Auto Clima

[Raul_sbd]

Quick question,

Does Auto regulation of the airflow only works with the AC on? Seems to be that when is in Auto but I have the AC off then the airflow never changes during my trip (cannot exactly know if it changes as it doesn't show the airflow strength on the screen display..

If Auto only regulates airflow with the AC on does it means that AC will need to be always on (even if the compressor only operates when it need it?)

Sorry for the confusion lol

Regards

 

[Ormesome]

Hmm good question. iv often thought of this but more to the point of when/if the compressor operates if the AC is left on, ie: does it detect moisture or only clicks on when a colder setting is needed.... With your question, its hard to tell really as if you put it on 23c in the morning (with AC off) then it will only slowly get there as it cant blast hot air because the car wont be able to produce hot air anyway. Have you tried to put the temp really low or high to see if the speed changes after the car is warm? Having said this, i swear the speed of the airflow in my A3 changes even in Auto with AC off.

 

[Raul_sbd]

Hmm good question. iv often thought of this but more to the point of when/if the compressor operates if the AC is left on, ie: does it detect moisture or only clicks on when a colder setting is needed.... With your question, its hard to tell really as if you put it on 23c in the morning (with AC off) then it will only slowly get there as it cant blast hot air because the car wont be able to produce hot air anyway. Have you tried to put the temp really low or high to see if the speed changes after the car is warm? Having said this, i swear the speed of the airflow in my A3 changes even in Auto with AC off.

Good question.. haha ehmmm.. I will try what suggested to change the temp really low or high when the car is warm with the AC off just to see if the airflow changes... I m sure it changed in the past but not gradually so just when I set up or down the temp just do one ajustment on the airflow now and there. On previous cars i had Seat Leon 2013 with auto clima i remember was showing the flow speed on the screen and when changing the temperature then was progressively coming up and down also taking in account the outside temp.

Anyone can tell if leaving AC on means the compressor is working all the time and spending petrol etc...? Or just comes on (as the Auto switch is on) when its needed..?

 

[Ormesome]

If you go to your DIS display on your speedo. click the option part which gives you the menus. Choose the second down, then scroll through until you see a green bar. This will say "air-con" or something. not sure if it chenages (on or off) when it engages or if it shows on there full time when the button is pressed. Not to be confused by the actual heater/blower system as i think its 2 sections on the bar option. im off out in a bit so ill check

 

[Raul_sbd]

If you go to your DIS display on your speedo. click the option part which gives you the menus. Choose the second down, then scroll through until you see a green bar. This will say "air-con" or something. not sure if it chenages (on or off) when it engages or if it shows on there full time when the button is pressed. Not to be confused by the actual heater/blower system as i think its 2 sections on the bar option. im off out in a bit so ill check

You mean on the eco menu on DIS? let me know what you find out on there

 

[Ormesome]

Ok so on the DIS if the air blower is on then it will always show "Air Conditioner" no matter if Air Con is on or not or if Auto is on or manual mode selected. With Air Con on or off, if i put the temp up or down drastically then the blower goes up in speed. If i just add 1c then it operates slowly. From when the engine is cold to normal operating temp the airflow seems the same speed, i set it at 22c.

 

[pburv]

Good question.. haha ehmmm.. I will try what suggested to change the temp really low or high when the car is warm with the AC off just to see if the airflow changes... I m sure it changed in the past but not gradually so just when I set up or down the temp just do one ajustment on the airflow now and there. On previous cars i had Seat Leon 2013 with auto clima i remember was showing the flow speed on the screen and when changing the temperature then was progressively coming up and down also taking in account the outside temp.

Anyone can tell if leaving AC on means the compressor is working all the time and spending petrol etc...? Or just comes on (as the Auto switch is on) when its needed..?

