Tesco, which is committed to reducing the operational carbon footprint of all its stores by 50% by the year 2020, has installed Monodraught Windcatcher natural ventilation systems in its new 17,000ft² superstore in Marlborough, Wiltshire.
Hollyann Holdsworth of Tesco says the four Windcatchers, which will deliver natural ventilation to the store’s main sales area, have been specified to reduce the amount of energy used in its stores, which in turn reduces energy bills and Tesco’s carbon footprint.
Monodraught Windcatchers are based on an innovative technology that is helping to reduce a supermarket’s reliance on air conditioning, which in turn reduces the carbon emissions produced by burning fossil fuels. Windcatchers are widely recognised as the most effective means of utilising the temperature of external air when suitable as a natural alternative to mechanical air handling units.
Roof mounted and designed to operate with virtually no moving parts, they use established atmospheric principles and the natural effects of the wind to bring fresh air into a building and extract stale warm air, using only natural forces. Warm air rising to roof level decreases the air pressure within buildings, allowing cooler air to enter the building via Windcatcher units.
The resultant change in air pressure produces sufficient airflow to make the space comfortably fresh. Wind blowing onto the windward side of a ventilation stack increases the through-put of air and encourages stale and stagnant air to be extracted through the leeward side of the roof unit.
Commenting for Tesco’s environmental consultancy WSP, Peter van Os explains: "The natural ventilation strategy for Tesco stores operates between 18°C and 25°C, allowing the air conditioning to be turned off at certain times when the outside temperature can be used to cool or heat the interior, particularly in spring and autumn. The Windcatcher systems also help to balance the ambient temperature in order to optimise running costs for the store’s open and glass door chiller cabinets which, after air conditioning, are among the highest consumers of electricity in supermarkets."