Air conditioner install

[Pulse]

Hi all, I'm after some advice installing a cheapo A/C. The brand is Nexus 6kW split sytem ($529). I'm installing it next week in Cobar. Previously I've done the setup and the fridgie has vacced it out for me. I've got all the gear I need (pair coil pipe, flaring tools etc) but the bit I'm having trouble with is the chinglish in the manual:

Exhausting with refrigerant.
1. screw the nut in the indooor and outdoor connecting part.
2. unscrew the nut of gas pipe (the bigger pipe) half cycle only.
3. screw off the nut of liquid valve.
4. after 10 seconds, the gas will be exhausted form the nut of the gas pipe, then screw the nut of the gas pipe with a spanner.
5. screw off the nut of the gas valve, unscrew the valve core of the gas valve with a spanner farthest along anticlockwise.
6. screw the valve nuts of two valve cores

(if available use vacuum pump to exhaust)

Can anyone translate this? My other question is, if you do have a leak at a flared joint how do you redo the joint without losing all the R22. Or is that the point at which I make a sheepish phonecall to the fridgie?

My best guess is that both valves have caps covering the "valve cores" that can be opened with an allen key. The R22 is in the liquid side of the compressor and is released when the liquid valve core is opened. Are they suggesting that I half loosen the gas flared fitting and vent through that?

Step by step australian english instructions would be great!!!

Cheers
Pulse

[Iain]

Why not do the physical install and get in vacuumed out in case it is not properly emptied, doesn't take long, then the installer could just turn all the right screws for you, should be done in under half an hour and you know it will be right.
My aircon, split charged and supposedly with a vacuum in the indoor bit, had insufficient gas and the vacuum was non existant, cost me $50 to get it pumped out and topped up.

[Pulse]

Yeah good plan, I think the peace of mind factor is worthwhile. I'll watch carefully and learn too.

Cheers
Pulse

[durwood]

Make sure you carefully flare the pipes, remove any traces of burrs etc

After you connect all the piping connecting the vacuum pump will remove all the air in the pipes. This should be done for about 30 minutes.
Then leave the vacuum alone for about 15 minutes and note if any movement takes place in the guage. If the vacuum drops you have a leak.

It is important to vacuum for an extended period so all air and moisture is removed. Moisture in the line may be enough to freeze and block the valve causing excessive pressure build up.

Once everything looks Ok you can open the valve and let the gas into the lines. It will fill up the vacuum in the pipes and you can then close off and remove the pump.

[kompsj]

This is 100% correct.

Why Vacuum??
Folks, if you want 100% efficiency out of the unit, you need to vac it below 500 microns using preferably a 2 stage vacuum pump and a vacuum gauge to measure. This removes all the air and moisture in the copper and indoor unit. You want ZERO air and moisture in the lines. If left in the lines it creates acid in the pump and your pump will rust like an old Torana (sorry Holden fans). Also causes blocked/frozen capillary which increases pressure in the system. This will eventually cause PREMATURE mechanical failure. Hence, this is WHY the warranty guys will not touch self installs and insist on a professional install.

Why NOT bleed?
Some people bleed them, but this removes some of the gas (which is also illegal). Some of the smaller unit ONLY carry about 300 grams of gas and the larger ones carry 1.5 - 2 kilos. If you bleed a unit even quickly, i'd be guessing you have removed about 100 grams at a absolute minimum, as the gas can come out at over 150PSI. So on a small unit you just removed 30% of the gas. This removes the efficiency of the unit by 30%. Best way to describe this.. Have you ever been in a car with even low refrigerant gas? It really struggles to cool, especially on very hot days when you need it most. Then you get it topped up and its freezing on hot days.

WHY WELD copper joins? and HOW?
These new R410 gas units run extremely high pressures, up to about 550psi. Scary. My car tyres run at 30-40 psi, my air compressor runs 150psi, so you can see why I like to weld joins with brown tip silver rods. You must run dry nitrogen through the copper when welding or the copper fills with black carbon which destroys the unit. At these pressures, I like to MINIMISE the flared joins. However, you will need to flare for connection to the compressor using a R410 compliant flaring tool due to the extremely high pressures and heavy gauge copper lines. When flaring, make sure the flare is the full width of the screw. It must barely pass the thread. The now older R22 gas unit run much lower pressures in comparison.

