Waitrose is to introduce an ‘invisible door’ that it is claimed has the potential to save British retailers a combined £1.5bn per year by reducing their energy bills.
Wirth Research’s AirDoor concept prevents warm air being lost from the store during colder temperatures and cold air being lost during warmer temperatures as customers enter and leave.
The technology derives from computational fluid dynamics (CFD) modelling of air flow carried out in motor racing. Wirth Research president Nick Wirth is a former technical director of Virgin Racing’s Formula One team and in the late 1990s was chief designer for the Benetton team.
Wirth’s AirDoor provides an archway that sits outside the store, around the frame of the entrance. It incorporates an array of sensors to detect airflow in both directions, which is then counteracted by an opposing, self-generating wind. The result is an invisible, active ‘barrier’, preventing unwanted outside air flowing into the building and inside air escaping. There is minimal disruption to the customer and it negates the need for revolving doors or lobbies.
It is expected to perform particularly well in extreme temperature or pressure differences as well as strong winds.
Waitrose will introduce the AirDoor first at its Berkhamsted supermarket later this year. If it works there, it will be rolled out further.
Nick Wirth said: “AirDoor is a response to a global and increasingly urgent issue – and there is no direct competition. It represents a solution that improves the customer experience, delivers annual energy savings and reduces carbon emissions – exemplifying Waitrose as a standard-bearer in the supermarket industry when it comes to ‘green’ thinking. The UK high street is facing ever-greater competition from online retailers, but AirDoor combats this by incorporating the energy-saving advantages of an actual door without creating a physical barrier to the customer.”
Jim Burnett, Waitrose & Partners senior manager for technical services, said: “We are always looking to find innovative ways to reduce our impact on the environment and while we know we still have a lot of work to do, the potential of the AirDoor could be key in helping us make our shops even more sustainable in the future.”
In early 2019, Waitrose rolled out the Wirth Research EcoBlade, a twin-bladed strip fitted to the front of fridge shelves to reduce cold air being lost into the aisles, using the same techniques that channel airflow more efficiently around racing cars to enable them to corner at higher speeds.
Development of the AirDoor was co-funded by the government’s Innovate UK programme.
Wirth Research used its own high-resolution CFD model to measure supermarket energy loss caused by wind infiltration, based on weather, door opening data and building dimensions for three different-sized stores. From this, it calculated that each store spent between £5,000 and £10,000 to compensate for energy loss.