Very hard to find an AC company today with "experience, pride, and ownership". Five companies out to date, lots of money spent on service calls and still not functioning as designed. I learned HVAC in the military (long time ago). Back to school I go. Your videos are very helpful. I have ordered the book and workbook as well and look forward to them both. Hopefully, I can find what no one else seems to be able to.
I came across your refrigeration educational series when I did a search for understanding the basics. Here you provide an easy-to-understand representation of saturation and how it relates to a particular refrigerant type. I had no idea of this concept until watched this video and nearly all of my questions were answered for saturation. This is excellent for a newbie like me! Thank You!!!
This guy is a life saver for newbies. I had a hvac technician he said I had 32 degrees of superheat at the low side line and that was way off. I have piston 25 year old Trane X1200 metered system. I told him about the wet bulb, dry bulb method and he was confused.
I usually wait until a company contacts and wants to bring me in for a one or two day training event. I need the organization to have the equipment, location, and techs ready for the training event and for the funding for such an event. Thanks for your comment! I also don't love travelling since I have young kids and trying to be a good father and husband so this is the main way I reach techs!
I am glad you mentioned the point about taking away refresh every time you put your gauges on a system. There are ways to minimize the loss but there will still be a loss. You can tell a lot of things without putting gauges on. After hooking gauges every visit you can end up with like you said possibly a low charge. Due diligence says you should try to find the leak but there may not be a leak but when you need to add refrigerant it throws the homeowner into panic mode. OMG I have a leak!!!!!
i was 90% sure i had a piston/orifice because i saw the nut but i wasnt able to confirm by looking behind the panel because its proving to be a real hassle getting it off..its like the panel is also connected to a bracket that also holds the evap coil..so i feel like i need 2 people..whole units going to need replacing anyway..so thanks for the info! really love your vids..i have like 30 in a playlist that i watch for hours on my study days
Great explanation. Like how you show that the superheat is a moving number. That's why I always check the superheat again after adding or remvoing refrigerant.
seems like most people don't even bother with wet/dry bulb and just derive superheat from guages and temp of outside suction line... great video, thank you. I want to do it right.
Total superheat is a massive pain in the ass. Thank God almost everything is TXV these days. But this cleared a lot up for me and I've been doing this for 10 years.
Mr. excellent..... video, I'm sure this way is a little bit easier on u and faster don't have to hook up all the equipment to show the same illustration, also you actually show more in less time, thanks again I'll be buying one of those books
Start Thinking on doing one book, for basics, there some out there but they are like puzzles, like they don't have clear scenarios, or context, hope you do one day,!!!
Hey Silver Shark, I mention the troubleshooting in this book but the beginning chapters are for beginners. The content in this book is exactly what I would teach a new student to bring the tech from nothing to troubleshooting. Remember this is 229 pages long and the EPA 608 is integrated in the book, thanks!
Like your videos always watch them when you release a new one. Just realized when you mentioned having to walk back in the building and then back outside again to check your wet bulb and your dry bulb. all temperatures as they change waste a lot of time and Time is money. Highly recommend Fieldpiece wireless gauges with the measure quick app. Or at least the Fieldpiece app. When every minute from morning to night is billable hours and every day you have more work than you can possibly get done. Those few minutes wasted on every job walking in and out of the building add up by the end of the day and that could be one lost job every day in wasted time just to check measurements when it could’ve been done through Bluetooth gauges and you never had to stand up once to go check another gauge. At $150-$200 plus an hour That could add up to one lost job every day for the entire year. That adds up to the total price of a new service van or service truck just by losing that one daily hour. Think about it
I agree, have you checked out my total superheat video using the SMAN 460 and wireless wb sensor and wireless outdoor temp reader to automatically calculate target superheat. I also did a video using the probe set, thanks!
For wet bulb temp, Essentially, Digital psychrometer as close as you can to the evaporator coil? If you got to drill a small 3/8s holes, as long as you get your psychrometer as close to the evaporator coil, correct? Thank you your videos are incredibly well put together!!
You should stay back a little bit if possible anywhere 6 inches to 2ft upstream of the coil or the psychrometer will measure a higher wb if its right next to the evap coil, thanks
How can you tell what type of metering device your A/C has without removing the evaporator coil? My evap coil was installed by some earlier company or service tech. There are only two small holes in the plenum and they're filled with putty. I don't want to unsolder the evap coil just to see what kind it is.
Thx Craig I'm really enjoying your Hvac videos,Service bk,Work bk as well as your three Quick guides templates. Do u hv any plans for heat systems (Books)? thanks again!
I think that is how all of those false rules of thumbs were created by trying to find a short cut but really we need to see that superheat and subcooling to tell how the system charge is doing but I agree it would be nice, thanks!
