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Situation: RRC and hot environment (UAE - yesterdays temps 42C and 80% humidity) .

Have a question: How do you deal with the weak AC in the RRC? Did you make modifications on it?

- The system is converted to R134a and honestly it sucks. I ensured that everthing is in working order but the stock AC seems to have its limitations.
- Followed already the advice to close all gaps around the ducts so the the cold air cant escape into the dash.
- the windows are tinted all around and I have put an isolation layer between roof and headliner.

One of my ideas is to install bigger AC aux fans to increase the air flow through the condenser. this should bring some improvement while idling (traffic lights etc.)
But otherwise I am dealing even with the idea of a swap with a system of Toyota or Nissan to push the performance.

Any input is appreciated.
 

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1995-2002 Range Rover P38A
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Yeah, I've made a few trips to the UAE and the heat can be unreal. Not sure the RRC is up to it. However, with that said, I restored and swapped over my RRC A/C during a years assignment in the Mississippi delta south of New Orleans and was very happy with the results.
A couple things I noted during my rebuild:
1) Did you change out the expansion valve when you switched over to R134a? R134a requires a different expansion valve than the old R12 to properly manage the expansion of the gas in the evaporator.
2) Have you checked the recirc vent flap function? (the flap is electo switch vacuum motor actuated and closes the outside air vent when the selector switch is in the A/C position and the fan on) The electro vacuum switch is buried in a tough spot to access (but not impossible) in the dash. The vacuum supply comes from a vacuum hose off the manifold, through a check valve, to a vacuum reservoir (funky black ball near the ignition coil) then on to a vaccum hose penetrating the firewall and on into the vacuum electro actuator switch... :doh: ... yeah, there's a lot of places for this to leak, and if it's not working properly large quantities of fresh, hot, outside air are being dumped into the vehicle when moving forward. The check valve (missing/removed in many vehicles) insures the vent stays shut when at idle and low manifold vacuum. Worth a good look over.
3) There's a variable resistor connected to the temp slide lever that integrates a bias to the evaporator thermal switch which controls the on/off operation of the compressor. In short, if this isn't working right your compressor won't run long enough to really cool down the evaporator. Watch your compressor clutch in and out with the lever at max (blue) cool. Does it run almost continuously in real hot weather? Get an A/C techs thermometer and place it into the A/C plenum. On the hottest swampy day I could get 50 deg F out of the vent.
 

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Discussion Starter #3
rtkraken said:
Yeah, I've made a few trips to the UAE and the heat can be unreal. Not sure the RRC is up to it. However, with that said, I restored and swapped over my RRC A/C during a years assignment in the Mississippi delta south of New Orleans and was very happy with the results.
A couple things I noted during my rebuild:
1) Did you change out the expansion valve when you switched over to R134a? R134a requires a different expansion valve than the old R12 to properly manage the expansion of the gas in the evaporator.
This I have to check with the previous owner...job was done in workshop, but you never know!?!?

rtkraken said:
2) Have you checked the recirc vent flap function? (the flap is electo switch vacuum motor actuated and closes the outside air vent when the selector switch is in the A/C position and the fan on) The electro vacuum switch is buried in a tough spot to access (but not impossible) in the dash. The vacuum supply comes from a vacuum hose off the manifold, through a check valve, to a vacuum reservoir (funky black ball near the ignition coil) then on to a vaccum hose penetrating the firewall and on into the vacuum electro actuator switch... :doh: ... yeah, there's a lot of places for this to leak, and if it's not working properly large quantities of fresh, hot, outside air are being dumped into the vehicle when moving forward. The check valve (missing/removed in many vehicles) insures the vent stays shut when at idle and low manifold vacuum. Worth a good look over.
This was the very, very first thing I did...was my first suspect. Fortunately it works (unfortunately on the other hand - would be a easy fix)

rtkraken said:
3) There's a variable resistor connected to the temp slide lever that integrates a bias to the evaporator thermal switch which controls the on/off operation of the compressor. In short, if this isn't working right your compressor won't run long enough to really cool down the evaporator. Watch your compressor clutch in and out with the lever at max (blue) cool. Does it run almost continuously in real hot weather? Get an A/C techs thermometer and place it into the A/C plenum. On the hottest swampy day I could get 50 deg F out of the vent.
The compressor runs always! The car inside temp is not reaching a level worth to disengage the compressor clutch.
 

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Can say from living in a climate where a week of overnight temps in the 30's and daily tops in the low to mid 40's is not uncommon, that the RRC hard dash AC system is not upto the job at all and one of the big deciding factors in me buying a softdash, which has the disco heatbox/vent system and quite frankly is about 3 or 4 times better than the hard dash setup.

I miss the older style car, and am thinking about going back to one, but an aftermarket ac system would be part of that decision. Theres a few about which are designed to run from 12V, but a second battery might be the go as well to ensure the cars electrical system isn't overloaded at times. I am talking about refrigerated units, which can be roof mounted, or even split systems with under car mounted compressor units.
 

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I read about a guy with a classic Saab 900 in Dubai who sealed his fresh air intake and coated the entire condenser box in insulating foam. However, he was still running R12 refrigerant. His dedication to running a Saab in such a climate was amazing to me. Running an RRC in that climate also seems amazing too.

This may be a little impractical of me to suggest, but like preparing a house for hot weather, perhaps you should look to both insulating the RRC and increasing the AC's efficiency. One way, not cheap, would be to switch back to R12 refrigerant to gain greater cooling efficiency. You can also tint the windows with silver infrared (heat) reflecting tint, if you can still find anyone selling it. You can insulate the roof better with Mylar sheeting ("space blanket") and foam above the fiberglass headliner. You can also insulate under the carpets with Mylar sheeting and foam to minimize heat transfer from the hot road surfaces. You might even want to add an additional aftermarket air conditioner, powered electrically like the rear A/C in a Disco.

Of course, I've never done any of these things myself, in my relatively mild climate. This week I've been thinking about it mightily because of our sudden heat wave, but it is cool and dry by UAE standards.

Scott
 
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