Posted by markzoom on February 21, 2007, 3:17 pm
On 21 Feb, 19:13, gfretw...@aol.com wrote:
> On Wed, 21 Feb 2007 11:27:25 -0500, Joe Fischer
> > The biggest problem is buying, begging, or borrowing
> >a good enough oil induction vacuum pump to vaporize all
> >moisture in the system and suck it all out to get it dry before
> >putting the freon in.
> > Otherwise, the orifice will freeze up constantly.
> If you don't mind "venting" a little into the air all you really need
> to do is purge the system and use a new dryer. Turn the can over and
> shoot liquid in the high side until it comes out the other end. HVAC
> techs used to do that all the time before the rules about discharging
> changed.
> If you use R134 it is not prohibitively expensive.
> That is not as good as using the proper vacuum pump but millions of
> systems were charged that way and worked.
> A new dryer will take out all of the moisture normally in a system but
> that still doesn't do anything for the inert air.
Is Butane any good as a refrigerant? Most of the system would be
outdoors.
Posted by Dan Bloomquist on February 21, 2007, 6:51 pm
markzoom@digiverse.net wrote:
> On 21 Feb, 19:13, gfretw...@aol.com wrote:
>
>>On Wed, 21 Feb 2007 11:27:25 -0500, Joe Fischer
>>
>>
>>>The biggest problem is buying, begging, or borrowing
>>>a good enough oil induction vacuum pump to vaporize all
>>>moisture in the system and suck it all out to get it dry before
>>>putting the freon in.
>>
>>> Otherwise, the orifice will freeze up constantly.
>>
>>If you don't mind "venting" a little into the air all you really need
>>to do is purge the system and use a new dryer. Turn the can over and
>>shoot liquid in the high side until it comes out the other end. HVAC
>>techs used to do that all the time before the rules about discharging
>>changed.
>>If you use R134 it is not prohibitively expensive.
>>That is not as good as using the proper vacuum pump but millions of
>>systems were charged that way and worked.
>>A new dryer will take out all of the moisture normally in a system but
>>that still doesn't do anything for the inert air.
>
>
>
> Is Butane any good as a refrigerant? Most of the system would be
> outdoors.
Propane is superior to r-22.
Posted by Jeff on February 22, 2007, 11:59 pm
Dan Bloomquist wrote:
>
>
> markzoom@digiverse.net wrote:
>
>> On 21 Feb, 19:13, gfretw...@aol.com wrote:
>>
>>> On Wed, 21 Feb 2007 11:27:25 -0500, Joe Fischer
>>>
>>>
>>>> The biggest problem is buying, begging, or borrowing
>>>> a good enough oil induction vacuum pump to vaporize all
>>>> moisture in the system and suck it all out to get it dry before
>>>> putting the freon in.
>>>
>>>
>>>> Otherwise, the orifice will freeze up constantly.
>>>
>>>
>>> If you don't mind "venting" a little into the air all you really need
>>> to do is purge the system and use a new dryer. Turn the can over and
>>> shoot liquid in the high side until it comes out the other end. HVAC
>>> techs used to do that all the time before the rules about discharging
>>> changed.
>>> If you use R134 it is not prohibitively expensive.
>>> That is not as good as using the proper vacuum pump but millions of
>>> systems were charged that way and worked.
>>> A new dryer will take out all of the moisture normally in a system but
>>> that still doesn't do anything for the inert air.
>>
>>
>>
>>
>> Is Butane any good as a refrigerant? Most of the system would be
>> outdoors.
>
>
> Propane is superior to r-22.
>
You can use isobutane and propane for R-12. Whatever you do, you'll want
a refrigerant close to what it was designed for.
Jeff
Posted by Neon John on February 21, 2007, 4:23 pm
On Wed, 21 Feb 2007 12:13:40 -0500, gfretwell@aol.com wrote:
>If you don't mind "venting" a little into the air all you really need
>to do is purge the system and use a new dryer. Turn the can over and
>shoot liquid in the high side until it comes out the other end. HVAC
>techs used to do that all the time before the rules about discharging
>changed.
>If you use R134 it is not prohibitively expensive.
>That is not as good as using the proper vacuum pump but millions of
>systems were charged that way and worked.
>A new dryer will take out all of the moisture normally in a system but
>that still doesn't do anything for the inert air.
For about $30, one can get a venturi-type compressed-air operated
refrigeration vacuum pump from many places. Harbor Freight, NAPA,
etc. It only does about 28" of vacuum but with a new dryer and a
couple of "suck and purge" cycles (add refrigerant, suck it out,
repeat as necessary), the system will be more than dry and airless
enough.
For that matter, the compressor from an old refrigerator or freezer
(free, perhaps, from a used appliance dealer or scrap metal processor)
will do an adequate job. Not nearly as good as a proper vacuum pump
intended for the purpose but adequate for experimenting and personal
work.
John
---
John De Armond
See my website for my current email address
http://www.neon-john.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
Posted by Vaughn Simon on February 21, 2007, 5:33 pm
> On Wed, 21 Feb 2007 12:13:40 -0500, gfretwell@aol.com wrote:
> For that matter, the compressor from an old refrigerator or freezer
> (free, perhaps, from a used appliance dealer or scrap metal processor)
> will do an adequate job. Not nearly as good as a proper vacuum pump
> intended for the purpose but adequate for experimenting and personal
> work.
I use a tiny compressor salvaged from a junked out 5000 BTU window unit.
Works fine for my purposes. When not in use, I keep it sealed up in a used
5-gallon plastic paint can.
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> > The biggest problem is buying, begging, or borrowing
> >a good enough oil induction vacuum pump to vaporize all
> >moisture in the system and suck it all out to get it dry before
> >putting the freon in.
> > Otherwise, the orifice will freeze up constantly.
> If you don't mind "venting" a little into the air all you really need
> to do is purge the system and use a new dryer. Turn the can over and
> shoot liquid in the high side until it comes out the other end. HVAC
> techs used to do that all the time before the rules about discharging
> changed.
> If you use R134 it is not prohibitively expensive.
> That is not as good as using the proper vacuum pump but millions of
> systems were charged that way and worked.
> A new dryer will take out all of the moisture normally in a system but
> that still doesn't do anything for the inert air.