You mentioned before that having to much superheat is an indication of a bad TXV or a restriction in the line so having high sub cooling is the same indication ? Thanks for your help and happy new year
May I ask a question, if vapor pumps can’t compress liquid....why charge equipment in the liquid form? Meaning We charge 410 or puron equipment in liquid
This is to keep the 50% 50% mixture of R-410a consistent as it leaves the bottle. plus we can meter it in slowly so the refrigerant has a chance to flash before it goes in. R-410A is made up of R-125 and R-32 thanks!
I love this channel. You are explaining very clearly. One question: Can I use a standard digital temperature reader to measure the inside (WB) temperature? Sure this will not the correct temperature, but I can get only a standard digital temperature reader in this country. Can I do anything to bring it to a WB value? Thanks a lot!
You know I really had no idea about these procedures and practices such as the superheat and subcooling methods. I was it interested in what I could do to make my refrigeration system cooler and more efficient. Well now I'm hooked on desire to learn more and you certainly cover a lot of information in a easy way to follow along! So before this highly scientific method, how did the technician determine whether or not the system was properly charged? Thank you for the great video!
A way to stop losing charge when checking a system every year I think it's best to preload liquid/service(yellow) hose with the correct refrigerant. With normal size hoses that should hold roughly 1.5 oz.. Should be enough to offset any loss. Hopefully ppl are bleeding liquid line back in after disconnecting.
Yes hopefully techs are doing the proper disconnect procedure to move the liquid refrigerant back into the vapor line. If they are then they wouldn't be loosing but a little vapor so that would be much less than 1.5oz and they could also use test probes or test gauges without hoses which will loose less but I am with ya, at some point you need to add some back in, thanks!
Good job I got a question for you, if you see this and you reply I would appreciate it . There is a 3 ton heat pump ,with a 14inch round duck and 6vents ,and 20/20 return grill it’s a commercial place , I got DT 26 76F return and 50F supply air Low side pasig it’s 125, line temp it’s 42 degree S.H it’s 11 High side it’s 300 psig line temp 95 degree F. S.C it’s 4,3 And it’s with a piston not Txv. Personally I think there it’s small duck size and not enough vents ,what’s your thought on this ?
You can use a target superheat chart or a formula such as ((3xwb)-80-db)/2. I have all of this laid out in the book along with what to do when the target lands on the x instead of a number in a dry climate scenario, thanks!
Hi, i bought E-Book few months ago and i really like it, now i'm thinking to get paperback version. My question is: will you ship it to canada ? and what's the shipping cost? thanks!
Hey Jeff, yes we ship to Canada fairly frequently for paperback purchases on our website www.acservicetech.com/store and there is an international automatic shipping calculator there once you enter your address. Any questions, just email me at info@acservicetech.com thanks!
I am planning on doing a video on temp rise to determine airflow. I would love to do a furnace book but I have a few other resources to build before that, thanks!
You should use a digital temp meter such as the st4 for dry bulb temp readings. Wet bulb can be taken with a psychrometer or a method discussed in this video. There is a temp sensor with a cloth over it for sale in the store at www.amazon.com/shop/acservicetech thanks! nnth-cam.com/video/PIYJBaOdGx4/w-d-xo.html
Wb temp is while the unit is running so that you know the target superheat at the same time that you are measuring your actual total superheat, thanks!
Hmm. Thanks for the reply. I'll read up on WB. I get that it's to be taken as close to the same time a s possible. Also it measures the airs capacity to absorb moisture. But wouldn't it give a different reading depending on the velocity of the air? Higher velocity = faster evaporation. Also, as the saturation is occurring in a closed system with no direct contact with house air, why is it relevant? Cool temperature to condense maximum latent heat?
@@Spencerbuildsit A high wb temp air crossing the evap coil is a higher heat load for the refrigerant to absorb since the coil is meant to condense and then reject the condensate out of the building as well as for the refrigerant to move heat out of the building. This work is done to reduce the humidity and while this is happening you will see a lower delta t especially in the case of a fixed orifice. The delta t is low because the superheat is high due to the added humidity that is getting condensed. thanks!
Got it! So the calculated SH takes the latent heat into account. Wondering why leave any SH on the table? How about minimizing the SH, then have a liquid sensor that returns liquid to the top of the evaporator, or a small evaporator, as a anti slugging device? How about using flat plate heat exchangers as evaporator in air to water heat exchangers? I have one that is useless as it needs a control board. DC inverted driven air to water heat pump. Haven't found much info. Learning so much from your contributions. Thank you. Will you be doing a few videos on design? Air handler selection and matching?. Latent vs specific heat and how to design for dehumidification? Static pressure and duct design? So many questions. Thanks for sharing
Have a quick question. Does your book go into the diagnostics of 2 stage condensing units? Or how to differentiate wiring of a 2 stage versus a single stage? I noticed in one of your tutorials about furnace and thermostat wiring, you have no explanation about Y1 and Y2 wiring. Would be nice if ducting and manual D are explained in your new book. That I’m guessing is not in the book?
