What is Positive Input Ventilation (PIV)?
With the ever increasing cost of heating our homes, good quality home insulation, along with double glazing and energy efficient boilers and appliances can have a dramatic effect on reducing annual energy costs. However, with the high levels of insulation added to many older properties to minimise heat loss, a new problem has occurred – condensation – which leads to damp patches and mould.
All properties need to breath, the moisture laden warm air needs to be kept moving to minimise condensation forming. In properties built up to the 1990s, this was achieved by air bricks, or built-in vents. But, with the emphasis on keeping all that warm air in the house, cavity wall and other forms of insulation often blocked the vents, minimising air circulation and increasing humidity.
Positive Input Ventilation is a means of increasing air circulation and upping air pressure. The incoming fresh air forces the moisture laden air out through all available gaps in vents, bricks, under doors, and through floorboards. As this damp air is expelled, overall humidity in the house drops to below 55%, reducing the risk of condensation, damp and mould.
How Does a PIV Unit Work?
The most basic PIV unit is a small, low powered, mains driven adjustable speed fan, which draws air in through an air filter, and drives it out through the outlet. In the average UK house or bungalow, the unit can be fitted in the loft. A small vent is fitted through a ceiling, usually on the landing of a house, or the hallway of a bungalow, and flexible pipe connected from the fan outlet to the vent.
For those who have no loft, or who live in a flat, the PIV unit can draw air from outside, through a wall vent or similar. Units are available which include an optional heating element to heat that cold external winter air before releasing it into your home.
Installation and Operation:
Installation is simplicity itself for anyone with basic electrical and DIY skills. The unit requires connecting to the mains power, and holes drilled through ceiling or hallway to accommodate the vent. If air is to be drawn from outside, a hole also needs to be drilled through the external wall and a grill fitted.
The electric motor is virtually silent, and because the unit is more efficient with very low air movement you won’t be bothered by the sound of air rushing through the flexible pipe work or exit vent. With everything connected and running, don’t fall into the trap of turning the fan to maximum to speed up the dehumidifying process. Gentle air movement is more efficient. It may take a few days to spread throughout your house or flat, but keep the unit at a speed where you can feel a slight draught blowing onto your hand or face when close to the grill.
Dehumidifier V PIV:
Most dehumidifiers are portable, and deal with one room at a time. A PIV unit will dehumidify a whole house. Even the most expensive dehumidifiers may well cause irritating noise, especially at night. A PIV unit is virtually noiseless.
Finally, the most important reason of all to choose a PIV unit is running costs. Dehumidifiers are big eaters of power, while the small PIV motor costs literally pence to run, helping maintain your energy costs as low as possible.
If you are still unsure if you need a PIV unit, you can speak to the experts at PAM ties today.