How cold will it get?

[Thisisausername]

In theory, this will work. Why not do that with a small compressor first to get a feel for how well it works? Hand valve expansion devices work as a demo, but they're not a great way to get results long term.



Volume is a good start. You want the evaporator mostly full, the liquid line completely full and enough liquid backed up into the condenser to give you some subcooling. Calculate the volume your tubing holds for each portion and work out the volume, then just calculate for the liquid density of your refrigerant. Start with less than that and tune the charge from there based on your desired operating parameters.

Most small compressors specify a maximum refrigerant charge for the system. Make sure your refrigerant comes in under that (generally not hard).

Okay, a few more questions for you guys . What is the downside to the hand valve which renders it impractical? I've heard this elsewhere. Also, as you decrease orifice size, pressure difference grows, system gets colder. I realize this increases strain on the system, does this decrease in size also lower overall cooling power?



As I continue to maintain my scavenge for systems, I wanted to ask. I've been assuming that the larger the system is, the more cooling power will be built into it. Does a freezer have a much larger compressor than a similarly sized fridge?

Also, is it possible to modify a capillary tube by, say, crimping it, in order to Increase deltaP? or would that be unsafe.

My continuing gratitude to all of you, this is a great help on what I consider to be a very important project