This book is 229 pages and focuses on refrigerants and procedures used to prepare a system for refrigerant, how the systems work, charging, troubleshooting, and airflow testing. The entire outline including sections and subsections are found at the website. This one is not about the electrical wiring. Those wiring diagrams were just focusing on single speed units and units that control speeds at the control board such as for heating, thanks!
AC Service Tech LLC - never ever a criticism of your videos or instruction. Just a shame since you are such a great teacher to exclude those important aspects of HVAC. Maybe in your next book. Until then, thanks for all your hard work.
@@BartSimpson-nr1dy I had to stop somewhere and 229 pages is considerable as it is, otherwise I would never had completed it. That was a 3 year project. We are working on the workbook now for schools for this book, thanks!
Thanks for the video,have really learned a lot and gained much knowledge.Hope you could do one on where the airflow of an indoor coil/or an air handling unit.using an avenometre could be demonstrated. Regards from India. Am in the process of buying ur book.
Ok, kind of in depth question about having high head pressure on a 2.5 ton split system with 22. My suction is 84 liquid is 94 degrees. My total sub is 43 and super is 43. I have ran down all the troubleshooting in your book and cant seem to find the culprit. Did pump down and checked the orfice, purged with nitrogen and if it was under charged my sub would be over 25.. I can give link to my fieldpiece check and charge and manifold data l9gger
I have a system which has TXV on it. The sub cooling is 13 and the superheat is 32. When the system reaches the set temperature and the system is off, I can hear hissing sound from inside of evaporator for a couple of seconds, then I can hear another different sound like water flowing away from evaporator to outside condenser unit along the lines (not sure suction line or liquid line). The hissing sound last around 4 seconds and the water flowing sound last around 2 seconds. Should I replace the TXV? Thank you so much
Superheat is high, possible restriction on liquid line, low airflow or low on charge. Not enough refrigerant in liquid line near txv making gurgling sound look like water flowing. Probably that sound is here all the time when system running but maybe you not hear bcz of blower motor noise. What is pressures on low and high?
Superhydrophobic, That is the system pressures equalizing while the system is off. That is normal depending on the type of txv. There is no problem with that. The superheat does sound a little high though. Make sure to recheck that again and also check the delta T. If the superheat is high and your delta T is low then that could be a partial liquid line restriction. That was why Mister was asking what your low and high side pressures were, thanks
Good morning Craig. In reference to air flow, what do you think of the way "emerson check a charge" recommends checking air flow? They take indoor dry-bulb inlet, wet- bulb, and indoor dry-bulb outlet to calculate air flow. Your thoughts? Thanks again for your hard work. Praise God.
Hey Dylan and Deanmmartin, that would be depending on the refrigerant charge being accurate before checking airflow but we are usually trying to verify correct airflow before running the the refrigerant through in order to check the charge. It is nice though and thanks for bringing that up Dylan. may the Lord Bless you both, thanks a lot!
Yes the spanish paperback and spanish ebook version are both available at www.acservicetech.com/store and the paperback is also available on amazon and the ebook is also available on google play, thanks!
Dear Craig, You're doing a great job not also for professionals but also for amateurs. I have a few quick questions for you. if you answer them I would be very grateful. what is the main reason that we should not use the subcooling method fixed orifice systems? Since my condenser unit has a subcooling chart what I should do? Honestly I would like to use subcooling method for piston metering device. Thanks...
A fixed orifice will allow superheat to change based on operating conditions so we need to check with superheat. Subcooling is only checked when the TXV metering device controls the superheat and keeps it steady. You could damage your compressor by using subcooling to try to check the charge because superheat is not being monitored. Definitely would not be able to check the charge properly with subcooling for a system with a fixed orifice, thanks!
I always enjoy your videos. They are very detailed and informative. Keep up the good work. Once superheat or subcooling is adjusted, and the job is completed, is there a need to recheck the superheat or subcooling at a later date if there is no system leak? Put another way, once superheat or subcooling is adjusted, will it always fall within the superheat/subcooling chart readings if the gauges are later placed on the unit to check pressures? Thanks.
Ben these are the images we used in our book at www.acservicetech.com/ac-book and I would like to build an online course eventually too but presently we have the paperback, ebook, and quick reference cards, thanks!
