Damp proofing in Portsmouth
Positive Input Ventilation in Portsmouth
Positive input ventilation (PIV) in Portsmouth. A PIV unit gently pushes filtered fresh air through the home, keeping humidity down across the whole house rather than one room.
Get a quote in Portsmouth
A free, no-obligation survey and a written quote.
Positive Input Ventilation
Positive Input Ventilation across Portsmouth
Positive input ventilation (PIV) in Portsmouth. A PIV unit gently pushes filtered fresh air through the home, keeping humidity down across the whole house rather than one room.
It is a quiet, low-cost answer to condensation and mould in Portsmouth homes, and we set it up to run efficiently and explain what it costs to run.
What’s included
What positive input ventilation in Portsmouth covers
Every quote varies depending on the property and what the job needs, but here is what a typical positive input ventilation job in Portsmouth covers from start to finish.
- An assessment of how the property breathes
- Extractor fans for kitchens and bathrooms
- Positive input ventilation for whole-home control
- Humidity-sensing controls where suitable
- Advice on running costs and daily use
How we do it
Positive Input Ventilation in Portsmouth: the process
Step 01
Assess
We look at where moisture is made and where it collects.
Step 02
Specify
We recommend the extraction or whole-home system that suits the home.
Step 03
Install
Units are fitted neatly and set up to run efficiently.
Step 04
Explain
We show you how it works and what it costs to run.
Positive input ventilation in Portsmouth
Positive input ventilation is the simplest lasting answer to condensation and the mould that follows it. Rather than extracting damp air room by room, it gently dilutes it across the whole house. It suits some properties very well and others not at all, so it is worth understanding before you buy one.
How a positive input ventilation system works
A positive input ventilation system is a single low-wattage fan unit, normally mounted in the loft, drawing air through a filter and introducing it into the home at a gentle, continuous rate, usually through a diffuser in the landing ceiling.
That slight positive pressure pushes stale, humid air out through trickle vents, gaps and background leakage. Instead of removing moisture at source the way an extractor does, it keeps the humidity of the whole house below the level at which condensation forms on cold surfaces. Better units sense humidity and temperature and vary the rate accordingly.
Positive input ventilation pros and cons
The advantages are real. It is inexpensive to install next to mechanical ventilation with heat recovery, cheap to run, needs almost no maintenance beyond an occasional filter, works across the whole property rather than one room, and deals with condensation without asking anyone to change how they live.
The drawbacks are equally real and less often mentioned. It introduces outside air, so in cold weather a basic unit can make a landing feel draughty unless it has a heater or tempers the incoming air. It relies on air being able to leave, so a very airtight home, or one with every trickle vent taped shut, will not work well. It does nothing for rising or penetrating damp, and it will not fix mould caused by a leak. In a flat with no loft a unit is wall-mounted instead, which suits some layouts and not others.
Is PIV right for your Portsmouth home?
PIV suits houses with a loft, general condensation across several rooms, and mould appearing in the usual cold spots. It is a poor answer where the moisture has one obvious source, such as a bathroom with no extractor or a tumble dryer venting indoors, because dealing with that directly costs less and works better.
We survey the Portsmouth property, take humidity and surface temperature readings and tell you honestly which it is. Sometimes the right recommendation is a decent extractor fan and better trickle ventilation rather than a PIV unit at all.
Positive input ventilation cost in Portsmouth
Installation is usually straightforward: the unit, a ceiling diffuser, a power supply and commissioning, typically completed within a few hours. Running costs are low, often only a few pounds a year, because the fan draws very little power and most units modulate rather than running flat out.
We quote each Portsmouth installation in writing after the survey, setting out the unit we recommend and why it suits your property.
PIV installers near you in Portsmouth
We cover PO2 and the villages around Portsmouth, including Portsea, Eastney, North End, Stamshaw, Hilsea and Copnor. As damp specialists rather than a ventilation-only firm, we will tell you when a positive input ventilation system is not the right fix for the problem you have.
Book a free survey and we will measure the humidity before recommending anything.
Book a free positive input ventilation survey in Portsmouth
Tell us what you have noticed and we will come out, find the cause and provide you with a written quote with no obligation.
The quote
Positive Input Ventilation in Portsmouth costs
Every property is different, so we quote each Portsmouth job on its own after a free survey rather than off a description. These are the things that move the figure, and we set it all out in writing before any work starts. The visit is free.
- Whether you need single fans or a whole-home system
- The number of rooms being ventilated
- The type of controls fitted
- How the units run and where they vent
Common questions
Positive Input Ventilation in Portsmouth: your questions
What is positive input ventilation?
Does a PIV unit make the house feel cold?
Are the fans noisy or expensive to run?
Will ventilation on its own cure my mould?
Where does a PIV unit go?
How much does ventilation cost to run?
Get a quote in Portsmouth
A free, no-obligation survey and a written quote.
Looking for a service other than Positive Input Ventilation in Portsmouth?
We cover the full range of damp and timber work for Portsmouth homes:
Not in Portsmouth? Still looking for Positive Input Ventilation near you?
We provide positive input ventilation across Hampshire, including:
We also provide positive input ventilation to: Portsea, Eastney, North End, Stamshaw, Hilsea, Copnor