Date:         Thu, 9 May 2013 09:53:56 -0500
Reply-To:     JRodgers <jrodgers113@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         JRodgers <jrodgers113@GMAIL.COM>
Subject:      Re: AC 134a refrigerant leak down
Comments: To: Tom Hargrave <thargrav@hiwaay.net>
In-Reply-To:  <052301ce4c6d$c9870b60$5c952220$@net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Tom,

Thanks for putting this out there. Probably the single biggest factor
with a Vanagon in converting to 134a is the compressor. I find my van AC
is adequate with the 134a. I have not had the problem- yet - but from
what I understand, the compressors often fail when the 134a is used
because they are not designed for the higher pressures that are required
by the 134a.

NEW later model Sanden compressors that fit the Vanagon and are designed
for 134a can be had from the 'Bay" for around $200 or so. A while back I
looked at one for $215.

John

On 5/8/2013 11:29 PM, Tom Hargrave wrote:
> R134a only has 80% of the thermal mass of R12 which means that R134a will
> only cool 80% as effectively as R12. Newer designs have compensated by
> making the evaporator 20% larger.
>
> Freeze 12 & other mixed gases come with their own troubles. In most if not
> all cases the mix ratio has to stay exact or the stuff stops cooling. This
> means that if you have a small leak somewhere the lighter gas leaks out
> first & the system stops cooling. Then you have to dump the system, pull a
> vacuum and start over because you can't just top the system off.
>
> I am AC certified and I've run all of them. One of my cars - my 1953
> Mercedes 190Dc - is still R12 and if it ever gets low I'll buy R12 off
> Fleabay before I convert. Same goes for any other old car I pick up that
> still has R12 in the A/C system.
>
> If you want to run something comparable to R12 then you should look at
> Autofrost R406A. It's performance is comparable to R12. You'll need a
> license to order. If you can't buy it then your local A/C tech can.
> http://autofrost.com/auto.html.html
>
>
> And you can still buy R12 - but 30# will set you back $1300. The last 30#
> can I bought cost me $770, but that was a long time ago.
> http://www.refrigerantsales.com/shop/index.php?main_page=index&cPath=1_4
>
> Thanks, Tom Hargrave
> www.stir-plate.com
> www.towercooler.com
> www.kegkits.com
> www.grow-sun.com