Ground ventilation system addresses aircraft noise
The first phase of an earth-tube heat-exchange system for a school in Hounslow has been completed. Polypipe supplied over 376 m of its Ridgistorm-XL large-diameter pipe in 900 and 1050 mm diameters to main contractor Galliford Try. It is installed underground and preconditions incoming air before it enters the building, making possible 100% fresh-air ventilation and reducing energy requirements for heating and cooling.
Westbrook Primary School is under one of the main flight paths for Heathrow Airport. Noise from aircraft is a major problem, particularly during the summer when windows need to be opened to provide ventilation — a problem addressed by the underground system.
Consulting engineers WSP worked with Polypipe and BSRIA to devise a ventilation solution that minimised environmental impact while limiting noise pollution.
As part of major new construction works at the school, WSP took the opportunity to introduce a new ventilation system to stabilise temperatures without compromising the learning environment. The ground-source energy system uses earth tubes, a passive technology that enables the ground to heat or cool ventilation air.
Earth tubes operate on the principle that earth temperatures are relatively constant throughout the year just a few metres below the surface. Fresh air drawn through the tubes will be cooled in summer and warmed in winter.
The Polypipe Ridgistorm-XL tubes have a smooth internal lining to reduce resistance to airflow and an external corrugated profile to increase contact with the ground. The system at this school has an anti-microbial lining and prefabricated condensate chambers.
A second earth-tube system is due to be installed at the school towards the end of 2014.
