Any AC experts out there?
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Senior User
Joined: Jan 2003
Posts: 338
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From: Tucson
Any AC experts out there?
Hello, my eratic AC is fixed with a new fan clutch. Big difference is performance loss but makes sense. I have temps and pressures under different conditions and would like someone to tell me what they think and if there is any performance to gain in the ac dept. I live in Arizona so I want all I can get.
1. Fans on high windows up rpm at 1800 94 degrees 20 feet from vehicle and 99 degrees 2 feet in front of vehicle.
260h
40l
44 degrees at register
2. Front only on Max AC all other parameters same conditions
270h
32l
42 degrees at register
3. Front only on low all other parameters same condition
High side 180-225 cycling
Low Side 45-23 cycling
36 degrees at register
So how does all that look? I would like to improve on that due to the fact that the AC is this vehicle really doesn't seem to have the capacity and airflow needs for the space to be cooled. I know they build these vechiles for average condition but I don't live in an average place. Can there be any benefit to changing orifices. I think I could get away with a colder evaporator due to the very low humidity here. Any thoughts or ideas appreciated.
Dave
1. Fans on high windows up rpm at 1800 94 degrees 20 feet from vehicle and 99 degrees 2 feet in front of vehicle.
260h
40l
44 degrees at register
2. Front only on Max AC all other parameters same conditions
270h
32l
42 degrees at register
3. Front only on low all other parameters same condition
High side 180-225 cycling
Low Side 45-23 cycling
36 degrees at register
So how does all that look? I would like to improve on that due to the fact that the AC is this vehicle really doesn't seem to have the capacity and airflow needs for the space to be cooled. I know they build these vechiles for average condition but I don't live in an average place. Can there be any benefit to changing orifices. I think I could get away with a colder evaporator due to the very low humidity here. Any thoughts or ideas appreciated.
Dave
Tuned
Joined: Feb 2003
Posts: 495
Likes: 0
From: Cincinnati, Ohio
You could lower the setting on the pressure switch to around 20, that will lower the center discharge temp assuming the switch is set above 20 since you say it cycles at 23. Is the system charged with exactly the amount of R-134 that the system calls for as indicated on the tag at the front of engine compartment or by the evaporator case? I have found that R-134 is very much more capacity sensitive than R-12 and a small variance can make a big difference in center discharge temps.
John
John
Senior User
Joined: Sep 2003
Posts: 394
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Lower or even bypassing the low pressure switch will not make the system colder when the Low side is at 40psi.
You need to remove more heat.
That is what the condenser does.
A larger or modern condenser may do the trick.
An auxillary cooling fan may do the trick.
With front and rear air, the evaporators should be large enough, but the condenser is the same on the front air only application.
You need to remove more heat.
That is what the condenser does.
A larger or modern condenser may do the trick.
An auxillary cooling fan may do the trick.
With front and rear air, the evaporators should be large enough, but the condenser is the same on the front air only application.
Senior User
Joined: Dec 2004
Posts: 134
Likes: 0
From: Churchville MD Harford co
When a Limo is built they add a second condenser to compensate for the extra evaporator
Dodge caravans have dual condensers
you can add a universal condenser in series after the main one
that requires custom mounts, lines and refrigerant capacity
Dodge caravans have dual condensers
you can add a universal condenser in series after the main one
that requires custom mounts, lines and refrigerant capacity
