Getting a Property Ready for the Hottest Months

Almost every maintenance company in Dubai publishes a version of this article, and almost all of them start from the same wrong idea: that air conditioning is about to be switched on for the season and needs waking up.

That is how it works in Europe. It is not how it works here. Your units have been running day and night, every month of the year, and they have not had a rest at any point. There is no season starting.

The machine is not waking up. It never went to sleep. That is the whole reason it needs looking at.

What does change is ambient temperature, and higher ambient makes some specific things harder. Those are the things worth attending to, and they are a much shorter list than the usual article suggests.

Heat rejection gets harder, so a dirty coil hurts more

An air conditioner works by moving heat from inside to outside. The bigger the difference between the two, the harder that is.

A condenser coil coated in dust is already struggling. When the air it is trying to reject heat into is considerably hotter, that struggle becomes a genuine loss of capacity, and the room stops reaching temperature at all rather than just reaching it slowly.

This is why a coil wash is worth more before the peak than after it. Not because a season is starting, but because the same amount of dirt costs you more when the ambient is higher.

Marginal faults stop being marginal

A unit slightly low on refrigerant, a capacitor on its way out, or a fan motor that has been noisy for a while will all keep working while the load is moderate.

Push the same equipment harder and those margins disappear. It is why call-outs cluster when ambient is highest, and it is worth being precise about what that means: the fault existed for months. The heat did not cause it. It removed the headroom that was hiding it.

Outdoor units in direct sun

A condenser standing in full sun on a villa roof or an unshaded balcony is trying to reject heat into air that is already hotter than the air a few metres away in shade.

Shading it helps, but only if the shade does not block airflow, which is the mistake people make. A cover that sits directly over the unit is worse than no shade at all. What works is something high enough and open enough that air still moves freely around all sides.

Clearing the space around it matters more than shading it. Anything stored against a condenser, and people store a great deal against condensers, is reducing the airflow the machine depends on.

Cold water stops being cold

This one has nothing to do with air conditioning and catches everybody new to Dubai.

Water tanks on villa roofs and in exposed positions heat up, and the cold tap starts running warm. Insulating the tank and any exposed pipe run is the practical answer, and it is a job worth doing once rather than every year.

Drains carry more water

Higher ambient means higher humidity load, which means an air conditioner produces more condensate. A drain line that was coping while the load was moderate can stop coping when the volume increases.

The pan overflows, and it overflows into whatever is under it. It is the cheapest job on any service sheet to prevent and one of the more expensive to repair.

The short list

If you do nothing else, this is the order we would do it in:

• Wash the outdoor coils, properly, on every unit
• Have refrigerant pressures read so a slow leak is found while it is small
• Flush the condensate drains before the volume increases
• Clear anything stored around an outdoor unit
• Deal with any unit that has been slightly weak for a while
• Insulate an exposed water tank if you have one

And what is not on the list

Being fair about the other direction, several things that get sold at this time of year are not urgent.

Duct cleaning is not seasonal and should be decided by an inspection rather than a calendar. Deep cleaning is worth doing when a unit smells or its airflow has dropped, not because of the month. And a maintenance contract is worth taking on its own merits rather than because somebody has attached urgency to it.

The genuinely useful version of this advice is much duller than the version usually published: equipment that runs continuously needs looking at on a schedule, and the schedule matters more than the timing.