@@AirConAcademy you already answered back in the course. Back in those days I was a rookie. Your course was the first I have enrolled, now i'm doing great with My business put into practice everything I have learned. Who would Say that 15 bucks inverted in a course would put a better plate to my table. God bless you Julio
@@albertogerman1075 I am so glad to hear you are doing well!!! that make me want to do this even more!!! Thank you so much for you and may God bless you and your family also!!! and thanks for watching!!!
Julio thank you very much for your teaching we really appreciate it you , we learned allot from all your teaching videos , stay safe tc we need you here so we can lean more, God bless you and all your family, thanks again from Boise Idaho
From Boise Idaho? Thank you for letting me know! And yes, I hope to get some more videos out soon! Thank you for watching and thank you for your comments!
This is a great tutorial, it provided a ton of information to get me familiarize with VRFs and how to relate the refrigeration cycle to it. Great work Julio!!
Ha ha! I can see that. Unfortunately, I don't have time in the videos to talk about so many things. But yes! They are finding ways of adjusting to speed on motors and fans (liked with ECM Motors) to give you the correct cooling capacity or dehumidification. Thank you for bringing that up. Like I tell the guys in class., Technology is crying every day and basically I putting mini VFD's in everything these days. But thank you for watching! And thank you for sending your message in. And thank you for watching!
You are a great teacher! I have now understood more than I have ever known. Please, keep more coming especially troubleshooting multi v system compressors. I was challenged recently by Toshiba multi v outdoor unit breakdown with error code= H02.
I am so glad to hear I could help!!! That is why I am doing this. There are a lot of people that do not have things explained in an easy to understand manner. Thank you for your comment!!! I will see what I can do about the other videos!!!
Julio, excellent overview of the subject matter. Clear and concise. I have been an instructor of gas technicians for many years however I would be honoured to be a student of yours. Take care.
VRF, the future of HVAC, paired with an ERV. Game over. And my sheet metal union is confused about why I wanted to switch to a service tech. Here in Seattle, sheet metal and hvac service are in the same union but separate
Yes, the industry is changing a lot. I recently put a mini split in a cabin that should have only had a 1 ton unit. I put a 2 1/2 unit in there with three evaporators. This gave them the option of having as much heat and or cooling as they wanted. Now that the temperatures have been down in the teens they have had enough heating to keep them comfortable and they are so extremely happy! I think if we are going to stay in this field we need to sharpen up on these PRFs because like I said they will be the future of this industry.! Thanks for watching!
very good information on VRF. I think only DAIKEN is using this system in their machines. Please show this machines working and also charging this system as it is looking more complicated compare to conventional machines. Thanks.
Your a man that knows his profession and it's tech very well. Wish you were in GA. I've been getting quotes on converting from forced air to whole home ductless. Honestly, I don't think any of them really understand what they are selling or how to best configure.
tellMeSomething thank you very much. Sometimes I wish I was in Georgia and not in Northern Virginia! A lot of people here are doing the same. Converting to the ductless mini split. A customer wanted the mini-split in their 4 level townhouse in Washington DC VA not too long ago. We made it all work and they have been very happy with it. It was a lot of work running the lines through the walls and installing the boxes at each level so we could branch off to different indoor units. Good luck out there. And Thanks again!
I would like too see more of your videos in vrf systems. With its receiver tank,thermistor location and so on in vrf systems. I got confused in the last part because when one of the inside unit is satisfied is sends a signal to close the eev in the branch box . And when all unit are satisfied it pump Down and close all eev in the branch box. I am just saying. Willing to learn more about vrf. Awesome video.
