Mini-Split Heat Pump: Nitrogen Pressure Test
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- Опубліковано 27 сер 2018
- In this video, I'll be doing a pressure test for leaks using nitrogen on a mini-split heat pump.
Imperial Tubing Bender: www.amazon.com/gp/product/B00...
Bubble Leak Detector: www.amazon.com/gp/product/B00...
Nitrogen Regulator: www.amazon.com/gp/product/B00...
1/4" Core Removal Tool: www.amazon.com/gp/product/B01...
5/16" Core Removal Tool: www.amazon.com/gp/product/B00...
Hilmor Flaring Kit: www.amazon.com/gp/product/B01...
BluVac Pro Micron Gauge: spwindustrial.com/accutools-a...
Thanks to everyone for watching! - Авто та транспорт
Of all vids out there, this was the most straightforward, easy to understand and had no nonsense to waste time.
In 11 minutes, you've covered everything I needed to refresh my memory.
When everything is completed I want to see you in the air conditioned garage enjoying the cool air. Things are looking really good Terry.
wyattoneable Yep, everything looking good Wyatt! Only thing left is doing a vacuum and firing it up. Of course for the closure on that video, I’ll be inside the garage. 😀👍
great video. I learned to do this as a DIYer from older youtube videos which were helpful, and allowed me to install 7 minisplits for myself and family members, but your videos are much better and more clearly explained.. i have another 2 units to do soon so i thought I would brush up.. Glad i found your videos.. you will allow many other DIYers to tackle this as well and save the $1000-2000 they would pay to have a pro do the work in a day... and although some pros are top notch, many others do not nitrogen test nor take the care that a caring DIY homeowner will. Subscribed.
Thank you very much chicchoc9 s!
Uhhhh are you licensed to install them!?
Great video and good info. Only 1 issue, at 4:00 he forgot to mention he isolates the tank from the test by closing off the low pressure (blue) valve. You can see him close the valve off.
Thanks Mike!
I questioned that while watching the video and it was hard to see closing the valve .. saw your comment and it was spot on!
He did that at ~ 2:45
thank you!
Many thanks for this I’ve shared this with som of my work colleagues in the Uk
Glad to hear the video was helpful!
I've never waited so long to find a leak ! Just a little tip : when you finally release your nitrogen outside, you can do it in one shot by quickly opening your valve, so it's gonna kick all the crap inside more efficiently
Extremely well done.
Thank you very much Craig!
Sir you are a great instructor I have much more confidence on installing my own mini split dual zone after watching all your videos. Thanks for taking the time and sharing
Thank you Joseph for the kind comments and for watching the videos! Since there are a lot of DIYs who are installing mini-splits, I wanted to give them all the information that would help them in having a successful installation. Good luck on your installation and I'm sure that it will be a great one!
@@stuzman52 Well I live in Hawaii so everything is expensive here and I now have 2 kids in college so when my mitsubishi mr slim failed (after 17 years) they quoted me $4750 to replace. I got an off brand 18000 dual zone and with your videos I will save $2400. Much in part because you explained every step so well. Thanks Again I will let you know how the install goes when it gets here.
joseph graham Sounds good Joseph! Let me know how it goes! 😀👍
@@stuzman52 Sir I would like to tell you that I have successfully removed my old system and installed a brand new 18000 BTU Mini Split AC/ Heat Pump with 2 9K zones in the house. In great part because of your videos. Had a few minor problems but was able to get through all of them Thank you so much for taking the time to do these videos. I will be forever grateful and so will my kids when I can pay their tuition because you helped me save money.
joseph graham That’s great to hear Joseph and glad to hear that you saved money to help your family. Always glad to help and have a great weekend coming up. 😀
Nice work Terry, looks good to go.
Thank you Jonathan!
this is the neatest, well-disciplined, professional installation ever , you rock the hvac industry Sir!
Thank you very much Ray!
He's idiot and made multiple mistakes. Not purging his lines, not knowing how to used a high pressure valve. So many mistakes... this video should be taken down.
Great video, easy to follow, good camera placement.
Thank you very much for the comment and have a great day!
Vacuum, service and you'll have a nice cool garage in the summer and cozy warm in the winter!! Looking good Terry!!
I was working in the garage yesterday with the wife doing a little organizing, and it was very nice inside for sure. Thanks Bob!
Good video with good instructions.
Thanks very much.
Sorry Wim for the delay as UA-cam did not contact me. Thank you very much!
this was a great video put together very well I need to do this exact procedure on Sunday thank you very much for posting this
Thank you and good luck on getting your unit installed!
@@stuzman52 thank you everything went great
k adel Glad to hear all went well!
Excellent video, thanks for sharing!! Now I need to get my HVAC convinced to do a proper pressure test since I have had past issues with leaks. Id like to see a prolonged length of wait time, more then 15 minutes in my case
Thank you Eddie for watching the video and for leaving a comment!
thank you for this precious gem !
Thank you hafizhan for the comment and have a great day!
Very well done!
wysetech2000 Thank you very much! 😀
That's as good as it gets! You explain it very well. Hopefully people are paying *close* attention because after you let refrigerant into the lines through the low-side of the gauge set and adjust the regulator valve to get the line pressure to 200 PSI, you *close off* the low-side valve of the gauge step, which cuts off the feed of nitrogen from the N2 tank, otherwise that would overcome the pressure lost by any leaks and be self-defeating. You don't mention that's what you're doing at that step though, you just crank the gauge blue (low-side) valve closed. and that's a really important step! My Daikin outdoor compressor installation manual says to pressure test at 550 PSI, but don't exceed that. Also recommends holding the pressure for 24 hours but I think it says minimu of 1-2 hrs.. Not sure if all mini-splits can handle 550 PSI, but from what I understand r410a generally reaches a pretty high pressure in mini splits. Anyway the higher PSI test might catch some leaks lower pressures won't, so why not?
