Streaming windows
Where condensation forms regularly on windows, especially during colder months.
Maintenance Time
PIV & Whole House Ventilation
Positive Input Ventilation can help improve whole-house airflow and reduce condensation and mould risk in suitable homes.
When a PIV system may help
PIV is not magic, but in the right property it can make a big difference to stale air, condensation and mould risk.
Stale or humid air
Where the property feels stuffy, damp or musty and moisture is not clearing properly.
Recurring mould risk
Where mould is linked to poor background ventilation and moisture build-up inside the home.
How PIV works
Positive Input Ventilation gently changes the air inside the home
A PIV unit is usually installed in the loft and supplies filtered air into the property, often through a ceiling diffuser on the landing.
This creates gentle positive pressure, encouraging stale, moisture-laden air to leave through natural gaps and ventilation routes.
Photo Space 1
Insert a PIV installation photo
Good for: loft-mounted PIV unit, landing diffuser, installer at work or clean finished installation.
Suitable homes only
PIV is useful, but it is not the answer to everything
A PIV system can help with condensation and mould risk, but it will not repair leaks, defective gutters, high ground levels, blocked air bricks or serious building defects.
That is why we look at the property first. If the cause is not ventilation, selling a ventilation system is just expensive nonsense wearing a fan casing.
Simple principle
PIV works best when the property needs better background airflow and has suitable routes for air movement. Assessment matters.
Photo Space 2
Insert a landing diffuser photo
Good for: ceiling diffuser, hallway/landing position or completed PIV outlet.
Photo Space 3
Insert a condensation improvement photo
Good for: window condensation, mould-prone room, before-and-after or airflow check.
What we check first
Before recommending PIV, it is sensible to understand the building and the moisture problem.
Moisture sources
Bathrooms, kitchens, drying clothes indoors, occupancy levels and general humidity patterns.
Existing extraction
Whether bathroom and kitchen fans are present, suitable, working properly and used effectively.
Building defects
Leaks, drainage problems, high ground levels, blocked vents and other faults that ventilation alone will not fix.
Related ventilation help
PIV is one option. Sometimes another form of ventilation or repair is the better answer.
Thinking about a PIV system?
Send a brief description of the issue and, if possible, a few photos. We’ll help you work out whether PIV is likely to be the sensible next step.
Ask About PIV