air cion and heating

[macafee2]

outside temperature is 12 degrees.
Heating controls set to 21 degrees.
Start car from cold.

Am I wasting my time by having the heating and air con on as the engine coolant temperature is below the air temperature?

Am I right, you cant get the air con on without the heating on?

macafee2

[topman]

Are you wanting hot air quickly after you've started the engine, is that what you mean?

[macafee2]

Originally Posted by topman

Are you wanting hot air quickly after you've started the engine, is that what you mean?

the situation is hypothetical but yes

macafee2

[COLVERT]

Originally Posted by macafee2

the situation is hypothetical but yes

macafee2

You will only get hot air when the engine gets hot.--

[macafee2]

Originally Posted by COLVERT

You will only get hot air when the engine gets hot.--

just as i thought, thank you

macafee2

[Falcon Flyer]

Originally Posted by COLVERT

You will only get hot air when the engine gets hot.--

Or immediately if you have pre-heated with the Webasto parking heater

[SD1too]

Originally Posted by macafee2

Am I wasting my time by having the heating and air con on as the engine coolant temperature is below the air temperature?

Hello Ian,

My first reaction upon reading your question was: "Are you sure about that?". Did you measure both ambient air and coolant temperature using the instrument pack's facilities? In my experience, the coolant is always above the air temperature.

But the answer to your question is yes, you are wasting your time having the air conditioning on ('Auto' mode) because you don't want to cool the incoming air. Simply select 'Econ' for heating.

Heat is available all the time. The amount is controlled by the temperature setting. If you want to "turn it off", select a lower temperature or even 'LO'.

Am I right, you cant get the air con on without the heating on?

The heating is "on" all the time. Coolant is always flowing through the matrix. It cannot be stopped. To reduce the heat output, lower the temperature setting. That will give you cooler fresh air without any refrigeration.

This is how it works. The incoming air passes over the air conditioning evaporator first. If you've pressed 'Auto' or the windscreen demist button, the evaporator will cool the air to about 4 degrees C.
This refrigerated air then can take two routes. It can either be directed immediately to the vents or it can pass over the heater matrix, which is always hot (or warm in the case of your diesel! ). Usually you get a bit of both. This is how the automatic "climate control" achieves a stable and comfortable temperature inside the car, by blending cold and hot air in variable proportions.

When you want hot air as quickly as possible after starting the engine from cold, use the 'Econ' mode not 'Auto'.

Sorry this is a bit long-winded! I hope that I've covered all the questions that may be coming to mind but if not, please get back to me.

Simon

[macafee2]

thanks, the reason for asking is on another forum someone questioned why you would turn the air con off and my thought was :- if air temperature is well below that of the heating control you are wasting your time. Turn aircon and heater off and let the engine warm up first.

macafee2

[Mike Trident]

If you are using "auto" surely the air con won't turn on if it's 12 outside and your heater setting is on 21?

I presumed the auto setting used either engine heat / air con or a mixture of both as necessary to keep the air temp at 21.

Surely if I go out to my car and it's minus 10, it won't start the aircon pump?

[Mike Trident]

Originally Posted by macafee2

outside temperature is 12 degrees.
Heating controls set to 21 degrees.
Start car from cold.

Am I wasting my time by having the heating and air con on as the engine coolant temperature is below the air temperature?

Am I right, you cant get the air con on without the heating on?

macafee2

The car is clever in that under the circumstances you mention, it doesn't start the fan blower until the engine temp is up to the 40's, so it's not blowing cold air at you.