Electric AC, Installation. |
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Electric AC, Installation. |
914Toy |
Sep 7 2020, 04:50 PM
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#1
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Senior Member Group: Members Posts: 727 Joined: 12-November 17 From: Laguna beach Member No.: 21,596 Region Association: Southern California |
I have just finished installing an AC system with an electric 12V AC compressor with an "odd" collection of condensers which to my happy surprise appears to be working well or at least well enough! I committed to this some four or so weeks ago after much input from Steve, who has done most of the research, and had already bought most of his parts and tools to install a similar system to mine. He kindly lent me the tool to crimp the hose attachments, and the tools to charge the refrigerant into the system.
I purchased: 1) a new Benling 12V electric compressor from Steve, 2) a new Mini- cooler AC only evaporator from Southern Rods, 3) four used radiators/condensers (two 911 front condensers, and two early 2000’s Ford Explorer auto transmission oil cooler radiators from a wrecking yard (“El Cheepo”), 4) a new drier, also from Southern Rods, and 5) most of the Reduced Barrier hoses and fittings from Air Parts and some from Mesa Hose. The pics show the compressor installed in the frunk behind my oil cooler shroud, the evaporator under the glove box, two 911 condensers “sandwiched” together with my Mazda engine oil cooler – all threes under the same slightly modified cowling with the 12” fan pulling/pushing the heated air through the bottom of the frunk, and a poor picture showing one of the modified Ford radiators (now AC condenser) with a 7” fan located in front of the passenger side rear wheel – the other similarly located in front of the driver side rear wheel. The drier is attached to the driver side frunk wall. I had the Ford 10”x7” radiator hose fittings modified to fit AC O ring seal hose fittings. Other than simple challenges to fabricate the mountings for the compressor and the evaporator, the space and angles of available surfaces to attach the two condensers in the wheel wells were challenging but doable after much trial and error and adjustments to the aluminum brackets I fabricated. The hose sizes and fittings were a challenge. The normal #10 and #8 hose fittings to the compressor are too bulky for my application, but Classic Retrofit came to the rescue supplying their efficient/elegant compressor/hose fittings. I learned that the modern Reduced (outside dimensions) Barrier (required to contain R134a refrigerant) hoses are more flexible, and need less space. With the system running now, I measured the amps being generated by the alternator and the amps being absorbed by the compressor, all with a fully charged battery. The compressor is pulling 40 amps, and the alternator is generating 40 amps at 900 rpm engine idle speed, but 70 amps at 2000 and above RPM. I have a Denso 175 amp alternator on order, which should arrive tomorrow! So we will see how all this performs later this week. My grandson’s 3D printing skills produced three 45 degrees slip-on cold air “direction adjustment tubes” which is a nice finish for this application (see pics)! The road test today was short but encouraging. I am joining the caravan from S. Cal Wed. morning to the Red Rocks Classic 2020, and expect to give this system a serious test through the desert!! |
914sgofast2 |
Sep 13 2020, 05:32 PM
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#2
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Senior Member Group: Members Posts: 645 Joined: 10-May 13 From: El Dorado Hills, CA Member No.: 15,855 Region Association: None |
I too am considering using an electric AC compressor when I add Ac to my car. Which model of Benling compressor did you use?
I found an interesting old book entitled "How to Air Condition Your Car" written in 1993 by Timothy Remus and Jack Chisenhall, and published by Motorbooks International. It advised that the condenser used should be 25% larger than the evaporator in capacity. From your post, am I understanding it correctly that you used two Porsche 911 condensers, as well as a Ford 10"x7" radiator repurposed into a third condenser? |
914Toy |
Sep 14 2020, 04:51 PM
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#3
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Senior Member Group: Members Posts: 727 Joined: 12-November 17 From: Laguna beach Member No.: 21,596 Region Association: Southern California |
I too am considering using an electric AC compressor when I add Ac to my car. Which model of Benling compressor did you use? I found an interesting old book entitled "How to Air Condition Your Car" written in 1993 by Timothy Remus and Jack Chisenhall, and published by Motorbooks International. It advised that the condenser used should be 25% larger than the evaporator in capacity. From your post, am I understanding it correctly that you used two Porsche 911 condensers, as well as a Ford 10"x7" radiator repurposed into a third condenser? I used two 911 front condensers (one 911 SC (pressure hose fitting) and one Carrera series (O ring fittings)) sandwiched together directly in front of a Mazda oil cooler, and two (one in front of the passenger rare wheel and the other in front of the driver side rear wheel) Ford 10"X7" transmission oil coolers with AC modified hose connections, each with a 7" fan placed directly on the modified condensers. I was advised, after purchasing and installing the 911 condensers, that two identical condensers sharing the same cooling air passthrough would only increase their cooling capacity by about 15%, not 100%! |
Chris914n6 |
Sep 14 2020, 06:25 PM
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#4
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Jackstands are my life. Group: Members Posts: 3,393 Joined: 14-March 03 From: Las Vegas, NV Member No.: 431 Region Association: Southwest Region |
I was advised, after purchasing and installing the 911 condensers, that two identical condensers sharing the same cooling air passthrough would only increase their cooling capacity by about 15%, not 100%! That's why radiators are only 1" thick on new cars these days. The temperature differential is negligible after that. Your oil cooler is hardly cooling anymore. How did the long test drive go? |
914Toy |
Sep 14 2020, 08:52 PM
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#5
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Senior Member Group: Members Posts: 727 Joined: 12-November 17 From: Laguna beach Member No.: 21,596 Region Association: Southern California |
I was advised, after purchasing and installing the 911 condensers, that two identical condensers sharing the same cooling air passthrough would only increase their cooling capacity by about 15%, not 100%! That's why radiators are only 1" thick on new cars these days. The temperature differential is negligible after that. Your oil cooler is hardly cooling anymore. How did the long test drive go? I was expecting a 170 amp alternator to arrive in time to be installed before Red Rocks, but it arrived a day too late. Given the possibility of overheating the existing alternator and burning it up, including a possible fire, I chose not to test it further than the 20 minute successful test I did before leaving. I will be installing the new alternator this week and will be reporting back. |
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