One can use higher pressure, but never exceed the test pressures of the indoor or outdoor coil and use the pressure which is lower. No particular reason for the lower pressure and even if there was a small leak at 200psi, it would have showed up.
Ha ! I now notice multitudes of us in the comments have picked up on the “failure to close low side valve” , a mistake Stuzman is unlikely to repeat now
Great work 👏🏾🙏🏽
Thank you!
Thank you for your video I was successful at testing my line thanks forYour time and making your video it was brilliant. Keep up the good work.
Glad to hear that it all worked out for you Brandon! Have a great day!
Great video pal cheere
Thank you very much Isaac!
Nice to see it held pressure. If you seen a leak it would have been go time eh:) I have to try that bubble fluid. Nicely done Terry. 👍
STEVE ROB REVIEWS Yes, you are correct that if there was a leak, the pressure would have dropped off fast, even for a small leak. I’ve used all kind of stuff for bubbles over the years and this stuff is amazing. You won’t be disappointed! 😀👍
Now it's time to evacuate, charge and enjoy the cool fruit of your labor!
You are correct Glen; almost there now :)
Very informative, thanks for posting this. Any chance you could note part numbers for the equipment you used to pressure test this mini split?
Well done. Thank you
Thank you Raymond!
If you don't shut off the nitrogen tank, the pressure will keep up 200 psi until the nitrogen tank is depleted. Therefore, this is only good to check for leaking with bubble test or with other leak test devices.
Feliz, you don't have to shut off the valve on the nitrogen tank. The valve is closed off on the manifold gauge set where the nitrogen is going through the compound gauge. If you want to close the valve on the nitrogen tank, you can but it's not necessary.
where do I buy my nitrogen and tank? I already bought a nitrogen regulator. Thanks. This is the best and filled with clarity nitrogen testing video on UA-cam.
I had responded to another viewer with the same question so I'll just post a copy of it here for you Freddy. You can buy nitrogen for about $25-30 a tank. If you don't have a tank, then the company will allow you to buy one. I believe the price for the tank and fill it is around $110. When you empty the tank, bring it back and they'll give you another tank already filled. Give them the empty, pay the refill fee and you don't pay for the tank again. I did this through airgas which is in my city. I'm sure that you have one or a similar company if you want to get a tank of nitrogen.
@@stuzman52 Thank you very much, Sir.
Freddy Panes Glad to help!
@@stuzman52 yes, airgas is all over, lots of local locations
@@cengeb For sure cengeb!
Well done. Thanks.
Thanks Mike and have a great day!
While you were at it , I would have cracked the high side nut on the outdoor units and purged the line completely with nitrogen, then later when you get to vacuum testing you are only dealing with nitrogen in the lines.
Nice !
Excellent Video. By far the best video on you tube on pressure testing a mini split. You mentioned another video for vacuum the system, Is that available to view? Thank you
steve bates Thank you very much Steve and the vacuum video will be posted this afternoon! 😀
It's awesome bro, thank. you
Thank you Rudy!
Good videos.. 1) He did not mention it, but he did shut off the supply of N2 to the system by turning the low pressure valve off...if you fail to do this the bubble test will still be valid, but the decay test won't be as N2 will still be supplied from the regulator. 2) You could purge the full line set and inside unit by waiting to tighten the upper flare fitting while you let some N2 into the system.. to remove air and moisture. This would give you the best decay test (less effected by temperature changes) I'm no HVAC expert just a Mech Engineer about to install a Mini split.
I forgot to mention about closing the low pressure valve, but it was done at the 4:00 timeline. Others have mentioned this also. Thanks for watching and for the comment! And good luck with the installation of your mini-split unit.
Fantastic video, thank you for providing this resource. One question- at the start, do you need to remove the schrader core, or does the schrader core remain in the service port for the duration of the test, since it's a 1-way valve that lets the high pressure nitrogen in?
Hi Kevin and hope you're doing well. The biggest reason to remove the schrader valve is for the next step where the air is removed using a vacuum pump. With the valve removed, it takes considerably less time since you won't have that restriction. You could leave the schrader valve in, but it would take longer to evacuate the system. Have a great day!
Thank you very much
You are quite welcome. Have a great day!
Terry, I could be wrong but I think you did the pressure test wrong. Now I will admit that the soap bubbles proved that the system wasn't leaking, that's settled, but I feel that you needed to close the valve on the nitrogen bottle to prevent the bottle from replenishing the lost nitrogen there would be if there were any leaks. I don't think that closing the low side valve does much for you because you can't then tell if the leak is happening beyond the valve as the gauge is then isolated from everything downstream from the valve and the gauge itself is being replenished by the nitrogen bottle. For this test to be valid I think you need to close the valve on the nitrogen bottle.
That's okay Dennis and we're all here to learn. When the valves on the manifold gauge set are closed, the nitrogen tank is isolated from the equipment. The gauges are then only reading the pressure inside the system. Even if there is a leak inside the system, the nitrogen tank is not going to replenish the system with any more refrigerant. It's the same if you were going to charge a system with refrigerant. With the valve on the refrigerant tank open, you charge they system. Do you turn off the tank supply valve to measure the pressure? No, because when the manifold gauge valves are closed, you're reading the equipment pressure which is isolated from the main supply pressure on the tank. Here is a link to how manifold gauges work ua-cam.com/video/xGQ1OwqEppU/v-deo.html And here is a link to a master HVAC tech who is doing the same exact procedure ua-cam.com/video/2REIP5Ddn60/v-deo.html There's no problem in turning off the main nitrogen supply tank, but it's really not necessary :)
Brilliant video, just a question, if I close the nitrogen valve after pressurizing the system. If the pressure is sustained at 200 psi (as in the video), do I still need to do the soap leak test.
