What should I look for in a compressor for a chiller?

[afireinside]

I'm gona use a 20' 1/4" OD evap and condensor and the captube sizing I have saved somewhere. Refrigerent will be R290 propane (where can I get pure enough to use propane?)
I found this on ebay:
"NEW - UNUSED
SAMSUNG SK390C-LOZ REFRIGERATION COMPRESSOR.

115 volt, 60 Hz, Single phase.
For use with R12 refrigerant and rated at 1211 BTU.
The unit is UL approved.
This is a great replacement unit for any refrigerator that needs a hermetic unit and uses R12 refrigerant."

It looks intresting but the refrigerator part doesent sound to good :(
Where else can I look for compressors other than at a junk yard/old ACs?
I want a quiet low temp compressor. I'm 13 so its not like I could hop in my car and drive around looking for old freezers :p:

[water_cooler 20]

thats about the same btu as the compressor i used to have on my water chiller and it worked pretty good and was quiet

[afireinside]

up up up

[NesQuiK]

me too , im only 15 . i dont have a car and mom doesnt like my project but ill still do it :)

[afireinside]

SCORE! I found 3 copeland 1/3 HP 5510 BTU R12 units :D

[kommando]

Lucky bastard, there is a fridge shop that have thrown at some :banana: :banana: :banana: :banana:ing huge frige with this masive compressor. Might ask whats up with it and if it works then ill hack away the compress and use it :D

[lalPOOO]

If its a fridge shop, I don't think they'd throw away a working fridge, they'd probably just fix it :p:

[kommando]

Nah its some huge fridge thing, ill ask if it works one day.

[Miles_Teg]

afireinside,

guys, plz correct me if I'm wrong, but...
BTU/h and horsepower are both ways to express the same thing, cooling capacity, right? Then something must be wrong with the info afireinside mentions about the compressors he found. 5510 BTU/h and 1/3 hp do not match each other.

- 5510 BTU/h = 2.1 hp = alot, these compressors are used for A/C purposes, and usually work with R22 / R404 / R507.
- 1/3 hp = 840 BTU/h = average for large domestic fridges, usually for R12 / R134a.

Again, I'm still novice in the field, so do correct me if I'm wrong.

[Gary Lloyd]

BTU and horsepower are not the same thing. Just by coincidence, in an air conditioning application, 12000 BTU uses roughly 1 HP. So a 12000 BTU A/C compressor is about 1 HP. As evap temp drops, the BTU drops, so in a low temp application, a 1 HP compressor pumps a lot less than 12000 BTU.

[Miles_Teg]

Gary,

Hmm, so I see. So if I get this correctly, the BTU rating is related to evaporating temperature, while the HP rating just shows how strong a given compressor is (as in what pressure it can build).

If I'm getting this correctly, there must be a certain temperature at which compressors receive their BTU rating, right? (as it's fluctuating by temperature influence). Lemme guess, you know that temperature this is, right? ;)

Edit: Typo's