Question: What do you do when the WB temperature is 60F and the outdoor DB is 100F? I live in South Florida, and those conditions are pretty typical in the summer. According to the chart, that lands on a blue X. I just went and checked the measurements of my own A/C. R22 WB=69.1F, DB(ouside)=82.2F, Low Side Pressure = 70.0 PSIG. Suction line temp= 64.0 Calculated SH = 22.4, Target should be aprox 21F. Close enough for me, but in the middle of the afternoon when the outdoor temperature goes up to 95 degrees or higher, and indoor WB is around 60F, that lines up with an X. My A/C has a fixed orifice, not a TXV. Usually around the point in the late afternoon when the "X" condition is met, I can clearly hear flashing at the piston. What prevents liquid from coming back to the compressor at those conditions? The evaporator coil has a raised manifold or "header" higher than the coil itself where the suction line is connected. My theory is that my particular evaporator coil also acts as an accumulator. Any help will be appreciated. I recently passed my EPA608, but that definitely does not make me a "know it all."
You are on the right track. That is exactly the problem with installing a system with a fixed orifice in a location that can be dry and hot. Arizona is a good example. In those scenarios, a txv should be installed to maintain superheat let alone for efficiency. An accumulator can also be used. It won't act quite like an accumulator but that design may help a little. You may be on the verge of having sat temp in the compressor. Everything you are saying, and how you are saying it is all right on. I am impressed for you just getting the EPA 608. I just got done answering about 70 comments and this one sticks out for some good knowledge for a newer tech, thanks!
@@acservicetechchannel Thanks for the answer. I am not working in the HVAC trade right now, but I have always wanted to. I have always been fascinated by it all. Currently I am in IT, and manage the chiller plant and thermal storage system at my day job.
@@acservicetechchannelIt's awesome what you are doing. I bought a whole bunch of equipment, including 5 recovery tanks, recovery machine, gauges, hoses, vacuum pump, spare parts, etc. I figure that if want to get into commercial HVAC as a tech, I have a bunch of stuff to get started. However here in Florida, starting pay for that type of work would not cover my bills. I am really good with computer programming, microcontrollers, and electronics in general. One day an opportunity may present itself. I am somewhat familiar with JCI Metasys. Again thanks for all the education!
Craig Sherman - Man, keep your job working IN the air conditioning not ON it! Just kidding of course, this is coming from a guy that works in a 90+ degree shop every summer.
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Very hard to find an AC company today with "experience, pride, and ownership". Five companies out to date, lots of money spent on service calls and still not functioning as designed. I learned HVAC in the military (long time ago). Back to school I go. Your videos are very helpful. I have ordered the book and workbook as well and look forward to them both. Hopefully, I can find what no one else seems to be able to.
I came across your refrigeration educational series when I did a search for understanding the basics. Here you provide an easy-to-understand representation of saturation and how it relates to a particular refrigerant type. I had no idea of this concept until watched this video and nearly all of my questions were answered for saturation. This is excellent for a newbie like me! Thank You!!!
This guy is a life saver for newbies. I had a hvac technician he said I had 32 degrees of superheat at the low side line and that was way off. I have piston 25 year old Trane X1200 metered system. I told him about the wet bulb, dry bulb method and he was confused.
When are you doing boot camps, ??? In Texas we need real Pros like you, the way you explain, teach, is very sharp, accurate!
I usually wait until a company contacts and wants to bring me in for a one or two day training event. I need the organization to have the equipment, location, and techs ready for the training event and for the funding for such an event. Thanks for your comment! I also don't love travelling since I have young kids and trying to be a good father and husband so this is the main way I reach techs!
I am glad you mentioned the point about taking away refresh every time you put your gauges on a system. There are ways to minimize the loss but there will still be a loss. You can tell a lot of things without putting gauges on. After hooking gauges every visit you can end up with like you said possibly a low charge. Due diligence says you should try to find the leak but there may not be a leak but when you need to add refrigerant it throws the homeowner into panic mode. OMG I have a leak!!!!!
You are right for sure, thanks Marvin!
Very clear information thank you sir u r the master
Glad you enjoyed the video John!
i was 90% sure i had a piston/orifice because i saw the nut but i wasnt able to confirm by looking behind the panel because its proving to be a real hassle getting it off..its like the panel is also connected to a bracket that also holds the evap coil..so i feel like i need 2 people..whole units going to need replacing anyway..so thanks for the info! really love your vids..i have like 30 in a playlist that i watch for hours on my study days
Great explanation. Like how you show that the superheat is a moving number. That's why I always check the superheat again after adding or remvoing refrigerant.
Absolutely, thanks!
seems like most people don't even bother with wet/dry bulb and just derive superheat from guages and temp of outside suction line...
great video, thank you. I want to do it right.
Total superheat is a massive pain in the ass. Thank God almost everything is TXV these days. But this cleared a lot up for me and I've been doing this for 10 years.