Sustained pressure would mean there are no leaks in the system ?, kindly correct me, if am wrong.
Your almost right , the answer: turn off the low side valve. And de-pressurise the nitrogen supply side. You then measure nothing but the machine to the low side gauge. With not the remotest chance of replenishing from the gauge set.
He did turn off the gauge set to disconnect the system from the nitrogen bottle but he didn't mention that step. See it at the 4:00 mark.
@@DonBarthel 4:00 mark didn't show any turning to close. Thus causing question from lot of people.
Great, informative video series on how to install a mini split. One question - where did you buy your nitrogen tank and gauges, and where would one get a nitrogen tank filled? Thanks
The tank and nitrogen was purchased and AirGas Supply which is a national chain. You probably have one near you. The gauges and regulator for tank were purchased from Amazon.
Excellent
Thank you Marco!
Just installed a senville 9k myself held vacuum 2 hours solid, still did a soap and water leak test while running to be double sure... OCD...
Works fantastic, 120° vent temp 50° ambient that's almost as hot as gas
You did a great job Dodd! Congratulations!
Nice video thanks
You're welcomed!
thanks for the video. Quick question. Do you need those yellow jacket gauges? The tank regulator holds at 200psi, isn't that telling you there is no pressure leak?
You could get away without using the manifold gauges, but they do offer a higher resolution than the gauge on the regulator. Thanks for watching Tim and have a great day!
Hi , do you have a video on pressure testing and vacuum of a 36000 BTU ( 4 } four zone mini split ( four 9000 BTU indoor unit ) Not sure if all 4 line sets need to be vacuumed individually or is there way to do all one shot ?
Thanks Jay
Sorry I don't have a video for multi-zone systems. I've never done one of these systems, but would think that the manual would offer some information about it. My guess it that since each system is isolated, each would have to be tested individually. If the manual doesn't offer any help, you could call the manufacturer and I'm sure they could point you in the right direction.
I've watched all your mini-split videos and they are the best by far. Was wondering if all you need compound gauges for install is for nitro press test. Can I avoid buying set?
It's good to have them marc if only to monitor the pressure over a period of time to see if the pressure drops. If you don't use them, then you'll have to solely rely on the bubble test.
Seems to me you could just hook the nitrogen bottle directly to the service port. Nitrogen bottle has a perfectly good gauge on the reg. Once pressure is at the desired test point close the bottle valve to isolate it. Would that not work just as well? Less complicated, fewer lines, valves.
hey sir great video! but how do u nitro test a multi split? do you nitro individually on each service valve or just 1?
I've never done a multi-split unit, but from what I understand, you'll pressure test each unit separately, especially if you have a separate service valve for each zone.
Awesome! Thanks for your informative video. Just a quick follow up questions here. 1. Did the Nitrogen gas get into outdoor unit? (I suppose not) 2. What is the purpose of the adapter at the service port? Just for changing the size of the head or for other reasons?
To your first question, the service valves are closed, so when you add nitrogen to the line-set, no nitrogen will go into the outside unit. And the purpose of the added adapter on the service port is for two reasons. It will isolate the high pressure of the refrigerant when it's released from the micron gauge and will prevent any refrigerant oil from contaminating its sensor. Thanks for the comment and have a great day!
Excellent video series that gave me confidence to purchase and install my own mini split system. Really enjoyed the classroom lesson in the first video. Quick question, how much nitrogen would you estimate you used for your 12k system. Many thanks. John
Thank you very much John and glad to hear that you liked the videos. I couldn't say about how much nitrogen was used, but it was very little. I've used the same tank to test other systems and the tank is still pretty much full.
Very good video
Question. After installed mini split lines, we need to do this first before vaccum? And when you vacuum. What are you really vacuum since all the nitrogen was released?
The pressure test with nitrogen is to verify that the system doesn't have any leaks. The vacuum is to remove the air which contains moisture out of the system.
Thank you for putting these very detailed videos for everyone! I'm about to attempt to replace the outdoor unit and already swapped those and connected lines and power. Have a couple questions as I want to be clear on couple things before continue:
1. I assume this is new pre-charged system. So it's OK to test lines (and indoor unit) when both valves (under caps) are closed?
2. I don't need to do vacuum procedure prior to pressure test, right? Just connect lines to unit and proceed following steps in video?
Thanks!
Yes, you will leave both valves closed when you're testing the line-set and indoor unit for leaks. It's always a good idea to pressurize the system with nitrogen because small leaks will be revealed when it's under the nitrogen pressure. If you ignore this step and proceed to vacuum the system, it may appear to hold vacuum for a period of time. But I can remember several times where I just vacuumed the system without pressurizing it with nitrogen. Pressure stayed around 30" Hg for several hours. Opened the valves and about a month later, I found out that I had a very small leak. And what if you just vacuumed the system and saw that the pressure didn't hold? How are you going to find a leak under vacuum? Not possible....So, pressurize the system with nitrogen to ensure there are no leaks and then proceed with the vacuum. Have a great day!
@@stuzman52 Thank you !!!
@@kirill_gusev Glad to help!
thanks for this video, after you are done with pressure test with nitrogen, how you gona release or get rid of the nitrogen in the system ? did you mentioned it , sorry if this question is very noob. i have noticed at 9:55, are you releasing all the NItrogen there ? but i am not sure
Yes, you are correct Steven. After the pressure test is completed, the nitrogen in the system is released to the atmosphere.