If left on auto then yes compressor is on all the time........I think...lol

 

[Raul_sbd]

Ok so on the DIS if the air blower is on then it will always show "Air Conditioner" no matter if Air Con is on or not or if Auto is on or manual mode selected. With Air Con on or off, if i put the temp up or down drastically then the blower goes up in speed. If i just add 1c then it operates slowly. From when the engine is cold to normal operating temp the airflow seems the same speed, i set it at 22c.

Many thanks for the info!!!

 

[Neil C]

What is this "air conditioning" that you speak of ?
(condenser broken since last summer. Stone damage )

 

[GSB]

If left on auto then yes compressor is on all the time........I think...lol

Sorry mate. It's not.

The compressor is equipped with a magnetic clutch which is activated by the climate control system when it wants to drop the temperature or reduce the humidity. If it stays on all the time you end up turning your HVAC unit into a block of ice, so it regulates. Sometimes it only needs a few seconds of operation, other times a little more.

The climate control system uses measurements of air temperatures both inside and outside the cabin, water temperature sensors on the engine, plus sensors on the dash looking at sunlight intensity. It uses this data and some fairly elaborate Proportional Integral & Derivitive (PID) controllers to regulate the supply of heat from the engine or cooling from the air con compressor in order to maintain your desired temperature. It also regulates the use of the compressor unit to demist the windows (using aircon removes moisture from the air making demisting much faster). If it's cold outside and you want it warm inside, it won't come on very often, if at all.

Don't mistake the air con systems fitted to modern cars for the industrial cooling plants fitted to cars of the past. All that top gear stuff about turning off the air con for a drag race or air con consuming vast amounts of fuel is all outdated rubbish. The compressor (and alternator these days) is taken out of service automatically at wide open throttle, so you always have access to full power, and whilst they do sap some power from the engine at other times, the units are very efficicient and the fuel use is tiny. It's certainly less than that used when you open a window to cool down instead.

 

[pburv]

Sorry mate. It's not.

The compressor is equipped with a magnetic clutch which is activated by the climate control system when it wants to drop the temperature or reduce the humidity. If it stays on all the time you end up turning your HVAC unit into a block of ice, so it regulates. Sometimes it only needs a few seconds of operation, other times a little more.

The climate control system uses measurements of air temperatures both inside and outside the cabin, water temperature sensors on the engine, plus sensors on the dash looking at sunlight intensity. It uses this data and some fairly elaborate Proportional Integral & Derivitive (PID) controllers to regulate the supply of heat from the engine or cooling from the air con compressor in order to maintain your desired temperature. It also regulates the use of the compressor unit to demist the windows (using aircon removes moisture from the air making demisting much faster). If it's cold outside and you want it warm inside, it won't come on very often, if at all.

Don't mistake the air con systems fitted to modern cars for the industrial cooling plants fitted to cars of the past. All that top gear stuff about turning off the air con for a drag race or air con consuming vast amounts of fuel is all outdated rubbish. The compressor (and alternator these days) is taken out of service automatically at wide open throttle, so you always have access to full power, and whilst they do sap some power from the engine at other times, the units are very efficicient and the fuel use is tiny. It's certainly less than that used when you open a window to cool down instead.

Who am I to argue with that Grant.....

...

 

[Ormesome]

Sorry mate. It's not.

The compressor is equipped with a magnetic clutch which is activated by the climate control system when it wants to drop the temperature or reduce the humidity. If it stays on all the time you end up turning your HVAC unit into a block of ice, so it regulates. Sometimes it only needs a few seconds of operation, other times a little more.

The climate control system uses measurements of air temperatures both inside and outside the cabin, water temperature sensors on the engine, plus sensors on the dash looking at sunlight intensity. It uses this data and some fairly elaborate Proportional Integral & Derivitive (PID) controllers to regulate the supply of heat from the engine or cooling from the air con compressor in order to maintain your desired temperature. It also regulates the use of the compressor unit to demist the windows (using aircon removes moisture from the air making demisting much faster). If it's cold outside and you want it warm inside, it won't come on very often, if at all.

