There is a common misconception that trickle vents are required in all new openings for windows and doors but this is not technically true. If you have trickle vents in your existing windows or shown on your new plans then you will need to cater for a form of background/passive ventilation.
All new builds since the early 1990’s require passive ventilation and the easiest and simplest form of achieving this has been trickle vents in windows and doors. However, they affect the acoustic performance of high performance windows allowing airborne sound to travel through the frame. In the days of low u-value and thermal performance they also mean your nice new windows and doors have holes drilled through them. As well as often looking unsightly these factors mean that it is worthwhile investigating other solutions; one of which is a Positive Input Ventilation system, or PIV system.
A Positive Input Ventilation system is relatively cheap to purchase, c.£300, and can provide a whole house with a basic form of mechanical heat recovery and also filter the air coming in. You will require installation by an electrician or similar experienced trades person.
The units use the tiles/slates and/or the loft space itself to warm the incoming air before delivering it into the home. Solar air collectors can also be used for even greater pre-heating of the ventilation air. This has the effect of helping to heat the home which can result in lower fuel bills and, for those interested in the environment, reduced carbon emissions.
South East to South West facing tiles or slates absorb energy from the sun. Even the loft space itself is a substantial source of energy. During the heating season it will almost always be warmer than outside because of solar gain and conduction and convection losses from the home.
Unlike extract systems which draw in unheated, unfiltered air, even a basic positive input ventilation unit gently supplies tempered, filtered air into a home using otherwise unused heat within a roof.
The benefits of this are enormous:
A properly designed and installed unit will ensure that old, contaminated, vapour laden air in your home is continuously diluted, displaced and replaced with good quality air.
Read our previous post - « Blog: How To Choose Sliding Sash Windows