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PostPosted: Sat Dec 18, 2010 8:59 am 
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Location: snow city - it's wet!
A question came up on the Lotus Talk forums about installing AC in a '70 Lotus Europa. While most Locost drivers won't need AC, those of use building cars that include a roof, doors and windows might find AC a necessity. I expect that I will since my build is also based off the Lotus Europa, like the original poster on Lotus Talk.

A quick search of the forums here comes up with three threads that I could find. The first thread here is also part of the "In Theory" section, but that thread is focused on ideas for providing heat. The second thread is here in the BEC section, but immediately goes off topic. The third thread is over here in "Off Topic" and is a humor thread.

The AC problem seems to come in two distinct flavors. The first is more straightforward and would involve finding components that could be adapted from a car engine & donor (or aftermarket supplier like Vintage Air) and packaged reasonably into a Locost.

The second problem is more complex and is a closer fit to the problems faced with a BEC, or in my case, a Lotus Europa. A good place to start researching solutions is this thread from the diyelectriccar.com forums. This may sound like a stretch, but the builders there face similar problems when trying to add AC to their vehicles. Not being able to just bolt on an AC compressor on to the front of an engine seems to be the biggest problem. Limited available electrical power is also a common constraint. The thread there has some good ideas that I will be digging into more when the time arrives.

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PostPosted: Sat Dec 18, 2010 10:47 am 
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I went through this with the Duratec/Alpine. About the only pump to consider is the Sanden (Sankyo) "505". It was made to be bolted onto an engine using brackets. None of the modern stuff found in junkyards can make that claim and are no smaller. About the best you could expect would be a stock pump bolted into the stock location.

Another inside unit to be aware of is the Old Air products "Hurricane" in dash unit. It is a combo heater/AC/defroster. I found it would go behind the dash of the Alpine and be less intrusive than any under dash unit I could find.

I just do not see using an electrically driven pump on an ICE. What is gained? How big would the alternator have to be? Last resort only type of solution.

Bill


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PostPosted: Sat Dec 18, 2010 11:19 am 
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BBlue wrote:
I went through this with the Duratec/Alpine. About the only pump to consider is the Sanden (Sankyo) "505". It was made to be bolted onto an engine using brackets. None of the modern stuff found in junkyards can make that claim and are no smaller. About the best you could expect would be a stock pump bolted into the stock location.

Another inside unit to be aware of is the Old Air products "Hurricane" in dash unit. It is a combo heater/AC/defroster. I found it would go behind the dash of the Alpine and be less intrusive than any under dash unit I could find.

I just do not see using an electrically driven pump on an ICE. What is gained? How big would the alternator have to be? Last resort only type of solution.

Bill

I agree, but with a bike engine, I'm not sure I want to modify the case, block or any shafts to accept a belt or pulley. What is interesting is that it looks like hybrids have opened some doors technologically to help solve this problem. Modern hybrids tend to use an electrically driven AC compressor, which might allow for a fairly conventional system. Here is example of one such pump: http://www.globaldensoproducts.com/hvc/electric_compressor.html

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PostPosted: Sat Dec 18, 2010 11:24 am 
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bunch of us hvac/r techs here as i recall. .. probably more with an m cert than i'd guess too which is a good thing since i don't do mobile, some of the materials and uses are different from my experience. using fire to create cooling? uhhuh... but thats what an propane fired fridge does. .. and it works. "flooded evaporator" is the phrase to remember, that and a flat plate condensor will get the physical dimensions as small as possible for the output. an interesting point of an electric driven ac is using a pwm motor to directly control output pressure rather than an adjustable orifice or a clutch. imhop much more efficient and can run on a smaller size since the start and stop creates a heavy torque draw and the need for a larger motor. for example .. (disregarding the multispeed capable systems of the last 10 years) a residential ac is designed to operate at a set pressure and process refrigerant at a set rate over time (single speed fans on both ends) until there is no more demand whilst a "cop" system repeatedly turns on and off as the pressure spikes and ebbs. .. as does airflow. a residental ac is typically under 3hp with 80% torque at 0rpm and iirc an automotive ac system can draw up to 7hp at engagement, huge amp spike to get a home ac to turn on but thats no longer an issue if you don't start at full rpm especially once you consider that an initial start doesn't have any back pressure to work against. you can control motor rpm as a direct response to system pressure as adjustment for the difference in heat exchange from changing airflow or if you don't mind a bit of waste and a slightly lower max output, use calculated leak rates to determine max system (back)pressure and therefore max available cooling. i have no idea what the erosion rates are for steel and r134 but i'm sure thats something to consider if going the second route.

