Climate Control question

[briantilley]

After picking up my 58-plate FR 550 a couple of weeks ago, I soon noticed that the air from the vents wasn't as cool as I expected, even with the system on AUTO and the temp control on minimum. It certainly wasn't as chilly as the air from my previous cars with aircon.

Anyway, the dealer had a look at it whilst they were programming a second flip key for the missus. They said they found a sticking valve and re-gassed the system. It seemed a bit better, but by then the weather had gone cooler.

After leaving the car out in the sun today, the outside temp was about 17-18 degrees but it was hot inside the car. I set off and set the system on 16 degrees, the fan went up to max but the air from the vents still didn't feel really cool, and it took a long time to get the inside temp down. I tried it in AUTO and with re-circulation on.

Soooo, for those of you that have a Leon with Climate Control:

Should it be possible to have the system pump out air that is cooler than the outside air?

If so, what are the best settings to use to get that to happen?

Thanks very much.

 

[Nath.]

Sounds like you have a fault. maybe the gas leaks over a period of time, like a slow puncture.

Your dealer can re-gas the system and add a dye so the leak can be spotted.

 

[phil3012]

Was the ECON mode on or off at the time?

 

[briantilley]

Thanks for the responses, guys

Was the ECON mode on or off at the time?

The system was not in ECON mode.

If there isn't a system fault (though it sounds like there may be from the first reply above), will ECON mode make a difference one way or the other?

So am I right in thinking that it should be possible to get the system to blow cooled air...?

Thanks again!

 

[cuprascott]

Thanks for the responses, guys



The system was not in ECON mode.

If there isn't a system fault (though it sounds like there may be from the first reply above), will ECON mode make a difference one way or the other?

So am I right in thinking that it should be possible to get the system to blow cooled air...?

Thanks again!

Mine runs ice cold mate and i keep it between 18 and 20 - sounds like somethings goosed with yours.

On another note if you hold the AUTO button down for a few seconds it will let you change temp on both sides by just using the drivers controls.

 

[phil3012]

It should be able to blow cold air. It's by no means the best system I've had but does the job. Sounds like yours has something up with it.

ECON is basically economy mode which means the compressor for the air con isn't running. Much the same as a standard heater in a car without aircon. It will take air from the outside for cooling but not chill it.

 

[eltawater]

Knock it down one time further from 16c and you should see LO in the display - that should give you an ice cold blast.

If it doesn't, it's b0rked.

 

[stuartsjg]

I find that its better to leave the CC set at what temp you want and let it work out how much cold or warm air needs to be supplied.

Mines is set always at 20 and if the car is very hot inside then it decides it needs full cooling and will give as much as it can.

Also, the AC can only remove so much heat from the air, it doesn't'make' cold air, it only cools the incoming air as much as its capacity allows.

If its 15C outside (ie. intake air temp) then the air coming out the vents will be X temp.
If its 20C outside, then the air coming out the vents will be warmer by 4-5C.

If you put it on recirc. you will get cooler air if the cabin is cooler than outside but this can lead to stale air so dont drive about all the time with this on.

If your also just sitting in traffic or at low rpm then the AC doesn't work at full power, i dont think you need many rev's, probably upwards of 1500rpm you will get full ac power.

If you are concerned that its not cool enough, run the fan at a the lowest speed with the CC set at LO and see how cold it gets, if your happy, increase the fan speed one notch at a time, leave to settle for a min and see how cold it is. Perhaps measure with thermometer placed into the vent at each speed. Also note the outside temp.

I would say leave it at each setting for 3-5 mins before reading your temp and keep your revs above 1500 (just sit parked). You will probably find that for the first few fan speeds the temp stays about the same, towards the top it may get warmer. Ill try and do the same over the weekend and see what i get as im curious myself.


Stuart

 

[briantilley]

Thanks again for the help, everyone.

I tried it again with the temp setting on LO. The fan went up 1 speed, but it made no difference to the temperature of the air coming from the vents, it was just coming out faster...

From what you all say, I'm certain it's not working as intended, so I've booked it in again next week for them to hook it up to the diagnostic kit and check it out.

 

[Bedlam]

I find that its better to leave the CC set at what temp you want and let it work out how much cold or warm air needs to be supplied.

Mines is set always at 20 and if the car is very hot inside then it decides it needs full cooling and will give as much as it can.

Also, the AC can only remove so much heat from the air, it doesn't'make' cold air, it only cools the incoming air as much as its capacity allows.