Don't mistake the air con systems fitted to modern cars for the industrial cooling plants fitted to cars of the past. All that top gear stuff about turning off the air con for a drag race or air con consuming vast amounts of fuel is all outdated rubbish. The compressor (and alternator these days) is taken out of service automatically at wide open throttle, so you always have access to full power, and whilst they do sap some power from the engine at other times, the units are very efficicient and the fuel use is tiny. It's certainly less than that used when you open a window to cool down instead.

Great read thanks mate. Guess its fine to leave the AC on all the time then. Iv always been worried about leaving it on, especially as in the past the AC has drunk fuel and zapped performance but then it was in inferior cars.

 

[cuke2u]

Good question.. haha ehmmm.. I will try what suggested to change the temp really low or high when the car is warm with the AC off just to see if the airflow changes... I m sure it changed in the past but not gradually so just when I set up or down the temp just do one ajustment on the airflow now and there. On previous cars i had Seat Leon 2013 with auto clima i remember was showing the flow speed on the screen and when changing the temperature then was progressively coming up and down also taking in account the outside temp.

Anyone can tell if leaving AC on means the compressor is working all the time and spending petrol etc...? Or just comes on (as the Auto switch is on) when its needed..?

It makes a very little difference to the mpg and the compressor will turn off at temps below a certain level. I left mine on all the time with my A3 and I still got average mpg of up to 65...

 

[GSB]

It makes a very little difference to the mpg and the compressor will turn off at temps below a certain level. I left mine on all the time with my A3 and I still got average mpg of up to 65...

They really don't make a huge difference. It's the same technology as your fridge, and do you lie awake worrying how much it's costing you to keep half a pint of milk, last nights leftovers and a load of frosty ice cubes cool? No.

Unless you're one of these tightwad cretinous 'hyper-milers' that seem to revel in burning everyone else's fuel as they struggle to get round the selfish congestion causing pillocks, it really isn't worth worrying over. My old Mazda 6 defaulted to air-con ON every single time you started it. Misers, scrooges and people who would rather trade comfort for an additional mile per tank and arriving everywhere with sweat patches and smelling like a postmans sock would have to make a conscious effort to to turn it off on every single trip.

 

[Steve2016]

Sorry mate. It's not.

The compressor is equipped with a magnetic clutch which is activated by the climate control system when it wants to drop the temperature or reduce the humidity. If it stays on all the time you end up turning your HVAC unit into a block of ice, so it regulates. Sometimes it only needs a few seconds of operation, other times a little more.

The climate control system uses measurements of air temperatures both inside and outside the cabin, water temperature sensors on the engine, plus sensors on the dash looking at sunlight intensity. It uses this data and some fairly elaborate Proportional Integral & Derivitive (PID) controllers to regulate the supply of heat from the engine or cooling from the air con compressor in order to maintain your desired temperature. It also regulates the use of the compressor unit to demist the windows (using aircon removes moisture from the air making demisting much faster). If it's cold outside and you want it warm inside, it won't come on very often, if at all.

Don't mistake the air con systems fitted to modern cars for the industrial cooling plants fitted to cars of the past. All that top gear stuff about turning off the air con for a drag race or air con consuming vast amounts of fuel is all outdated rubbish. The compressor (and alternator these days) is taken out of service automatically at wide open throttle, so you always have access to full power, and whilst they do sap some power from the engine at other times, the units are very efficicient and the fuel use is tiny. It's certainly less than that used when you open a window to cool down instead.

Very informative thank you. I must admit I'm one of the people who will turn off the aircon during the colder months and after reading somewhere that if its 16' or less outside then using aircon has no impact unless it's damp and I need to demist. Reading this article has changed my mind now though, thanks again

 

[cuke2u]

An article that explains why you should leave it on all of the year http://www.honestjohn.co.uk/faq/air-conditioning/