Not sure you can turn off the AC alone. You have to turn off the Climate Control.

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Hello, does anyone know how to resolve this issue?
air con seems to be on despite the button not being pressed, nor is the heating on “auto”.
driving today I noticed on two occasions steam coming out of the vents which I have only had with aircon on. Also shown on the eco page that ac seems to be on. Is this the min setting that you can set on the centrla screen settings to low/ med / high? View attachment 181873

If it’s like x250, compressor (if that’s what you meant) is always on and the refrigerant flow is controlled instead. Car will consider fuel economy in controlling the flow. So it’s not a big deal to switch it off.

 

So why have a separate ac button if you cannot switch it offcompletely? So are you saying that if say the outside temp is 20c and you set the inside temp to 16, it will work harder then say setting it to 19?

 

If you have selected A/C Yes. and that’s to keep fan speed down for less noise. In a standard car compressor works with 100% capacity when switched on and disengages when off. This mean with A/C on at idle engine works harder which is not necessary. In XF, compressor is permanently engaged and it’s cooling power is controlled. When a/c is off, the flow is set to minimum and it’s not controlled to keep room temp or humidity down.I quote from x250 WM:

“The A/C compressor is a permanently engaged variable displacement unit which is driven by the engine accessory drive belt. To protect the system from excessive pressure, a pressure relief valve is installed in the outlet side of the A/C compressor. The pressure relief valve vents excess pressure into the engine compartment.”

“
A/C Compressor Control
When A/C is selected the ATC module maintains the evaporator at an operating temperature that varies with the passenger compartment cooling requirements. If the requirement for cooled air decreases, the ATC module raises the evaporator operating temperature by reducing the flow of refrigerant provided by the A/C compressor. The ATC module closely controls the rate of temperature increase to avoid introducing moisture into the passenger compartment.
If the requirement for cooled air increases, the ATC module lowers the evaporator operating temperature by increasing the flow of refrigerant provided by the A/C compressor.
When A/C is off, the compressor current signal supplied by the ATC module holds the A/C compressor solenoid valve in the minimum flow position, effectively switching off the A/C function.
The ATC module incorporates limits for the operating pressure of the refrigerant system. If the system approaches the high pressure limit, the compressor current signal is progressively reduced until the system pressure decreases. If the system falls below the low pressure limit, the compressor current signal is held at its lowest setting so that the A/C compressor is maintained at its minimum stroke. This avoids depletion of the lubricant from the A/C compressor.”

if you car blows really cold air with A/C off then there could be a problem with DPS valve which at age of your car is very unlikely. DPS is the valve that controls the flow.

 

You can turn off the a/c by going into the climate control part of infotainment. The eco system still shows 0.3 GPH though

 

Would have been nice to switch it off completely. But if I read hamedhbb description It sounds like the cooling is inverted proportional to the delta t from the set temp compared to the outside air temp and that the ac button overrides it all for max cooling.
does anybody know if it drys the air to much. I hate to be drying out too much when driving. Also .3 gph seems quite high for the effort of not having to add a compressor clutch , which I thought are quite reliable anyway. But hey I’ll get used to it

ill have to have a look in the infotainment system gav. Thank you both

 

Would have been nice to switch it off completely. But if I read hamedhbb description It sounds like the cooling is inverted proportional to the delta t from the set temp compared to the outside air temp and that the ac button overrides it all for max cooling.
does anybody know if it drys the air to much. I hate to be drying out too much when driving. Also .3 gph seems quite high for the effort of not having to add a compressor clutch , which I thought are quite reliable anyway. But hey I’ll get used to it

ill have to have a look in the infotainment system gav. Thank you both

It shouldn’t be that much because it’s almost running freely when a/c is off. Is the 0.3gph only for compressor or that includes blower fan, etc. ?
the compressor does have a clutch but that only disengages when there is a fault. Maybe you can test the change in consumption by taking the compressor fuse out. (I am not familiar with infotainment system in x260)
Following Pete’s post, don’t underestimate the humidity impact on your cabin trim on longer terms.

 

Drying the air too much? Hmmm, what's "too much"?
There some serious calcs when sizing air handling units for air conditioning based on mass air flow, air temperature, air humidity, cooling load, etc. All of which I once knew but have long forgotten. (BTW, it is a misnomer to call what goes into a car "climate control" or even "air conditioning". It is neither without controlling the humidity which is what air handling units do in large buildings.)
There's only one real way to attempt to control humidity in a car . . . . open a window.

 

Drying the air too much? Hmmm, what's "too much"? [snip..]
There's only one real way to attempt to control humidity in a car . . . . open a window.

Not according to Jaguar John:

"Humidity within the cabin is controlled by raising and
lowering the evaporator temperature. An increase in
evaporator temperature increases the moisture content in
the air entering the cabin. Lowering the evaporator tem-
perature reduces the moisture content in the air entering
the cabin."

From page 125 of this: 711-JAG_Noted_04_12.pdf

 

Only just had a chance to read peteA document which makes sense. Got used to it now and just accept it as part of the car. thanks you for all your replies.