@@stuzman52 thanks
I have a pioneer 36k 4 zone that I am about to nitrogen test ,pull vacuum and top off the lines with 410a since I extended them past 100 ft..Should I pressure test at 200 or higher?? The unit has a sticker on it with max and min pressure numbers that the system produces. IS 200 Enough psi for the test or should I go a littke more?? I don't want to over pressurize the system butvI also want to check real good for leaks since it's 150ft on lines and 4 zones..That's alot of flare connections.thanks Your videos have really helped me.I purchased 1000 in tools to do this job right.
Hi Daveboy! I would go to 300-350psi and shouldn't be any problem. A lot of folks want to test at 500-600psi but this high of a pressure is not necessary. At those high test pressures, the indoor and outdoor coil has already been tested. You're only testing the flare connections. Sounds like with your invested tools, you're going to do a great job! Have a great day!
Can we use nitrogen gass pressure test in compressor and condenser coil(outdoor unit) also, I mean Nitrogen Gass will be dangerous for compressor winding or pump?
I'm still watching and haven't read the comments... I'm at 4:43 . Could you close the valve on the source tank and watch for pressure drop? A small leak might not drop the needle if you have a constant feed of gas. Back to watching.
Oops... I missed that you closed the low side valve. 9:30 you opened it again to drain the charge.
Thomas EXOVCDS I knew you would catch it. Have you done much AC work since your boss will let you guys work on it? Oh, a little tidbit for you regarding R1234YF refrigerant. I figured out what YF stands for. You’re Fucked! Thanks for dropping in Thomas!
LOL... that sounds about right (from what I have heard about that stuff). No way my boss is gonna invest in another machine to service those systems. We're still only dabbing with AC. Mainly for when heater cores are done... we have checked some vehicles with lack of AC complaints, but most ended up being control / input related faults as opposed to low on charge / leaks.
I think I mentioned that to you Terry when I questioned you on the wisdom of buying a recovery system with this change coming around the corner. The two refrigerants are completely incompatible therefore you're going to need two machines.
SATAMAN Schmidt Dennis, I appreciate your thoughts, but I was aware of the two refrigerant types having incompatibility and that you can’t use a R134a machine on R1234YF. I know that it’s flammable and very expensive. I’m not planning on working on vehicles with type refrigerant. EPA mandates that all USA vehicles must use this refrigerant by 2021, Recently I purchased a 2016 vehicle, but I made sure it uses R134a. There will still be quite of ‘new’ vehicles on the road in upcoming years. I realize that R134a will start to cost more as it is being phased out, but that will be a few years. Mercedes along with other European manufacturers have been using this R1234YF for a few now. There was a front end collision with a Mercedes and a refrigerant line split. This refrigerant spewed out onto a hot exhaust manifold and caught on fire. The car burnt to the ground. Mercedes is considering to switching back to R134a. So, who knows what the future may hold.
In a heat pump, I believe flow is reversed when switching from heating to AC. So, the high side must become the low side. In our home heat pump the two lines have different diameters, usually the low side is big diameter line and the high is small. If flow is swapped every season, why don't they have lines with the same diameter? Won't a big diameter high pressure line cause some kind of problem?
spelunkerd Your operation about a heat pump is correct. Evidently the diameters of the lines isn’t an issue as all the lines I’ve seen on heat pumps have two different diameters. I don’t have a good answer to why they wouldn’t be the same. Good question!
Because the larger line is always vapour and the smaller line is always liquid. Regardless of whether you’re in heating or cooling
do you have to remove the schrader valve when pressure testing or vacuum testing? Also my iQool9 (electriq) has no info on what pressures to test to so I have no idea whether 200psi or 300psi or even maybe 150psi?
No, it's not a requirement that you remove the schrader valve. The reason for removing it is to allow a faster evacuation of the air in the line-set to minimize the restriction. If you want to go a little higher pressure than me, you could use 300psi, but the other pressures are fine too. Have a great day!
Looks like you did not close the bottle after getting the pressure you wanted. Maybe it’s safer to close it. Thanks for the video
Good information! One question is, since the pressure doesn’t drop, why do we still need to do bubble test? They seem duplicate to me. Thanks!
When using an analog gauges, it could take awhile to be able to notice a pressure drop. If I was using digital gauges, the pressure drop would have been noticeable earlier. With the bubble test, it's just another assurance, that there isn't a leak. It's more of a peace of mind that the system is leak free before opening those valves. Have a great day!
Hi Stuzman, thanks for this video.
I watched it again and I noticed you didn't shut off the nitrogen tank when doing the pressure test. If there is a leak then wouldn't the nitrogen keep the pressure level up? Shouldn't you shut off the tank while doing the test?
thanks
I did close off the valve on the manifold gauge set. Take a look at the timeline at 4:00 and you'll see that. Have a great day!
@@stuzman52 Okay, thanks! I had to watch it again to see you do it. Thanks again for your help.
Would inert welding gas work instead?
Great video!
Yes, it should be fine.
If valves O rings are damaged and charged. In that case how will we vacuum condenser , accumulator etc ?
thanks
You're welcome!
Thanks for the video I have a lg mini split 2 zone but I can't pressure test all the lines can't figure out why ?? Any suggestions
I believe Kevin that you'll have to pressure test each one separately.
Amateur question: If I don't have a gauge set, could I connect the nitrogen directly to the mini-split port and use the gauge on the nitrogen regulator to read by ? I'm assuming I'd pressurize to 200psi on the regulator gauge, the shut the valve on the tank, and if it holds good for 15 minute or so, I'd be good to go ??
