Date:         Sun, 17 Jul 2005 21:52:46 -0700
Reply-To:     John Bange <jbange@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         John Bange <jbange@GMAIL.COM>
Subject:      Re: AC Drip Drop
In-Reply-To:  <23604-42DAAB8B-94@storefull-3176.bay.webtv.net>
Content-Type: text/plain; charset=ISO-8859-1

> Lets read this direct quote again John.
> 
> "The system was out of freon"
> 

You know better than to believe the word of the customer. If he was an
authority on whether his AC was empty vs. just low, why would he take
it to a mechanic to fix it?

> Now, while your explanation is half true, as the AC system is self
> levelling.
> Your low on charge on the the suction side your low on the pressure side
> too, and unfortunately there is no way around that.

How so? does the expansion valve magically let more through when the
low side is low without also inducing additional cooling? That's the
only way it could happen, as the compressor provides more than enough
compression to keep the high side high, regardless of the pressure of
the low side. You only start dropping pressure on the high side when
the compressor starts pulling the low side down to where it can no
longer keep the high side up.

> You have pressure on one side you have pressure on the other.
> You cannot overload, or underload either side unless of course you have
> a failing, and plugged expansion valve orifice, a internally collapsed
> hose, or a plugged up dryer.

What the heck are you talking about?  The high side fills until it
reaches max pressure and the high pressure switch turns off the
compressor. A compressor that runs 50% of the time when pressure is
correct  can keep the high side at full pressure until the low side
drops below half its normal pressure. This is simple physics. In most
systems, both in industrial refrigeration and automotive, there is a
"pressure window" between those two points where the evaporator
temperature goes below freezing.

> 
> So for a evaporator to be freezing up is due to a queefed out part not a
> undercharged system.
> 
> I thought for sure you would know this.

Sorry man, I'd take the opinion of the HVAC techs I know over yours.