[ausev] A/C in an EV

[Claire Sorenson]

I guess I have two agendas currently.  One is to get something temporary
that can cool me down just a little bit "now" (just me not the whole car).
Meanwhile, this will buy me some time while I reasearch and then put into
place something permanent.  I really appreciate everyones ideas, which will
help for the short term and long term. I can see that the portable water
cooler can be a real hassel for the long term, but I think it will get me
through the summer until I see what works best for my car.  The two biggest
issues appear to be space and power.  Every inch appears to be used under my
hood.  I have room under the back seat.  I have 5, 6 volt batteries up front
with a 12 volt for accessories and 11 6 volt batteries under the back hatch
area.  I'm not sure where I would put evaporators, compressors, fans, extra
motor, etc.  Since I am new to this, it will take me some time to work it
all out.  Meanwhile, even a few degress cooler is better than nothing.  I
found two more websites with 12 volt portable water coolers if anyone else
wants a short term fix.  They are listed below:

http://www.swampy.net/hprices.html
 
http://www.kooleraire.com/

I have also seen small 12 volt air conditioners for trucks and trailers that
fit on the roof.  It depends on what you want the car to look like.

CS Unlimited
Claire Sorenson
Ph: 512-689-5911
Fax: 512-282-9942
 

-----Original Message-----
From: ausev-bounces at austinev.org [mailto:ausev-bounces at austinev.org] On
Behalf Of Christopher Robison
Sent: Wednesday, June 13, 2007 2:07 AM
To: AustinEV News Announcements and General Discussion
Subject: Re: [ausev] A/C in an EV

On Tue, June 12, 2007 9:06 pm, Claire Sorenson wrote:
> Gary, thanks for the tip.  I think this is the best A/C alternative I 
> have seen so far. I was looking for something portable and 
> enviro-friendly.  It may seem expensive, but probably no more than 
> retrofitting motors, and evaporators, and compressors, fans etc.

The difference is that doing the latter will give you a system you'll be
happy with for a long time. The costs can't really be directly compared,
because what you're getting is so different.

A few people have tried icewater air conditioning, including Mark Kapner who
did it for a while in his Geo, and I briefly experimented with my own hacked
together version a few years ago when I was without A/C in my Civic. In
general, most people who try this find the experience interesting but
dissatisfying.

First, although it seems fun in the beginning, you soon realize: that's a
lot of ice. And when you get where you're going, you now have a lot of
*water* to get rid of. That much water is really heavy, and it sloshes
around in the cooler, making it difficult to handle. You're not going to
want to carry that water very far, so you're probably going to dump it on
the parking lot. Be careful not to slosh it on your upholstery or yourself
-- ice chest lids don't seal well. A related issue is, where do you get all
that ice?  I recall that Kapner got it from the office ice machine; I wasn't
so lucky and had to use what little ice my freezer could produce. 
Dealing with this every day gets to be a hassle after the novelty wears off.

Second, it's just not really that effective at cooling. I don't know exactly
how cold the evaporator of an automotive A/C gets, but I'll bet it's a bit
colder than ice water. At any rate, the chilled water only remains at
icewater temperatures part way through the radiator warming up as it goes,
whereas in an A/C evaporator, you've got that refrigerant phase change
helping to absorb more heat.

For maybe twenty bucks in parts, I didn't feel like I'd lost much; it was an
interesting experiment and I got what I paid for. Maybe this guy has built a
more effective design, but I don't think there's any way in the world he
could improve it enough to be worth a fourth of what he's asking.

Feel free to try this, but don't expect that you'll be happy with it for
long -- spend accordingly.



--
Christopher Robison
chris at ohmbre.org
http://ohmbre.org          <-- 1999 Isuzu Hombre + Z2K + Warp13!

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