Positive input ventilation (PIV) is the UK's most popular low-energy whole home ventilation method. PIV is a highly effective cure for condensation dampness and its associated problems within residential properties. It pushes harmful air out of the home and replaces it with fresh, filtered air. Some units can even provide a small heater to warm the fresh air coming in.

PIV works by drawing fresh air in through the unit that's usually, but not always, installed in your loft. This air is then filtered and gently diffused at ceiling level, creating a positive pressure within the home that forces air pollutants out through the natural leakage gaps found in every UK property, both old and new.

Q. How does it stop condensation?

A. If the PIV vent is installed correctly, the process of air being replaced in the living area is repeated once every hour. For achieving this many cycles of a change of air, the humidity in the living area is kept in an acceptable range of between 40 - 60% which prevents condensation and black mould growth.

Q. Are they expensive to run?

A. There are two types of Positive Input Ventilation (PIV) Systems For Lofts models with most brands. Non heat and with heater. We always recommend with heater options. The reason for this is that air in the loft space is barely a few degrees warmer than outside temperatures especially in the winter months. It can quite literally be below zero degrees centigrade on occassion. To have cold air delivered into the living area can be a discomfort, especially in bungalows with shallow ceilings and of course, the heating is working to warm this air up. The heater version have integral low watt heaters that deliver the chilled air into the living area at around 10 degrees which has removed the cold chill. Typical annual running costs are @ £20 - £25 per year non heater and £30 - £35 per year with heater based on a unit of electricity costing 15p. Cost difference is negligable but well worth the comfort.

Q. Does a PIV unit cure damp and condensation?

Condensation is a fast-growing problem: it's estimated that one in five houses in the UK is poorly ventilated and at risk of streaming windows, mould growth and poor indoor air quality. The average family produces up to 10 litres of water daily through simple everyday tasks such as cooking, washing, bathing and drying clothes indoors.

New and modern homes are at risk of condensation: poorly heated homes are prone to condensation dampness. In contrast, well-insulated homes with double glazing or insulation can trap moist air inside the house. When it comes to curing damp and condensation, PIV is the most cost-effective whole home system in the market today: that's why it's trusted by so many homeowners and landlords across the UK.

Q. When would you recommend using a PIV unit?

Positive input ventilation is a highly trusted, cost-effective, and simple solution to ensure clean air flows freely throughout your home, making poor indoor air quality a thing of the past. PIV units are used for a few different reasons, including the displacement of indoor pollutants, including stagnant and humid air. The installation of PIV units is generally recommended if you're not looking to carry out a full renovation of your home yet require ventilation throughout the dwelling without removing any walls.

Should you wish to get a estimate for a PIV system to be installed please contact us to arrange a site visit and free estimate.

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