I agree that increase in evaporator size will lead to higher suction pressure but it is confusing when you state that as a reason the temperature of air leaving the evaporator will go up (~ 5:00 min). If the air temperature and air flow entering the evaporator is the same, the suction pressure would increase slightly if the evaporator is sized bigger without impacting the outlet air temperature. I think you meant if the air flow rate increased and the evaporator is sized bigger, right? I think the capacity will roughly be the same and air outlet temperature would be higher leading to an increase of suction pressure
Thank you for your comments. When the size of the evaporator is increased it is going to generate more gas than the compressor is designed to handle (because it is a single speed compressor) and because of that, the pressure in the low side will go up. When the suction pressure goes up the evaporator temperature will also increase. One thing to keep in mind is that the greater the temperature difference the greater the heat transfer rate is going to be. If the evaporator temperature goes up because the suction pressure increased, then there will be less temperature difference and it will transfer less heat, increasing the temperature of the supply air temperature. The other thing I was saying in the video was that by increasing the speed of the compressor we can drop the suction pressure therefore lowering the evaporator temperature and creating a higher temperature difference between the evaporator and the return air temperature increasing the heat transfer rate. I hope this makes sense. Thank you for your message!!!
This was a great video! Made things very clear on the basics of how these systems work. I'm working on a project with a particular (popular) manufacturer of these systems. One question that seems unanswered is what happens if your indoor units have a total capacity that's larger than your outdoor unit? The project is for 3 or 4 zones but because the smallest indoor units are only available as 9,000 BTU/hr coils, we wind up being way over capacity for the actual peak load from the manual J for some zones. We'd like to size the outdoor unit for the peak demand of the whole system, but that means it will not be able to keep up with peak demand capacity of the indoor units...doubtful that all the indoor units would be calling for full load all at once very often if ever.
Matthew Hester Thank you, sounds like a tough situation. You are correct a lot of times the indoor units will not be all on so you will not fully work the outdoor unit. But of course we cannot depend on this. Fortunately I have noticed that some minisplits will do more cooling and if it’s a heat pump more heating then what it is rated for. With mini splits are usually try to oversize them slightly because of the ability of adjusting the motor speed and the compressor speed we don’t have to worry about the same issues that we would have on a straight split AC unit. Good luck with this issue but like I said I usually try to just slightly oversized them so that I don’t have to worry about this. Thank you for your comment.
very good information and great explanation with pictures. would you be able to explain the three pipe VRF systems. I know they have one suction and liquid line in addition to another line can be neither nor. Not sure how it works, when three pipes going to branch selector boxes and the room zoning one called for heating and the other one for cooling. much appreciated.
A quick explanation would be that the third line would be the discharge line from the compressor. This way at the box/manifold they can heat a room while simultaneously cooling other rooms. So they are turning an indoor unit in to a condenser to heat the room. I hope this explains your question. Good luck!
At 7:18 why would suction pressure go up? I’m assuming liquid line would drop because the flow is going to 2 evaporators but would thought suction would go down also
Thank you for the question and for letting me know the time frame you were talking about. One thing I was talking about there is that if we did not have a variable speed compressor. Then you would be feeding the compressor with the gas for two suction lines making that pressure go up, you would be feeding the evaporators, or the liquid lines I should say from one liquid line so that would drop pressure. With a variable speed motor/compressor the compressor would speed up/Run faster bring the head pressure up and the suction pressure down so that you could maintain that 40°F evaporator. I hope this explains it. Thank you for your message and for watching!
If it is not running on the auto start, it could be that one of the safeties has it out. Make sure you check all of your safeties and maybe look for a loose wire. With the small amount of information it is hard for me to really be able to tell you what could be wrong. I hope this helps.
Thank you for another good one. Questions: Why do we have these? Where are they installed,commercial or residential, and why? If residential, are they replacing "plain old" split systems?
Do you know any books about parallel rack system or super market refrigeration. I would really appreciate it if you get back to me on that one. I asked around but no one helped me on that.
Very well explained. What if I have Dx system 1- 1 (5tr) and VRF system (5Tr) which is also DX. Both type of system has inverter compressors but why VRF system piping length is allowed upto 100mtr and normal DX system upto 15mtrs only ?
The inverter compressor is great because they can adjust the speed and have it operate at different capacities. Meaning that they can dehumidify only, or they can call in dehumidify by adjusting to speed. Because of that they can have a longer line set because the compressor can operate at a faster speed making up the capacity that a regular split phase motor cannot do. I hope this makes sense. Sorry it took me so long to answer.
