Help tackle condensation, damp and mould linked to poor ventilation. A PIV unit installed in your loft gently introduces fresh filtered air into your home — diluting and displacing the moist, stale air that causes condensation problems.
Condensation forms when warm, moist air meets cold surfaces — windows, walls and ceilings. In a poorly ventilated home, the humidity generated by everyday activities (cooking, bathing, drying clothes, breathing) has nowhere to go, so it settles on surfaces and eventually leads to mould growth. The traditional response — opening windows — is impractical in winter and does nothing to address the underlying problem.
A PIV unit takes a different approach. Installed in the loft, it draws in air, gently warms it using natural loft heat, and introduces it into the home at a low, continuous flow rate. This positive pressure gently pushes moist, stale air out through natural gaps in the building fabric — helping manage one common contributor to condensation rather than masking symptoms.
PIV is one of the most cost-effective solutions for condensation problems in existing homes. Installation is typically completed in a few hours, running costs are minimal, and results are usually noticeable within a few weeks.
Our engineers assess your home and confirm whether PIV is the right solution for your condensation or damp problem.
Get a Free QuotePIV is a simple, effective and affordable way to solve condensation and indoor air quality problems in existing homes.
Helps address a common cause by diluting moist air before it can settle on surfaces.
Lower indoor humidity helps reduce the conditions mould needs to grow.
Continuous supply of fresh filtered air throughout the home.
Typically under £20 per year in electricity — almost nothing to run.
Runs in the background without any noticeable noise in the home.
Quick loft installation with no major building work required in most homes.
PIV is effective in any room that suffers from condensation, damp or poor air quality.
Condensation on bedroom windows eliminated with continuous low-level ventilation.
Fresher air in main living spaces throughout the day.
The central distribution point for fresh air throughout the home.
Reduces cooking moisture accumulation between uses of the extractor.
Complements bathroom extraction to reduce background moisture levels.
Reduces moisture from tumble dryers and wet laundry.
Can help reduce mould risk in cold corners, although insulation or thermal bridging may also need attention.
A single unit provides whole-house benefit from one loft installation.
A quick, clean installation typically completed in a few hours with minimal disruption.
We assess your loft, the areas affected by condensation and your home layout.
We confirm the best location for the loft unit and ceiling diffuser position.
The unit is installed in the loft and connected via a short duct to the hallway ceiling diffuser.
The unit is set to the correct flow rate and you're shown how to adjust the settings.
Standard PIV units require a loft space. For flats or properties without a loft, we would recommend a different ventilation solution such as a through-wall PIV unit or a decentralised MVHR unit. We'll advise the best option during the survey.
Most homeowners notice reduced condensation on windows within a few weeks of installation. It takes slightly longer to see results in areas that already have established mould, as the underlying moisture content of walls needs to reduce over time.
PIV units draw in loft air which is naturally warmer than outside air. The temperature reduction is minimal — the low, gentle airflow rate means the impact on your heating is negligible and balanced against the benefit of reducing stale, humid air.
PIV units have a simple filter that should be checked and cleaned annually. We can include this as part of a ventilation service visit alongside any other systems you have installed.
Request a free survey or ask a technical question. We'll confirm the right next step for your property.
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