Jane Powerson shops with open doors
Imagine heating your house to a nice comfy temperature: warm enough for you to swan around in shirt sleeves even though it's bitterly cold outside. Then, having got your home all snug, imagine leaving your hall door wide open all day.
The mind baulks at such an image, setting off a clamour of mental alarm bells. Waste of fuel! Waste of money! Global warming! Together they issue an urgent command: shut the damn door! And, indeed, no person in their right mind would leave the front door open for more than a minute or two during winter. Yet walk down any pedestrian-heavy high street in any major town or city in Ireland and you'll pass a wide-open door every few seconds.
The open door is a common strategy among retailers to increase "footfall", although few will admit it. My own informal research (as in asking petulantly: "Why is the door open?") has resulted in convoluted answers of Bertie Ahernesque proportions, as well as various untruths, including the offensive "It's for disabled customers".
Some shops have energy-guzzling blow heaters over their doors, whooshing great quantities of hot air into the street (warming the planet twice, by baking it as well as by pumping carbon dioxide into the atmosphere). Amazingly, these devices are supposed to keep the heat in, by presenting a shield of hot air that is impenetrable to the outside cold air. A more sophisticated "air separation technology" gizmo is the "air curtain" (a glorified blow heater), which is designed to prevent any warm air escaping into the great outdoors.
My research outside the open door of a well-known chain store (one given to making frequent pronouncements about its environmental righteousness) showed a marked temperature difference, despite the air curtain inside. The air was 1.7 degrees warmer outside the doors than it was a few metres away, where there were no open doors. Electric-powered air curtains made by one of the leading manufacturers vary in power from 4.8 to 14.4 kilowatts (a domestic blow heater is two kilowatts), which is a lot of energy to expend (and carbon dioxide to emit) just so the doors can be left open.
Of course, not all shops that leave their doors gaping have air curtains, so those owners make no attempt at all to stop heat cascading out. A survey of 600 urban premises carried out for the Royal Institution of Chartered Surveyors in Britain found that while 40 per cent left their doors open in winter, three-quarters of those had no air curtain fitted. I know, that's Britain, not Ireland, but, somehow, I doubt we're any better. And, air curtain or not, a heated premises with an open door in winter is an act of selfish madness. It might boost sales, but it's also boosting the speed of climate change. So, please, can we keep the door closed?