@@AirConAcademy thank you for responding. How if the normal split unit have inverter compressors ? Now a days all Dx units are upgraded with inverter compressors but still piping length is specified upto 15mtr-20mtrs only
@@siddharthvadangar6827 from what you're saying this all depends on the type of unit. A lot of units that I have seen do not have inverter motors. If you have a VRF system then the indoor unit will also be inverter with possibly an electronica expansion valve which will allow you to use the longer refrigerant lines. It is the combination of all of the electronics that allows you to go to a longer length of lines.
Thank you so much! Love you right back from the US! I'm glad you like the video, and I hope you learn a lot! It makes me happy to know someone in Pakistan likes the videos! Thank you for watching!
Great video and a great teacher. Can you descripe the controll of the compressor a little bit more in detail? You said, that the speed of the compressor depends on the active units. So, is there a related speed for every amount of active units? Or is the compressor controlled by the suction pressure?
The speed of the compressor is controlled by the demand. With these new units they have sensors and those sensors will tell the compressor what it needs to be doing by converting the pressure to temperature. Of course there are different types of units so one may be slightly different than the other asked how they control the speed of the compressor. I'm sorry I cannot be more specific. I'm glad you like the video! Thank you!
Is there a video for how does the control box work? Is it heat exchange or refrigerant in and out when one of the evaporators needs it? What is the best refrigerant to use in this system? Thanks boss you’re amazing 👍🏽👍🏽
Thank you!!! these boxes are just refrigerant in and refrigerant out. They have solenoids inside that will direct the flow of refrigerant to which ever evaporator is calling for cooling. For right now it is mostly R410a that is being used in the systems. Soon 410a is going to be replaced and we will see other refrigerants in these systems. At the moment it is hard to know exactly which refrigerant will take the place of 410a, it may be 454b? but we are not sure at the moment. thank you for your comment!!!
That is a tough question to answer. There are a lot of variables to think about. I just recently put a 2 1/2 ton unit in a cabin that should have only needed a 1 ton. The insulation is not that good and the windows were awful. I did a 1 ton on one side of the living room, another 1 ton on the other side and a half ton in the dining room/kitchen area. Because of the different units they can control how much cooling or heating they will be needing. This way they can dehumidify and cool as needed. Also in the winter time they will have plenty of heat. What you gave me might work but it all depends on how big the rooms are and how the evaporators will be placed. I wish I could be more specific but there are a lot of variables that go into something like this. You are looking at about a 3 1/2 ton unit but with these VRF units you can also set them to dehumidify so that might be enough?
@@AirConAcademy Julio the reason I asked this question is the contractor for the project had installed 2 ton condensor for all the units and many had condensation problems at the indoor air handlers. The LG company on island did not carry the indoor air handlers (special order) so we went with another company that completely changed out 2 unit's systems with a 4 ton condensor with no issues. We had the LG company upgrade the condensor and they installed a 3 ton which did not fix the condensation issue. Mahalo for your tutorial and reply. We live in Guam which is high humidity and these apartment units are only 1.5 years old.
@@brucewilliams1924 when you say that they were having condensation issues, what do you mean? Does it mean that it was generating too much condensate? Was the condensate leaking out of the hanging wall units? Was it not dehumidifying? I am trying to understand exactly what your issues are to see if I can help. I'm sorry I'm asking so many questions. I was thinking that, if you have condensate leaking out of the air handler's check the drain line. I have seen it that when the drain line is not completely straight and at a downward angle the condensate will back up into the air handling unit that is hanging on the wall. This will cause the condensate to come out of the air handling unit. If you are having an issue with condensate coming out of the unit please check your drains even if it has the smallest dip in it it will back up. These units do not use traps so that drain must be straight and without any low spots in it. Please let me know if this helps and what other problems it is that you're having. My son was stationed in Guam for three years and he used to tell me how humid it was there. So I am thinking you have too much humidity.
@@AirConAcademy Julio the condensation is at the air handler. The drains are not plugged. Per the other AC company that replaced 2 units the condensor is too small, they are using 48BTU, where as the original condensors are 24BTU.
