yay for window AC Units...

[Pf.Farnsworth]

...now to pick one

I am shopping around for a window ac unit, was going to ask what gas should I look for. Reason I ask is because of the oil in the compressor. I was looking for something I can charge with another gas down the road so it needs to be compatible. I guess I am looking for something that uses oil that would work with most refrigerants we use. Or something... I dont know how to even formulate the question. Anyone want to drop a few words of wisdom?

while on the topic can anyone recomend a good refrigerant, something with a lower boiling temperature then R22 but something that can be managed with a single setup, dont want to get in to cascades ont his project


also any of these look good to you guys?

http://www.nextag.com/serv/main/buy...gePersistent=60
(I sorted by price *have to scroll down past the junk* trying to stay under 200$, pretty broke lol)

 

[Ad Rock]

I believe most of the common window A/C units will use r134a as the gas, however I am not too sure of what type of oil they use in them. Really though if you think about it, if you are going to go through all the trouble of using a different gas "down the road" then the extra effort to change the oil out should not be a concern.

Are you planning on making a DD out of one of those units? If you are I would strongly suggest you think about just buying the individual parts (compressor, condensor, drier and tubing) and make a unit from scratch. It really is not that much harder and since you will have to "open" the system anyway you are going to have to braze as it is.

The reason I am suggesting this is rotary compressors are MUCH louder than hermetic compressors, plus you can fit a made from scratch hermetic unit under your case if you got the skills to make a case for it.

As for refridgerant I can not really help you since the only option to me up here in Canada is r290 so I have no experience with other gasses.

I hope your project goes well for you man.

 

[rhino56]

links not working but chances are your ac unit will have r134a if its a new one.

 

[Pf.Farnsworth]

thanks for the advice. The reason I wanted to go with a window ac unit is because it has a nice condencer, huge, that I want to submerge to chill water. No DD this time guys, maybe on the next rig. You are right though, I know how much trouble I am going though with all this, I am making my own case and making it nice, which means lots of money, and time pulled for good craftsmanship.

Also another reason is I dont like ebay that much, bidding and that jazz. I just want to click and buy allt he parts that I need, no fuss. Does anyone know of a good site to shop on for HVAC supplies and parts. I live in US so I guess I need a business that is baised here since over sea shipping is a huge money sink right? I have spent so much time looking for a side to shop for a compressor and other parts but no luck

 

[Ad Rock]

You should check out harbourfreight.com they have a decent set of gauges that can be as cheap as $24.95. Also they have a decent looking flaring tool for $12.99, I could not find a swagging tool on the site but you can pick one up at a local refridgeration supply store for pretty cheap.

You can grab some pipe bending tools, and a pipe cutter from Home Depot, and while you are there you can pick up your brazing torch and some MAPP gas.

Brazing rods you really should proboly look at eBay for since you can get them for a steal of a deal if you look enough.

Also using a A/C unit for a chiller is perfect and your project should go rather well, just make sure you are EXTRA careful when bending the copper pipe leading to and from the condensor to make sure you dont kink it.

 

[matttheniceguy]

links not working but chances are your ac unit will have r134a if its a new one.

Pretty much all AC units still use R22. R134a is in fridges and freezers and all that stuff, but it is just to crappy of a refrigerant to work well in a AC unit. The AC unit I bought new about a month ago had R22, and I'll bet the one you are looking at does as well.

 

[sandman001]

Yea, R22 can't be beat as a heat pump.

R134A just doesn't have the capacity.

 

[rhino56]

i believe my ac unit is 134a its a newer one, maybe it is r22, i thoguht they changed over

 

[Pf.Farnsworth]

r22 is nice but you cant just blow it off in to the atmosphere if you have to open the loop up to rework it. But I assume a window ac unit has a valve of some sort you can hook up to a tank and pump it in to it.

either way I am starting to belive people when they are telling me to not get an ac unit and make my own since I will need to open the loop up anyway. That and I wanted to get specific parts in it anyway to fit just right in my case. We'll see lol.

 

[matttheniceguy]

But I assume a window ac unit has a valve of some sort you can hook up to a tank and pump it in to it.