Mr. excellent..... video, I'm sure this way is a little bit easier on u and faster don't have to hook up all the equipment to show the same illustration, also you actually show more in less time, thanks again I'll be buying one of those books
Thanks a lot Ali Baba, the work on the front end is less but the back end is much more on these videos, thanks!
I already bought your ebook, you changed my world man !! Thank you !
Start Thinking on doing one book, for basics, there some out there but they are like puzzles, like they don't have clear scenarios, or context, hope you do one day,!!!
Hey Silver Shark, I mention the troubleshooting in this book but the beginning chapters are for beginners. The content in this book is exactly what I would teach a new student to bring the tech from nothing to troubleshooting. Remember this is 229 pages long and the EPA 608 is integrated in the book, thanks!
Like your videos always watch them when you release a new one.
Just realized when you mentioned having to walk back in the building and then back outside again to check your wet bulb and your dry bulb. all temperatures as they change waste a lot of time and Time is money. Highly recommend Fieldpiece wireless gauges with the measure quick app. Or at least the Fieldpiece app. When every minute from morning to night is billable hours and every day you have more work than you can possibly get done. Those few minutes wasted on every job walking in and out of the building add up by the end of the day and that could be one lost job every day in wasted time just to check measurements when it could’ve been done through Bluetooth gauges and you never had to stand up once to go check another gauge. At $150-$200 plus an hour That could add up to one lost job every day for the entire year. That adds up to the total price of a new service van or service truck just by losing that one daily hour. Think about it
I agree, have you checked out my total superheat video using the SMAN 460 and wireless wb sensor and wireless outdoor temp reader to automatically calculate target superheat. I also did a video using the probe set, thanks!
Awsome video. Do i have to shut off the condenser when checking the indoor wet bulb? Thks
For wet bulb temp, Essentially, Digital psychrometer as close as you can to the evaporator coil? If you got to drill a small 3/8s holes, as long as you get your psychrometer as close to the evaporator coil, correct? Thank you your videos are incredibly well put together!!
You should stay back a little bit if possible anywhere 6 inches to 2ft upstream of the coil or the psychrometer will measure a higher wb if its right next to the evap coil, thanks
Great video, but i cannot understand what is the right pressure when machinr is on
How can you tell what type of metering device your A/C has without removing the evaporator coil?
My evap coil was installed by some earlier company or service tech. There are only two small holes in the plenum and they're filled with putty. I don't want to unsolder the evap coil just to see what kind it is.
This is the best, so many hacks out there SP's >.2 over under charged systems, duct leaks, cost an xtra 1k year in kwh cost.
You need to be educated for sure, thanks AD!
Make sure all dampers and registers are open, as well as nothing blocking the return grilles
Yes absolutely, thanks!
Thx Craig I'm really enjoying your Hvac videos,Service bk,Work bk as well as your three Quick guides templates. Do u hv any plans for heat systems (Books)? thanks again!
Thanks for the video. It would b nice if there was a cheat sheet. Kind of like a pt chart
I think that is how all of those false rules of thumbs were created by trying to find a short cut but really we need to see that superheat and subcooling to tell how the system charge is doing but I agree it would be nice, thanks!
Thank you for all of your and sharing your knowledge
Glad to help Scott!
excellent videos, put out some new stuff...i always look for the latest videos, haven't seen any new stuff yet..
What type of content are you referring to and desiring to see?
You mentioned before that having to much superheat is an indication of a bad TXV or a restriction in the line so having high sub cooling is the same indication ? Thanks for your help and happy new year
Do you have a video on using the anemometer ?
Not to date but I would like to do some airflow videos in the future, thanks!
Thank you.
You're welcome!
Thanks for all the knowledge shared. I've purchased both cant wait to get my hard copy.
Thanks and let me know what you think of the book after reading it!
May I ask a question, if vapor pumps can’t compress liquid....why charge equipment in the liquid form? Meaning We charge 410 or puron equipment in liquid
This is to keep the 50% 50% mixture of R-410a consistent as it leaves the bottle. plus we can meter it in slowly so the refrigerant has a chance to flash before it goes in. R-410A is made up of R-125 and R-32 thanks!
Very Good video, !!! Very explicit, very pro, technical, and I like the computer screen for clear example, you getting better!
Thanks Silver Shark, glad you enjoyed this layout!
I love this channel. You are explaining very clearly.
One question: Can I use a standard digital temperature reader to measure the inside (WB) temperature? Sure this will not the correct temperature, but I can get only a standard digital temperature reader in this country. Can I do anything to bring it to a WB value?
Thanks a lot!
You can add a small wet sock over the temp sensor to measure the wb temp, thanks
You know I really had no idea about these procedures and practices such as the superheat and subcooling methods. I was it interested in what I could do to make my refrigeration system cooler and more efficient. Well now I'm hooked on desire to learn more and you certainly cover a lot of information in a easy way to follow along! So before this highly scientific method, how did the technician determine whether or not the system was properly charged? Thank you for the great video!