I’m an old timer. Been in sales for a while so when I left the field VRF wasn’t really a thing to concern myself with. I have sold them but it’s just really a high-level view is all I need for sales to be honest
I go and help people a lot of times. I retires a few years ago and VRF's were not around when I was doing more work. BUT I still like to learn as much as I can so I can pass it on. I hope you enjoy the videos!!!
pls need help ! i have Samsung 48k vrf outdoor unit pressure is good , NO ERRO CODES , i have 2 indoor units 2x24k ducted , both indoor units workd fine for last couple years ! but last 2 weeks im having problem with only 1 indoor unit it blows 78 deegress on the cool setting 64 degrees ( while other indoor working fine 64 deegres , when i shutoff good working indoor unit my outdoor compressor start freezing up, can you pls explain what it is the issue can be? I try to call samsung customer serves no help on they behave
I am not sure if I understand, I think you're saying that the one evaporator works well when you shut off the other one? Also I think you're saying that the compressor starts to freeze when you have that one evaporator working? Or is it on both when it freezes? I would suggest making sure you have enough refrigerant, make sure that you have plenty of sub cooling because that could be starving one evaporator. If that is not it you might have a restriction on that one evaporator that's not working right. It may have to be replaced. I would first start by checking my charge and making sure I have enough refrigerant, and do that by making sure you have plenty of sub cooling. I would say 15 to 20° F of sub cooling. I hope this helps. Good luck!
@@AirConAcademy when I shut off one of the working unit & let bad unit running only then compressor freeze, but when both units are running no problem, but ones again only 1 indoor unit cooling, freon good pressure
@@Ray-wr2wr have you been able to check the superheat on that one unit when the compressor is freezing? Also have you checked the airflow and that one unit? If you have too much refrigerant going through that unit, It is possible that the compressor would freeze? If you don't have enough airflow I could also affect it. Is that fan working like it should?
On most of these units they all have to run in the same mode, either the heating or the cooling. If you have three lines going from your outdoor unit to distribution box then yes, they can each run independently of each other. But you would have to purchase a unit that is specifically made to do that. And yes, those work very well! Thank you for watching!
So I’m doing a job right now that has 25 units. But 2 of those units have to run cooling all year (electrical rooms). Those 2 units have their own outdoor units, while the rest of the VRF system (the other 23 units) run off of two massive outdoor units
Hello sir, Your videos are very helpful to understand the concepts. I have been working as service engineer in VRF system. Could you please help me what could be the possible reason of higher temperature of liquid refrigerant entering into evaporator?
Typically when you have high temperature of liquid refrigerant entering the evaporator that would mean that you do not have enough sub cooling. That a lot of times means that you are low on refrigerant and you need to add more refrigerant. Of course I do not know the type of system you're working on but if you have enough refrigerant in the system the sub cooling will increase and your units will work more efficiently. I hope this helps.
When you install that control box you mentioned, what would be the best optimal location to place: nearest place to all evaporators or nearest place to the condenser (outdoor) unit?
So it’s been 8 months and no ones answered you, so I’ll answer, honestly, I’ve run 120 ft runs to a branch box and it didn’t matter. So that answer is, it doesn’t matter since it’s a pressurized system, for the most part, the distance doesn’t matter
Thank you for the explanation! I have a VRF system Of Toshiba The upper units in the rooms produce ice while operating on cooling (It can be one unit or several units together) What could be the reason?
My guess would be that the unit may be low on refrigerant. You may need to add refrigerant to it because of the length of the lines add or you may have a leak. There are a lot of variables but I would be my first guess.
so, if the Compressor speed slows down, it will just make the AC Cools less, and not something dangerous, because the expansion valve is the one adjusting the point where the refrigerant is superheated? so we could attach the Compressor to any energy source? because I'm thinking if we could make a infra-subwoofer doubles as a compressor to cool the amplifier making the amplifier still *cool while quiet*
On these VRF's sometimes they will adjust the speed of the compressor and the fan at the same time. if you are using a TXV the TXV will make sure that you do not flood the compressor. By slowing the compressor down you're such impress will increase and do less cooling. I hope this helps! Thank you for watching!
If we were to charge this system would I have to take superheat readings at each individual evaporator or is it okay taking it at the suction line 'systemSuperheat'
With the systems typically you add refrigerant according to the length of pipe you are adding. Because the metering devices in these systems adjust you would not do a superheat reading. You would do sub cooling but the manufacturers want you to weigh the charge in according to the length of pipe.