Nope. It would be compleatly sealed with no valves or anything. To properly remove the refrigerant you have to use a line tap valve. essentially it is a valve that you clamp onto the tubeing of the unit, and it will pierce the tubing so the valve is connected.

Even if you are going to open the loop up and change things, an AC unit is a good source for parts. I got mine for $95, and the rotary compressor in it sells alone for something like $300 at the local HVAC supply store.

 

[Pf.Farnsworth]

Even if you are going to open the loop up and change things, an AC unit is a good source for parts. I got mine for $95, and the rotary compressor in it sells alone for something like $300 at the local HVAC supply store.

.....................

I dont want a rotary because they are noisy, hermetics are better no? lol. But thats still impressive. Essentialy I want 3 things exactly how I want them. Compressor, evap (condencer *submerged in coolant*), condencer.

As far as a compressor goes I think I will go for 1/2 hp, thought of 2/3hp but I dont know, might be to noisy/consume alot more power? maybe not, I dont know really. Definetly want a hermetic not a rotary.

For the condencer and evap I want to use something like in the window AC units. It had a crazy amount of super thin fins:

Not some I have seen used like this that have just a few thick fins:

 

[Zork]

r22 is nice but you cant just blow it off in to the atmosphere if you have to open the loop up to rework it. .

Even r134a and r404a is lawfully illegal to vent into the atmosphere.. Although they are Zero ozone depleting they do add to the greenhouse effect.. Take that bit of info how ever and in what ever way you wish though?

I suggest good old BBQ r290 (A.K.A propane) if oil is an issue.. R290 will work with any refrigeration oil and will give you respectable temps for a single stage.. Also no recovery tanks required (not illegal to vent r290), its cheap, plenty available, no license required to purchase, and a charge adapter can be made for under 10 bucks..Just make sure to pull a proper vacumm..

Good luck with your decision.. Also check to see if you have a Johnstone supply near you, if your lucky you can talk them into selling to you as an individual..

 

[Pf.Farnsworth]

Even r134a and r404a is lawfully illegal to vent into the atmosphere.. Although they are Zero ozone depleting they do add to the greenhouse effect.. Take that bit of info how ever and in what ever way you wish though?

I suggest good old BBQ r290 (A.K.A propane) if oil is an issue.. R290 will work with any refrigeration oil and will give you respectable temps for a single stage.. Also no recovery tanks required (not illegal to vent r290), its cheap, plenty available, no license required to purchase, and a charge adapter can be made for under 10 bucks..Just make sure to pull a proper vacumm..

Good luck with your decision.. Also check to see if you have a Johnstone supply near you, if your lucky you can talk them into selling to you as an individual..

Thanks for the advice, I will look in to calling them.

by the way, what refrigerant would you sugest taking in to consideration a 1/2 - 2/3 hp hermetic compressor, single stage, lowest possible temperature achivable?

I was thinking R170 (ethane). Boiling point at -88C and a molecular weight of 30. It's a much more suitable stand-alone refrigerant than R50 while the boiling point is nice.

Also any idea where I can find a nice condencer like the first one I posted above?

 

[sonicdrive]

what i have found for a easy way to make a liq line and vapor line is gage hoses. if the seals are new and you use some pipe dope on them they will hold the ref quite well. they flex and move and it is easy to change heads for experimenting and mounting with. you just have to use a little more r134 a for the extra space. For every foot of gage line is approx 1/2 oz

 

[{PMS}fishy]

I could not find a swagging tool on the site but you can pick one up at a local refridgeration supply store for pretty cheap.

Where are these stores that you speak of. I can't find them anywhere.

 

[Pf.Farnsworth]

anyone know where I can get condencers like the one in the pic above? Having a hard time finding something nice like that.

 

[{PMS}fishy]

anyone know where I can get condencers like the one in the pic above? Having a hard time finding something nice like that.

Junk yard.

 

[Pf.Farnsworth]

Noncense, I want to pay lots of $$$ for one... lol. Not really just lazy, would be nice if I could buy one online. I think I will go visit the local HVAC shops and see whats up. Want to get something nice for this project.

 

[stockhatch]

Where are these stores that you speak of. I can't find them anywhere.

I got mine from a local hardware store, but Johnstones and REMichel both carry them as well.