— our services
Positive Input Ventilation (PIV)
Whole-house ventilation using a loft- or wall-mounted PIV unit that continuously introduces fresh, filtered air throughout the property, the most effective single measure for resolving condensation and mould caused by inadequate ventilation.
— about this service
Positive Input Ventilation (PIV)
Unlike extractor fans that target a single room, a PIV unit ventilates the entire property from a central point, reducing background relative humidity levels across all rooms and addressing condensation at source rather than treating its symptoms. Procure Damp Proofing Group sources and installs PIV units specified to the property size and construction, including full commissioning and airflow setting on completion. PIV is particularly effective in properties with persistent black mould, condensation on cold external walls and window reveals, and rooms with no opening windows or inadequate trickle vents.
— our process
How It Works
Condensation Assessment
A Procure Condensation and Mould Survey confirms that condensation is the primary cause of the problem and assesses property size, construction and existing ventilation to specify the correct PIV unit and mounting position.
Installation and Commissioning
The PIV unit is installed, typically at the loft hatch area of a house or in a hallway for a flat, and commissioned with airflow rates set to the correct level for the property volume and construction type.
Post-Installation Guidance
Clients are shown how the unit operates, advised on filter maintenance intervals and given a clear picture of what to expect in terms of condensation and mould improvement over the weeks and months following installation.
— benefits
Why Choose Us?
Addresses condensation across the whole property
A PIV unit ventilates every room simultaneously, reducing background humidity levels throughout the property. Unlike extractor fans, which only address the immediate room in which they are installed, PIV provides whole-house coverage from a single unit.
Non-invasive and low-energy
PIV units require only a single installation point and consume minimal electricity, typically less than a standard low-energy light bulb, making them a cost-effective, long-term condensation control solution with no significant running costs.
Installed following a proper assessment
Procure installs PIV units as part of a surveyed, evidence-based programme. If PIV is not the right solution for the property, the survey report will say so. Clients receive an honest recommendation, not a default product.
— faq
Frequently Asked Questions
No. PIV units introduce air very gently and the airflow is barely perceptible in the living space. In loft-mounted units, air drawn from the loft is slightly warmer than outside air due to solar gain, helping to avoid cold draughts reaching habitable rooms.
Resolve Condensation and Mould at Source
Contact Procure Damp Proofing Group today for a condensation survey and honest, no-obligation advice on the right solution for your home.
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