The superheat of HBP and LBP are the same ? Can i use the target superheat chart in LBP ?
Thank you guys, I will get the book.
Thanks Daniel and let me know what you think of it after reading it, thanks!
I really like your video's. I learned the old school way and the tools and information is way better today. Many thanks for the great video's.
Thanks a lot Waterman!
Thanks!
Thank you very much Doug!!!
A way to stop losing charge when checking a system every year I think it's best to preload liquid/service(yellow) hose with the correct refrigerant.
With normal size hoses that should hold roughly 1.5 oz.. Should be enough to offset any loss. Hopefully ppl are bleeding liquid line back in after disconnecting.
Yes hopefully techs are doing the proper disconnect procedure to move the liquid refrigerant back into the vapor line. If they are then they wouldn't be loosing but a little vapor so that would be much less than 1.5oz and they could also use test probes or test gauges without hoses which will loose less but I am with ya, at some point you need to add some back in, thanks!
Good job
I got a question for you, if you see this and you reply I would appreciate it .
There is a 3 ton heat pump ,with a 14inch round duck and 6vents ,and 20/20 return grill it’s a commercial place ,
I got DT 26
76F return and 50F supply air
Low side pasig it’s 125, line temp it’s 42 degree S.H it’s 11
High side it’s 300 psig line temp 95 degree F. S.C it’s 4,3
And it’s with a piston not Txv.
Personally I think there it’s small duck size and not enough vents ,what’s your thought on this ?
Thank you for quick response just ordered one
Thanks Pete!
Going to get you're ebook and service book
Thanks and please let me know what you think of it after reading, thanks!
Excellent explanation, I would like to know what is the average value for the superheat that indicates a refrigerant charge correctly
I didn't catch the formula you used to determine target superheat bases on indoor wetbulb and outdoor drybulb.
You can use a target superheat chart or a formula such as ((3xwb)-80-db)/2. I have all of this laid out in the book along with what to do when the target lands on the x instead of a number in a dry climate scenario, thanks!
Hi, i bought E-Book few months ago and i really like it, now i'm thinking to get paperback version. My question is: will you ship it to canada ? and what's the shipping cost? thanks!
Hey Jeff, yes we ship to Canada fairly frequently for paperback purchases on our website www.acservicetech.com/store and there is an international automatic shipping calculator there once you enter your address. Any questions, just email me at info@acservicetech.com thanks!
Can you do a video a cfm at the supply registers in the house?!
I certainly would like to do one in the future, thanks for the reminder Lance!
Is there a video on the temperature rise method to set air flow, in cooling and hearing mode, will there be a book for furnaces as well ?
I am planning on doing a video on temp rise to determine airflow. I would love to do a furnace book but I have a few other resources to build before that, thanks!
AC Service Tech LLC that’s awesome, will definitely keep a look out for the book, also you think you would be doing any videos on communicating ??
Great job and video
Glad you enjoyed it
How do you figure target superheat
Sir how can I get the exact superheat of LBP ?
By the way, great videos - and thanks for everything you do. I am going to order your book right now.
Thanks a lot Craig!
Can I use regular thermometer to find the wet bulb temp and dry bulb temperature?
You should use a digital temp meter such as the st4 for dry bulb temp readings. Wet bulb can be taken with a psychrometer or a method discussed in this video. There is a temp sensor with a cloth over it for sale in the store at www.amazon.com/shop/acservicetech thanks! nnth-cam.com/video/PIYJBaOdGx4/w-d-xo.html
simple question, but not mentioned. when sampling indoor WB temp. with fan running or not? static temp vs. a wind chill effect.
Wb temp is while the unit is running so that you know the target superheat at the same time that you are measuring your actual total superheat, thanks!
Hmm. Thanks for the reply. I'll read up on WB. I get that it's to be taken as close to the same time a s possible. Also it measures the airs capacity to absorb moisture. But wouldn't it give a different reading depending on the velocity of the air? Higher velocity = faster evaporation. Also, as the saturation is occurring in a closed system with no direct contact with house air, why is it relevant? Cool temperature to condense maximum latent heat?
@@Spencerbuildsit A high wb temp air crossing the evap coil is a higher heat load for the refrigerant to absorb since the coil is meant to condense and then reject the condensate out of the building as well as for the refrigerant to move heat out of the building. This work is done to reduce the humidity and while this is happening you will see a lower delta t especially in the case of a fixed orifice. The delta t is low because the superheat is high due to the added humidity that is getting condensed. thanks!