Once Vacuum'd and no leaks, you can open the cores on the gas pipe and the liquid pipe which releases the gas into the indoor unit. Ready to go.

I am a licensed fridgy, quite happy to sign of self installs to comply with your warranty, if they are installed properly. This is not illegal. However, conditions, are

1) Install is done well, indoor unit/outdoor unit is level and correct clearances to walls, refer to installation manual for these, simple really.
2) Correct copper used for gas type, I am finding many of the cheaper types are coming with the copper pipe supplied. The cheaper units seem to work fine. I have one at home and love it. Simple really.
3) Only I flair the copper, as this must be done correctly with the correct tools that I trust, and you need to make oil traps sometimes and sometimes not, depending on install. Most back to back systems are quite simple.
4) I weld the copper joins if required as you have to use the correct silver content rods depending on the type and run dry nitrogen through the pipes in order to comply.
5) I vac the unit and check for leaks, as I have the latest tools, including 2 stage vac pump, leak detectors, and gauges.
6) I put more gas if needed due to extended runs. Although rare on installs. You pay for the extra gas, fair enough.

Price = $120-$140 depending on location. This buys 1-2 hours of my time. I'm in Preston, Vic,close to Melbourne CBD and do these on weekends or weekday evenings. Call me on 0417 209 552 or email me. Always happy to help a DIY person (me being one). Will do topups and full installs, as well. You can help me, we can chat and you can learn, I'm ok with that.

[kompsj]

FOLKS. These units will last a very very very long time, like the old fridges, if installed correctly. I'll explain.
A friend of mine is a warranty guy and I know they carry ACID test kits which test if the system has been vacuumed properly (kits cost around $10). If the system has not been vacuum'd properly then it develops acid instantly (from memory, it is hydrolchloric acid) which starts rusting the inside of the all pipes, and pumps very quickly. This rust will occur very quickly, its worse than salty water, ITS ACID. Now, the system might go for about 1, 2, 3 years tick tick tick, but will eventually decrease performance due to blockage and sieze the pump, Hence its not fixable or covered under warranty. If vacuumed properly, I have seen these units go for 30 years + still going and have not leaked. Like the good old kelvinator fridge, will keep going and going. This is why the manufactures DEMAND professional installs in order to comply for your warranty(and it is illegal to self install. Insurance people also know this and will ask for it in the event of an incident). It protects their brand and covers them in the event of an exploded pipe incident. You know the saying, "I had a Kelvinator fridge that lasted 35 years and I out grew it so its chuggin along in the garage now. Keeps my beers really really COLD." They will last a long long long time if installed correctly. Also they ask for the license no of the installer and contact them if an issue arises. Hence no warranty if not installed by a licensed fridgy.

[lnt9000]

Caution, plumbing commision doesn't take kindly to diy installs, or even genuine installs by qualified fridgies who dont comply with the rules, you see the problem lays with the compliance certificate, as well as an annual license fee they want all contractors to issue a compliance certificate on each and every install, at $22 bucks per certificate thats their bread and butter, and are clamping down on rouge operators, they have investigators some ex police force combing through installers records, apparantly they have the power to enter your home to inspect a unit without your consent, bah! you might baulk, how would they know that I did a diy, well how did you pay for it? credit card?, checking through their records no compliance was ever recorded for joe blow who bought an aircon from hardley normal hmmmm interesting, this scenario would then lead to the owner being investigated who will provide details of the fridgy who gassed it and both can be fined
up to $5 grand.
moral of the story: Pay by cash or get a certificate.....

[kompsj]

Yes, The law says, you will need a certificate if the works is above $500.

[ajt]

Yes, The law says, you will need a certificate if the works is above $500.

