DIY water chiller - reading suggestions?

[BruceM]

Ebay seller sent me R22 by mistake.  Grrr.

[broncodriver99]

I did find a R410a refrigeration pipe size calculator that goes to 0.8 tons online:
https://efficientcomfort.net/asp/LineSetCalc_Web/LineSetCalc_Web.asp

It says 1/2 inch  even dialing down to 1 foot and 0.8 Tons, or 1 ton at 94 feet. It won't ever 3/8, so I'm suspicious.
I'll try to find some 1/2 ACR tubing in the area tomorrow.

Here is a calculator that I use on smaller stuff. https://boxload.tecumseh.com/RefLineSizing.aspx

I used input data of R-410A, Suction Line, 40 degree Evap temp, 105 liquid temp(This should be about 10+ degrees above your expected ambient temperature with a minimum of about 105), 6 ft equivalent length(if there are any bends in the pipe this goes up), and 12,000 BTU capacity.

You can select different tubing sizes and it gives you the velocity, pressure drop, and temperature drop. I was taught and always use 750-2500 FPM for suction velocity and a max of 2 psi and 2 degrees for the pressure and temperature drops.

A very broad rule of thumb as you play around with the variables; your suction temp is generally 10-15 degrees below your desired fluid temp and your desired fluid temp is about 10-15 degrees below your desired load temperature. So, if you want a a 60 degree slab, best case is a 50 degree fluid and 40 degree suction temp. I checked every pipe sizing chart I have and they all recommend 1/2" for 12,000 BTU at Medium/High temperature suction.

[broncodriver99]

Ebay seller sent me R22 by mistake.  Grrr.

Well that was a several hundred dollar mistake. The price of 22 has gotten outrageous. 2 lbs of 22 is a few hundred dollars these days. Been working on a system with 3600 lbs of it for the last few days .

[BruceM]

Good to know the Tecumseh calculator is trustworthy.  I tried it but didn't know what temps to plug in.
Now I know why the seller was so cooperative.     And I thought R410a was bad...

Even with a bulk discount, 3000 lbs of R22 !!!  The industrial insurers would squeal over changing an older system R22 to Propane.  You could eat some engineering re-certification and special insurance costs for that kind of money.  Somebody must be doing it, with that kind of money involved. 

Gary sent me a great flare/expander tool kit, found in my mailbox on the way to way to the post office.  It looks great, thanks, Gary!







 

[mobile_bob]

so what does a 30 lb can of r22 sell for these days?
wholesale? retail? usd?

btw, what does r-12 fetch?  bet that stuff is regarded as contraband these days?

inquiring minds want to know?



bob g

[32 coupe]

Bruce,
I use a flair kit just like the one I sent you.

Just a tip I do. I don't have the hand strength the tighten the "wing nuts" on the bar clamps to
hold the copper while working on it. I use the sliding bar on the flair tool to tighten the "wing nuts"
 I don't know if it was designed for that but it sure works.


Did you get the silver solder to flow out ?

Gary

[BruceM]

Rain the last 2 afternoons has curtailed my copper brazing practice.  Soon!
R22 on ebay, around $720/30 lbs plus $50 shipping.  Ish.
$24/lb x 3000 = $72,000. plus freight.

The 2 lb R22 containers run $175 incl. shipping.

[broncodriver99]

Even with a bulk discount, 3000 lbs of R22 !!!  The industrial insurers would squeal over changing an older system R22 to Propane.  You could eat some engineering re-certification and special insurance costs for that kind of money.  Somebody must be doing it, with that kind of money involved. 

Propane and Isobutane are a BIG no-no. There is a limit of a few ounces when it comes to charge due to flammability. There are many retrofits for R-22 these days and a couple that I use and seem to work well. This particular system is a liquid overfeed system with a flooded evaporator vessel which does not work well with the retrofit refrigerants as they are blends and all of them have at least 5 degrees of glide. So, for now they are stuck with R-22.

[broncodriver99]

so what does a 30 lb can of r22 sell for these days?
wholesale? retail? usd?

btw, what does r-12 fetch?  bet that stuff is regarded as contraband these days?

inquiring minds want to know?



bob g

I haven't bought any 22 in a while, although my cylinder is almost empty.  Last time I did it was about $1100 for a 30 lbs cylinder. I imagine it is higher than that now. On refrigerants 5X cost is about the norm when it comes to mark up. I have heard of guys charging way more than that though. I haven't used R-12 in over a decade. It is still available from wholesalers and I think is still above $1k a cylinder but there just isn't any R-12 equipment around that hasn't been converted to a replacement refrigerant. I have a 50 lbs cylinder that has been sitting in the shop for 10 years. I traded a guy half a cylinder of R-410a for it as he needed some refrigerant in a piece of equipment and he had no use for the R-12, nor did I but did it as a favor. That's just the way it goes, ultimately the retrofits and conversion end up being cheaper over time.

[guest18]

About a year ago I looked into the price of R-22 and the price was fluctuating from just over $700.00 to over $1,400.00. On the internet from people that try to sell to people that are not CFC certified.

Refrigeration supply companies only deal with people that are CFC certified or, businesses that are licensed contractors. And the suppliers are the best place to purchase refrigerants at decent prices (legally). It’s getting to the point that some suppliers are starting to be cautious selling refrigerants to people that are only type I certified. Some say it’s company policy and I understand their concerns. I was fortunate to get my universal certification back in 2002 and built up a good relationship with my local suppliers.

 Be careful buying refrigerants on line from an unknown source. You don’t know what your getting. And here in the US it’s illegal to purchase refrigerants without the proper certification.

