Air conditioning is much more than just an additional comfortable feature in your car. The coolness it provides in case of high outside temperatures is sometimes a condition for driving at all. Equally important as the air conditioner’s cooling air flow is its second effect: it reliably dries the interior air in summer as well as in winter.
|Air conditioner construction and functioning|
|Air conditioner damage|
|DIY air conditioner repair|
|1. Beginner’s level|
|2. Advanced level|
|3. Only for professional garages|
More than just comfortable
A properly functioning air conditioning system is very suitable for avoiding moisture damage as well as for defrosting the windshield on the inside.
The system requires your attention to enable it to perform these functions.
Part of the maintenance you can undertake yourself.
Function of the air conditioning in the car
Air conditioning in the car functions by the principle of compression and absorption. Gasses which are suddenly compressed, heat up. Reversely, gasses cool just as quickly when their volume is suddenly increased. The air conditioning’s cooling unit is a closed system circulating an evaporating agent. The tightness of the system is decisive for the functioning of the air conditioning unit. The coolant is being compressed in the compressor and de-compressed in an evaporator. This causes the coolness, which is conducted via an air flow into the car interior. The compressor is driven by a belt, generally timing belt or V-belt, driving in addition to the air conditioning compressor, the power-steering pump, the cooling pump and the generator.
Air conditioner damage
A weak point of an air conditioner is the tightness of the closed cooling system. The pressure in the ducts causes coolant to gradually escape. As a driver, you can’t stop this process. If the air conditioning performance deteriorates, probably too much coolant has escaped. This is no reason for panic. The air conditioner can be topped up and sealed again.
The cold air is blown into the interior by a blower on account of which the air passes through a series of filters to clean the cooled air of particles. Since approximately 25 years, the pores of these filters are so fine that they can hold pollen. Organic particles such as these deposit in the filter and decompose over time. Accumulation of organic particles in the filter causes an unpleasant smell in the interior. In that case the filter needs replacement. This replacement always comes with a thorough cleaning and disinfection of the air ducts.
In the technical sense, all components of the air conditioning system are subject to wear. The air conditioning compressor is particularly sensitive to it. For its replacement, the cooling system must be opened. As the coolant is a chemical waste and a dangerous substance as a rule, you should not perform this repair in your own garage.
Finally, drive belts are subject to high wear too. Depending on the belt type, the failing air conditioning system is the slightest problem when the drive belt tears off. If a water pump, an alternator and a valve train at worst are driven by the same belt, a tearoff may cause serious engine damage. Here helps only timely replacement according to the maintenance plan.
DIY repair of your air conditioner
In order to ensure continuous adequate functioning of the air conditioning system, several maintenance works are necessary. Several of them you can undertake yourself, and by doing so, save a lot of money for garage visits. We mention the most common maintenance steps, enabling you to determine which task you trust yourself with.
1. Beginner’s level:
1.1 Replacement of filter and cleaning of the air conditioner
The air conditioning system should be thoroughly cleaned every two years. This always includes replacement of the pollen filter. You will find its location in the car manual. It is a long, narrow box right under the front windshield. A pollen filter is very easily accessible. Opening its housing and removing the filter requires no special tools.
Before replacing the pollen filter by a new filtering element you first need to clean the air ducts. The specialised shop offers several solutions, such as disinfection foam and interior vaporiser. The disinfection foam must be sprayed directly into the inlet ducts of the interior fan. The vaporiser is to be placed behind the driver’s seat. Both possibilities have their advantages and disadvantages.
1.2 Disinfection with cleaning foam
Prior to disinfection of the air inlets, dry the evaporator thoroughly. You can’t see this component, but you can dry it with help of the blower and the heating system. Turn on the air conditioner and fully turn up the heater, let the air circulate and let the engine run for 10 minutes. Now the evaporator should be dry.
Spray the cleaning foam generously in all ducts which are visible from the opened pollen filter box. You can use at least half a spray can. In this case: the more the better.
Start the engine and turn on the blower. Turn off the heating system and the air conditioner. Change the direction of the blower every three minutes. As soon as foot area, head area and the windows have been fully ventilated for three minutes, repeat the procedure. Now use the rest of the spray can and allow all the ducts to blow clean thoroughly. Install the new pollen filter; close its casing and you are done.
1.3 Disinfection with fogger
Instead of cleaning the air ducts from the outside, some manufacturers offer simpler solutions. The interior fogger is placed on the bottom of the car behind the driver’s seat. A firm piece of cardboard prevents the canister from falling over. The beam must be able to shoot straight up. Start the engine, open the canister, causing the disinfectant to spray out. Shut doors from outside and put the interior fan on full-blast for twenty minutes. Then remove the cardboard, the canister and possible residue from the back of the seat.
This method ensures an additional, thorough disinfection of the whole interior. Prior to use, please make sure that the interior upholstery can handle this treatment. Asthma and allergy patients might be affected by this procedure.
2. Advanced level:
2.1 Replacement of parts
With exception of the drive belt and the blower, replacement of every air conditioner component requires drainage of the coolant. This can only be done by certified garages. If you want to replace the compressor, absorber or air conditioning ducts by yourself, you first need to have the coolant removed by the service provider. Prior to refilling it, the garage conducts a leakage test. This will show if you did everything correctly.
If the drive belt for the compressor is not used for valve control as well, its replacement is relatively simple. You will recognise the difference by the shape of the belt: if it is a flat belt, clearly toothed over its entire width, it is probably a timing belt. Its replacement can be done by a DIY mechanic with plenty of exercise and knowledge, though requires sufficient experience. A wedge-shaped belt does not play any part in the valve control. This applies to V-belts without toothing as well. This belt shape has a different meaning: instead of valve control, toothing on V-belts is only meant for bending a particularly small radius.
For garages only
3.1 Filling the air conditioner
Draining and filling the air conditioner can only be done by certified professional garages.
DIY-solutions which are sometimes offered, are not recommended as their results cannot be compared to those of a professional garage.
Conclusion: simple tasks can be done by laymen
The air conditioner is a very comfortable component making driving the car very pleasant. As a technical layman you are generally able to perform the most important maintenance tasks. The replacement of a pollen filter and disinfection of the ventilation can be done by everyone. This way, you get to know your car better, meanwhile saving a lot of money.
Foto: Romaset, Nor Gal, chartphoto, MoonAngelEyes, Monika Wisniewska, kryzhov, sima, ANURAK PONGPATIMET, rawinyeepinyo / shutterstock.com