Want to install a couple of mini-splits fro my own house, and can't really see buying a set of gauges since the unit is pre-charged. Already bought a 40cf bottle of nitrogen & regulator set + a decent Robinair vacuum pump & low micron gauge for the next step (evacuating the system before turning the gas loose). The line runs are short, so no extra freon will need to be added.
You could do that Ed but the gauges on the nitrogen bottle wouldn't have the resolution unless you had a pretty big leak. More importantly, you would be using a bubble/soap solution around the fittings to find the leaks. Good luck on your installation!
@@stuzman52 OK...thanks for the reply ! And GREAT video by the way. Thanks for the time and effort you put into it.
Ed Smith Thank you very much Ed! 😀
Im curious 1/ the need to remove the schrader?
2/ was the LP shut off at 4:02.? Nothing was said. But it's a critical juncture meaning nitro doesn't top itself up.
3/ how can you be satisfied using foamy bubble check? Micro sized bubbles will never been seen, get non foamed liquid.
Removing the schrader valve was in preparation for the next step, (next video) to pull a vacuum. Removing the valve allows for a faster and deeper vacuum. Yes, the low pressure gauge was closed on the manifold gauge set. Using a gel to check for bubbles is a standard used in the field. Also, the low pressure gauge was monitored for a pressure drop. And the unit is still working well.
Personally, I would do a drop test for a few hours in addition to soap testing the fittings. My current mini split system says to test for several hours.
Simple to do. Just shut off the nitrogen once you have your pressure (200# in this case). Crack a fitting to verify the gauge is not stuck. Visually observe the gauge drop a little. Tighten fitting and allow the pressure to sit for a few hours. Nitrogen will not expand /contract like "atmospheric air". So, ambient atmospheric temperature changes should not be observed in the gauge. Check on it after 15 minutes, 1 hour. If you have a pressure drop you have a leak. Pressure increase might mean the nitrogen valve is not completely off or sealed or ambient temperature increase causing increase in pressure (not likely with nitrogen). This will allow you to test all of the system. Areas that are sealed and lines that are insulated. Not just the fittings.
Thank you for the comments and have a great day!
hello ..i purchased a della 36 btu 3 zone unit that i'm currently installing
and noticed when i was attempting tonever install the line sets to the condenser units that they are filled and capped off (plastic caps) with nitrogen from the factory.
i've never seen this before, is there a procedure that i should be using since the condensers are filled with nitrogen, or do i just release it and hook up line sets and vacuum???
Hi Sabrina... I looked over the installation procedure for your unit. There is only one set of lines which goes to the indoor cooling unit that will have nitrogen in them and these lines are capped to prevent the nitrogen from coming out. When you remove the plastic caps, you will hear the nitrogen being released. This is normal. The refrigerant is stored in the outdoor cooling unit which is prevented from coming out by the two service valves located on this unit. As for the line-set itself, there is no nitrogen inside of them. You would make all of your line-set connections, pressurize the system with nitrogen to check for leaks and if that looks good, then you would vacuum the system and release the refrigerant into the line-set.
how frequently does a system test fine with pressure and vacuum and then later develop a leak at flare joint?
if pressure testing good with a digital probe and holding under 500 microns with the micron gauge should one be confident in the flare joint longevity?
I would suppose there's always a chance that you could have a very small leak and have a leak later down the road, but it's not likely. If you leave it pressurize say for an hour and especially if you're using digital gauges, it will show up. Now, looking at it from the other end where you only vacuum the system with a micron gauge and it holds steady under 500 microns, then you most likely don't have a leak as the micron gauge is very sensitive to any pressure changes. But, if you do have a leak while under this scenario, you're back to pressurizing the system to find the leak. So, to save time, pressurize the system to check for leaks and if that looks good, vacuum the system. And Merry Christmas and Happy New Year to you and your family!
I don't understand why you would only test up to 200psi, in heat mode the pressures are closer to 450-500psi on the high side, I know it is a common procedure for a leak test but in my way of thinking you should at least get the test pressures up to operating pressures, your thoughts?
You could set the pressure higher as you mention and should be fine. I believe most people look at it if there's a leak, at 200psi you should be able to see it. Of course, with the higher pressure, you probably can find it quicker because of bigger bubbles. :) Seems like a lot of techs use 200psi for a leak test as shown here hvac-talk.com/vbb/showthread.php?1273751-Pressure-test-and-vacuum-on-split-systems
The molecule size of nitrogen is far smaller than that of the hfc molecule and the leak will show up at 200 psi
Is there a way to make this test on the unit BEFORE install? I have a store-return unit with damaged fins, and want to ensure it does not leak before purchasing further equipment.
Yes, you should be able to still pressure test the unit.
Hi sir ,would want to hear your opinion on my issue ,here we go . I have a two story home with two central ac systems .one for first floor , one for second floor ,my second floor condenser just failed ,not worth fixing it uses the r22 gas.I can replace with a 4 ton rheem for about $4000 , or just replace it with 3 zone mini split ,one for each bedroom ,i feel i will have better control as far as i dont have to have the whole second floor cool when only one person is in the bedroom.The mini splits would cost about the same .But i heard that since i already have the duct work ,a central would be better . thanks again
That's a toss up for sure! I would go for what your needs are. Since you want better control, maybe the mini-splits could give you better control. But you might want to look into zone dampers which can go on your existing duct for the Rheem that would do the same thing. You may want to take advantage of your existing duct work since you have it.
i am installing a multi zone mini split. Do you pressure test and vacuum each zone separately or can i use the main svcvalves and pressure test/vacuum the complete system?
