Getting Air Conditioning Through the Summer

Why it fails in August and not in March

Air conditioning here runs near its limit for several months. A dirty coil, a half-blocked filter or slightly low refrigerant is invisible in mild weather and becomes a failure when the system has nowhere left to go. The repair is also slower in peak season because every contractor in the city is busy.

What a proper service covers

• Clean or replace filters and wash the indoor coil
• Clean the condenser coil and check the fan
• Check refrigerant pressures and look for leaks, rather than simply topping up
• Clear and treat the condensate drain and tray
• Tighten and check electrical connections and contactors
• Check airflow and temperature difference across the unit
• Check thermostat operation and settings

Signs a system is in trouble

• Rooms that no longer reach the set temperature in the afternoon
• Water marks on a ceiling below an indoor unit
• Ice on pipework
• A noticeable jump in the electricity bill with no change in use
• Smells when the system starts
• Repeated refrigerant top-ups, which means there is a leak

Repair or replace

Below roughly ten years old, with a sound compressor, repair almost always makes sense. Beyond that, with a failing compressor or repeated leaks, the running cost of an old unit usually makes replacement the cheaper option over a few summers. When we replace, we recalculate the cooling load rather than matching whatever was fitted before — oversized units cool fast and leave rooms humid.

Duct cleaning and air quality

Ducts do not need cleaning every year. They do need it after construction work in the house, if there is visible dust at the grilles, or if anyone in the family has worsening allergies. Sealing leaking duct joints often does more for comfort and bills than cleaning does.

The simplest protection

Two services a year — one before summer and one before winter — and filter cleaning every month catch nearly everything that causes a peak-season failure. If you travel, or own the villa as a rental, putting that on a contract means someone is responsible for it on a date rather than when you remember.