Cergy, 20 July 2016 – With France now experiencing its first heat waves of the summer, Jack Moncharmont, Director of the Energy Efficiency Technical Division at SPIE Ile-de-France Nord-Ouest, provides some simple tips for employees who are (still) in the office, on how to protect themselves from the scorching heat.
Many employees don’t work in air-conditioned offices – how can they best protect themselves from the heat?
Jack Moncharmont: There are many common-sense measures that can be taken, but sadly, far too few workers think of them. With the first heat wave of the summer now upon us, it would be a good idea to go through them again: before you leave the office, pull down the blinds and close the windows on the east side of the building (where the sun rises) so that when you arrive the following morning the office isn’t already overheated, and keep all other windows shut during the day but leave them open at night, to let fresh air in.
One solution that is better known is ‘home-made’ air-conditioning, which involves placing a bowl of ice cubes or a chilled bottle of water in front of a fan, and keeps you cool for around half an hour or so. While this ‘DIY’ technique may appear rather basic, it certainly allows you to work in a more pleasant environment during heat waves! If you work in an office with tiled or lino floors, another, less well-known solution is to mop them several times a day in order to make the office feel cool. As a final example, you can coat windows with special films that reflect sunlight but keep the windows transparent.
Can we also take action on ventilation systems?
Yes, and there’s one method in particular that’s very straightforward. Modern air units in office buildings ventilate the offices by drawing in air from outside. They are usually switched off at night, in order to save energy. This is obviously the sensible and right thing to do… except when there’s a heat wave, when ideally they would be left on overnight so that they can draw in the cooler air from outside and consequently cool down the offices at no great expense. This is what is known as ‘free-cooling’.
Many offices today have air-conditioning. Is there an ideal temperature during very hot weather?
When we want to get more comfortable, we often tend to set the air-conditioning too low. An office temperature of 26 or 27 degrees is not bad in itself. We should be aiming to keep the indoor temperature around 5 degrees lower than the outside temperature. So, when it’s 30 degrees outside, an indoor temperature of 25 degrees is ideal.
There are likely to be more and more heat waves over the coming years – have any solutions been devised that are more long-term?
Yes, of course. In fact, these solutions can already be seen in the most modern office buildings, where tasks that employees once had to do themselves are now fully automated: the blinds on east-facing windows are automatically lowered in the evening, temperature sensors are able to switch on the air units at night, and so on.
Air-conditioning systems are another obvious example, with many office buildings these days being equipped with them. One drawback with these systems is that they often produce chilled water and so consume a great deal of energy. The biggest development that we have seen in modern office buildings over the past few years is the increasingly frequent use of completely natural techniques with lower energy costs, such as geothermal energy, Canadian wells, solar power... When combined with high-performance insulation, these solutions are nowadays even making it possible to design energy-plus buildings.
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