Many vehicles when you switch on the "defog" mode, switch on the A/C as well to dry the air.

The range rover pressing program seems to put heaters on and electric heaters built into windscreens I haven't my air con wired in maybe that's why just read hand book by pressing programe puts the best ( heat) setting for dismisting windows ...,
 
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On your Range Rover the air con is always on unless you physically turn it off with the air con off button. It's the fastest way of clearing steamed up/fogged up windows. Air conditioning does what it says, it conditions the air. It dehumidifies it, and by virtue of the fact it fridges it as well it kills a lot of bacteria, though these will grow on your evaporator. It works with the heaters on any temp and will help to keep the inside of your car dry. As for the economy side of things, on a car as thirsty as a 4.6 p38 it makes pretty much naff all difference, especially as it's a modern day system that cycles the compressor on and off. There always used to be a thing for removing the belt on cars to save fuel, but seeing as with the compresor off it's just an idler pulley that makes sod all difference as well.
A lot of big engined cars like V12 jags, Rolls Ryce and Bentley etc also rely on the air conditioning for fuel cooling. Disconnect the air con, no fuel cooling leads to a massive increase in evaporative losses and actually costs you more than if you where using the system./
Having worked in the prestige vehicle sector all my working life it does grind a little when people buy a big luxury car with a big engine and then gripe about the amount of fuel it uses. Changing your driving style and keeping things maintained is far the biggest fuel saver.
 
On your Range Rover the air con is always on unless you physically turn it off with the air con off button. It's the fastest way of clearing steamed up/fogged up windows. Air conditioning does what it says, it conditions the air. It dehumidifies it, and by virtue of the fact it fridges it as well it kills a lot of bacteria, though these will grow on your evaporator. It works with the heaters on any temp and will help to keep the inside of your car dry. As for the economy side of things, on a car as thirsty as a 4.6 p38 it makes pretty much naff all difference, especially as it's a modern day system that cycles the compressor on and off. There always used to be a thing for removing the belt on cars to save fuel, but seeing as with the compresor off it's just an idler pulley that makes sod all difference as well.
A lot of big engined cars like V12 jags, Rolls Ryce and Bentley etc also rely on the air conditioning for fuel cooling. Disconnect the air con, no fuel cooling leads to a massive increase in evaporative losses and actually costs you more than if you where using the system./
Having worked in the prestige vehicle sector all my working life it does grind a little when people buy a big luxury car with a big engine and then gripe about the amount of fuel it uses. Changing your driving style and keeping things maintained is far the biggest fuel saver.

Exactly:D
 
On your Range Rover the air con is always on unless you physically turn it off with the air con off button. It's the fastest way of clearing steamed up/fogged up windows. Air conditioning does what it says, it conditions the air. It dehumidifies it, and by virtue of the fact it fridges it as well it kills a lot of bacteria, though these will grow on your evaporator. It works with the heaters on any temp and will help to keep the inside of your car dry. As for the economy side of things, on a car as thirsty as a 4.6 p38 it makes pretty much naff all difference, especially as it's a modern day system that cycles the compressor on and off. There always used to be a thing for removing the belt on cars to save fuel, but seeing as with the compresor off it's just an idler pulley that makes sod all difference as well.
A lot of big engined cars like V12 jags, Rolls Ryce and Bentley etc also rely on the air conditioning for fuel cooling. Disconnect the air con, no fuel cooling leads to a massive increase in evaporative losses and actually costs you more than if you where using the system./
Having worked in the prestige vehicle sector all my working life it does grind a little when people buy a big luxury car with a big engine and then gripe about the amount of fuel it uses. Changing your driving style and keeping things maintained is far the biggest fuel saver.
theoretically its on but it isn't is it,as it comes on and off with the Temperature settings you have indicated that you require ie hot not on morning start up programe not on including settings you have set, so if you require heat it,s not actualy on is it! Only when you lower temp settings it activates itself with its Temperature sensor .
 
