Positive Input Ventilation (PIV) Systems For Lofts To Prevent Condensation

Positive Input Ventilation (PIV) Systems For Lofts To Prevent Condensation

Positive Input Ventilation (PIV) Systems For Lofts To Prevent Condensation can be a confusing decision making process for homeowners and landlords.

This is a very busy market place for our business and we supply lots of Positive Input Ventilation (PIV) systems especially to private landlords so here are some of the frequently asked questions we get.

Q. What is PIV ventilation?

A. It is the process where by air in the loft space, which is a generally better ventilated area, is drawn mechanically through a vent which is covered by a filter to capture dust particles, and delivered through a panel in the ceiling. The air from the loft area will be less humid and cleaner air than the air in the living area. Because the process is working 24/7 the motorised delivery of air from the lodt in turn, displaces and replaces the air in the living area.

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. Do I need to have anything else installed?

A. No brand of PIV vent will work on its own with great results unless they are supported by good quality extract fans in the Kitchen, Bathroom and Utility room if one is present. The function of an extract fan is to capture as much humid air, (vapour), generated by showers, hot water taps, cookers, washing machines, tumble dryers, etc at the source it is generated and remove as much of it as quickly as possible preventing the travel of vapour or moisture laden air around the property.

Q. What else is needed?

A. The principal of the process is to have the stale air replaced by the fresh air from the loft. This is ideally achived by it being ‘pushed’ out of the property by the new incoming air. Trickle vents, air bricks, extract fans, window and door openings are all passive ventilation points where air can both go out and come in. If a property is very well sealed with no passive ventilation points then the occupants would ideally open windows slightly to allow the process to work to its full benefit.

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. Who should install PIV loft vents? 

A. The very basic requirement is for a Part P qualified electrician as there are electrics involved. However, we do recommend you use an electrician who has an understanding of ventilation systems to ensure the unit is installed correctly and in the best position to maximise the full benefit of the vent.

Q. Can I buy off the internet and organise my own installer?

A. Yes you can but you should be aware if you buy off Ebay or Amazon your guarantee rights are often null and void and a returns process if the unit fails a few month or a year in will have no or very limited success if you went back directly to the manufacturer. We advise you deal directly with an appointed distributor such as ourselves who have direct supply relationships with all our manufacturer supply partners and we can handl all guarantee claims or returns processes.

Q. What brands do you recommend?

A. Recongnised brands are; Nuaire, Envirovent, Vectaire, Vent Axia, Kair and we offer our own branded, high quality, DryFix DampPro PIV loft unit. Other brands are available, we have just mentioned ome of the more well known names. They all offer a minimum 4 year parts guarantee, some are even longer but if you buy from a less than established appointed distributor the guarantee will be worthless. By the way, there are no actual guarantee certifiactes provided by any of the manufacturers. Your guarantee is your purchase invoice so keep that.