Little Chilling project.

bubata · 09-19-2009, 08:52 AM

Hi Guys,

I have been reading this forum since it's beginning. Always been amazed and drooling over some of your work

. So this year I have decided to quit the programming and the IT altogether been more then 12 years. Never been happier. Decided to join my dad's trade, his been a HVAC journeyman for more then 25 years. So just about 6 months as an apprentice

. I came over this forum again. Started the project couple a day ago.

Parts used so far:

1. Guted a R22 based Walkin freezer unit.
1.1 Dual pressure control
1.2 Tecumseh 1/4h medium temps comressor (find one brand new around the shop 10 years old

R502
1.3. 10 feet .026
1.4 Some evap made just for testing.

Without a load gone to -47 easy. Need some pointers on improving the unit

.

Above unit build first start on the 19.09.2009

Fist test evap (dont laugh

3th day

I have been working whole weekend on it . Quite a few questions where answered. Using a vacuum gauge and sub 500 micron is tiresome . I have changed the whole unit to a much smaller one due to excess power and noise. Going to buy necessary supplies today and continue testing/tuning it. Currently using PEO R404/R507 1/3hp 2400BTU Tecumseh low temp compressor. Will test today different cap tubing from 0.026 to 0.031, flex suction is needed as well.

New Evap

4th day

Completely redone it after work today . Extended suction to 8 feet (dont want to cut the flex house till fittings done). 12 feet 0.026 cap tube most of it is inside the 1/4 pipe which is inserted into the hose (can move the evap easier). End at e 1/4 flare and to the evap. As with the above setup Head pressure is around 20 vacuum, high is around 140-155 that is using R404A. That pressure yields more then -49 cant measure correct . Compressor is happy normal working temperature. Something is wrong with this setup still cant figure it out . This stuff is much different than walkin coolers/freezers that I am used to work on. Now I have realized that all my temp metering devices maxout at -49 . Cant find anywhere online or not a temp reading device for below -50c? Located in Calgary,Ca by the way. Funny thing is my evaporator is colder at the suction rather then at the bottom of the evap where it should be? Cant figure out how to test under load without a PC around . Still waiting for the shipment to arrive.

at -50c everything sticks just fine

gosmeyer · 09-19-2009, 09:33 AM

Welcome!

If you have been reading from the beginning you have a solid understanding of who are the best at what they do. All of them will answer any questions you have.
Don't be fooled by -47 unloaded

fatguy1992 · 09-19-2009, 12:08 PM

Whats your load temp?

clear cmos · 09-21-2009, 10:12 AM

Quote:

Originally Posted by gosmeyer

Don't be fooled by -47 unloaded

-47 to +47 with 260 watt load

Asylum1 · 09-21-2009, 08:28 PM

Pics or it never happend. LOL

bubata · 09-22-2009, 07:05 PM

pics dont cool

. first post updated

sdumper · 09-22-2009, 07:21 PM

Nice work I have never built a chiller but it looks fun.

runmc · 09-22-2009, 08:24 PM

I would say your off to a good start

My first suggestion would be to get away from those flare fitting

I'm sure in the HVAC business there is a place for flares. The only place I can think of in our business would be an expansion valve. If you could get an expansion valve with sweat joints, I would use that one.

Keep up the good work.

Oh yeah - you need to point that filter/drier down toward the cap tube.

bubata · 09-23-2009, 12:23 AM

The pics are from the first attempt. Lots of mistakes identified

. As of now I am using much smaller setup in terms of size/noise etc. No more flares, no sight glass, no high/low pressure controls. Plain and simple Tecumseh 2400BTU 1/3hp, larger condenser, 7.1ft 0.026. That goes down to -54C at 18 vacuum and 155 high pressure using R404. Can somebody tell me what is the normal pressure for this setup? Dont think thats the best tempreture for the setup. Have read lots of info still cant get it right

. Too much work cant figure out what load tester to build/use.Still waiting for the pc parts to arrive. Need to order an evap as well.

clear cmos · 09-23-2009, 01:14 AM

Quote:

Originally Posted by bubata

The pics are from the first attempt. Lots of mistakes identified

. As of now I am using much smaller setup in terms of size/noise etc. No more flares, no sight glass, no high/low pressure controls. Plain and simple Tecumseh 2400BTU 1/3hp, larger condenser, 7.1ft 0.026. That goes down to -54C at 18 vacuum and 155 high pressure using R404. Can somebody tell me what is the normal pressure for this setup? Dont think thats the best tempreture for the setup. Have read lots of info still cant get it right

. Too much work cant figure out what load tester to build/use.Still waiting for the pc parts to arrive. Need to order an evap as well.

18 psi on suction..... i think u overcharged

very good temperature

, we hope your unit can hold some load

bubata · 09-23-2009, 06:20 AM

Wonder why the system always works in vacuum? I do charge really slowly. I diddnt use the scale last attempt. What should be the typical charge of small system like this 3 oz-4 oz??? I think i had in it at least 0.5-.6 lbs

clear cmos · 09-23-2009, 09:09 AM

Quote:

Originally Posted by bubata

Wonder why the system always works in vacuum? I do charge really slowly. I diddnt use the scale last attempt. What should be the typical charge of small system like this 3 oz-4 oz??? I think i had in it at least 0.5-.6 lbs

18 psi on the suction means is still a lot of liquids forms refrigerants, It will make the compressor work harder, suction accumulator installing might help or more easily if you degassing, most people do charging with approximately

bubata · 09-23-2009, 03:31 PM

Just about to order the evap from chilly

. PC components arrived today but my evap is way of

also the bracket is garbage. The news that made my day is that I had to change 2 perfectly working hitachi rotary 12000btu

.

Now I have realized that I have to change the oil from R22 Mineral to comfort R507/508 POE? Anyone on how to change oil in a rotary unit?

bubata · 09-24-2009, 08:26 PM

Evap ordered

. This time around will not rush anything.

clear cmos · 09-25-2009, 02:18 AM

Quote:

Originally Posted by bubata

Evap ordered

. This time around will not rush anything.

wanna see your update, my friend....

bubata · 09-26-2009, 09:36 AM

Evap is on its way

. Also got a full jug of R507 ready for abuse. Draining/changing oil of a rotary=pain pain

. The compressor was shaken for about 1 hour heated a little drained for 12h and the result is just over 200ml of oil

. By spec it holds 385+-20ml.

Found really nice rubbers

Preparing the new test bed. Temporary using flares to change the drier, oil replacement process will be tedious, need to get more then 90% POE in to the system ideally 95%.

Test setup is waithiiing

Asus P55 Pro & i5 750

bubata · 09-26-2009, 09:26 PM

Finally some success

. Managed to get -64c no load to -55c 250w load

. Thats with Hitachi SGC653 rotary 12000BTU/3,5kw charged with R507 and some 8 feet of 0,026 cap tube. Including whole day of vacuuming/purging and oil changing. And it became clear that more testing answers much more then posting and asking for help

. Any one changing the oil in a rotary compressor PM me will save you tons of hassle.

clear cmos · 09-26-2009, 10:16 PM

nice temp

Can you show a picture when the ss is running?

teyber · 09-27-2009, 07:45 AM

holy very nice!!!

bubata · 09-27-2009, 07:26 PM

Perfect day today went golfing on a 200km drive up the rockies

. Here are the pictures fiddling with the gas so it's not the lowest temp. Another thing I did notice: when starting both the compressor and the heat load temp does not go over -45c.