Hi! I am sorry to say that I do not have a class on VRF. I really do not know who might have one online. I sure wish I could help you! All I have is the videos that you saw online for now. Thank you for watching, and good luck!
Sir please tell me 2 ton rotary and 2 ton reciprocating or 2 ton screw compressors efficiency same? They are working and will give same result. Can I replace ich and another type comp. Not same example can i change hermetic except screw compressor compressor ?
as long as you are removing a 2 ton and putting in a 2 ton, or taking out a 4 ton and replacing a 4 ton. it should not matter and it has not mattered in the past replacing a reciprocating with a scroll. I hope this helps
Very good question!!!! VRF (Variable Refrigerant Flow), VRV (Variable Refrigerant Volume and DVMs are basically the same. They will control the flow of refrigerant so you can have several mini-splits doing or performing what it is needed. With a DVMs you can cool one room and heat another room with the same outdoor unit. In most mini-splits you can only cool or heat with all of the units at the same time you cannot have them independently of each other like with Some of these DVMs.
Do units have sensors in them and they are actually sensing the pressure, plus the communication cable that goes from the evaporator unit/section to the condenser section will communicate all of that plus the the branch box or the branch distribution box is what will be controlling the flow of refrigerant. Thank you for watching and thank you for your comments!
ohhh that is hard to say. In some places you only need a 2 ton compressor for a small space and at other places you may need a 5 ton compressor or unit for a larger space. We have to do a heat low calculation to see what the capacity of the compressor and or the system needs to be. I hope this helped. Thank you
Phew... To paraphrase The Wizard of Oz, "We're not in residential anymore." I thought you were going to talk about TXVs... they're "variable refrigerant flow" aren't they? (Lot to learn here. Don't mind me - for us residential students, this is like county boys going to the city for the first time. ) Thanks for making! PS: I have to wonder about the speed of the condenser fan - is that variable too, like the compressor? (Lot to learn here. Thanks for an excellent, "user friendly" intro to the subject.) Here's how VRFs are talked about "out in the market": th-cam.com/video/vie4kHN_iYU/w-d-xo.html Have to start a separate playlist for this, HVAC - VRF. .
Thank you so much for your comments. And with these units yes everything is variable. The indoor fan, the outdoor fan, the compressor and sometimes the metering device is an electronica expansion valve. These units are a totally different animal as you stated, and one of your funny comments that you made! Yes, there is a lot to learn and a lot to say about them I just wish I had the time to make more of these videos. Thank you for sending that link!
You can have both heating and cooling VRF system simultaneously. So what that means is Air handler a.k.a. cassette can be heating while another one is cooling.The systems can be huge one condenser to 60 to 70 evaporators
@@rogernevez5187 I am not too familiar with Brazils economy but I have had students that have gone back to the country were they were from and started their own business there. This industry will do well everywhere as long as the government does not tax you to death and you can easily start a business.
so, if the Compressor speed slows down, it will just make the AC Cools less, and not something dangerous, because the expansion valve is the one adjusting the point where the refrigerant is superheated? so we could attach the Compressor to any energy source? because I'm thinking if we could make a infra-subwoofer doubles as a compressor to cool the amplifier making the amplifier still *cold while quiet* **bass**
Julio is awesome. I took one course with him and every single question I had, julio would get back to me with a answer.
Hi I recognize your name!!!
I hope all is well what is your question?
@@AirConAcademy you already answered back in the course. Back in those days I was a rookie. Your course was the first I have enrolled, now i'm doing great with My business put into practice everything I have learned. Who would Say that 15 bucks inverted in a course would put a better plate to my table. God bless you Julio
@@albertogerman1075 I am so glad to hear you are doing well!!! that make me want to do this even more!!! Thank you so much for you and may God bless you and your family also!!! and thanks for watching!!!
