Why use Subcooling for TXV's & Superheat for Fixed Orifices? Refrigerant Charging!

In this HVAC Training Video, I Explain Why we need to Measure the Refrigerant Charge with Subcooling when a TXV Metering Device is used. I Explain why the Total Superheat Method is used when the System has a Fixed Orifice such as a Piston or Capillary Tubing. These Charging Methods refer to Air Conditioning Systems with a Single or Two Speed Compressor. Supervision is needed by a licensed HVACR Tech while performing tasks as Experience and Apprenticeship garners Wisdom and Safety.
Tools Used In The Video
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Refrigerant hoses with valves - amzn.to/2aBumVI
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Our Related Videos/Articles
• Explaining Superheat a...
• The Refrigeration Cycl...
• Why Measure Both Super...
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• Superheat Charging Cha...
• Check the Air Conditio...
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⚠️ Disclaimer:
Information in this video is intended for educational purposes only. Any work related to the topics in this video should be performed by licensed technicians or by apprentices under the supervision of licensed technicians. AC Service Tech LLC is not responsible for any possible damages or injuries caused by the use or misuse of any information provided. ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
#hvacr #hvacr #hvactrainingvideos #hvactraining #hvactraining101 #acservice #acservicetech #refrigerants #TXV #subcooling #superheat #explained #airconditioner
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[@acservicetechchannel]

My Paperback, E-Book, Workbook, Quick Reference Cards: www.acservicetech.com/store E-Book: play.google.com/store and search "AC Service Tech" My Paperback and Quick Cards: www.amazon.com/shop/acservicetech Tool List: www.amazon.com/shop/acservicetech Support the Channel: www.patreon.com/acservicetech Related Videos: Explaining Superheat and Subcooling to Your Apprentice! kzbin.info/www/bejne/aISodZhmq52Jhrs The Refrigeration Cycle Explained Step By Step! kzbin.info/www/bejne/r5vQo3Z7dpatf6M Why Measure Both Superheat and Subcooling? kzbin.info/www/bejne/d3W5fot3g82isJY Total Superheat Method! kzbin.info/www/bejne/qWqsYpSMqsyXobs Superheat Charging Chart- How to Find Target Superheat! kzbin.info/www/bejne/mHqvanWogKiooMU Connect, Measure, Disconnect Procedure! kzbin.info/www/bejne/aqCoZKOhna-spLM Checking the Charge Tools: Yellow Jacket Refrigerant Gauge Set amzn.to/2aenwTq Refrigerant hoses with valves amzn.to/2aBumVI Yellow Jacket Gauge set & hoses amzn.to/2vLVkV9 Yellow Jacket 4 Port Manifold w Hoses amzn.to/2BkuGIq Digital Refrigerant Scale amzn.to/2b9oXYl Ratcheting Service Wrench amzn.to/2dGV4Nh FieldpieceSMAN360 Digital Manifold Set amzn.to/2BdoaD4 FieldpieceSMAN460 Digital Manifold Set amzn.to/2nB4Fe6 Compact Ball Valve for Refrigerant Hose amzn.to/2KUisW8 QuickDisconnect 90 for refrigerant hose amzn.to/2MMtVcg RectorSeal Bubble Gas Leak Detector amzn.to/2ckWACn Fieldpiece ST4 Dual Temp Meter amzn.to/2wc1ME3 Fieldpiece Bead K Type Temp Sensor amzn.to/2DBwKfs Fieldpiece Wet Bulb Temp Sensor amzn.to/2RRI7Tw Fieldpiece TC24 Temp Clamp amzn.to/2qHLyjZ Electrical Diagnosis Tools: UEI DL389 Multimeter amzn.to/2xAdaJf UEI DL479 Multimeter with temp sensor amzn.to/2jtsUbJ Magnet Jumpers- amzn.to/2PyKPQZ Alligator Jumpers- amzn.to/2PxqJXn Irwin Wire Stripper/Cutter/Crimper amzn.to/2dGTj2V Vacuum Tools: JB 6 CFM Vacuum Pump - amzn.to/2nqbvo8 CPS 4 CFM Vacuum Pump - amzn.to/2DxgPwY Appion Valve Core Removal Tool - amzn.to/2uYr8WL Appion Blue 3/8" to 1/4" Vacuum Hose - amzn.to/2uYlVyc Appion Red 3/8" to 1/4" Vacuum Hose - amzn.to/2uYg6Ro Yellow Jacket 1/4" by 1/4" 3’ hose - amzn.to/2umtcod Appion 1/4" by 1/4" and 3/8” hose - amzn.to/2Zyxzx9 Uniweld 1/4" by 1/4" 2’ hose - amzn.to/2GFov1Y CPS Vacuum Micron Gauge - amzn.to/2v1nM3O JB Vacuum Pump Oil - amzn.to/2mGrlXy Flaring Tools: Yellow Jacket Flaring Tool - amzn.to/2OBxGlM Spin Flaring Bits 1/4", 3/8", 1/2", 5/8", 3/4"- amzn.to/31BCs8Z Yellow Jacket Flaring Tool with Set Depth - amzn.to/2QIKsQH Yellow Jacket Torque Wrench - amzn.to/2NRR68Q Uniweld Swage and Flare Kit- amzn.to/2T55jyn Nylog - amzn.to/2MLJcch Ridgid Tubing Cutter - amzn.to/2DnjjR1 Wolverine Tube Reamer - amzn.to/2QGLyMV Swaging Tools: Manual Copper Tube Swage/Expander- amzn.to/2WRPa1M Spin Swaging Bits 1/4" to 7/8" for the Drill- amzn.to/2YQwwqS Uniweld Hydraulic Swaging Tool- amzn.to/2MlrI8m Uniweld Swage and Flare Kit- amzn.to/2T55jyn Uniweld Hammer Swage kit- amzn.to/2CzWMMU Uniweld 3/4" Hammer Swage- amzn.to/2CzXsSs Uniweld 7/8" Hammer Swage- amzn.to/2Mja5WE Uniweld Multi-Size Hammer Swage- amzn.to/2T3Cx1b Brazing Tools: Air Acetylene Torch setup - amzn.to/2aQalsb 15% Silver Brazing Rods - amzn.to/2gVLyLc Ameriflame Oxy Acetylene Torch Setup #1 &#2 Tip - amzn.to/2SRm3JF 40cu B Tank to 10cu MC Tank Acetylene Tank Fitting - amzn.to/2GxZZPi Nitrogen Regulator - amzn.to/2bXdR5f Uniweld NitroVue Flow Regulator - amzn.to/2GnsaAo Uniweld Nitrogen Flow Meter - amzn.to/2brvoBg Stay Brite #8 Silver Bearing Solder and Flux - amzn.to/2XIDJsY Aluminum Braze Rods - amzn.to/2IGNMu Refrigerant Leak Detection Tool: Accutrak VPE Ultrasonic Leak Detector amzn.to/2nFYKVe Shop through Amazon! Your Purchases through Amazon provide a means for channels such as mine to earn advertising fees from all purchases after clicking through. Prices are the same as normal.

