Best Practices for System Evacuation [2024 Version]

Jim demonstrates essential techniques and tips for mastering HVAC evacuation. Whether you're a seasoned professional or just starting in the HVAC industry, this guide will provide you with valuable insights to ensure efficient and effective evacuation. Learn about the tools you need, the best practices, and common pitfalls to avoid.
Key takeaway from this video: Place gauge as far
from the pump as possible (don’t place on vacuum pump
, and don’t place on core tool).
Chapters:
0:00 - Introduction
0:45 - Importance of Proper Evacuation
2:15 - Necessary Tools and Equipment
4:00 - Preparing for Evacuation
6:30 - Step-by-Step Evacuation Process
10:00 - Common Mistakes to Avoid
12:45 - Testing and Verification
15:00 - Maintenance Tips
17:30 - Final Thoughts

[@deltaf222]

Fabulous information for the HVAC install & service side- Follow these tips and tricks!

[@RATCHETMAN1001]

i wish u would teach automotive ac, tom lech has helped me a lot and he turned me on to you guys and man its what none of us no is crazy, but now i can do better from watching and learning. if you have not watched some of those top guys in automotive doing ac you would fall down and cry. thanks for taking time and helping. and they will tell me they been using shop air for pressurizing the system for leak checks and when i say thats a no no, oh man they give me hell. at that point i challenge them to check u guys out and ask their local residential ac tech would they use shop air. they some times will clam up but i dont think some will ever learn. but i am even at 67,this old dog still learning new tricks. thanks thanks thanks

[@timrob0420]

I’d love to see how long it takes for you to pull down on a used circuit with the compressor

[@infinitivesolutions786]

That's a whole other beast! We usually try to purge the system as much as we can with Nitrogen. Pull a vacuum and use the 3 evacuation method. But sometimes that still isn't enough. So we purge again and keep repeating. Replacing the oil on the pump constantly. It is not fun and it takes a while. I am also curious to see how he does it! Maybe he can shine some light on a best practice.

[@FroggieBeluga]

Can I ask what conditions were in the room? Db and wb? And can we talk about expected vac times in humid environments? Or on service 20 year old unit with converted compressor from Mo to Poe?

[@Giggles907]

I have a similar question because I have a hard time pulling a vacuum below 400 on a 15 year old system in the PNW. I have seen your video, Jim, of you in the field pulling a vacuum quickly but it takes well over an hour for me to get below 500 in most cases.

[@proxybox]

Thanks Jim. The moisture explanation is excellent as it relates to heat pumps and metering devices.

[@harrycastro592]

Thanks a lot to you!!!

[@brianmcdermott2430]

Great info. Thank you, Jim.

[@user-gv3km9os6n]

Great video Jim

[@Elisummit845]

Jim you're looking great. With God's help you should have a full recovery.

[@RATCHETMAN1001]

if u have not did one maybe do a system that was working with oil in system ,then let that system open and show how much longer it would take to get a vacuum

[@HVAC-prochiller]

🔥

[@terrytrebelhorn8563]

Good information. What's your thoughts on micron guage placement with mini-splits?

[@measureQuick]

On the core tool is the best and often the only place.

[@vincentgelles3805]

I have the tru blu hoses and the BluVac pro micron gauge. I do a lot of retrofit system changeouts and 99 percent of them are heat pumps. When I’m pulling a vacuum on a new system ( evaporator coil and lineset only) I always pull a one hose vacuum. I also do a lot of service work and I replace a lot of compressors, reversing valves, and condenser coils and I use 2 hoses to evacuate the system in those cases. I’ve found that I can pull the new systems below 100 microns but when I’m pulling on the entire system and the compressor oil I often times can’t even get below 500 microns with an 8 cfm pump, clean oil, and tru blu hoses. I have a lot of calls to do everyday and I have to get the systems working before I leave so I can’t leave my pump running over night and come back the next day. Is it going to hurt the system if I can’t get some of these compressor or reversing valve jobs below 500 microns?

[@measureQuick]

On existing systems it sometimes hard even pull below 1000. At that point you need to make sure you change out the dryer with a larger capacity model and let the dryer handle the moisture. I would also install a moisture indicator designed for the refrigerant that you’re using so you can verify in a week or two or have a customer verify that the system is indeed dry.

[@vincentgelles3805]

I usually do upsize the drier to at least a 16 cubic inch. I stopped even carrying the 5 and 8 cubic inch driers on the van. Thanks for the response! Sometimes I feel like I’m doing the customer a disservice when I can’t pull a deep vacuum on an existing system but I’m always being rushed to get to the next job, especially this time of year. The moisture indicator is a great idea and I’m definitely going to suggest it to my service manager. It would be nice to know whether or not the drier is handling any moisture that wasn’t removed from the evacuation.

[@lynncomstock1255]

Consider the "triple vacuum method", breaking with dry nitrogen.

[@user-hx1gy8mj9c]

I run into the same issues, Vincent. I put two new condensers in( indoor coils could convert r-22 or 410a with a metering device change.) So two new txvs in after making sure pressure test passed 450 psi and vacuum test.. During vacuum (2) 1/2" hoses I had to break the first system twice with nitrogen and the second three times with nitrogen. New filter Driers. They would both pull down below 225, but one side, when I isolated individually, would slowly and gradually rise up to above 1000 and kinda hang out about 2800-3300; it took about 15-20 minutes. I had both of these on a vacuum probably 5-6 hours. My hunch is likely fighting moisture and refrigerant boiling off

[@w0lvez1]

​@@vincentgelles3805 I tried making a Vacuum tank out of a disposable cylinder then filled it with a molecular sieve. I can't tell if it is boosting my pump's overall performance or just the CFM. But when micron reading gets stuck I just isolate the pump to let the micron reading go up then as soon as I open the valve it will pull to a lower micron reading.