If its 15C outside (ie. intake air temp) then the air coming out the vents will be X temp.
If its 20C outside, then the air coming out the vents will be warmer by 4-5C.

If you put it on recirc. you will get cooler air if the cabin is cooler than outside but this can lead to stale air so dont drive about all the time with this on.

If your also just sitting in traffic or at low rpm then the AC doesn't work at full power, i dont think you need many rev's, probably upwards of 1500rpm you will get full ac power.

If you are concerned that its not cool enough, run the fan at a the lowest speed with the CC set at LO and see how cold it gets, if your happy, increase the fan speed one notch at a time, leave to settle for a min and see how cold it is. Perhaps measure with thermometer placed into the vent at each speed. Also note the outside temp.

I would say leave it at each setting for 3-5 mins before reading your temp and keep your revs above 1500 (just sit parked). You will probably find that for the first few fan speeds the temp stays about the same, towards the top it may get warmer. Ill try and do the same over the weekend and see what i get as im curious myself.


Stuart

Don't you mean that if the cabin is set at 20C and
It is 15C outside (ie. intake air temp) then the air coming out the vents will be will be warmer by 4-5C.
It is 20C outside, then the air coming out the vents will be warmer by 0C (i.e. ambient temperature)?

Presumably if the ambient (outside) temperature is 22C (some hope in the uk) then
the air coming out the vents will be cooler by -2C

Personally I find this system is either over complicated or more likely badly described in the owner manual as I can never get it right

I find the quickest way to warm yourself is to hit the defrost front screen button

 

[briantilley]

I find that its better to leave the CC set at what temp you want and let it work out how much cold or warm air needs to be supplied.

Mines is set always at 20 and if the car is very hot inside then it decides it needs full cooling and will give as much as it can.

That's how I expected it to work. I only started playing around with the temp setting because when it was on 19 (my normal setting in my last car) it wasn't blowing chilled air, even when the temp inside the car was considerably higher than that and the outside temp was around 19-20.

I'll have to try to get hold of a suitable thermometer, as you suggest.

Thank you very much for offering to experiment with your system over the weekend - I will be interested to read the results

 

[Paulki]

With the air-con set to LO the air coming out of the centre vents closest to the evaporator should be less than 8C, anything above this means you have a problem with the system; it could be that the flap controlling the hot air flow is stuck open.

Go back to the dealer and get them to check the air temperature with a digital thermometer.

 

[GainfulShrimp]

Don't you mean that if the cabin is set at 20C and
It is 15C outside (ie. intake air temp) then the air coming out the vents will be will be warmer by 4-5C.
It is 20C outside, then the air coming out the vents will be warmer by 0C (i.e. ambient temperature)?

Presumably if the ambient (outside) temperature is 22C (some hope in the uk) then
the air coming out the vents will be cooler by -2C

Personally I find this system is either over complicated or more likely badly described in the owner manual as I can never get it right

Nah, I'm pretty sure he was saying that the aircon only cools the air - relative to the ambient/outside temp - by a certain amount. So if the outside temp is 25C the aircon might be able to deliver e.g. 10C at full power, but if the outside temp is only 15C, you'll get very chilly air coming out of the vents.
In summer on very hot days, you might only get 20C out of the vents even on full blast with a working system, because the cooling power of the system can only take a certain amount of heat out of the air... it's the relative difference in temperature which determines how cold you can go.

When you first enter a hot car, the air will be warm out of the vents no matter what setting you use, because all the pipes and vents will be very warm. The cool(er) air from the aircon will gradually cool them down though and after a few minutes you should have cool air out of the vents.

If the air is never cold even after a few minutes running at LO and even when the outside temp is only moderate, it's a sure sign that your system is broken (or just needs regassing, if it hasn't been done for quite a while).

I find the quickest way to warm yourself is to hit the defrost front screen button

Good call! I do the same with my Golf although I find it makes my eyes sore if I leave it on for long after the screen has cleared and the car's warmed up a bit.

 

[si289]

I have the same problem, also my heater doesn't seem to heat the car up very well. Well until the Engine warms up that is. Is there a separate heater unit or does it just warm the air up off the heat of the engine?

Think I might go see the dealer this afternoon and get a diagnostics.

 

[phil3012]

The system is simple but badly described in the manual.

Basically set it to the temperture you want either side and the car will try and maintain that temperature. Remember room temperature is around 20 to 22 degrees so that's the temperature most people find comfortable in the car.

You can also set it to High or Low if required to have a continous blast of hot/cold air respectively.

