On Wednesday, July 19, 2000 3:09 PM, Erik Quackenbush
[SMTP:erik@midwestfilter.com] wrote:
>
> If you have an air compressor you can get an inexpensive air (venturi)
> operated vacuum pump for less than $50 from JC Whitney or Harbor Freight.
I own one of the venturi vacuum pumps from JCW, and IMO it is not adequate
for A/C work. Before filling a system that has been opened (or a new one),
you need to pull a hard enough vacuum to boil off any water that has been
adsorbed into the desiccant (dryer). The JCW pump just don't cut it, not
to mention that it uses a _lot_ of air, far more than my (fairly honest
<g>) 2.5hp compressor can put out for the 30 minutes or more that you need
to hold the vacuum.
I can't find it listed on the JCW web site (and HF seems to be down).
Perhaps they've discontinued it because it's a piece of junk ? NAH, this
is JC Whitney <g>
According to the A/C FAQ (at http://www.vettenet.org/acfaq.txt ), an old
refrigerator or A/C compressor also works, but I haven't tried it.
Randall
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