I'm not sure how your system is configured, but the norm is to pressure test/vacuum each zone. Otherwise, if you do the entire system, how would you know which zone the leak would be in?
Are you using Dry nitrogen?
If so, where can you purchase?
Thanks
Why do you need the manifold gauges? Can't you connect the nitrogen tank with its gauge and hose directly to the service port?
Sorry for the delay Phil as UA-cam did not contact me. The manifold gauges have a higher resolution than the gauges on the tank which makes it a little easier to see small leaks. :)
so doesn't the line set and indoor coil have a little air and moisture in it before you even add the nitrogen? If so , how is it purged before the nitro goes in ? Otherwise you have a mixture of nitro, air and moisture in the line and unit ?
Yes, there is a small amount of air and moisture within in the system. In the field, the nitrogen is added to the line-set to check for leaks using the pressure. Afterwards, the nitrogen is released and then a vacuum pump is attached which removes the air and moisture.
Dear stuzman! Why are you using only 200 psi? Could you Tell me the refrigenerant gas inside the ac? Thanks
You could use a higher pressure if you like, but stay under the lowest test pressure of the outdoor or indoor unit. This was a R410a unit.
A very informative and high resolution video. Can you recommend any textbook which explains all the pressure settings and procedures? I don't quite understand why this or that value of pressure are used. Thanks a lot!
Sure thing! I can highly recommend two books which can be purchased from www.acservicetech.com/ One of the books is listed for inverter mini-splits and the other is a/c book which also covers heat pumps. You can get both in paper or electronic version and you can get both with workbooks if you like. I have both books and they are filled with a wealth of information. They are also available on Amazon, but the price is the same. Good luck with your education on a/c systems.
Thanks a lot!
Are you a professor in university?
@@AKK105 I'm a retired electrical controls engineer. And have extensive background in other fields also. Have a great day!
@@AKK105 You are welcome!
Can I close the valve of the nitrogen bottle, as soon as the pressure for the system has been set? This should not affect the pressure test? Or is there something against it?
Yes sir, you can close the valve on the nitrogen tank and will not effect the test. I opted to use the valve on the manifold gauge set. Either method is fine to use. Have a great day!
Hi Terry, EXCELLENT videos!. Could you please explain why you would perform both a nitrogen test and a micron test? Seems redundant to me as both tests check for leakage. Thanks in advance!
Using nitrogen to pressurize the system makes it a lot easier to find leaks if there are any. If I was to only use the micron gauge, I could detect there could be a leak, but now, where is the leak when it's under a vacuum. I don't know of a method to check where a leak is while it's under a vacuum. Using nitrogen makes it much easier to find a leak.
@@stuzman52 OK, duh, I overlooked the obvious. A line in a vacuum won't blow bubbles. Now it makes sense. So that brings up another question. If you did the micron test first, which showed that you had no leaks, there would be no reason to do the nitrogen test, correct?
Paul Creel yes, that’s correct if it didn’t show a leak.
Use nitrogen to find the big leak plus you can purge by cracking open high side fitting to remove air noncondensable gas that have moisture out. Vacuum only can not get all the air 100% out, nitrogen is 99% dry. Moisture degrades compressor oil and over time and form acids. Vacuum micron gage will show if any small leaks and get the last of the moisture out if any is left. then slap a over size catch all dryer on with sight glass with moisture indicator system will last 20 plus years if you keep up with the maintenance and watch that moisture indicator.
Thanks Paul for the added info and have a great day!
I agree that the absolute test would include closing the nitrogen bottle. However the manifold trapped the nitrogen. If any case the manifold was faulty the tank being open could botch the test.
So is it necessary to vacuum the lines after the nitrogen test? Seems like it might not be necessary
Yes Jake, you MUST vacuum the system after doing the nitrogen test. Otherwise, you'll have air in the system. Have a great day!
Waleed7rrag RRAG
I do thank you very much for your excellent instructions and great detailed explanations. You are during your video answering all the what, why, how and what not to do with great details and explanations. I must say the video recording very sharp and pleasant. Having said that, if you would please answer a few questions:
1. As you know the mini split AC of all brands and kind has no high side shredder valve and I do not know why, so is it good idea to install one out side the system near the low side shredder valve?
2. I have a mini split AC under full maintenance including a leak repair on the condenser, as you know the metering device is just at the end of the condenser going to the evaporator, in this case is it OK to feed nitrogen gas from the low side all the way to the condenser to test the condenser leak repair? will nitrogen pass through metering device? and if so will it affect the metering device and or the high side of the compressor?
3. After doing system and line set vacuuming, is their a need to add 2 ounces or may be less of a compressor oil? I can not find any sold information on this issue?
Last but not least, thank you very much for teaching and helping so many people !!!
For question 1, I'll refer you to an article by Craig who is a HVACR technician about why there isn't a high side service valve, and I would not install a valve on this side as it's not needed and you're not going to gain anything from it. Here is the link to his article along with many others. You'll find the information about the valve further down in the article www.acservicetech.com/post/checking-the-charge-of-a-mini-split-unit Also, you can get more useful information from his UA-cam channel located here. ua-cam.com/channels/OZR-1IqsAer9wzlvFgb4mA.html?disable_polymer=1
Question 2: When you're checking the condenser for leaks, I would use an ultrasonic leak detector or you could use a sniffer while the unit is running. Although a bubble test may work, you will have to cover a larger area covering both sides of the outdoor coil. This would be the best method to check for a leak while the unit is running. And you may not have a leak. The procedure you're describing with nitrogen will require you to recover all the refrigerant, fill the system with nitrogen, check for leaks using ultrasonics or with bubbles, pull a vacuum and finally recharge the system with refrigerant by weighing it. That would be a lot of wasted time if you find that you don't have a leak. If you did have a leak, you would have to do all of the above of course. But just use the first method and you only do the second method if you find that you have a leak. Putting the nitrogen in the system would pass through the metering device so no problem there.
