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I have replaced all the AC parts in the system, and the coldest it will blow is 45- 50 degrees. I let 3 different shops look at it and they all said that's about all I am going to get out of a system that was made for R12.
Over the winter a mouse chewed a hole into the rubber line and all the freon leaked out, so now its upgrade time. Will a larger condenser produce colder temps? Are there other upgrades that would help? Would a bigger compressor make a difference?
On the newer trucks they have canisters of some type on top of the compressor, I am guessing these are filters or reserve tanks for freon? Would anything like that help?
I have thrown a lot of money into the AC and I haven’t gotten good results in return, so this time around I want to do it right.
I am to assume that you have a retro system and are trying too make it work better. 45-50 degress of vent temp is not too bad if your return air temp is around 65-70 deg.
if you can achieve more than 15 deg. of delta t than you system is working fine. It is true that retro systems do not cool as well due to the fact that r134a operates at a higher pressure and concequintly, a higher tempeture. This requires the condenser to dissapate a higher amount of BTU's than it was designed for. You have a couple options. One, Install a electric fan that flows more air than your stocker. this will help with other things as well. Two, swap in a larger condenser.Three, install a suction line heat exchanger. this device allows head pressure to be cooled by suction gas, and suction gas to be heated by head pressure. Kill two birds with one stone. You will get cooler vent temps, plus you can set you cycling switch to a lower pressure and not worry about low superheat readings at your pump. good luck.
bustech81, tell me more about the suction line heat exchanger. Is that what the canisters on the newer trucks are?
Were can I buy one?
I did forget to metion that it has been converted to R134A
The canisters that you are refering to are probrobly mufflers, and they do not play a major role in system operation. Do a google search for them and you should have several to choose from. The only down side to such a componet is that you are going to have to make new hoses. more than likely all of them except for maybe one. Which is a good idea anyway if you have'nt done that already. R134a is thiner than r12 and will seep though non- barrier hose. The tricky part about this failure is that it is almost impossible to detect. With a suction line heat exchanger, new hoses, and fresh clean 134, If you evacuate properly, you will have a rockin system. good luck.
just a quick thought but did you make sure to switch the orifice valve when you converted? there is a red and a blue valve one is for r134a and the other is for r12. that will make a world of difference.
just a quick thought but did you make sure to switch the orifice valve when you converted? there is a red and a blue valve one is for r134a and the other is for r12. that will make a world of difference.
I used the red oriffice
bustech81, Thanks for the tips and if you have anymore be sure to send my way.
hmm Do you have a receiver dryer and an acumulator setup?
Most likely you have an acumulator since you have a fixed orfice tube. If not then get one fast before running the ac too much more.
The thing with the condenser is that they only get so cold. They hover just above 32*F to prevent the condensation from the moisture in the air that its removing from freezing and blocking the system up.
Also are you running your system on Max ac which is where your recirculation door is open where your cooling the air that has already been coole dinside the cab or are you pulling in air from outside. Air from outside will not get as cold as if you recycle the air that has already been cooled.
An electric fan will work wonders. Im going to add one to mine later on. But im getting sub 50* out of my ductwork but it moves up to around 70* when i stop and sit in traffic for a few moments. Electric fan will do wonders for the ac.
the little cannisters are MUFFLERS, vehicles are so quiet inside anymore every little underhood noise is heard inside, hench the mufflers.
A largerand MODERN condenser will boost your cooling capacity.
Also make sure on RECIRCULATED air and no outside air infiltrates the cab.
Also a heater shutoff valve is helpful, the heater will kick AC's butt everytime.
A modern condenser dosent mean much. Im running a 28 yo condenser and a 28 yo R12 system converted to R134a and im seeing easily 45 - 50 degree temps out of the vents and the hottest ive seen was 65 degrees with 100 degree ambient temp and sitting in traffic. You will need an electric fan. But if you have the old condenser and evap dont swap them out. If your compressior goes, it is easy to flush the older condenser and evap out cause the tubes are larger than on modern systems. If your system dosent have a reciever dryer and acuumulator combo, you might want to look into putting an accumulator between the evaporator and the compressor. It will help with protecting the compressior from damage and it also helps with the cooling and performance of the system. It is also a requirement if you use a orfice tube over the regular valve.
Before the mouse chewed a hole in the rubber line, I was getting about 50 degree vent temps while going 70 mph and it was only 80 degrees outside. At an idle I was getting 60-65 degree vent temps
hhott71, I like the idea of a heater shutoff valve, I bet that would make a big difference.
So which system would be more efficient, suction line heat exchanger or an accumulator? Can I add both?
What happens if I make the system too big for the truck? Is there such a thing as to big?
Rusty_S, I wanted to add an electric fan, but with the external trans. cooler that's in there I couldn’t get one to fit without leaving the grill off.
ahh yea thats a problem for you. I have alot of room between my condenser and my grill.
But like you im limited in space though cause the metal line from my receiver drier runs infront of the condenser at the bottom so im limited to a 10" fan max and cant mount in center due to the hood safety latch bracket is too close
A modern condenser dosent mean much. Im running a 28 yo condenser and a 28 yo R12 system converted to R134a and im seeing easily 45 - 50 degree temps out of the vents and the hottest ive seen was 65 degrees with 100 degree ambient temp
A modern condeser could lower vent temps to 35* and 40* at 2pm in 100+ heat on a sunny day with 90% humidity.
ANYTHING that can help remove heat from the condenser will make the system work better.
Electric fans, the proper engine fan in a fan shroud etc.
GR8ride, you already have an accumulater. the purpose of which is to be a moisture filter, and keep the pump from sucking liquid. It has no effect on how well you system preformes. SLHE devises are widely used in commerial units because there very compact. If you have the ability to make your own hoses, its the way to go in my opinion.