How A/C works

Why recharge your car air con? There are many reasons to get your air conditioning recharged besides the most obvious one being to keep you and your passengers cool on journeys in hot weather. If you like getting the most out of your tank of fuel then you might be interested to know that recharging your air con increases fuel efficiency. This is because when your air con refrigerant is low, the air con system struggles to cool the air and so works harder to try and produce cold air. This extra work uses more fuel.
Similarly it pays to recharge regularly if you don’t want to have to pay out for expensive air con parts and repairs later on. The refrigerant used in your air con system is extremely cold and has the added benefit of cooling down the air con compressor. Without refrigerant, or if it were to run too low, the compressor would get dangerously hot resulting in an expensive bill.  
Air conditioning even has its uses on cold winter days. If you are struggling to demist your windscreen, pop the air con on to produce dry warm air to rapidly clear your view. Turning your air con on during the colder months of the year also ensures the system doesn’t seize up and will continue to work effectively when the temperature starts to warm up.How does air conditioning work?
Ok so here’s the science bit. (science can be fun) Inside the air conditioning system is a compressor which contains a refrigerant – this is the gas which needs refilling regularly. When the air conditioning system is switched on, the gas travels to a condenser ( the radiator at the front of the car) . Fresh air from outside the vehicle passes over the condenser and the temperature of the gas drops quickly and causes the refrigerant to liquefy. Now in liquid form, a drier removes impurities before reaching a thermal expansion valve which essentially allows the driver to control the temperature in the car by limiting the liquid flow. Lastly the liquid is turned into vapor as it travels through evaporation coils ( the hard to get to radiator behind the dash) and is then blown into the cabin as cool air. Meanwhile, the refrigerant, now back in gas form, returns to the compressor to start the process all over again.