no mufflers
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it has one big storage tank.
A/C questions
- Thread starter no mufflers
- Start date
it has one big storage tank.
needlenose
Full Access Member
This simplifies the charging process significantly.
Can you remove the tank and weigh it on another scale? I doubt the scales are off in your machine, but....
If you're weighing in the charge per the sticker, then I doubt it's undercharged. Not unless there's something wrong with the machine. If you're charging from cans, some people don't realize they have to purge the lines, then reset the scale per can to get a clean, accurate charge.
Macrobb
Full Access Member
So... Just a (possibly off-topic) question for people who know more than I do about AC:
Adding more will increase that temperature, effectively making the system work less, right? Because you've got less of a temperature differential between ambient and the evaporator, right?
Wouldn't it be better to just add a thermostat to the evaporator coil(say, right after the expansion valve) so that you shut the compressor off as soon as the temperature gets down to 33F or so? Wouldn't that give you the coldest air possible, under varying conditions?
Why?
Adding more will increase that temperature, effectively making the system work less, right? Because you've got less of a temperature differential between ambient and the evaporator, right?
Wouldn't it be better to just add a thermostat to the evaporator coil(say, right after the expansion valve) so that you shut the compressor off as soon as the temperature gets down to 33F or so? Wouldn't that give you the coldest air possible, under varying conditions?
gnathv
Full Access Member
The evaporator and line freeze when the charge is low. The pressure is to low out of the evaporator which causes the freon to be below freezing. Look at a pressure temperature chart and you'll see. You have to raise the pressure to raise the temperature and stop the freezing. Yes the pressure switch should cut out the compressor to prevent this. The compressor would probably be short cycling.
gnathv
Full Access Member
With what he has changed it is a little bit of a guessing game. If compressor is good and there is no restrictions (his pressures seem to indicate it's good) His hoses are slightly longer I think he said and he is using a different orifice tube. Both of those would require some adjustment to charge weight. It just doesn't take much to be off enough that it just doesn't cool right.
gnathv
Full Access Member
Actually to use a thermometer on the evaporator you would check your temperature just after orifice tube (Evap inlet) then you would check the temperature at the outlet of evaporator and charge until evap is saturated (outlet will be a few degrees less than inlet) It will be close but not exact.
Macrobb
Full Access Member
But what I'm asking is: If it's getting below freezing, isn't that a /good/ thing? It means it /really/ works!
I mean... aside from the whole freezing water problem, wouldn't the lower temps be better? Really cold air?
(of course, the freezing water problem means that you either have to limit the temperature, or give it a defrost cycle every few minutes...)
CDX825
filtration nut
The pressure switch on the accumulator is supposed to cut the compressor off before the pressure drops low enough to freeze the evaporator. If you evaporator is freezing that means that switch is bad.
gnathv
Full Access Member
You can't blow air through ice and Defrosting it every few minutes will not give sufficient cooling in the very short time it's on.
Or someone has fiddled with the adjustment and messed it up.
Macrobb
Full Access Member
Or you have a different refridgerant than original in there - Pretty sure that the pressure/temps for R12 are different than R134A or anything else that might be in there...
no mufflers
Full Access Member
back on topic. with my current charge I was at an average of 58*
I have the hood off to work on it and I was putting on some door seals so while I was there I figured why not bypass the heater core. so I took one hose off and connected the other hose back to the coolant filter. it wasn't really hot yesterday but very humid so I had some time to try the a/c.
well I got an average temp of 52*, maybe even in the high 40s on the PS vents. over all it did seem to help but Im still going to see if I can get it a little cooler.
I have the hood off to work on it and I was putting on some door seals so while I was there I figured why not bypass the heater core. so I took one hose off and connected the other hose back to the coolant filter. it wasn't really hot yesterday but very humid so I had some time to try the a/c.
well I got an average temp of 52*, maybe even in the high 40s on the PS vents. over all it did seem to help but Im still going to see if I can get it a little cooler.
gnathv
Full Access Member
I have a 97 and am now in Louisiana, plenty hot and humid. Vent temp is 40 at idle. Plenty of condensate out of box as well, almost a stream. I would measure my pressures for you but just moved and gauges are packed still. Your temps are high. You should get much better cooling. I know it's frustrating, but something is being missed. Partial restriction, overfill on oil, etc. I wish I was close enough to help.