Got it! So the calculated SH takes the latent heat into account. Wondering why leave any SH on the table? How about minimizing the SH, then have a liquid sensor that returns liquid to the top of the evaporator, or a small evaporator, as a anti slugging device? How about using flat plate heat exchangers as evaporator in air to water heat exchangers? I have one that is useless as it needs a control board. DC inverted driven air to water heat pump. Haven't found much info. Learning so much from your contributions. Thank you. Will you be doing a few videos on design? Air handler selection and matching?. Latent vs specific heat and how to design for dehumidification? Static pressure and duct design? So many questions. Thanks for sharing
Great video
Glad to help!
This is interesting
Have a quick question. Does your book go into the diagnostics of 2 stage condensing units? Or how to differentiate wiring of a 2 stage versus a single stage?
I noticed in one of your tutorials about furnace and thermostat wiring, you have no explanation about Y1 and Y2 wiring.
Would be nice if ducting and manual D are explained in your new book. That I’m guessing is not in the book?
This book is 229 pages and focuses on refrigerants and procedures used to prepare a system for refrigerant, how the systems work, charging, troubleshooting, and airflow testing. The entire outline including sections and subsections are found at the website. This one is not about the electrical wiring. Those wiring diagrams were just focusing on single speed units and units that control speeds at the control board such as for heating, thanks!
AC Service Tech LLC - never ever a criticism of your videos or instruction. Just a shame since you are such a great teacher to exclude those important aspects of HVAC.
Maybe in your next book.
Until then, thanks for all your hard work.
@@BartSimpson-nr1dy I had to stop somewhere and 229 pages is considerable as it is, otherwise I would never had completed it. That was a 3 year project. We are working on the workbook now for schools for this book, thanks!
Excelente video !!! Book versión español ?gracias saludos
Sergio, we don't have the book translated yet but we are planning to in the future, thanks!
@@acservicetechchannel Good, once it gets fully transladed i'm planning on buying it. Cheers!
We now have a Spanish version Ebook
www.acservicetech.com
@@acservicetechchannel excelente, ya lo compre ,muchas gracias por la vercion en español
Love your videos.
Thanks a lot Yo-Pops!
Thanks for the video,have really learned a lot and gained much knowledge.Hope you could do one on where the airflow of an indoor coil/or an air handling unit.using an avenometre could be demonstrated. Regards from India. Am in the process of buying ur book.
Thanks Kenneth, I would like to do some airflow examples in the future, thanks!
Ok, kind of in depth question about having high head pressure on a 2.5 ton split system with 22. My suction is 84 liquid is 94 degrees. My total sub is 43 and super is 43. I have ran down all the troubleshooting in your book and cant seem to find the culprit. Did pump down and checked the orfice, purged with nitrogen and if it was under charged my sub would be over 25.. I can give link to my fieldpiece check and charge and manifold data l9gger
thank you for shared
Thanks ZE!
Hi, can i use this method for residential split unit ductless system?
How long do you recommend placing your wet bulb in airflow to get an accurate reading?
It doesn't take very long, usually 30 seconds to 1 minute per reading just until it stabilizes, thanks!
I have a system which has TXV on it. The sub cooling is 13 and the superheat is 32. When the system reaches the set temperature and the system is off, I can hear hissing sound from inside of evaporator for a couple of seconds, then I can hear another different sound like water flowing away from evaporator to outside condenser unit along the lines (not sure suction line or liquid line). The hissing sound last around 4 seconds and the water flowing sound last around 2 seconds. Should I replace the TXV? Thank you so much
Superheat is high, possible restriction on liquid line, low airflow or low on charge. Not enough refrigerant in liquid line near txv making gurgling sound look like water flowing. Probably that sound is here all the time when system running but maybe you not hear bcz of blower motor noise. What is pressures on low and high?
Superhydrophobic, That is the system pressures equalizing while the system is off. That is normal depending on the type of txv. There is no problem with that. The superheat does sound a little high though. Make sure to recheck that again and also check the delta T. If the superheat is high and your delta T is low then that could be a partial liquid line restriction. That was why Mister was asking what your low and high side pressures were, thanks
Wheres your vaporizer Lol jk 🤣 Your the man I love all your tutorials!!
Yeah Yeah, ha ha. That was a good one! Thanks Anthony!!!
You're the best man 👌
I appreciate that!
Good morning Craig. In reference to air flow, what do you think of the way "emerson check a charge" recommends checking air flow? They take indoor dry-bulb inlet, wet- bulb, and indoor dry-bulb outlet to calculate air flow. Your thoughts? Thanks again for your hard work. Praise God.
I use the same app. I like it to double check myself. Its a good way to check for correct airflow without an anemometer
Hey Dylan and Deanmmartin, that would be depending on the refrigerant charge being accurate before checking airflow but we are usually trying to verify correct airflow before running the the refrigerant through in order to check the charge. It is nice though and thanks for bringing that up Dylan. may the Lord Bless you both, thanks a lot!
