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douggiestyle
28-02-2006, 07:14 PM
i have no idea what im doing, so please go easy on me.

i have a 1/2 hp compressor using r134a.
i am planing on using a capilary tube.

the evaporator is 36" of 3/8" titanium tube. it will be submerged in water.

will this work?
do i have to worry about super heating?
do i have to worry about slugging?

Peter_1
28-02-2006, 09:48 PM
will this work?
do i have to worry about super heating?
do i have to worry about slugging?

It can work under certain circumstances.
Yes.
Yes.
And any other things.

douggiestyle
28-02-2006, 10:56 PM
will the evaporator size dictate the slugging/super heating? if so how do you figure the evaporator size. or do i just use a some type of metering device like a tev?

Peter_1
28-02-2006, 11:15 PM
If superheat is to small, then you will have slugging and compressor will damage.

If it's too high, then your compressor can overheat.

You can't predict nor calculate these things, you will need to test it in a real situation by the well proven trial and error method.

A capillary can do the job if the load remains stable.

A TEV can adapt better to the load but then your condensing unit needs also a receiver.

You can begin with selecting a capillary or a TEV, starting from the compressor capacity at 32°C evaporating.

What is the purpose of this 'thing'?
It's sounds a bit like a beer cooler with a brine storage.
36" is +/- 12m. is this correct or is it 80 cm?
I'm living in that part of the world that uses SI units, sorry:p

What temperatures/heat-load will it work?
If it needs to cool 1000 gallons of 180 F to 40F, then it won't work. You understand what I'm trying to say...we need more info from you.

douggiestyle
28-02-2006, 11:28 PM
thats cool haha.
1.27cm dia. x 91.44 cm
36"=91.44 cm
it will be operating in a vary stable environ. the avg temp will be 26.6 degree celcius

apx 220 gallons with a with 40.6 normal temp being chilled to 26.5. regulated by a thermastat.

apx. 14 degree celcius take down.

would prefer a cap tube.

douggiestyle
28-02-2006, 11:32 PM
please explain superheat low/high.

if i over heat the evaporator woundnt that cause liquid in it thereby causing slugging.

douggiestyle
01-03-2006, 02:55 AM
i hope im making some sense.
i only have experience with home appliance repair no commercial refrigeration or hvac.
i wish to build my own water chiller with an old frig.
everyone ive spoken to says that if i dont match the evaporator correctly with the cap tube and compressor, i will slug the compressor.

Peter_1
01-03-2006, 07:45 AM
They're indeed right, it all has to match together.

If I compare it to a beer cooler with ice bank, then you need for a 1/2 HP +/- 20 m of tube. So the difference is too big and it will evaporate very low or you need a smaller compressor.

It all depends what your actual heat load is. You first have to determine what the load is and then selct the equipment.
Not vice versa like having the equipment and looking then what you can do with it.

douggiestyle
01-03-2006, 03:41 PM
similar designs that i have looked into that are available commercialy. use 3/4" x 4.5 meters for a 6000 btuh comp. but also similar desings that i have looked into are using 3/8" x 1.5 meters for the same comp size.
how to caculate heat load?
both designs are claiming to handle the same heat load.

douggiestyle
02-03-2006, 02:02 AM
so i should just add a suction accumulator and that would solve most of my problems?

Peter_1
02-03-2006, 08:21 AM
From my experience it won't work, but you can give it a tr.
Is not that much work (+/- 1 hour) to connect it al together and try.
A suction accumulator isn't made for this purpose, at least not to hide or solve the faults of a wrong or bad concept.

douggiestyle
02-03-2006, 08:53 PM
so this is a wrong or bad concept?

douggiestyle
04-03-2006, 03:48 AM
thanks for all the help.

take care now, you hear.