Improving the AirCon performance

[SuperMono]

Given that Victoria (and all places south) have been suffering 35+C for the last week or so I wanted to pose this question.
How can you safely improve the perfomance of the standard A/C system?

I have thought about blocking or bypassing flow around the heater core as I don't see much point leaving all that thermal energy inside the car during summer. Anyone tried this?
Would be easy enough to do.

[101RRS]

I cannot help with the specific question - however I also live in a hot area in summer and find my A/C works fine - on a hot 35 day the fan might be on 3 but the car remains cool. On 40 degree days fan is on 4 and really noisy.

Maybe you need to get your A/C serviced because the standard Freelander system is up to the task.

I find removing the hot air from the car by opening the passanger window and the tailgate window really helps. Once the heat is removed and the windows are closed, running the A/c on recirc rather than taking in hot outside air is a real help.

As far as the heater matrix being hot all the time - I assume you are correct but I have never felt this heat entering the cabin area.

Cheers

Garry

[beforethevision]

Im not sure where it sits in the freelander, but often when i was doing auto electrics, we would put a resistor in series/parallel with the sensor on the inside of the car. This meant that the compressor would stay on for longer -> colder. It worked well.

As far as the water through the interior, im not sure. If it does flow, then yeah, putting a tap/bypass would make a big difference.

[SuperMono]

Maybe you need to get your A/C serviced because the standard Freelander system is up to the task.

It was serviced in October and the report was that all was well, once you get the temperature down it hangs on OK, but if the car is sitting around then driven at low speed it seems that the ability of the A/C to pull the temperature down is not quite up to it.


As far as the heater matrix being hot all the time - I assume you are correct but I have never felt this heat entering the cabin area.


On a few occassions when at low speed (up down hills etc) off road or stop start traffic on road, the heat soak into the HVAC system has been enough to cause everything to start pouring out hot air. The effect is like turning the heat control all the way up, even though it is all the way down.
The A/C will take that down to neutral or luke warm, then as you get a bit of speed up it will recover and pull the temperature right down again.


we would put a resistor in series/parallel with the sensor on the inside of the car. This meant that the compressor would stay on for longer -> colder.

Thought about this, there is a fairly detailed description of the system in the workshop manual. However I'm not convinced the issue is making the evaporator colder, just not letting so much heat mix with the cooled air after the fact (when it travels through the heater mixing assembly)


As far as the water through the interior, im not sure. If it does flow, then yeah, putting a tap/bypass would make a big difference.

Only real concern I have (so asking for the extra input/experience) is ensuring that I don't create an additional vapour/air lock in the plumbing, or further increas the underbonnet temperatures, which are considerable already.

Maybe I should add an extra vented radiator assembly and use a two way valve, hot days direct the water through the external radiator, cold days direct through the heater matrix?

[101RRS]

As I said - I do not have this heat soak problem and my car is over 10 years old. Yes the A/c does take a while to pull the temp down when the car has been in the sun but all cars have the same issue - opening the windows when starting off the get the interior to the same temp as outside fixes this.

Sorry I cannot be more of a help - good luck with it though.

Garry

[SuperMono]

As I said - I do not have this heat soak problem

Maybe the V6 sheds a bit more heat than the Oiler into the water system?

Thanks for the replys, all suggestions useful if not actually used :)

Just noticed what is in your sig, you have a sad fascination with pommy automotive examples. The Jag would be nice on a Spring day!

[sclarke]

Your all soft...lol

i work in the heat on roofs and in ceiling spaces... and that gets warm...

Any AC in a car is a luxury and if it works then thets great.

But your missing the big point with AC...

They can only drop the temp inside V outside by a specified amount dictated by the gas used... if it drops the TD by 20k your doing Great...

if its 35 out, then you might be lucky to have the front of the car at 40 -45 deg c road temp is higher and stop and start in traffic does not help. The compressor works best at a certain RPM. if your idling its hardly even working....
So get on a hwy and then it will work better.

Better still get a Defender and open the vents and enjoy the flowing Air.:D

[SuperMono]

I actually do understand the basics of working with refrigerants.
I also understand the basics of working with air/water heat exchangers.

So given a fixed (maximum) performance available from the refrigerant system, removing a heat source from inside the vehicle (the heater matrix) should give better cooling efficiency, but mabye not a lower achievable interior temperature.
It will just get there faster and stay there longer.

Or I could be wrong and speaking gibberish :)

[davesq]

get a tint on your windows.
my freelander does not have tinted windows but the wife's camry does. the heat difference in the two cars is quite noticably on hot days.
Dave

[beforethevision]

I had a look through the workshop manual, and yes, it does continually pump hot water through the heater element. A valve of some variety on either side (probably better the inlet for pressure reasons) would cut alot of heat getting into the dash area.

Thats heat that the AC has to then remove again. Thats an interesting thought.

Im preapring the car today for Mt Mee, but if i get some spare time ill take a closer look and see how feasable it is.

Cheers!


EDIT: how does the K series cycle the water when warming up? becuase apart from the main radiator line, the only other is the heater element. So if the engine has no internal circ, then it wont be able to pump at all....

EDIT 2: the gearbox cooler and heater element are parallel, so blocking the heater off mostly will just cool the gearbox more...
Someone engine minded inform me please!

[Lotz-A-Landies]

Given that Victoria (and all places south) have been suffering 35+C for the last week or so I wanted to pose this question.
How can you safely improve the perfomance of the standard A/C system?
As has been implied, one way to get better performance is to change the gas, when we changed from the now banned CFC's to hydrocarbon "Care" we achieved about a 3 -5 degree better performance on freezer trucks and a noticeable improvement in my Range Rover classic's aircon.

Don't know how a change would affect your Freelander though!

Diana

[beforethevision]

To which gas?


Ive only ever done installs of R134a... and thats what the freelander runs.

[Lotz-A-Landies]

To which gas?


Ive only ever done installs of R134a... and thats what the freelander runs.
Care 30 is a replacement for both R12 and R134a.Welcome to www.care-refrigerants.co.uk--What is CARE? (http://www.care-refrigerants.co.uk/hmpg/hmpgdisplaylev1.asp?catid=3&idofuser=) and is a BOC product. You could talk to your local BOC agent and enquire about a "fridgy" using Care 30.

You would need to remove the 134a, replace the drier and evacuate the system then add the Care 30.

Diana

[beforethevision]

Does this Care30 fit onto the same taps that R134a does? Because i hated changing the taps when doing R12 conversions...

Cheers!

[Lotz-A-Landies]

Does this Care30 fit onto the same taps that R134a does? Because i hated changing the taps when doing R12 conversions...

Cheers!
My brother is the fridgy - so has the adapters on his gauges so sorry I'm not sure about the fittings on the Freelander.