Condensation, damp and mould are all unwanted intruders in your home and Positive Input Ventilation is one way to help combat the issue. The right PIV unit type will help push clean air through your home and get rid of the old stale air. It’s this process that helps reduce the chances of mould and damp making an appearance.
Positive Input Ventilation can be installed in any home, but which type you choose will depend on the property you live in. Here ventilation experts reveal the different types of PIV units available on the market and which one will work best for your home.
Thomas Oldham has spent the past four years using his expertise of working in the engineering and construction industry for over a decade to develop the UK Construction Blog - a leading online platform dedicated to empowering individuals and businesses in the construction industry.
PIV unit options
(PIV) Positive Input Ventilation units while performing the same task are available in different types. These are typically used in different property types to get the best performance. Here, Thomas Oldham, Co-Founder, UK Construction Blog gives a quick overview of the different options.
Loft-mounted units
The most common type, installed in the loft space to draw in fresh air from outside and filter it before distribution throughout the property.
Wall-mounted units
Designed for properties without lofts, such as flats. These are fitted directly to an external wall.
Heater PIV units
Include built-in heating elements that warm incoming air during colder months, preventing cold draughts.
Loft units are among the most commonly used PIV options. Positive Input Ventilation (PIV) units are typically installed in the loft, with the diffuser mounted on the ceiling directly below. This setup simplifies installation, allows the system to use fresh air drawn in from roof vents, and helps keep noise and clutter to a minimum.
While basic loft PIV units are popular, many systems come with integrated heaters to warm the air before it circulates, reducing cold draughts in winter. Some models also include sensors to automatically adjust the heater based on air temperature, improving efficiency. More advanced units may feature hygrometers that adjust airflow according to humidity levels, ensuring optimal performance.
The cost of PIV units varies depending on features. Basic loft units typically range from £200 to £300, while models with heaters, sensors, or central control panels can cost between £400 and £1,200.
For homes without loft space, wall-mounted PIV units are a practical alternative. These units operate similarly to loft systems but draw fresh air from outside. They are best positioned on an external wall to minimize the amount of ducting required. Prices for wall-mounted PIV units generally range from £150 to £500, with compact, quiet-running models with integrated heaters at the higher end of the scale.
Try these PIV units to ventilate your home
The Nuaire Drimaster is a basic loft mounted PIV unit that comes with its controls integrated into the main unit. This allows you to set the airflow throughout your home.
A loft mounted PIV unit that comes with a two-speed 500W heater to warm the air when needed. Adjustable legs help secure the unit and all fixings are included.
A compact wall mounted PIV unit that is an alternative to loft based units. Multi-positional spigots allow for quick installation and only one external wall penetration.
How to look after PIV units
PIV units are generally pretty simple to look after and costs are minimal as Oldham shares, “One of the most significant advantages of PIV systems is their minimal maintenance requirements compared to dehumidifiers and air conditioners. They are fully autonomous systems requiring virtually no maintenance.”
The only maintenance is a regular service as Oldham continues, “Regular servicing involves filter replacements every three to five years, depending on installation location and environmental factors.”
And, the cost is negligible, “These filters typically cost £20-£40,” adding, “With service visits ranging from £80-£150 if professionally replaced.” Replacing a filter is a task that you can take on yourself, just remember to get the right filters for your PIV unit.
Can I install a PIV unit myself?
Installing a PIV unit can be tackled on a DIY basis, but if you have never done it before there is a lot that can be missed. Ideally you want to call in a professional as Oldham shares, “Whilst PIV units can technically be installed on a DIY basis, professional installation is strongly recommended.”
He goes on to say, “This is because components need installation in hard-to-reach locations such as lofts, systems require connection to mains electricity, which must be done by competent installers.”
A poorly or incorrectly installed PIV unit will prevent a property from appreciating the full benefits.
No-one wants condensation in the home and the right ventilation helps make sure its doesn’t take over and lead to mould and damp issues. Check out our building regulations Part F to see how regulations can affect a remodel and what your minimum house temperature should be.
EDITOR’S NOTE: An earlier version of this article included a quote from a purported expert whose credentials we have not been able to verify. The quote has been removed. We regret this lapse in our verification process and have updated our internal protocols to reduce the risk of recurrence.
