PIV units have been installed in over a million homes in the UK, with thousands more being added by the year. At Environ, we install PIV units across London for the lowest price you’ll find in the UK.
So why are PIV units so popular? And are they right for your property? Read my guide to find out everything you need to know about PIV units.
How do PIV units work?
PIV units work by creating positive air pressure in your building.
Positive air pressure means that the air pressure inside the building is higher than it is outside, which forces air out. If the air pressure is negative – higher outside than inside – air is drawn in.
By forcing air out the building, you cycle out old, stale, damp air without you having to open windows. Condensation is reduced to almost nothing, and your heating doesn’t have to work any harder.
In fact, if your PIV is installed in the loft, your heating demand may be reduced. Hot air rises and usually escapes through the loft, where all this heat goes to waste. PIV units recycle this warm air, keeping a more consistent temperature in your property.
Also, as you can reduce condensation and enjoy fresh air without having to open your windows, your heating demand is reduced even further simply through the change of living habits you will enjoy.
Can I have a PIV unit installed if I don’t have a loft?
Yes, while PIV units are ideally installed in the loft as the air they vent into the property isn’t as cold as air outside, PIV units can also be installed on exterior walls.
You may not like the idea of cold air flowing into your property, but remember, if you have negative air pressure, cold air will be entering anyway – that’s what causes draughts!
Are PIV units expensive to run?
Many people assume that because PIV units run constantly that they must add a huge amount to your electricity bill.
This couldn’t be further from the truth. The running cost of a PIV unit is a couple of pennies a day. And given the reduced heating demand after installing a PIV, they end up paying for themselves.
For a higher running cost, you can install a PIV unit that is equipped with a heater and a thermostat to warm up the air before venting it into your property. These are best used in external PIV installations where air is drawn in from outside the property rather than the loft.
Whichever PIV unit you install, running costs are nothing to worry and should never be a reason to avoid them.
Will a PIV unit reduce my condensation?
By far the most significant benefit of a PIV unit is the dramatic reduction of condensation in a property.
The positive air pressure created by a PIV forces moist air out of a property through its existing vents.
This is especially valuable in period or listed buildings which were deliberately designed to “breathe”, but have been subject to heavy handed insulation works that have sealed them up, with the nasty side effect of heavy condensation and damp.
Beyond property damage and expensive damp repair works, there are numerous adverse health effects to living in a damp property with moisture-heavy air.
According to the NHS, “…if you have damp and mould you’re more likely to have respiratory problems, respiratory infections, allergies or asthma. Damp and mould can also affect the immune system.”
Any other benefits of a PIV?
PIV units filter out dust and allergens such as pollen and dust mite feces from the air they draw in, whether it’s from the loft or outside, giving you fresh air without any of the particles that might aggravate you.
Studies have demonstrated a significant link between air quality and the occurrence of symptoms for asthmatic people and other allergy sufferers. By installing a PIV unit, you can significantly improve your quality of life if you live with such conditions.
Are PIV units expensive to install?
Terry Clark
