It depends! If you are installing a Positive Input Ventilation (PIV) system in an older property, there will likely be enough gaps in the building’s fabric to allow air to escape. However, in modern buildings designed to minimise air loss for energy efficiency, a PIV unit may struggle to expel stale air. In such cases, passive vents can be used, but installing demand-controlled Mechanical Extract Ventilation (dMEV) units is often more efficient.

Understanding PIV Systems

Positive Input Ventilation (PIV) systems are designed to improve indoor air quality by introducing fresh air into a home. They work by creating a positive pressure inside the building, which forces stale air out through existing gaps and vents. This is particularly beneficial in homes that may have issues with dampness or stale air.

How PIV Works

1. Fresh Air Intake: PIV systems draw in fresh, filtered air from outside.
2. Displacement of Stale Air: The introduced air creates positive pressure, pushing stale air out through gaps in the building fabric or through designated vents.
3. Continuous Operation: PIV systems typically operate continuously, ensuring a steady flow of fresh air.

The Role of Trickle Vents

Trickle vents are small openings installed in windows or walls that allow a controlled amount of air to enter a building. They are often used in conjunction with various ventilation systems to ensure adequate airflow.

Benefits of Trickle Vents

• Continuous Airflow: They provide a constant supply of fresh air, helping to improve indoor air quality.
• Prevention of Dampness: By allowing moist air to escape, trickle vents can help reduce the risk of mould and condensation.
• Energy Efficiency: When properly designed, they can assist in maintaining energy efficiency without compromising air quality.

When to Use Trickle Vents with PIV

Older Properties

In older properties, where the building fabric may have inherent gaps, the installation of a PIV system can effectively displace stale air without the need for additional trickle vents. The existing gaps often suffice to allow the necessary airflow.

Modern Buildings

Conversely, modern buildings are often constructed to be airtight to enhance energy efficiency. This design, while beneficial for reducing heating costs, can trap stale air inside. In these cases, relying solely on a PIV system may not be sufficient. Here’s how to approach it:

• Assess the Building’s Airtightness: If your building is highly airtight, additional ventilation strategies may be necessary.
• Consider dMEV Units: Instead of trickle vents, installing demand-controlled Mechanical Extract Ventilation (dMEV) units in kitchens, bathrooms, and utility rooms can provide targeted extraction of stale air. This method effectively balances the fresh air introduced by the PIV system.

Recommendations

1. For Older Homes: If you have an older home, you may not need trickle vents as the existing gaps will likely facilitate adequate airflow with a PIV system.
2. For Modern Homes: In newer constructions, consider installing dMEV units alongside your PIV system for optimal air quality management. This will help prevent stale air from accumulating and ensure efficient operation.

Alternatives to Trickle Vents

dMEV Systems

Demand-controlled Mechanical Extract Ventilation (dMEV) systems are an excellent alternative to traditional trickle vents. They actively monitor humidity levels and adjust airflow accordingly, ensuring that stale air is removed without unnecessary heat loss.

Benefits of dMEV

• Targeted Extraction: dMEV systems can focus on areas with high moisture levels, such as kitchens and bathrooms.
• Energy Efficiency: By only operating when needed, they help maintain energy efficiency and reduce costs.
• Improved Air Quality: They effectively remove pollutants and moisture, leading to a healthier indoor environment.

Conclusion

Ultimately, whether you need trickle vents with a PIV system depends on the type of property you have. Older homes may not require them, while modern, airtight buildings will benefit from additional ventilation solutions like dMEV units. Always assess your specific situation and consider consulting a professional to determine the best approach for your home’s ventilation needs.

To ensure optimal indoor air quality, consider the specific requirements of your property when deciding between trickle vents and PIV systems.