But dont forget that the $500 is including the appliance, ie Split System

[China]

Int9000. No one and I mean no one has the right to enter your private property 171 CLR Federal Court 91/004

[Jack E]

Price = $120-$140 depending on location. This buys 1-2 hours of my time. I'm in Preston, Vic,close to Melbourne CBD and do these on weekends or weekday evenings. Call me on 0417 209 552 or email me. Always happy to help a DIY person (me being one). Will do topups and full installs, as well. You can help me, we can chat and you can learn, I'm ok with that.

I agree with everything you said except your prices.
Don't come to QLD and charge like that, the rest of us licensed fridgies will go broke and you will be run out of town

As far as the purging that Pulse refers to, give it a miss.
The manufacturers should not be able to sell split systems if their instructions contain the purging procedure.
It is illegal and dodgy.
The unit should be pressure tested with nitrogen before letting any refrigeratnt in to the system.

Cheers, Jack

[built4thrashing]

you dont test for leaks on a new install with nitrogen. if you do the install corectly and use a vacuum guage you should vac down to 250 microns and let it sit for atleast 20 mins to see if it increases. it is allowed to increase slightly but shouldnt be any mode than 500 microns. if this is ok then there are no leaks.

Nitrogen is a way of finding a leak if it will not vac down properly. You pressurize the pipework to 2000kpa and test the joins / welds with leak detector (soapy water) for bubbles. if found then there is a leak at that joint. Nitrogen is also used to purge the pipes when welding to stop oxidisation.

On a side note the refrigeration that we all know R22 is being fased out and is being replaced with 410A. Systems with this gas opperate at a much higher pressure and really need profesional instalations. as even a small leak will require all refrigerant removed and new liquid refrigeration put in as it is a blended refrigerant and incorect blend will effect its efficiency and cooling ability.

Its getting so important to get split systems installed by qualified and experianced installers that i dont know why anyone would do it ya self.

[Jack E]

built4thrashing,

You do test new installations for leaks using nitrogen.

If you don't, how do you know you have done the install correctly?

That is one of the few things the poor instructions have correct.

As you said, R22 is being phased out, 410 is the gas I was refering to as it is all that is worth installing these days as far as splits are concerned.
If you were to rely on a vacuum alone to leak test 410 you would probably find yourself doing a fair bit of warranty work due to the higher pressures involved.
Regardless of the gas type, pressure testing via vacuum is not efficient.
You have negative pressure meaning the only indication of a leak is a change in pressure, which can be difficult to read on a guage.
It is also inefficient as you need to wait a fair amount of time to see if the pressure changes.

With nitrogen you have positive pressure and can leak check using bubbles, or add a trace gas and use a leak detector.
This way you can find a leak quickly, be more efficient and save your self time and your customer money.

You were right about one thing, it is definately worth having a professional install your system, regardless of the gas type.

Cheers, Jack

[ajt]

built4thrashing,

You do test new installations for leaks using nitrogen.

I'll second that, another advanage of pressure testing after vacuuming is that the dry nitrogen will help absorb any moisture content left in the system that hasn't boiled off in vacuum.

[Learner]

This is 100% correct.

Why Vacuum??
Folks, if you want 100% efficiency out of the unit, you need to vac it below 500 microns using preferably a 2 stage vacuum pump and a vacuum gauge to measure. This removes all the air and moisture in the copper and indoor unit. You want ZERO air and moisture in the lines. If left in the lines it creates acid in the pump and your pump will rust like an old Torana (sorry Holden fans). Also causes blocked/frozen capillary which increases pressure in the system. This will eventually cause PREMATURE mechanical failure. Hence, this is WHY the warranty guys will not touch self installs and insist on a professional install.

Thanks very much for sharing this valuable information.

The vacuum and acid formation has interested me. I found these papers explaining about acid formation in these systems. Also found this information about acid test kits you wrote about
.
And R407C Gas.

http://www.osti.gov/bridge/servlets/...ive/823889.PDF
http://www.actrol.com.au/natFlyers/aprMay07Flyer.pdf
http://www.actrol.com.au/techPapers/foraneR407Ctp.pdf