Quote:
Originally Posted by North_Pole_Guy
AC, I like the idea of two exchangers have to look at that and see if there is enough capillary to reach two exchangers mounted.
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Try to
not cut the cap tubes, since they are already the right length and diameter for R-12, instead, cut the larger copper tubes that the cap tubes are brazed onto. There's a lot of science that has already gone into the cap tube, so make it easy on yourself and keep the same or compatible refrigerant and compressor and associated cap tube.
R-12, huh? That refrigerant was the first one to go because it was such a powerful damager to the ozone. If you really trust your homemade freezer compressor > vacuum pump, you can probably use it to salvage and reuse your R-12.
The procedure would be
- arrange some tubing & valves so that you could connect to your storage bottle (I use old camping-size propane bottles, which I have pumped out to low-microns), then pump it and the connecting-line down.
- Next, find a good location for your piercing valve. I like to put mine on a high point, so I won't loose too much lubricant.
- Then connect your vac pump to the piercing valve
- pump your connecting line down,
- Then connect your still-vacuumized storage bottle to the output of your compressor.
- At this point, you will want your vacuum bottle to be as cold as possible. I do this stuff in the basement where my freezer is, so I put my storage bottle in the freezer for a while to get cold, and I leave it there until the transfer is complete.
- turn on your vacuum pump and very SLOWLY open your piercing valve (if you open it too quickly, you'll get too much lubricant out with your refrigerant).
I'm typing this in a noisy cafe, and I can hardly think, but that is the general outline. If you need a drawing of the valves, etc. to make it all work out, let me know.
The general idea is that you want your bottle and lines vacuumed down before you release refrigerant into them.
So R-12 is a different breed of cat than R-22 and R134a and R410a, etc.
I think the closest organic equivalent is Iso-Butane, which, along with Propane, is very dangerous to work with, especially so in an enclosed space.
The Enviro Safe outfit has an
R-12 equivalent refrigerant, called ES-12a. This may actually be IsoButane, I dont' know, I haven't used it.
I would guess that the R-12 / ES-12a / Iso-Butane setup would get considerably colder than R-22 / R-22a / R-290 setup.
Quote:
Originally Posted by North_Pole_Guy
I am attaching a picture of the data plate off the donor unit, looks like R-12 for refrigerant. How would I tell how big this unit is? In other words how many BTU's?
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(* I didn't see an attachment... but if you can find a model number on the plate, you could google that and find out. *)
If no model number, if you have a
Kill-a-Watt, you could plug in the de-humidifier, look at the
initial watts reading (the watt readung climbs the longer the compressor is running), double that and multiply by 3.412.
For instance, my compressor pulls about 225 watts at power-up. Doubling that gives me 450 (which is pretty close to the rated watts), multiplying that by 3.412 gives me 1535.4 BTU/hr, which is pretty close to the rated output.
[EDITED NOTE: I looked up similar Dayton models, they no longer make a 37 Pt per day, but they do make a 30 pint(495 watts) , and a 50 pint (650 watts), so I would guess yours is about 550 watt (550 x 3.1412 = 1727.66 BTU/hr)]
If you're considering doing an open loop HP system, you may have some trouble with brazed-plate HX. The reason being that the passage ways are a bit small and particles could eventually block them up. I think tube-in-tube or tube-in-shell HX offer less chance of fouling.
Using PEX or polyethylene loops in your pond would cost you a little efficiency, but would eliminate the fouling problem.
If the R-12 issues are stopping your progress, I have noticed that lots of R134a units are beginning to drift into the used market.
Best Regards,
-AC_Hacker