Hybrid approach Passively helps achieve 70% energy reduction in retrofit for the future

Innovative ventilation technology from Passivent is helping one social housing provider refurbish its homes to achieve a 70+% reduction in energy consumption.

Town & Country Housing Group is using a 1950’s semi-detached house in Rankine Road, Tunbridge as a Retrofit for the Future test for its plans to ‘future proof’ homes, to both minimize impact on the environment and fuel poverty for residents.

A key element of the strategy, proving to reduce energy consumption by 74% - from 69kg CO2/m2 pa to just 19kg- has been the inclusion of Passivent’s innovative iHybrid ventilation system, which combines the benefits of natural ventilation and heat recovery in one unit.

Paul White, design and quality manager at Town & Country Housing, observed, “We have worked closely with sustainability consultancy CEN on the project, to prevent uncontrolled heat loss through the building envelope yet ensure the property will remain comfortably warm and properly ventilated without worry of high fuel bills. The increased airtightness and insulation meant we wanted to be sure overheating was avoided. For that reason, questions were raised about ventilation systems which had no summer bypass for the heat recovery, and Passivent’s iHybrid seemed an excellent solution.”

Installed by one of Passivent’s Mastercare approved installers, the iHybrid system predominantly uses well-designed natural ‘passive stack’ ventilation, harnessing natural air movement principles to draw fresh air into a home and exhaust the ‘used’ internal air without any electrical consumption, coupled with ‘as and when necessary’ heat recovery.

An external thermostat monitors the outside temperature: when above 9°C, the natural ventilation wall vent remains open to provide fresh air into the dwelling, with ceiling mounted extracts drawing the ‘used’ internal air out via convection and the venturi effect (whereby warm air rises, and air moves faster with height, creating suction). When the external temperature falls below 9°C, the system senses the coolness and switches to heat recovery mode, closing the wall vent and switching air transfer to via the heat exchanger, transmitting warmth from the exhaust air to the cooler incoming air to reduce heat loss, and maintain a comfortable internal ambient temperature AND air quality.

As a result, the energy-using heat recovery element operates only when required; as the heat recovery element is used less, and the natural ventilation has no moving parts to need replacing or maintenance, lifetime costs in repair, maintenance and replacement parts are correspondingly cut- by approximately 39% over a 60 years lifespan of a dwelling. All units in the Passivent iHybrid system are SAP Appendix Q eligible, so can be used within appropriate calculations.

Passivent iHybrid is complemented by the company’s established range for domestic buildings, including natural, assisted and mechanical ventilation solutions for single person to multi-occupancy properties, plus a range of background window and through-wall ventilation solutions. The company now offers a servicing option, whereby the ventilation system will be inspected and maintained to ensure efficient operation, in line with new Building Regulations.

There are currently no comments for this article.

Login to comment. slider