[@itz_mohittt869]

Suggest me ac servise pump

[@acservicetechchannel]

are you talking vacuum pump or recovery machine? I have the tools I use linked at www.amazon.com/shop/acservicetech thanks!

[@itz_mohittt869]

@@acservicetechchannel im talking about pressure washer pump for ac cleaning

[@deker0954]

Energy is consumed in the middle and contained in the top.

[@eablau]

Bravo! The best presentation of the subject matter I have ever seen - short and to the point! And the visuals on the side, A-coil and condenser made that easily understandable for everyone.

[@acservicetechchannel]

I really appreciate that eablau!!!

[@primusheating1]

Hands down Craig you are the best. Any young tech I know that is entering the field I always suggest to check your you tube channel as a supplement to any other education they are receiving in the HVAC field. I love coming to your channel as refresher because you really make it easy to understand for anyone. We love you man. Keep up the good work and stay humble.

[@hvacdoc2338]

Great explanation !! I’ve been in the field for nearly 30yrs. and really enjoy and appreciate your videos !

[@Matthew-jr1xr]

Your videos are 2nd to none man. Much appreciated

[@acservicetechchannel]

I'm glad you like them!

[@bobwhitfield9491]

Your an awesome teacher and I appreciate you. These are perfect refresher courses to watch through school! Thanks from Las Vegas !

[@acservicetechchannel]

You are so welcome!

[@ApartmentMaintenance]

Great video Craig, love my quick reference cards 👍 Definitely worth the 20 dollars, I keep them in my Veto bag, & using them to help train my 2 techs.

[@acservicetechchannel]

That is awesome to hear that you are using them for training!

[@proc7867]

Sir, I have watched your last two videos on superheat and sub cooling. I need to go back and rewatch the last video as I will be starting an apprenticeship in about two months. I think I have a basic understanding but I need to go back and learn more now that I have a basic idea. Please correct me if I am wrong: superheat is the number of degrees that a liquid is above its boiling point (or during a state of change) and sub cooling is the number of degrees that a liquid is below its boiling point (or during a state of change). Again I’m trying to learn so please correct me if I am wrong or clarify and mistakes. I appreciate any responses from people who can help me understand this topic more! Thank you!

[@acservicetechchannel]

Superheat is the number of degrees that a VAPOR is above its boiling point. Glad to help, thanks ProC!