Question 3: When you have a leak, I would not worry about adding oil, because you don't know how much leaked out. During recovery of the refrigerant, the recovery unit may pull some oil out, and it's permissible to add back in the amount taken out. In other words, you know how much to put back in the system.
Hope that answers your questions and thank you for watching the videos!
@@stuzman52 I thank you very much for taking the time to answer my questions. Your answer was very sound and clear. Thank you again!!!
Waleed7rrag RRAG Glad to help and you’re welcome!
GOOD CAMERA , WHAT MODEL IS IT?
MOUNTAINAIRSOFT It’s an older camera today. It’s a Panasonic HC-V700.
hi, some of these units come with a mini condensate pump. when would i need to use that? thanks
The only scenario that I can think of is if the indoor unit is located in a basement which is below grade level. The pump would then pump the condensate upward to get above the grade level to be deposited on the ground. In most cases, the indoor unit is located above grade level where the condensate will move by gravity to be deposited on the ground.
These things run in the 400psi range I would take advantage of having the ability to go at least to 400psi on the pressure test
line set and evaporator coil on mini split don't ever see 400 psi in their entire life. so its not a good idea to go above 300 psi cause it will cause more leaks
@@lordjaashin hmmm..not even for mini split heatpumps when your eveporator becomes your condenser in the heating season?... could've sworn all mini splits i've seen were all factory pressure tested by at least 500 psi high and 300 psi low
Spot on.
You have to Strength pressure test at 1.43 times, and 1.0 for Tightness Test. This is all dependant on the refrigerant used.
R32 is pressure tested at 400psi (279.57 x 1.43)
Testing is carried out in 15 minutes increments up to the max test pressure, then down to tightness test for a slong as possible.
eg R134a at 32oC = 7 Bar x 1.43 = 10 Bar = 145 psi
@@truthfiend6909 can't say for heatpumps but my mini split user manual only recommends max 250 psi on evap coil and suction line. don't know why.
could blow the Fittings with high Pressure the connections
Hi thanks for your advice. I already ordered the nitrogen gas regulator from Amazon. I want to buy a tank; will a 5lb capacity work for my Split AC 24,000 BTU 16 foot line set? I have to reinstall a new line set. The flare provided is not enough and I got leaks so I will flare my own. The Hilmor Orbital Flare tool arrived yesterday. Now all I need is nitrogen gas. SO when my tank arrives; I will just take it to a gas company and have fill it up. Pls. tell me if the 5lb capacity tank is anough for my need.
Freddy, on the nitrogen tank, you go to the gas company and they will sell you a full bottle of nitrogen. They will charge you for the tank if you don't have one. Then afterwards, you will only pay for the refill of the tank. But, you will turn in the empty bottle and get another bottle of nitrogen, but you won't pay for the tank again. Never heard of anyone going to get a specific weight of nitrogen. It's not that expensive anyway.
Thank you Sir! My tank will arrive this week and I will go to the gas company and have it filled. Your advice really matters to me and I suppose to all your fans following you ion YT
I do not know if it has been pointed out in the comments but I would had cracked open the liquid line at the coupling to bleed or displaced ambient air from the lines. You just pressurized the system with a Nitrogen tank with air still in it. My 2 cents. Besides that, good video.
I appreciate your comment Giovanni, but that wouldn't be a recommended procedure. When you crack open the liquid line, you would be letting refrigerant into the atmosphere which is a EPA violation. And let's say that you did that. How much refrigerant would you let out to know when all the air has been released? At that point, why use nitrogen; couldn't we just leak test with an electronic leak detector or use soap bubbles. And now you'll be low on refrigerant. How would we recharge the system with the refrigerant that's lost? You can't just add an amount and use the subcool or superheat method of checking the refrigerant charge because mini splits have an electronic thermostatic expansion valve and the compressor runs at a variable speed based on the heat load. You'll have to recover the entire contents of refrigerant and then weight the refrigerant back into the system based on the manufacturer's nameplate of refrigerant charge. And if we were able to get all the air out through purging, would we need to pull a vacuum on the system? And here's what section 608 of the EPA study guide for certification says about high pressure systems, under Type II, C-2 for leak detection. "The first thing to do when a new system has been assembled (built up), and is ready for testing, is to pressurize with an inert gas and leak check. After installation of a field piped split system the unit should first be pressurized with nitrogen and leak checked." It says nothing about purging the line of refrigerant to remove the air before you put nitrogen in the system. If you look anywhere on UA-cam and follow the pros such as acservicetech, you'll see that no one cracks the liquid line to purge the system of air and then put nitrogen into the system. Have a great day!
@@stuzman52 not the service port on the condenser, the lineset you just installed. There isn't any refrigerant in it. Just to clear out any air. Sorry if you misunderstood.
@Giovanni Ciuro Okay, I misunderstood you. Yes, in that case, that would be fine.
Giovanni Ciuro , I got what you mean, but there’s no need to flush the air out per se . It is diluted during pressure test and comes out on release and during vacuum
can you pressure-test with argon or an argon mix? does it have to be nitrogen?
