Reduce overcrowding.
• Change cleaning methods to reduce spillage or splashing of water.
• Reduce influence on moisture generation by larger pets, or reduce the number of fish tanks.
• Reduce the number of houseplants.

Changes in lifestyle can cause dramatic improvements to internal room conditions without any financial outlay. Occupiers may need motivating to take a greater pride in their home, and they may need to be convinced that their own actions could have an effect on reducing condensation.