Any see that he is writing backwards, as well as writing with both hands? That's skill!
ha ha Thanks I love to teach what can I say!!! And thank you for watching!
i knew when I saw the batman shirt that this was going to be good. thanks
lol well? Thank you very much! I'm glad you liked it LOL
Best video on VRF, thank you
Thank you so much! Very kind of you and thank you for watching!
You are the best Mr Hulio.
Thank you so much!!!!
Julio thank you very much for your teaching we really appreciate it you , we learned allot from all your teaching videos , stay safe tc we need you here so we can lean more, God bless you and all your family, thanks again from Boise Idaho
From Boise Idaho? Thank you for letting me know! And yes, I hope to get some more videos out soon! Thank you for watching and thank you for your comments!
This is a great tutorial, it provided a ton of information to get me familiarize with VRFs and how to relate the refrigeration cycle to it. Great work Julio!!
Thank YOU!!!!!
*My heat pump is offended at what you said* @6:40
My unit is single phase here at home, VFD runs a 3 phase compressor 😁
And it has an ECM for the ODM
Ha ha! I can see that. Unfortunately, I don't have time in the videos to talk about so many things. But yes! They are finding ways of adjusting to speed on motors and fans (liked with ECM Motors) to give you the correct cooling capacity or dehumidification. Thank you for bringing that up. Like I tell the guys in class., Technology is crying every day and basically I putting mini VFD's in everything these days. But thank you for watching! And thank you for sending your message in. And thank you for watching!
You are a great teacher! I have now understood more than I have ever known. Please, keep more coming especially troubleshooting multi v system compressors. I was challenged recently by Toshiba multi v outdoor unit breakdown with error code= H02.
I am so glad to hear I could help!!! That is why I am doing this. There are a lot of people that do not have things explained in an easy to understand manner. Thank you for your comment!!! I will see what I can do about the other videos!!!
Yes indeed - Julio has a teacher's talent. People without teaching talent are basically just making "brain dumps".
@@hg2. Thank you!!!!
Ive never seen a video have hundreds of likes and not a single dislike. Bravo good sir!
Thanks with your help today
You are welcome! I'm glad I could help!
Julio, excellent overview of the subject matter. Clear and concise. I have been an instructor of gas technicians for many years however I would be honoured to be a student of yours. Take care.
Thank you that is such a compliment!!!
VRF, the future of HVAC, paired with an ERV. Game over. And my sheet metal union is confused about why I wanted to switch to a service tech. Here in Seattle, sheet metal and hvac service are in the same union but separate
Yes, the industry is changing a lot. I recently put a mini split in a cabin that should have only had a 1 ton unit. I put a 2 1/2 unit in there with three evaporators. This gave them the option of having as much heat and or cooling as they wanted. Now that the temperatures have been down in the teens they have had enough heating to keep them comfortable and they are so extremely happy! I think if we are going to stay in this field we need to sharpen up on these PRFs because like I said they will be the future of this industry.! Thanks for watching!
very good information on VRF. I think only DAIKEN is using this system in their machines. Please show this machines working and also charging this system as it is looking more complicated compare to conventional machines. Thanks.
Yes, they are very complicated systems. And I will see what I can do about showing that! Thank you!
Thanks for this, very clear explanation
I'm glad you liked it! And thank you for watching!
Your a man that knows his profession and it's tech very well. Wish you were in GA. I've been getting quotes on converting from forced air to whole home ductless. Honestly, I don't think any of them really understand what they are selling or how to best configure.
tellMeSomething thank you very much. Sometimes I wish I was in Georgia and not in Northern Virginia! A lot of people here are doing the same. Converting to the ductless mini split. A customer wanted the mini-split in their 4 level townhouse in Washington DC VA not too long ago. We made it all work and they have been very happy with it. It was a lot of work running the lines through the walls and installing the boxes at each level so we could branch off to different indoor units. Good luck out there. And Thanks again!
Thank you mr
You're welcome! And thank you for watching!
Great job Captain! 🫡
I'm glad you like the video, and thank you for watching!
Thank you, Is there an explanation for how simultaneous heating and cooling work?
You are very welcome. Thank you so much for watching!
Batherway Mr. Hullio,is that box you are talking about called ahybrid box or is something else? Thanks
Thank you for your question. We have always called them branch boxes. I do not know of another name. I hope this helps!!! Thank you for watching.