I'm not really sure Sam as I've never done it. Here are a few links that may help www.refrigeration-engineer.com/forums/showthread.php?8951-Using-Argon-to-pressure-test
www.hvac-talk.com/vbb/showthread.php?2198123-Use-Argon-to-pressure-test
www.peachparts.com/shopforum/diesel-discussion/191827-c-system-pressure-test-argon-co2-instead-nitrogen.html
So does procuring nitrogen require any special certifications? Can you rent a tank of nitrogen?
No Paul, it doesn't require any certification to get nitrogen. You can buy nitrogen for about $25-30 a tank. If you don't have a tank, then the company will allow you to buy one. I believe the price for the tank and fill it is around $110. When you empty the tank, bring it back and they'll give you another tank already filled. Give them the empty, pay the refill fee and you don't pay for the tank again. I did this through airgas which is in my city. I'm sure that you have one or a similar company if you want to get a tank of nitrogen.
The bubble test is fine. But as far as pressure drop, it seems to me that you kept the nitrogen tank ooen...so IF there was a leak nitrogen would keep coming from the tank, keeping pressure constant....at least for some time, depending of course of how bad the leak was...
Although the nitrogen tank valve was left open, I had the valve closed off on the low side of the manifold gauge set. One can close the valve on the tank if it's desired.
Understood, thanks Sir
where do you get nitrogen? I was curious if I can use it for my cars tires and also getting ready to install my first split unit.
You can get the tank and nitrogen from www.airgas.com/ This is a national chain and located in various cities. You may have one located near you. Good luck on your installation of your mini-split unit. Have a great day!
@@stuzman52 Thnx! Found with hdsupply, - ordered online. should deliver today tomorrow
@@arishem555 Excellent Ari! Happy Holidays!
Just noted you didn't purge your hoses before adding the nitrogen to the system?
HaHa, that's a good one Brian. I also didn't purge the line-set of air before introducing the nitrogen. Have a great day!
I was always told to pressure test to 400-500 PSI when using flare fittings
Hi Larry! The manufacturer has already tested the indoor and outdoor coil at these high pressures. The only thing that we're testing is the flared fittings which do not need these high pressures. 200-300 psi is more than enough for testing for very small leaks. Of course, if you want to test at the higher pressures, then make sure the pressures do not exceed the test pressures which are on the indoor and outdoor units.
hello sir i am from Indonesia. when you do drop test or leak test. there is gas or freon or not on ac system. do i have to dump the refrigerant all the way before do leak testing? should i open service valve and pressure line valve( smal one) when i do leak test. thanks for your help if you dont mind help my question cheers
When you pressure test the system with nitrogen Rachel, there is no refrigerant in the system. If you have refrigerant in the system and there is a leak, you can use the refrigerant pressure to find a leak. Methods include soap bubbles, ultrasonic leak detector or a leak detector that can 'sniff' the refrigerant itself. You do not open the service valves when doing a pressure test.
@@stuzman52 thanks u sir i really appriciate for answer my problem
Pressure test is not needed for home users and factory build units when professional tooling is used for pipes. The test came from engineered and build cooling systems where piping is soldered all around.
There would be some service technicians out there who would disagree with you. I would much rather test a system for leaks rather than just dump the refrigerant into the line-set and then find out later there is a leak. And one could look at brazed joints that if they were done professionally correct, then you wouldn't need to test those joints for leaks. Of course, whether to pressure test the system or not is up to the individual.
In this test both service valve LKEY WILL BE CLOSE OR OPEN? OR CLOSE ONLY SUCTION LINE LKEY CLOSE?
If I understand your question, both valves on the condenser are closed when you do a pressure test. They will be closed from the factory when the unit arrives. Then when the pressure test is okay and a vacuum has been pulled on the system, then you open both valves on the condenser.
@@stuzman52 Good work.... Thanks sir.
m saeed Thank you!
Hi good job,but you didn't tell how to put back the Schrader valve.
Thank you for watching the video. The schrader valve is installed in the next video after the system is pulled into a vacuum. You can watch the procedure here ua-cam.com/video/vSw-AWqHW0Y/v-deo.html
How long will that tank of nitrogen last? Or how many units can you test with one tank?
Don't know but I still have 2000psi on the tank and I've check several systems.
I wish they would have tested mine when it was installed. They had to come back 2 months later and charge the mini split again and fix the loose connection.
That’s why Terry that I try to work on my own stuff as much as possible! I know there are good techs out there, but I don’t know who they are. Even without a pressure test, they should have caught it when they pulled a vacuum using a micron gauge. Maybe they didn’t use that as some techs rely on the manifold gauge dial. Using that in my opinion is not sensitive enough unless you have a fairly large leak.
@@gerrypehl5602 I understand exactly what you mean Gerry as I've been in that dilemma myself over the years. You don't know who's good at HVAC, auto repair, building contractor and the list goes on. I decided years ago to do as much of the work for myself, know the job is as good as it will be, save some money and learn something at the same time. All a win-win situation. Good luck on whatever you do! :)
Can we use low pressure or hi pressure gage in testing by nitrogan gas please must replies
You can use either gauge, but you'll find that the low pressure gauge has a higher resolution.
No wonder it was holding the pressure, you did not shut off the valve between pressure regulator and manifold. In that case even with a leak, pressure stays as set.
Maciej, it may appear that I didn't shut off the nitrogen, but that is not the case. I didn't mention it in the video, but the low-pressure valve on the manifold was closed at the timeline of 4:05 in the video. Thank you for the comment!
Were valves towards compressor and condenser closed during this test?
Yes, that is correct, the valves are closed during this test and they remain closed when you're doing an evacuation of the system, (in other words when you pull a vacuum on the system).
@@stuzman52 thank you.
@@briekhnaa You are welcome!