Knowledge base
Why air-con servicing matters in winter too
Almost everyone thinks about the air conditioning when it is thirty degrees outside. That is exactly where the problem lies: a system that stands idle for six months deteriorates. The bill for that usually arrives in the first warm week — and it is considerably higher than servicing would have been.
Air conditioning does more than cool
The most important winter job of your air conditioning is dehumidifying. When you get into a car with misted windows and switch on the demister, in practically every modern car the compressor engages automatically. The air is first led past the cold evaporator, where the moisture condenses out of it, and only then heated. That way the window clears in a minute instead of five.
So if the air conditioning is not working you will notice it precisely in winter: windows that clear slowly or mist up again while driving. That is not a comfort issue — it is a visibility issue and therefore a safety issue.
What happens when the air conditioning stands idle for months?
Seals dry out
Circulating through the system along with the refrigerant is a small quantity of compressor oil. It does not only lubricate the compressor, it also keeps the rubber seals and O-rings supple. If the compressor does not turn for months, that oil no longer reaches the seals. They harden, shrink and start to leak — often precisely where replacement is labour-intensive.
Refrigerant disappears anyway
An air conditioning system is never completely hermetic. Even without a defect it loses on average around 10% of its refrigerant per year through hose walls and connections. After three years that is already almost a third. With too little refrigerant the system cools less well, but much more importantly: too little oil circulates as well, causing the compressor to run dry. A new compressor is by far the most expensive repair on the entire system.
Mould and that typical smell
Moisture condenses continuously on the evaporator. If the system stands idle in a dark, damp environment, that is an ideal breeding ground for bacteria and mould. The result is the musty „wet dog" smell on start-up. Unpleasant, and for people with asthma or allergies a genuine health concern as well. The air also enters your car through the cabin filter — a filter that often stays in place for years too long.
How often is servicing needed?
Rule of thumb: an air-con service every two years, and replace the cabin filter annually. If you drive a lot in town or regularly carry children or pets, opt for yearly filter replacement.
Do not leave the system unused in between: switch the air conditioning on for about ten minutes every month in winter too, preferably during a drive long enough to bring the engine up to temperature. The compressor then turns, the oil circulates and the seals stay supple. Many cars already do this automatically as soon as you use the demister.
What do we do during an air-con service?
- Extracting and weighing the refrigerant present — this immediately tells us how much has escaped.
- Evacuating the system and a leak test under vacuum.
- Filling with the exact quantity of refrigerant and oil prescribed by the manufacturer.
- Checking pressure on the high and low pressure sides and the outlet temperature.
- Assessing the compressor, condenser, hoses and connections.
- On request, cleaning the evaporator and replacing the cabin filter.
Systems with R134a and with R1234yf each require their own equipment and refrigerant; the two must not be mixed. We match this to your car.
Three habits that add years to your air conditioning
- Switch the air conditioning on briefly every month, in December as well.
- Switch the air conditioning off one or two minutes before the end of your journey while the fan keeps running. The evaporator then dries out and mould has far less chance.
- Keep the air intake below the windscreen clear of leaves. A blockage there causes damp and odours throughout the system.
Frequently asked questions
My air conditioning still cools fine. Is servicing necessary?
Yes. Refrigerant loss is gradual and you get used to slowly declining cooling performance. By the time you notice it, the compressor has often already been running with too little oil.
Why does my air conditioning smell musty?
Usually because of bacterial growth on the evaporator, often combined with a saturated cabin filter. Cleaning the evaporator plus a new filter generally solves it.
Can I top it up myself with an aerosol can?
We advise against it. Without extracting and weighing you do not know how much is in there, overfilling damages the compressor, and many of those kits contain leak stop that contaminates the measuring equipment and the system. Moreover, releasing refrigerant into the open air is not legally permitted.
How long does an air-con service take?
Allow about an hour for extraction, evacuation, leak test and filling. If cleaning or a repair is added, you will hear about it in advance with a clear quote.
This complaint belongs with the air conditioning service in Tilburg — measure first, refill after.