Great tutorial sir. It cleared all my doubts regarding vrf. Thanks a lot
Thank you so much for your comment! I'm glad you like the video!
can we take a moment to appreciate how he's both ambidextrous and can write backwards?
Thank you!!!!
I would like too see more of your videos in vrf systems. With its receiver tank,thermistor location and so on in vrf systems. I got confused in the last part because when one of the inside unit is satisfied is sends a signal to close the eev in the branch box . And when all unit are satisfied it pump Down and close all eev in the branch box. I am just saying. Willing to learn more about vrf. Awesome video.
Thank you for the comment! I do need to get more of those VRF's videos out. I think we are seeing more and more of them out there. Thank you!
Thank you very much. This video has given me a good understanding.
Good information. I like how you made it simplistic.
Thank you so much for your comment and I'm glad you like the video. Thank you and thank you for watching!
Please discuss how the proper pumping down parallel rack systems
Thank you so much for your comment I am making a note of it and I hope to get a video on that up soon.
Julio..my man well explained 👏GD
Thank you!!! I appreciate your comment!!!
Excellent, simple explanation. I love it. Thank you so much for effort.
Thank you! I'm glad you liked it and I hope this helped. Thanks for watching!
Absolutely love your vids. Love from London England
Thank you!!! From Falls Church Va. just outside of Washington DC USA
THANK you
I'm glad you like the video! And thank you for watching!
I agree that increase in evaporator size will lead to higher suction pressure but it is confusing when you state that as a reason the temperature of air leaving the evaporator will go up (~ 5:00 min).
If the air temperature and air flow entering the evaporator is the same, the suction pressure would increase slightly if the evaporator is sized bigger without impacting the outlet air temperature.
I think you meant if the air flow rate increased and the evaporator is sized bigger, right? I think the capacity will roughly be the same and air outlet temperature would be higher leading to an increase of suction pressure
Thank you for your comments. When the size of the evaporator is increased it is going to generate more gas than the compressor is designed to handle (because it is a single speed compressor) and because of that, the pressure in the low side will go up. When the suction pressure goes up the evaporator temperature will also increase. One thing to keep in mind is that the greater the temperature difference the greater the heat transfer rate is going to be. If the evaporator temperature goes up because the suction pressure increased, then there will be less temperature difference and it will transfer less heat, increasing the temperature of the supply air temperature. The other thing I was saying in the video was that by increasing the speed of the compressor we can drop the suction pressure therefore lowering the evaporator temperature and creating a higher temperature difference between the evaporator and the return air temperature increasing the heat transfer rate. I hope this makes sense. Thank you for your message!!!
Wonderfully clear lecture. I have learnt very much. You are a great lecturer. Thank you.
Thank you so much for the comment and for watching the video. I'm glad that you enjoyed it!
Your teachings are awesome. Thank you.
Such a helpful video great job!
Thank you!!! I appreciate your comment.
This was a great video! Made things very clear on the basics of how these systems work. I'm working on a project with a particular (popular) manufacturer of these systems. One question that seems unanswered is what happens if your indoor units have a total capacity that's larger than your outdoor unit? The project is for 3 or 4 zones but because the smallest indoor units are only available as 9,000 BTU/hr coils, we wind up being way over capacity for the actual peak load from the manual J for some zones. We'd like to size the outdoor unit for the peak demand of the whole system, but that means it will not be able to keep up with peak demand capacity of the indoor units...doubtful that all the indoor units would be calling for full load all at once very often if ever.
Matthew Hester Thank you, sounds like a tough situation. You are correct a lot of times the indoor units will not be all on so you will not fully work the outdoor unit. But of course we cannot depend on this. Fortunately I have noticed that some minisplits will do more cooling and if it’s a heat pump more heating then what it is rated for. With mini splits are usually try to oversize them slightly because of the ability of adjusting the motor speed and the compressor speed we don’t have to worry about the same issues that we would have on a straight split AC unit. Good luck with this issue but like I said I usually try to just slightly oversized them so that I don’t have to worry about this. Thank you for your comment.
very good information and great explanation with pictures. would you be able to explain the three pipe VRF systems. I know they have one suction and liquid line in addition to another line can be neither nor. Not sure how it works, when three pipes going to branch selector boxes and the room zoning one called for heating and the other one for cooling. much appreciated.