[@dipley3771]

Appreciate the info. Not a realistic demonstration though. You eliminated the hardest task from the picture. Need to try to pull down that low that fast with a Poe oil compressor after a repair. More of a realistic expectation on how those expensive hoses and tools will perform in the real world

[@measureQuick]

The reason pulling a vacuum on an existing system is so hard is because it was never pulled right in the first place. You are correct. It’s very hard to get below 1000 microns, let alone below 500 on many systems. At that point you have to install large capacity dryer to handle moisture. On a new system like this one however vacuums are very easy to achieve. It’s not only about freezing point but also about moisture load. The dryer can only handle so much and we want to have the system as dry as possible when we start so that the moisture does not end up in the dryer or the oil.

[@w0lvez1]

You can 't remove moisture from POE using a Vacuum pump.

[@measureQuick]

@@w0lvez1 You can, just not quickly. The best way to do so is with a liquid line dryer.

[@w0lvez1]

@@measureQuick The problem is there are no liquid line dryer. The manufacturer said not to install one. P

[@w0lvez1]

@@measureQuick That what Carrier Service Manual says. The manufacturer service manual is always a reliable source of stupid myth.

[@hvacslayer2929]

🤦🏻‍♂️ why companies making vac pumps with micron gauges on them.

[@georgekolos5255]

This is infuriating uninformative of actually being in the real world. No way in hell with even the best tools and test instruments unless in outer space that anyone pulls and can hold below 100 microns in the real world of being on planet earth. What sort of propaganda is this!?? I only have 30+ yrs of experience of pulling vacuums of even before we had fancy micron vacuum check tools. I use such these days. If I get below 500 microns, I valve off and charge immediately! 100% I know no leaks in at least a vacuum. + pressure test with nitrogen also! Some leaks I learned seal themselves under vacuum! This is a BS misleading propaganda video I say in comments. Back in the decades. The sound of vacuum pump was when we knew that we had a good vacuum! Still also today if one knows thier vacuum pump l!

[@measureQuick]

You caught me! I performed this demonstration on the back side of the moon.

[@RATCHETMAN1001]

yep i learned to listen to my pump, when vacuum starts getting good my pump gets quite. i work with automotive and i am having problems to get below aprx 1400 microns . my stuff has a lot of rubber hoses and usually been open to atmosphere for months sometimes. so lots of moisture absorbed. so with the triple nitrogen purge helps me a lot. but some customers dont want or have the money to do it right. just patch and go so they got ac the summer. im sure the residential customers maybe like that as well.the ones that can afford it will get it done right so it will last,but the ones who cant i do my best to help get them threw till better days. and drier replacement for us is not always an easy task. so as cars get older they need a complete ac system rebuild, but some times the car is not worth it ,so a patch sometimes goes a little longer, dont like to do it but u have to help that customer best u can also.

[@jeffb8437]

30+ years of experience and still ignorant. Congratulations

[@RATCHETMAN1001]

@@jeffb8437 dont take it that way please. i was the same for many years as well it worked why change, right. i do automotive ac. so others in my field dont want to learn a better way ,the right way. learn from the right people. watch as many u tubers doing auto ac and with the knowledge u get here u will see almost all those guys are so untrained. they believe that 10k machine solves all problems. all tools have a weakness ,once you find it u can correct for it .if u call them out their egos go off the charts. i watch here cause it applies to us. they have opened my eyes to my evil ways. i have made a vacuum chamber from a masson jar and put it all to a test. refrigerant oil sitting out to atmosphere, water, oil and water. Until u try this and watch what happens you may never understand, we cant see inside of ac systems but this chamber i made lets me see the mysterious things happening. then it became clear the visual affect is the eye opener. Even a so called empty jar put under vacuum will amaze u with micron gauge and measure the jar temp from top to bottom while pulling that vacuum and watch the micron gauge and those compound gauges .they sit their lying their ass of to you, wont tell u shit for vacuum

[@RATCHETMAN1001]

let me add this to the mix of things i have learned. I can get to 500 microns and less sometimes and no more than 200micron rise in ten minutes.practice makes perfect. i was disappointed at first . tom lech told me leave it on vacuum overnight i would be surprised. i was thats when i got the good numbers, just tickled shitless

[@davidgentz1731]

How many people you think are actually going to buy a vacuum pump and gauges on for their own stuff they're going to buy that tank with the holes that plugs in and fill it up and be on their way come on this would be something you would learn at a community college or at a union shop or something you just looking for a way to make a buck ain't you

[@coldfinger459sub0]

Some guys in automotive use their wet high % compressor shop air and inject it into the ac system to look for leak in a PAG , POE oil system. Then the even start the compressor will that wet air to see if the compressor will start and build pressure 🤯🤬 Not the sharpest tool in the shed

[@RATCHETMAN1001]

yep my tool is getting sharper because of you guys. ordered my dtek today aprx1100.00 just decided to bite the bullet for the bells and whistles, im sure you will be helping me more , tell me when you get tired of my voice. heeeehee

[@coldfinger459sub0]

@@RATCHETMAN1001 did you use my 8% discount code LECHAIR all one word all caps

[@georgekolos5255]

Some people even worse. Use Co2 to pressure test

[@RATCHETMAN1001]

@@georgekolos5255 please help, there is a system being sold called bullseye that uses it, check that out and please let me no why not use it( co2. )