Can anyone tell me what a serpentine evaporator is? A diagram, picture, etc. would be very helpful.
Tim or anyone from AMA,
What kind of evaporator do I have in my Suzuki kit?
It looks like an "s" shaped tube with fins. Like what you see on the back of your refrigerator.
Edited: Wed November 14, 2007 at 6:34 PM by bearing01
64 pass tube & fin.
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No, similar to the image posted with 64 passes.
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This article may help explain the different heat exchanger designs
http://www.hecat-inc.com/ACtion%20article%20Sep07.pdf
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Another view of a serp evap.
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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson
Edited: Thu November 15, 2007 at 8:56 AM by iceman2555
In MVAC, is there such a thing as a parallel flow evaporator?
Sure.
Parallel flow evaporator
B.
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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.
Plate and Fin would be similar but not exact.
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Nope you have a tube and fin core as I mentioned before.
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Hi Tim,
So, in your opinion, would a serpentine evap work better? For now, I'm going on the assumption that an OEM evap is of serpentine construction. If you think it might work better, I will try to source one and give it a shot. I do understand that this is a small a/c unit so it might not blow as cold as something larger, like in my Dodge truck. But, I'm willing to experiment and try different things.
We have those systems as originally sold cooling very well in the Arizona summer. If you only have a 20 degree temp as determined between you ambient listing and vent temp listing. You have some issue going on with the system. Hot air getting in, heater core issue or something else. Pressures indicate a cold evaporator core.
That just my opinion!
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Our kit cools fine in Arizona. I still think you should be looking at others areas besides the evap if you only have a 20 degree difference and a low side of 16 PSI. Core is cold at that point so why is the air only dropping 20 degrees?
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When faced with a perceived cooling problem...it is best to know for sure that the system is properly charged. Reliance on pressures is not always a true indication of a completely recharged system....esp with the smaller recharge rates of some vehicles....and esp with aftermarket kits. With a known specified recharge rate...a suggestion would be to insure that the system is fully and totally charged. If lacking the proper equipment to measure total recharge rates....suggestion would be to have the system recovered, evac'd and recharged using the proper equipment. This will remove a major assumption in the diagnosis procedure....how much refrigerant is in the darn thing.
Evaluate pressures...but keep in mind they may vary from perceived OE specs. Evaluate temp drops....post info...lets us know. From the original post...seems pressures were the first concern...then temps came into play. Get it charged....evaluate both test parameters.
Test at idle...max cool..high blower...doors open....also at an elevated rpm....1200-1500 is sufficient....doors open and closed...measure temps/pressures and post results.
Be sure to include ambient temps...measure at the front of the vehicle....foot or so in front of the condenser.
The issue of the evap....three types are available...serp....plate and fin....and tube and fin. All have different heat absorption characteristics...which is better....that is probably a matter for another many post discussion. The industry follows the plate/fin and serp idea. Tube and fins are favored by the aftermarket kit suppliers....the ability to manufacture to custom specs is probably one reason. These have been used successfully for many years...heck for decades. They will work and should cool your vehicle.
Keep in mind the temp exchange requirements of your vehicle....fire wall....top...and other areas of insulation. Also engine cooling systems are sometimes different for non OE A/C cars. This can play a part in vent temps also. Engine cooling is most critical for proper cooling operations.
Back to the evap issue....statement to locate a OE evap may not be a salvation....it may not fit in the air box of your system. Measure twice to insure. But think the system you purchased can be properly configured to operate to your expectations.
Good luck...keep us posted. But first and foremost...get the thing charged correctly.
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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson
Would it be possible (and accurate enough) to use a postal scale with 12 oz. cans of 134a to measure out the appropriate charge? Seems to me it should work if I disconnect the hose going to the can so it won't interfere with the scale reading?
A postal scale will work, and it is sure better than nothing. But if you're going to be working on your car and "others" like family memembers, friends etc, I would suggest you get a refrigerant scale and a 30lb tank of R134a. Prices came down on tanks of refrigerant during the year, and although I haven't bought one in over a month, you can probably get 30lb around $75 to $80 bucks now (I will have to check, since I'm almost out too) There is no more accurate way, and check out the price of that quality scale. Can't beat it...
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Chick
Email: Chick
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Freedoms just another word for nothing left to lose
Chick, why more scales are not used is a wonder. I have had a scale and heater blanket in my A/C tool bind for more years than I can count..or rather like to count. Sure comes in very handy when the R/R machine is tied up. For a mobile service van..these things are great. A small recovery only unit...a scale...blanket and wow....instant A/C service in a van.
It is amazing the number of operational shops (pros) today that lack the proper and legally required equipment to service automotive A/C systems. Often the cost of this equipment is stated as a reason...but the cost of a simple weight scale...a heater blanket is very small compared to the cost of doing a job over because the system was undercharged and the compressor failed. Add the benefit of knowing exactly how much refrigerant is in the system and being able to eliminate one aspect of the proper diagnostic procedure...go figure.
For about the cost of one compressor (new) one could have a scale and heater blanket and be assured that the proper amount of refrigerant is charged. With the decrease in recharge amounts, this ability to measure becomes much more important...on 14 oz recharge..how much does one take out of that second can??????
Thanks for the heads up!!!
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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson
Scoty, when addressing the issue of removing hose material to facilitate installation....how much was removed? Unless a large quantity was removed, it is doubtful that the recharge amount sufficiently changed. There is a formula for recharge determinations...have to research the files for a post. However, unless the hose length was reduced by many feet...think I would stay with the suggested recharge amount.
Since the hoses were cut...assuming you did the cutting.....how were the hoses reattached to the fittings....wondering what clamping method was utilized. Hate to see a possible location for future leaks.
Regarding the escalation of high side pressures because of 'heat soaking'.....the engine cooling system is a most important part of proper A/C operations. Pressure readings should always be taken at normal operational temperatures. We often monitor these pressure readings over a period of time....let the engine idle for a bit and test pressures over an period of time. One of the best methods to test for proper engine/condenser cooling is to test temperature drop between the inlet and outlet of the condenser. Not sure what size or type condenser TRB is using with this kit...however, expect the temperature drop to be app. 20-25ð. It is possible for it to be less...but make a test as soon as the engine reaches NOT. Retest at different times to determine if the temp drop changes...if the drop decreases...it is an indication that less heat is being extracted from the condenser...thus the elevated pressure readings. It is quite possible if the engine cooling system is not completely functional....one may see a complete inversion of the temp drop...the inlet becomes cooler than the outlet....this represents a serious problem. Hopefully this is not the case.
Also, it is not known if this vehicle was delivered without A/C. Some non OE A/C vehicles may lack sufficient engine cooling for the addition of an A/C system...in this case additional efforts may be necessary to insure correct cooling.
From the posted pressures and attempted recharge procedures (from your other post)...and unless something has changed drastically with the indicated pressures....the system seems to be functional...perhaps a bit of 'tweaking' here and there.
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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson
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