Home ventilation replaces stale, moisture-laden indoor air with fresher air. This may be achieved through extractor fans, trickle vents, background ventilation, continuous mechanical extraction or a whole-home system. The right method depends on the property and how its rooms are used.

Possible signs include persistent condensation, recurring mould, wet bathroom walls, lingering cooking smells, stale bedrooms and rooms that remain humid for long periods. Weak, noisy or ineffective extractor fans may also indicate that the existing ventilation needs attention.

Yes. When moisture produced through cooking, showering, drying clothes and breathing cannot escape, indoor humidity can rise. Water may then form on colder surfaces and create conditions in which mould can grow. Heating, insulation and other damp problems should also be considered.

Bathrooms and kitchens normally require effective extraction that removes moisture to the outside. The appropriate fan or system depends on the room size, existing ventilation, duct length and property layout. Continuous or humidity-controlled extraction may be suitable in some homes.

Positive Input Ventilation (PIV) introduces a controlled supply of filtered air into a property, usually through a loft-mounted or wall-mounted unit. The incoming air helps dilute indoor humidity and encourages stale, moisture-laden air to leave through existing ventilation routes.

Trickle vents are designed to provide background airflow and should generally remain open and unobstructed. Closing or blocking them may reduce ventilation and allow humidity to build up. However, trickle vents are only one part of the property’s overall ventilation system.

Opening windows can provide temporary airflow, but it may not offer reliable ventilation throughout the day or during colder weather. Persistent problems may require improved background ventilation, effective extractor fans or a properly specified mechanical system.

No. A photograph may show mould, condensation or an existing vent, but it cannot measure humidity, airflow, fan performance or the effectiveness of ducting. An on-site assessment allows the ventilation system and other possible moisture sources to be considered together.