ECON turns off the compressor but remember aircon isn't just about cold air in the car. It is called ECONomy mode as you use a bit of fuel (possibly around 5%) driving the compressor. With ECON it will be difficult to get the car cool.

AUTO keeps it to the temperature to set by also adjusting the fan speed.

Air recirculation uses the air in the car rather than taking air for the outside, useful if you have hayfever or to stop outside smells getting it, but the main reason is it doesn't have to recool or heat the air as much. It can cause windows to mist up though and you need to switch it off to demist the car.

 

[stuartsjg]

Don't you mean that if the cabin is set at 20C and
It is 15C outside (ie. intake air temp) then the air coming out the vents will be will be warmer by 4-5C.
It is 20C outside, then the air coming out the vents will be warmer by 0C (i.e. ambient temperature)?

Presumably if the ambient (outside) temperature is 22C (some hope in the uk) then
the air coming out the vents will be cooler by -2C

Personally I find this system is either over complicated or more likely badly described in the owner manual as I can never get it right

I find the quickest way to warm yourself is to hit the defrost front screen button

GainfulShimp is right.

Given any air flow (ie fan setting) the AC can only remove so many kW of heat from the air.

Think of an electric fan heater:
If its in a warm room, say at 20C, the air coming out will be, say, 65C for example.
If you have it a cold room which is 5C, same heater, the air coming out the fan heater will be cooler by 15C cooler than before, or 50C.

Now take the warm room example, here the heater is raising the air temp by 45C. If we increase the fan speed such that double the air flows, the temperature rise will fall by half meaning the air coming out is 42.5C.

The heater can only heat the air as much as it can, it doesnt make warm air to order.
AC is just the same but with cooling.


I would say that you should be able to get below 10C out of an AC system in 20C heat, if you have the fan on low, you may get close to 0-5C air coming out as i think most AC system use a valve to keep the cooling coils (evaporator) in the range of 0-5C.

Stuart

 

[Bedlam]

Now that I am fully awake, and thinking about it, I bow to your superior knowledge

I think I will now just go out for a before the bank holiday traffic builds

 

[stuartsjg]

I have the same problem, also my heater doesn't seem to heat the car up very well. Well until the Engine warms up that is. Is there a separate heater unit or does it just warm the air up off the heat of the engine?.

I think there is an option for a ceramic heater as in the manual there is a large fuse marked for this purpose but i don't have this, perhaps in the winter pack(?)

The heater coils take warm water which has left the engine block and passed through the EGR cooler (which cools the 400-1000C+ exhaust gas so it can be handled more easily).

I normally need to travel 2-3 miles before getting heat and perhaps up to full temp after 4-5 miles with mixed 30/40 limits.

If your idle or crawling its going to take for ever (ive found idle can take 20-30 mins to warm to full temp)

Coming home each night im straight onto a dual carriage way so ill be upto temp within about a 2 miles having had heat within 1/4 to 1/2 mile having accelerated upto 70ish (probably due to the EGT cooling as i dont think the engine block can warm up that quickly)

i've found its best to let the car do the heating. Don't set it to 26 thinking it will warm the car faster than it set to 20.
It will probably take longer as the CC will wait for a few more degrees of water temp before increasing the fan to deliver the heat.

Allot of people treat CC like the old hot-cold dial (my dad included, in his car the temp is up and down like a yo-yo. When he's in mine he's sometimes commented that the temp is comfortable, its cos i let the thing do its job!). With the old way you mixed the hot and cold air flows to give the temp you desired. CC does this mixing for you, you set the temp.

Stuart.

ps. found a guide which explains how AC works which may be of interest:
http://www.familycar.com/ac1.htm

 

[nc30rider]

Unfortunately the Leon only has 525 grams of refrigerant in the AC system. This is a relatively small amount compared to other cars. Usually 600-800 grams
Some Vauxhalls with climate have 900 grams.
It is cool but not freezing IMO
I re-gassed mine recently and I put a temp probe in the centre vents afterwards and temp went down to 6.5 degrees
I have done others where the temp goes down to 2 or 3 degrees

 

[briantilley]

Thanks for the continued ideas and suggestions

I re-gassed mine recently and I put a temp probe in the centre vents afterwards and temp went down to 6.5 degrees

Air output at 6.5 degrees would be fine for me, but I don't think mine is anywhere close to that.

I'll let you all know what happens after the dealer visit next Wednesday. I presume they should have the means to check the actual temperature of air coming from the vents?