13. AIR-CONDITIONING: What do I need to know about servicing it and can you list some specialists?

Switched off for long periods of time, water or air can get into the a/c system. The moisture will react with the refrigerant to create acid, which then attacks the seals and pipe-work leaving you with a hefty repair bill.

With a standard manually controlled a/c system you should leave the a/c on all the time, even if not using it to cool the car. You should also turn the system to full cold for ten minutes once a week – even through the winter if you can – in order to circulate refrigerant which contains lubricants for the system and its seals. Then switch to full heat through the same pipes to thoroughly dry them out. This gets rid of any moisture in the ventilation trunking where mould and bacteria might be accumulating.

Climate control systems, where the temperature is set by the operator should be left on all the time, as the a/c will be required to fine tune a reduction in temperature. The vehicle will decide for itself whether to engage the compressor or open the outside flaps and let in the outside air, which at 0 - 3c Celsius will have no moisture content anyway.

Opinions are divided on servicing. Most manufacturers say 3 years from registration or 30,000, then every two years after that. Chrysler recommends every 12 months for the Voyager, and Volkswagen now says every 24 months. Some manufacturers such as SAAB have suffered spates of compressor failures. Aircon specialists looking for business will tell you it needs servicing, preferably by a visit to an air-conditioning system specialist, every year. That way they can keep a record of how much gas is being lost from the system. But the only way to test the gas is to draw some off and lab-test it.

Re-gassing a typical air-conditioning system costs around £80 + VAT. A service and a new accumulator/dryer costs around £150 + VAT. Some a/c specialists argue that this needs to be done otherwise the silica gel desiccant in the dryer could break up and circulate through the system, severely damaging it. Refrigeration engineer Keith Wood believes that replacing the accumulator is not necessary and could be responsible for introducing harmful dirt or dust to the system. It should only be replaced if the system has lost gas and needs to be re-gassed. In his opinion the only regular checks should be for leaks. A pool of water under the car is, of course, not the result of a leak but of condensation dripping off the condenser and is entirely normal.

The two main causes of failure are lack of gas (via leaks at the system seals) and component breakdown. Low refrigerant means low lubricant, which is contained in the refrigerant, and this can lead to seals drying out, thus losing even more refrigerant and leading to failure of the compressor. Properly repairing a failed system is a four-figure job.

Older systems used CFC emitting R22 gas, now outlawed throughout the EC and replaced by environmentally friendly R134a.

For more information, link to www.autoair.co.uk

Air conditioning specialists include:

• Aircon Direct, Tel Tel 01474 832941 www.AC4cars.co.uk
• AVACS Limited Unit 2, Kerridge Industrial Estate, Station Road, Alton Hampshire GU34 2PT. Tel: 01420 80808.
• Autosolutions-Aircon (London) website: www.autosolutions-aircon.co.uk Sensible, straightforward FAQ answers, too. Tel: 02084221212.
• Institute of Vehicle Air Conditioning www.instvac.co.uk (some information out of date)
• Chilly Willy's Mobile Auto Air Conditioning Service, Spares and Repair (HJ's local guy. Doesn't do unnecessary work), tel Paul on: 01903 717199, Mobile: 07802 735692. Website www.chillywillys.org
• Automotive Cooling Services Agents and fitters of Diavia aftermarket air-conditioning systems, tel: 01604 639005, website: www.automotivecoolingservices.co.uk
• Air-Care-Automotive (Surrey and London) website: www.air-care-automotive.co.uk
• Coolair UK Ltd (guarantees its work), head office: Kingsley Road, Lincolnfields, Lincoln LN6 3TA, tel: 01522 682288, and ask for Emma Hayward or Nikki Miller to put you onto your local branch.
• David Norton, Kingsfold Garage, Dorking Road, Kingsfold, West Sussex RH12 3SB, tel: 01403 750202.
• Readerair www.readerair.co.uk, tel: 01483 726300.
• MotorClimate UK (Birmingham), tel: 0121 766 5006. Tel 0121-766-5006. E-mail Info@motorclimate.co.uk, Website www.motorclimate.co.uk
• Alpinair, Alpinair, Hanger Lane Gyratory www.alpinair.co.uk, tel: 020 8991 0055. Free Phone: 0800 197 2120
• Vehicle Air Conditioning Services. Service Centre: Unit 8, Wintersells Road, Byfleet, Weybridge, Surrey KT14 7LF; Parts: Unit A, 120 Oyster Lane, Byfleet, Surrey, tel: 01932 355825.
• Vehvac Ltd, Fircroft Way, Edenbridge, Kent TN8 6AJ, tel: 01732 868080.
• Halfords Garages (see local Yellow Pages for numbers).
• Autoclimate Ltd (trade only), Unit 37, Atcham Business Park, Atcham, Shropshire SY4 4UG, Tel. 0345 5050900, Fax. 0345 5050901 website: www.autoclimate.com.
• Air Bath, telephone 01225 481 563, ask for Tony
• Robert Newton MI AgrE, 16, Ridgeway, Hurst Green, Etchingham, East Sussex TN19 7PJ, tel: 01580 860489/07973 659391
• Express Repairs (Ozzies) 14-15 Severside Trading Estate, Sub-Meadow Road, Gloucester. Tel 01452 505599 Excellent air con repairs, refills from £52 inc vat.
• ColdStart, on little Tennis Street in Nottingham (a recommendation from The Backroom).
• Ariazone International Marcus Dixon at Ariazone International, Port Talbot Tel 01639 822111. info@ariazone.co.uk www.ariazone.co.uk
• Reader Air Conditioning Boundary Business Centre, Woking, tel 01483 726300
• Coolaircon www.coolcaraircon.co.uk Midlands based mobile service freefone 08700 669929. More than 9,500 a/c parts available online, mobile a/c re-charge, service and repair.
• Car Aircon Services Ltd www.carairconservices.com, Beehive Road, Brampton, Chesterfield, Derbyshire S40 2RD, run by Geoff Parker, telephone 01246 238284 or mobile 07836 368336.
• Aircon Direct www.ac4cars.co.uk Family run company. They have mobile units based in Northfleet Kent (Near the M25 Dartford crossing and Bluewater Shopping Centre). Cover Kent, a little of SE London and Surrey, Sussex or Essex when requested.
• Auto Air Con Services Tel: 01983 554904. Mobile: 07778 528986.

Airconditioning Compressor Remanufacturing Service, saving customers ££££££ Hundreds on the Vehicle Mfg Retail Prices:

• Compressortech (Birmingham) Tel 0121-766-5006
E-mail sales@compressoretech.co.uk Website www.compressortech.co.uk

Air-Conditioning and Fuel Economy

A lot of nonsensical generalisations have been written about this.

Basically a/c takes 5 - 10bhp from the engine.

So while it will affect the fuel economy of a car with 50bhp, the driver of a car with 500bhp won't notice it. And in fact, cruising at 70mph in a car with a relatively normal 110bhp, any increase in fuel consumed is insignificant. Opening the windows will have a far more detrimental effect because of the increased resistance the engine is forced to work against.

You will notice a more significant drop in economy in traffic because then the engine is idling and not moving the car very much for the time it is actually running, while at the same time it is turning the a/c pump. So in traffic or about town, at relatively low speeds, where opening the windows creates less aerodynamic drag, it will save more fuel to open the windows than to run the a/c.