No, it's on when you select hot. Temperature settings have nothing to do with it. The Evaporator temperature senesor is only there to stop the evaporator freezing up by turning off the compressor when a pre determined temp is reached. In the old days it used to be done by a thing called a ranco stat. Then you had variable suction throttling valves that could adjust the amount of fridge required and nowadays it's done electronically by a variable resistance temp sensor and cycling the compressor through an ecu. The other temperature sensor which on other systems is normally known as a 44 degree switch is there to hold off the fans until the heater matrix temp is at a certain point purely from a comfort point of view so when you climb in your car in arctic conditions you don't get a face full of frosty air.
Temperature settings have absolutely sod all to do with it. It should run all the time, from first start to switch off regardless of anything.
If memory serves me correctly, the old range rovers didn't have air conditioning, they simply had a fridge unit under the passenger side dash feeding a row of vents. That is a fridge system, not an aircon system and purely used for cooling.
Climate control with air conditioning is what is fitted to a Range Rover and that is exactly what it does unless you don't want it to, which is why they give you the aircon off switch.
 
No, it's on when you select hot. Temperature settings have nothing to do with it. The Evaporator temperature senesor is only there to stop the evaporator freezing up by turning off the compressor when a pre determined temp is reached. In the old days it used to be done by a thing called a ranco stat. Then you had variable suction throttling valves that could adjust the amount of fridge required and nowadays it's done electronically by a variable resistance temp sensor and cycling the compressor through an ecu. The other temperature sensor which on other systems is normally known as a 44 degree switch is there to hold off the fans until the heater matrix temp is at a certain point purely from a comfort point of view so when you climb in your car in arctic conditions you don't get a face full of frosty air.
Temperature settings have absolutely sod all to do with it. It should run all the time, from first start to switch off regardless of anything.
If memory serves me correctly, the old range rovers didn't have air conditioning, they simply had a fridge unit under the passenger side dash feeding a row of vents. That is a fridge system, not an aircon system and purely used for cooling.
Climate control with air conditioning is what is fitted to a Range Rover and that is exactly what it does unless you don't want it to, which is why they give you the aircon off switch.
Why would a unit that is a fridge run in Conjunction with heat .
 
Because it is a dehumidifier. This is something people don't seem to be able to get their head round. Stop thinking of it just as a fridge. It is a dehumidifier/air purifier. It just does this by fridging the air. And believe it or not, it allows the matrix to heat the air faster, bit like the old hot water freezes faster than cold water but in reverse. All to do with the physics of temperature gradients.
 
Because it is a dehumidifier. This is somoething people don't seem to be able to get their head round. Stop thinking of it just as a fridge. It is a dehumidifier/air purifier. It just does this by fridging the air. And believe it or not, it allows the matrix to heat the air faster, bit like the old hot water freezes faster than cold water but in reverse. All to do with the physics of temperature gradients.

Oic now regersted bit slow but got there :)
 
Because it is a dehumidifier. This is something people don't seem to be able to get their head round. Stop thinking of it just as a fridge. It is a dehumidifier/air purifier. It just does this by fridging the air. And believe it or not, it allows the matrix to heat the air faster, bit like the old hot water freezes faster than cold water but in reverse. All to do with the physics of temperature gradients.

Damn! Now I've got to fix my aircon to keep my windows clear this winter. Was gonna leave that one for next summer.
 
Because it is a dehumidifier. This is something people don't seem to be able to get their head round. Stop thinking of it just as a fridge. It is a dehumidifier/air purifier. It just does this by fridging the air. And believe it or not, it allows the matrix to heat the air faster, bit like the old hot water freezes faster than cold water but in reverse. All to do with the physics of temperature gradients.


There speaks a man who knows his aircon:D
 
Errr you could say I know a thing or two about it. :)


Unfortunately many people have no idea that warm dry air absorbs moisture whereas warm humid air releases it when cooled, hence the condensation on a cold windscreen from warm humid air in a non aircon car.
I know people that firmly believe that cold air clears the screen.
You only have to look at the number of people driving cars that are dangerously misted up to see the level of ignorance. It ought to be part of the driving test, how to use the heating/ventilation to keep the windows clear in winter.:)
 
Yes, after a long journey in the winter I used to open all windows for the last half-mile to get rid of the moisture I'd sweated / breathed out on the journey so I wouldn't have to deice the inside of the screen the following morning. Air-con much better!
 

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