What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks

Licence to chill - air conditioning and health

I wonder if you could publish an article about the possible hidden hazards of car air-con systems. I have just been made quite ill with breathing problems by a heavy scented smell in my Ford C-Max, which, despite air-con cleaning and valeting, would not go away.

This is nothing to do with it being a C-Max; it could happen to anyone. I was obliged to sell the car (traded it in so they were aware) to the local Ford Dealer, who fortunately had a very suitable low mileage replacement Ford C-Max on the forecourt. I had fallen into the trap of never using the air-con unless absolutely necessary as I thought it used up petrol.


Also, I would warn readers of the chemical dangers in the commercially produced air-con "bombs" available in car accessory shops; the fumes can be very dangerous if breathed in. I am still suffering from breathing problems, tiredness and disturbed sleep a month after it all started. Please could you also recommend frequent use of the air-con even in winter to prevent any bacterial infestation.

Asked on 14 March 2010 by ME, Penarth

Answered by Honest John
Aircon in cars is not a problem if, as I frequently suggest, it is used at least 10 minutes every week of the year to lubricate the system, as the lubricants are carried suspended in the refrigerant. Best to regularly run the system at maximum heat after running it maximum cold to dry out condensation in the trunking, this preventing bacteria from having anything to grow on.

Pollen filters preferably need replacing every year, at most every two years. The bacteria decontamination 'bombs' are supposed to be let off inside the car, with the engine running and the fan recirculating, while you stand outside the car. You were ill informed about the effect of a/c on fuel economy. At speed, a/c uses less fuel than opening the windows. It's only when idling in traffic that a/c significantly affects fuel economy.
Similar questions
I had my air-conditioning regased but when I went to put it on again the next summer it wasn't working and the same garage said it needed regassing again. They also said I should keep my air-conditioning...
Is it true that you should have your recirculation button on all the time in summer when you are running the air conditioning?
How often should the aircon be serviced on my car?