[@brucegreen8463]

Craig is a beast! Man, I have learned so much from you and your channel. The AC SERVICE TECH BOOK is written very well and is easy to understand even if your a noob like me! Thanks Craig!!

[@acservicetechchannel]

I am really glad that the videos and book have helped you that much! Really cool, thanks for letting me know!

[@Preludeddrivers]

Boy you are a bad man!!! loads of useful and CORRECT info Bravo, Bravo!!!

[@acservicetechchannel]

Thanks a lot Leon, glad to help! We just posted an article on "Top 10 Thermostat Problems" today at the website acservicetech.com if you want to check it out, thanks!

[@mematyi]

Great video! I'd have a question if you don't mind: When you check the charge with a TXV, based on the subcooling method, it is assume that there is no liquid reservoir in the system? I recently passed the commercial refrigeration course here in Europe, but I was taught to look up the capacity of the liquid tank and target a 75% refrigerant volume in the total reservoir size, if you are charging a new system. A TXV without a liquid reservoir is unknown to the books. We have quite different service education and habits, regulations here in Europe(with all the funky new refrigerants), but many service/measurement methods you describe are new to me, even though I passed with an Excellent grade. It seems that the american school of refrigeration service is a bit more technically developed.

[@ed6837]

With a receiver charging to 75% sounds right. Without a receiver charging to a specific sub cooling ensures that you have a solid collum of refrigerant to feed your expansion valve. Sub cooling shows that some liquid refrigerant is backing up in the condenser the bottom row or two will have liquid in it.

[@acservicetechchannel]

So air conditioning is a different beast than refrigeration. Air conditioners don't use a receiver but some have an accumulator. We make sure to drain the accumulator in cooling mode before checking the charge of single and two speed units in order to measure the real subcooling properly and also the total superheat. Check out the videos on the receiver and accumulator by searching acservicetech receiver, thanks!

[@kamechanicalhvac2891]

Great video ...... is it possible in the future to make video on water cooled units . Cooling tower ,condenser water pumps, here in NYC we work on alot of water cooled heat pump ..

[@peterdunai4073]

That's what I call teaching. 10/10

[@joeshmo5399]

I like the explanation of where to expect all gas at the top of the evaporator A coil. Could you do something similar with condenser coils comparing an older condenser coil that has a receiver tank and a newer oversized condenser coil without a receiver tank?

[@acservicetechchannel]

Joe, thank you for letting me know what you would like to see!

[@hvacpower8572]

Great video. Now I have a normal superheat 12° and 0° sub-cool on a fixed orifice. What can be causing this. Wrong size piston?

[@puravpatel5511]

Thanks a lot for the video, Craig. I have been reading your book, which is also great. I had a doubt about what happens to the subcooling incase of a fixed orifice. Will the subcooling remain constant (upon adding or reducing the charge) when we have a fixed orifice as the metering device? Also does having a receiver in the liquid line have any effect on the value of subcooling?

[@mark.r8900]

thank you for another awesome video. i was working on R410a system fixed orifice. my superheat was a little high. so i added refrigerant and brought it down to correct level (around 17F) according to wb and dry bulb formula. BUT even though my superheat was correct why is my subcooling only 3F? shouldn't subcooling be 10F to 12F? while adding refrigerant , ONLY low side paramters changed. High side unchanged? thank you.

[@tntheatingandairllc]

Great video buddy and the reference cards are the best I just received mine yesterday 👍👍

[@acservicetechchannel]

Thats awesome to hear! thanks!

[@anoopkravi]

Hey Craig, been your follower for long. Such nice presentation and great knowledge in refrigeration. I am basically from United Arab Emirates, i wonder how to order your book and cards locally here in the market? If I purchase online, will it get delivered here in UAE?

[@acservicetechchannel]

Anoop, I just got your email and responded. We can ship there, thank you very much for your interest!

[@carloscarrillo6651]

Great for explanation! Thanks for technical information..

[@acservicetechchannel]

Glad it was helpful!

[@frankroper3274]

It is called latent heat. That is when the liquid freon is absorbing heat from the air to turn the liquid into a vapor state. This absorption of heat energy causes the air to cool down.

[@zekenzy6486]

Great Video. Thank you for sharing

[@acservicetechchannel]

Thanks a lot ZE Kenzy!

[@scottk0623]

Outstanding job explains it.

[@acservicetechchannel]

Thanks a lot Scott!

[@ejohnfall]

Good teaching as usual thanks

[@acservicetechchannel]

Thanks a lot ejohnfall!

[@wasimedoo7994]

Nice explanations very good information thanks bro keep it up

[@MrChipBryant]

Thank you, great video.

[@acservicetechchannel]

Thanks a lot Chip!

[@ed6837]

Craig, a little off topic but do you have any videos on brazing AL to AL or AL to copper?

