What UAE residents should do with their air conditioning when going on summer holiday

Don't risk mouldy furniture or melted appliances – here's how to avoid a summer AC disaster

If your AC unit is getting old, replacing it could cut 40 per cent off the running costs. Getty Images

The arrival of summer in the UAE marks the exodus of many of the country’s residents. With school out and temperatures inching 50°C, many, understandably, head for cooler climes instead of just turning up the AC.

While you may be able to escape the buckling heat, your apartment, unfortunately, cannot. But if you are planning on leaving for any period of time, the air conditioning dilemma will inevitably arise.

Leave it on, and yes, you will return to find a nice, cool apartment, but it will come hand-in-hand with a not-so-nice electricity bill, which could cost as much as your vacation. Risk switching it off, however, and the cost could be just as high.

What could happen to your home if you turn your AC off?

From horror stories of returning to find an entire apartment covered in a thick layer of mould to items of furniture beginning to melt, the stifling heat can have devastating effects on our homes and their contents.

"I went on holiday for two weeks last summer and while I was away some sort of gross mould moved in," says Liz Cookman, a journalist at The National.  "My grey sofa had mostly turned lime green and was topped with a blanket of fine fuzz. It was on my kitchen counter, my other furniture, it had creeped across my kitchen, and bathroom ceilings and all the jackets, bags and shoes on my coat rack were completely engulfed."

Even clothes and food concealed in wardrobe and cupboards were covered with mould, she says, adding that the place “smelled like a tomb”.

“My landlord tried to say it was my fault because I should have left my AC on while I was away,” she says, “but this seems insanely wasteful to me. I feel too guilty to even have it on for long when I’m actually in it, let alone in a different hemisphere.”

After much back and forth, her landlord eventually agreed to have everything steam cleaned and repaint the ceilings, but the experience has certainly left its mark on Cookman. “Now I always make sure my bathroom fan is on and there is nothing that could evaporate left out,” she says.

And she’s far from alone in her experience. A quick search through online forums in the UAE will bring up countless similar tales, while others report having household items such as detergent bottles dissolve and leak, remote controls melt into sofas and watch straps crack and disintegrate.

What we should we be doing with our AC?

So what exactly should we be doing when we leave our homes in the summer months? “Before leaving, make sure that you leave your AC on, on low, setting it to turn on once per day for a short amount of time – don’t turn it off,” says Manar Alkassar, founder and managing director of Helpling Middle East. “The AC not only cools down the house but also removes humidity that could form due to condensation, which prevents mould spreading. It also avoids the overheating of the ambiences, protecting electronic items and furniture from being exposed to high summer temperatures,” he adds.

The optimum temperature for your home during the summer is 24°C, according to Helpling Middle East, allowing you to feel comfortable in summer-appropriate clothing. However, when you are not at home, they advise shifting the thermostat 4°C to 6°C higher; keeping your home at 29.5°C for eight hours a day can save you between five and 15 per cent on your water cooler bills each year.

This point is echoed by Dan Garner and Colin Thomas from We Will Fix It. “If you choose to leave your AC on while you travel we suggest aiming for a stable but higher temperature of 27-28°C, and choosing the fan-only option that turns the AC on only when needed,” they say.

“Leave all doors within your property open to promote airflow, and if you plan to only leave one AC operating within a villa, choose an upstairs AC as cooler air naturally falls, thereby promoting circulation with the ground floor. If you are confident about your natural airflow throughout your property and your AC system has the option of the fan-only coming on when needed, choose this too to save additional electricity costs.”

For those who have a programmable thermostat, setting your AC to come on for short periods of time each day is the most efficient way to cool your home. It will also allow you to control which rooms in the house are cooled. While switching your air conditioning on and off may seem like it will use more energy, it is actually a more efficient way to keep the temperature steady, as air-cooling systems work best at steadying temperature and dehumidifying when they are running at full speed. Leaving your AC running throughout the day on a less powerful setting will use more energy overall.

“Usually people are so busy packing that it is common to forget the basic things,” adds Alkassar. “So when they come back the house has a stink and even after cleaning, it will take a while to go away. So doing a checklist, for starters, is absolutely necessary.”