What Is Positive Input Ventilation (PIV)

Positive Input Ventilation is a whole-home solution designed to combat indoor condensation, dampness, and mould. It works by gently introducing filtered air into your property, creating a healthy, moisture-balanced indoor environment.

How Does Positive Input Ventilation Work?

A PIV unit—usually installed in the loft—draws in fresh air from outside or the attic space. This filtered air is diffused throughout the home, pushing out stale, humid air and reducing condensation.

When Should You Use a PIV System?

PIV units are highly recommended for:

- Homes with recurring damp or mould problems
- Older properties with limited ventilation
- Rental units that can’t undergo structural renovations
- Energy-efficient retrofitting projects

Why Is PIV So Important?

Without proper ventilation, your home becomes vulnerable to:

- Persistent condensation and black mould
- Allergens and poor indoor air quality
- Respiratory issues for occupants
- Higher maintenance costs and property degradation

Installing a PIV system helps prevent all of these—while improving comfort.

How Can PIV Help Landlords?

For property owners, PIV systems:

- Protect the structure and long-term value of your property
- Reduce repair and redecorating costs from mould damage
- Improve compliance with UK housing safety standards
- Boost tenant retention and satisfaction

What Are the Benefits for Renters?

Tenants experience:

- Better indoor air quality
- Less mould and fewer allergy triggers
- A reduction in window condensation
- A more comfortable, breathable space

Is PIV Cost-Effective?

Yes! With installation costs typically between £700–£1,000, and running costs as low as 1–2p per day, PIV systems offer long-term value. Heated models add warmth during colder seasons.

Can You Install PIV in Flats or Homes Without Lofts?

You can! Wall-mounted PIV systems are available for ground-floor flats, bungalows, and properties without attic space—offering similar benefits in compact packages.