How do u charge a orifice system
I want a book
Good Morning,
Thank you for your interest! To purchase a book, you can go right to our website www.acservicetech.com
thank's partner for sharing!!!!!
Glad to help Jimbola77!
How you measure if it's a mini split where it doesn't have a high side port?
And for what reason do you need the high side port on a minisplit?
Can the instructions and principles in this video apply to an R22 system?
Yes, any refrigerant.
hello do you have your book in spanish?
Yes absolutely! check out our spanish book at acservicetech.com/ac-book
Hi ,is this book available in Español.
Yes the spanish paperback and spanish ebook version are both available at www.acservicetech.com/store and the paperback is also available on amazon and the ebook is also available on google play, thanks!
@@acservicetechchannel thanks.
عمل رائع اتمنى لك النجاح
شكرا جزيلا!
Dear Craig, You're doing a great job not also for professionals but also for amateurs. I have a few quick questions for you. if you answer them I would be very grateful. what is the main reason that we should not use the subcooling method fixed orifice systems? Since my condenser unit has a subcooling chart what I should do? Honestly I would like to use subcooling method for piston metering device. Thanks...
A fixed orifice will allow superheat to change based on operating conditions so we need to check with superheat. Subcooling is only checked when the TXV metering device controls the superheat and keeps it steady. You could damage your compressor by using subcooling to try to check the charge because superheat is not being monitored. Definitely would not be able to check the charge properly with subcooling for a system with a fixed orifice, thanks!
I always enjoy your videos. They are very detailed and informative. Keep up the good work. Once superheat or subcooling is adjusted, and the job is completed, is there a need to recheck the superheat or subcooling at a later date if there is no system leak? Put another way, once superheat or subcooling is adjusted, will it always fall within the superheat/subcooling chart readings if the gauges are later placed on the unit to check pressures? Thanks.
Yes they should remain good unless there is a leak, thanks!
is that a simulator? what is it called and where can i get it?
Ben these are the images we used in our book at www.acservicetech.com/ac-book and I would like to build an online course eventually too but presently we have the paperback, ebook, and quick reference cards, thanks!
Question: What do you do when the WB temperature is 60F and the outdoor DB is 100F? I live in South Florida, and those conditions are pretty typical in the summer. According to the chart, that lands on a blue X. I just went and checked the measurements of my own A/C. R22 WB=69.1F, DB(ouside)=82.2F, Low Side Pressure = 70.0 PSIG. Suction line temp= 64.0 Calculated SH = 22.4, Target should be aprox 21F. Close enough for me, but in the middle of the afternoon when the outdoor temperature goes up to 95 degrees or higher, and indoor WB is around 60F, that lines up with an X. My A/C has a fixed orifice, not a TXV. Usually around the point in the late afternoon when the "X" condition is met, I can clearly hear flashing at the piston. What prevents liquid from coming back to the compressor at those conditions? The evaporator coil has a raised manifold or "header" higher than the coil itself where the suction line is connected. My theory is that my particular evaporator coil also acts as an accumulator. Any help will be appreciated. I recently passed my EPA608, but that definitely does not make me a "know it all."
You are on the right track. That is exactly the problem with installing a system with a fixed orifice in a location that can be dry and hot. Arizona is a good example. In those scenarios, a txv should be installed to maintain superheat let alone for efficiency. An accumulator can also be used. It won't act quite like an accumulator but that design may help a little. You may be on the verge of having sat temp in the compressor. Everything you are saying, and how you are saying it is all right on. I am impressed for you just getting the EPA 608. I just got done answering about 70 comments and this one sticks out for some good knowledge for a newer tech, thanks!
@@acservicetechchannel Thanks for the answer. I am not working in the HVAC trade right now, but I have always wanted to. I have always been fascinated by it all. Currently I am in IT, and manage the chiller plant and thermal storage system at my day job.
@@Craig1967 got ya well that explains it probably processing the thoughts of how the systems all work, anyway great thoughts!
@@acservicetechchannelIt's awesome what you are doing. I bought a whole bunch of equipment, including 5 recovery tanks, recovery machine, gauges, hoses, vacuum pump, spare parts, etc. I figure that if want to get into commercial HVAC as a tech, I have a bunch of stuff to get started. However here in Florida, starting pay for that type of work would not cover my bills. I am really good with computer programming, microcontrollers, and electronics in general. One day an opportunity may present itself. I am somewhat familiar with JCI Metasys. Again thanks for all the education!
Craig Sherman - Man, keep your job working IN the air conditioning not ON it!
Just kidding of course, this is coming from a guy that works in a 90+ degree shop every summer.
Great video