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View Full Version : Window Unit AC modification into Split System? Possible? Help.







dpzimmy
22-07-2016, 12:57 PM
I read this original thread some some ago and decided to give it a try.
http://www.refrigeration-engineer.com/forums/showthread.php?32940-Window-Unit-AC-modification-into-Split-System-Possible
Only performed the split idea and not the heat pump.
Having a bit of trouble on the pressures though. Getting high suction and low liquid readings. Given enough running time the pressures will all but balance out. Thinking that the lack of a metering device has caused this. I thought that there might have been one in the evaporator. The origional suction line was 3/8 and has not been changed except for the additional 6 feet on line. On the liquid side the original line was something like 1/8 this was removed and was changed to 1/4, again with the additional 6 feet of line. On the origional setup there was no presence of a metering device. Not sure if the small liquid line assumed this roll. Not sure now how to install a piston and calculate this piston size. I could re- insert the 1/8 origional line before the evap and maybe this would work but I have decided for some advice before proceeding with any other possibilities.
THANKS! !

Brian_UK
22-07-2016, 01:24 PM
Yes you cut out the 1/8 capillary metering line so the system will not work.

dpzimmy
22-07-2016, 01:35 PM
Looks like the removed section of liquid line was actually a capillary metering device. Which is something I had not encountered before.

dpzimmy
22-07-2016, 01:39 PM
What options are avaliable to the project now. Do txv valves come small enough? What about a piston?

Brian_UK
22-07-2016, 05:16 PM
I suppose you have discarded the original tubing.

dpzimmy
22-07-2016, 05:24 PM
I still have it however even withe the most amount of care the tube was crushed with the cutter. Also not sure how much line extends into the temporary fill port used by the manufacturer.

Brian_UK
22-07-2016, 08:40 PM
You normally cut capillary tubing by simply scoring a groove around the tube with a sharp blade and then snap it apart.

You should be able to get replacement tubing from an HVACR supplier.

dpzimmy
23-07-2016, 12:53 AM
If the line would be about 1.5 inches shorter than originally. Would this cause problems?

Brian_UK
23-07-2016, 04:46 PM
Maybe but hopegully not too much.

Put it in and see how it goes.

The MG Pony
23-07-2016, 09:27 PM
If the system is 12,000 btu/h you can easily get a TXV for R-22 you need a txv with a VGA or VPC100 power head (This is the air con temp range, the 100 is the max operation pressure the valve will allow during hot pul down.)

I been building a custom air handler for a similar project, only my system is 17.5K BTU/H I landed on the V-SBQ-A-VGA TXV from sporlan (V = R-22, SBQ-E is a OD sweat on type with external equalizer, A is the orifice size and will do 1.6 ton at 40F evap temp)

For you I'd go with external equalize sweat on, but you won't need balanced port so:
EBF - 2 - V - VGA - 1/4" x 3/8" x 1/4" Now that's for a sporlan valve, air conditioning at 1ton (12,000BTU/H)

Selected with sporlan bulletins 10-9 / 10-10 and for the balanced port valves 10-10-6

Or buy more 1/8 tubing and make a new cap tube metering device. Since you gon this far you may as well play with head control via fan cycling switch n so on :)