[mobile_bob]

back in '05 a friend of mine who was in the automotive business called me wanting to know if i wanted some r22. a local autoparts chain had ordered or bought what they thought was a remaining stock of r12, it turned out to be r22 and they had a semi truck load of the stuff.  i think he resold it to a local refer guy.

he bought 8 thirty pound cans for 65 dollar each.

seeing what it brings now? wow, maybe i should have bought the whole trailer load?

story of my life, day late and a dollar short!

bob g

[32 coupe]

I have used several of the "drop in" replacements for r22 and have found
r422 to be the best for what I do. (marine systems) The 2 local supply houses I deal with don't carry 22 at all.

I haven't seen r12 for years. I used "hot shot" for a few units that used 12
but I still have a half a jug of it because the systems I maintain have been
changed out to 134 units.

The industry is , and as near as I can tell, will always be a mess.
R22 was "outlawed" years ago but still available.

R11 was "outlawed" years ago but is in all the "cleaner" products.
I have a jug of r11 that I'm sure I'll never use.

You really have to wonder about the entire situation.
It is illegal to buy refrigerants without a card or license but it looks like
you can buy it on line without either. How does that work ?
Just another case of the left hand not knowing what the right hand
is doing.

410 is supposed to be phased out the next few years. Looks like
it will be replaced with the flammable types that I won't be involved with.
At my age a couple of years and I'm done with all of it except my own junk.




Reminds me of cars. They are supposed to meet fuel mileage standards. But if you pay the tax, epa fine or
what ever its called you can buy a new 800 hp car that gets mileage well below the standard.
I used to say we live in a crazy world. Now it's just stupid. Same old game, money talks.

Rant over, have a great day !

[mobile_bob]

i haven't done any refer work since the days of r-12
and that with the automotive applications.

i remember back in the mid 70s there was a bb machine gun that was powered by r12 one pound cans! i never had one, but have often looked back at how that added to the ozone problem.

but then again, back in the day, when you had to repair a system, you simply let her rip, changed out the part, vacuum down and recharge, if you had a leak, you just let it go again, fix the leak and repeat the process... r12 was cheap and we had no idea it was hard on the ozone layer.

i recall buying r12 in the one pound cans (might have been 14oz, but we called them one pound can's) for as cheap as 89 cents a can on sale at the local autoparts store.

sure miss working with r12 the systems were easy to repair and i don't know anyone that knew anything like all the stuff professional refer guys know today.

all we cared about was getting the vacuum down for maybe 10 minutes (tops), recharge until the sight glass cleared, and checked the vent for cold. if it got down to 40F or below that was a good job, and down the road it went.

we didn't know "superheat" from an "afterburner" 

thats probably why there was an ozone hole? 

bob g

[guest18]

You really have to wonder about the entire situation.
It is illegal to buy refrigerants without a card or license but it looks like
you can buy it on line without either. How does that work ?

People are selling it on Craigslist. They are not asking for any documentation.

Here it an example:
https://lynchburg.craigslist.org/mat/d/lynchburg-r22-refrigerant/7348275245.html

[BruceM]

Interesting 3000 lb system, Bronco.  Apparently German automotive and industrial co.s are going with propane/butane mix to meet their global warming goals.  While totally unsuited for some applications like marine, R290 would be fine for my application since the evapaorator/water chiller/brazed plate exchanger is just inside the wall of my ventilated propane water heater(s)  closet. 

You can get EPA section 608 certification via online open book exam.  There are many companies selling prep courses and testing services online.

The ebay sales places require a statement that you are buying it to resell or to give to a certified refrigeration tech.  That's a loop hole that makes my small project easier.  I waffled as it's irrelevant but decided to do my bit and am reclaiming the measly  20oz in my window unit via the system pump pressure side to vacuumed bottle method.  With losses in hoses and hose purges, this is dubious in real value, but old habits of a former AF engineer die hard.  Plan B was to make my own reclamation pump from a bare refrigeration compressor, but it's just not warranted for this small project since the high pressure capture method can be used.

I'll probably get my 608 certification if I decide to do any more refrigeration projects after this one.   I've long thought about a dual- remote compressor, freezer/refrigerator project with no motors or fans in the house, only linear direct 12V circuitry and dual plastic fiber thermostat signals).  That could replace my sealed combustion propane refrigerator.

I tried the brazing rods that Gary sent me.   As he suggested, I used the smallest tip I had for my oxy/acetylene torch.  It was easier than sweating water joints with mapp gas, no messy bubbling flux, and it wicks into the joint and flows at the right temp just like normal copper sweating.  I did a 1/2 ID water type copper fitting, and used  Gary's nice swager to fit 1/4 to 1/4 tubing.  Both were easy and I like the precision of the small flame when thinking about fittings near plastic bits and in tight quarters.   Thanks, Gary, the 15% silver brazing rods work like a dream. 

My two test joints, a 15% silver brazing rod and tiny torch tip below.

Now I have a fittings project; I need to adapt my inert gas regulator (argon/nitrogen) hose to the refrigeration gauge set hoses for purge/pressure test/flow. 

Bronco wrote:
"So, if you want a a 60 degree slab, best case is a 50 degree fluid and 40 degree suction temp. I checked every pipe sizing chart I have and they all recommend 1/2" for 12,000 BTU at Medium/High temperature suction."
Good to know the rule of thumb. So for a 70F slab, 60F water, 50F suction temp.  For in floor cooling, too cold water will cause condensation issues at the manifolds.

More project goodies today on the UPS truck, I hope.