[@acservicetechchannel]

I did this one- kzbin.info/www/bejne/i2OXl5WDgJxjd8U

[@theairconditioningguy]

If you could only check one. SH or SC on a 70 degree day which would it be? Reason I ask is because my old service manager cared more about super heat.

[@acservicetechchannel]

Superheat for a piston system and subcooling for a txv. However, you would still check superheat of a txv. Its not a matter of a preferred one so that is unfortunate that he only cared about that!

[@theairconditioningguy]

@@acservicetechchannel Agreed

[@erickandrade1921]

Hey man your videos are gold

[@Fox9582]

TXV Sub-cooling method Red gauge Liquid line= Thin line PISTON CHAMBER/CAPILLARY TUBE Superheat method Blue gauge Vapor line= Thick line Right?

[@acservicetechchannel]

Correct, thanks!

[@LivnTex]

If your HVAC nameplate does NOT show the subcool temp, what do you shoot for ? My HVAC is a Trane 13 SEER two stage unit.

[@marcoolazaran9193]

Question just changed a txv and subcool won't increase. Saturation was 52 and left it as is. Didn't want to add more refrigerant. 410a system. Return 77 and supply 64

[@nickmartinez1421]

Ahhhh okay so because the txv is constantly adjusting to it's target super heat, it makes more sense to rely on your subcooling readings which is before the txv. Is it the same principles for both r22 and 410?

[@acservicetechchannel]

Yes same principle for any refrigerant, thanks!

[@barronweir123]

I have gone back to working with my dad and brother. I’m learning hvac pretty much on my own. They don’t “believe” in checking subcooling or superheat regardless txv or fixed orfice…. They just only look at the suction pressure and 125 for 410a and 75 for r22. Do many people do this and get away with it? I recently had a liquid line restriction and their method didn’t do shit to tell me that’s what it was so they just replaced the coil and outdoor unit…

[@Woahnow1012]

Anything with fixed office or cap tube just look for 35 below indoor temp and always check super heat and sub coil if they are high that means it’s most likely a restriction

[@Ted_E_Bear]

Great information !!

[@acservicetechchannel]

Thanks a lot Jack!

[@deanmartin1966]

Great video

[@acservicetechchannel]

Thanks Dean Martin!!!

[@joseluna69jl]

If you are absorbing heat in the evap then why does that suction line coming out of the evap cold?

[@MaMa-qh4dy]

Craig, if I lived near you, I would make my son work for you for FREE just so he can learn everything the proper way!!!

[@acservicetechchannel]

Ha ha, thanks Ma MA!

[@jimbola77]

thanks, partner for sharing!!!!.

[@acservicetechchannel]

Thanks Jimbola77!

[@joseluna69jl]

If you are absorbing heat in the evap then why out of the evap cold?

[@beercanburr4058]

You are the man!!

[@acservicetechchannel]

Glad you enjoyed it!

[@jakesales7321]

What of it doesn't have subcooling on the name plate? How do you tell?

[@TRICKAIRCONDCHANNEL]

👍nice

[@acservicetechchannel]

Thanks a lot Trick!

[@jevonriley7920]

Thanks again

[@acservicetechchannel]

Glad to help Jevon!

[@christopherbrowne3236]

is the txv more common in households ?

[@Colt-wr6wx]

Do you have a video of pressure controls on refrigeration?

[@acservicetechchannel]

Just on air conditioning and heat pump pressure switches, thanks!

[@haroldcouch4168]

Can someone answer why early day before it's hot SC and SH in TXV is spot on but as it gets hotter outside the SH goes up and SC stays same

[@soulme8186]

Why do we need a P-trap when blower creates positive pressure in coil

[@acservicetechchannel]

The air will push through the hole and not let the water drain down it, thanks!

[@pedrobrando4606]

The condensate pan will dry out in the winter and possibly let bad smell into your home,if the condensate line is connected to a grey water drain.Most folks prefer there blower cycle on and off rather than run 24/7. If you have a unused bathroom in your home it is best to run a little water in the sink or bath tub now and then.You definitely do not want the water in a commode to evaporate.

[@pizzle1011]

As always 👍🏾👍🏾👍🏾

[@acservicetechchannel]

Thanks Piz11!

[@ejohnfall]

What's the link on Amazon

[@acservicetechchannel]

ejohnfall, www.acservicetech.com/shop/acservicetech thanks!

[@acservicetechchannel]

Any time there is a purchase made on amazon after entering amazon through this link, a small advertising commission is made for the channel. Prices are the same as normal, if the items are already in the cart before entering then they don't count. I also have all the tools I use linked there. Anyway, thats why its there, thanks!

[@R6Wick]

4:18 5:50

[@MyLeafy1]

no offense you talk to fast good intell

[@DiegoTorres-om1ho]

Super helpful, thanks.