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PostPosted: Sat Dec 18, 2010 1:10 pm 
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You have to draw the line somewhere! This is just wrong...

Where is the character building pain and agony? It's not sports without sacrifice. Once you do this then your going to install an "AOTP" ( air off to pass ) button on your steering wheel. What you aren't seeing is that you will lack the character and fortitude to actually use it because of the lack of pain and sacrifice in your life.

I can think of several options,
- keep a 5 lb. bag of ice on your lap, drill a hole in the floor, tell women it's because you're over-sexed.
- saw off the roof or take out the glass.
- install the Duratech with a Porsche or Subaru transaxle ( what God err Colin intended ).
- with advice from OldeJack install a 20 lb. CO2 tank, wear a divers dry suit, put a quick connect fitting in the base of the seat.

That's the best I can do and I greatly fear my good advice is steering a nice guy to the dark side...

How about instead of a CO2 tank, and this is where big male equipment comes in, use an Oxygen tank instead, Then after being used as a human evaporator, you plumb the waste and now warm O2 to the engine intake. Should work long enough for an autocross run... This I want to see, can you send pictures?

I don't know what to say, pain and suffering make you faster - what could be a better deal, they cost nothing...

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PostPosted: Sat Dec 18, 2010 1:20 pm 
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If you really need one, I'd compromise and use a unit sold by one of the many aftermarket hotrod companies. Then you know all the parts will work together, but of course there's still how to mount the compressor, condensor unit, and radiator.

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PostPosted: Sat Dec 18, 2010 1:31 pm 
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OK, so mount the compressor pulley to one of your halfshafts. Then make a set of air jacks like they use on Indy and F1 cars. You know you want them, they are way cool and will be useful all the time. They could double as emergency/parking brakes. Now if you need to use the air conditioner at traffic lights, just push the jack button and leave it in first gear.

Do not confuse the jack button with the AOTP button! :shock:

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PostPosted: Sat Dec 18, 2010 2:05 pm 
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So how do you mount a 200 amp alternator on a bike engine?

Bill


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PostPosted: Sat Dec 18, 2010 2:19 pm 
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Quote:
So how do you mount a 200 amp alternator on a bike engine?


Get a snow mobile engine instead and put a belt pulley on the crank as part of the transaxle adapter?

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PostPosted: Tue Dec 21, 2010 3:58 pm 
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Horizeenjob, I can't help but notice that your location is Massachusetts. If my average July high was in the low 80s, I'd mock people for wanting A/C, too. :lol:

If your heat index was 95+ for months at a time, you might consider A/C. Probably abandon it because of complications, but consider it.

when I had a car without A/C, I had my boss call me in for a meeting, because the client site was concerned about my 'unprofessional, disheveled' appearance. The consequence of sweat and slightly unruly hair.

In September. My commute was 55+ mph on the highway, not sitting at stoplights.

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PostPosted: Tue Dec 21, 2010 6:41 pm 
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I was just teasing Erioshi. His location said snow city, so I figured he wasn't in Texas.

Once you get to retro fitting AC to a bike engine, it seems attractive to consider trying to copy the Europa variant they ran on tracks instead. You need the extra tubing to run on the track anyway. The Hewland would be a bit expensive, but probably not more then a Porsche 911 type unit. Subaru would be doable maybe. We'll see what Erioshi comes up with....

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PostPosted: Tue Dec 21, 2010 10:25 pm 
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Marcus, I am with you on the ai jacks. That would be cool. Then get some revs up and drop the jacks and be off like a brides nighty.
:cheers:

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PostPosted: Wed Dec 22, 2010 4:52 am 
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horizenjob wrote:
OK, so mount the compressor pulley to one of your halfshafts. Then make a set of air jacks like they use on Indy and F1 cars. You know you want them, they are way cool and will be useful all the time. They could double as emergency/parking brakes. Now if you need to use the air conditioner at traffic lights, just push the jack button and leave it in first gear.



Ha ha - very clever, I laffed!!


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PostPosted: Wed Dec 22, 2010 12:42 pm 
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Here's the air jacks. The kit is $2899, so a little steep. They are a little heavy too. Seems like we could cost reduce it. I'll check and see which button that's supposed to be on Speed Racers steering wheel so we get this right...

http://www.pegasusautoracing.com/productdetails.asp?RecID=6208

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PostPosted: Wed Dec 22, 2010 3:22 pm 
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When I lived in Houston, I owned a Europa JPS. NO air of course. Never again.Never.
Temperature 96, humidity 90. Couldn't even drive the car nine months of the year.


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