A quick explanation would be that the third line would be the discharge line from the compressor. This way at the box/manifold they can heat a room while simultaneously cooling other rooms. So they are turning an indoor unit in to a condenser to heat the room. I hope this explains your question. Good luck!
Great video 💯💯💯💯
Thank you so much! I appreciate your comment! Good luck out there!
At 7:18 why would suction pressure go up? I’m assuming liquid line would drop because the flow is going to 2 evaporators but would thought suction would go down also
Thank you for the question and for letting me know the time frame you were talking about. One thing I was talking about there is that if we did not have a variable speed compressor. Then you would be feeding the compressor with the gas for two suction lines making that pressure go up, you would be feeding the evaporators, or the liquid lines I should say from one liquid line so that would drop pressure. With a variable speed motor/compressor the compressor would speed up/Run faster bring the head pressure up and the suction pressure down so that you could maintain that 40°F evaporator. I hope this explains it. Thank you for your message and for watching!
@@AirConAcademy thank you so much for explaining that!
@@JohnnyJr396 My pleasure!!!
Great explanation!
Great video 💯💯💯💯💯, I got a better understanding of the functionality of a VRF.
Sir help me have one vrf out door unit not outo start power off after on start but not outo start what's problem
If it is not running on the auto start, it could be that one of the safeties has it out. Make sure you check all of your safeties and maybe look for a loose wire. With the small amount of information it is hard for me to really be able to tell you what could be wrong. I hope this helps.
sir gud day.
can you discuss us about pumping down refrigerant on vrf/vrv system.the correct procedures.thanks a lot sir
I will try and see what I can do. Thank you very much for your request and for watching!
Thank you for another good one.
Questions:
Why do we have these?
Where are they installed,commercial or residential, and why?
If residential, are they replacing "plain old" split systems?
Cool!!!!
HA HA Thank you!!! and thank you for watching!!!
Very good Julio. Maybe you could do one when you can do heating and cooling at the same time.
Thank you for the suggestion I will see what I can do!!!
Do you know any books about parallel rack system or super market refrigeration. I would really appreciate it if you get back to me on that one. I asked around but no one helped me on that.
@@abelurrutia1192 i am sorry I am not sure if there are any out there. That is such a specialized trade.
Very well explained.
What if I have Dx system 1- 1 (5tr) and VRF system (5Tr) which is also DX. Both type of system has inverter compressors but why VRF system piping length is allowed upto 100mtr and normal DX system upto 15mtrs only ?
The inverter compressor is great because they can adjust the speed and have it operate at different capacities. Meaning that they can dehumidify only, or they can call in dehumidify by adjusting to speed. Because of that they can have a longer line set because the compressor can operate at a faster speed making up the capacity that a regular split phase motor cannot do. I hope this makes sense. Sorry it took me so long to answer.
@@AirConAcademy thank you for responding.
How if the normal split unit have inverter compressors ?
Now a days all Dx units are upgraded with inverter compressors but still piping length is specified upto 15mtr-20mtrs only
@@siddharthvadangar6827 from what you're saying this all depends on the type of unit. A lot of units that I have seen do not have inverter motors. If you have a VRF system then the indoor unit will also be inverter with possibly an electronica expansion valve which will allow you to use the longer refrigerant lines. It is the combination of all of the electronics that allows you to go to a longer length of lines.
Love u sir great love from Pakistan
Thank you so much! Love you right back from the US! I'm glad you like the video, and I hope you learn a lot! It makes me happy to know someone in Pakistan likes the videos! Thank you for watching!
Very good thanks
Thank you! I'm glad you like the video!
Thanks for sharing ...it is very educative
Thanks in a million.
Thank you for warching
Samsung DVM PLUS4 VRF System Error 458 How to repair please guide line training give me
I try to get enough information here to help you guys repair equipment. Let me know what you might be interested in.
is there used a liquid pump in vrf system...?
There is no need for a pump in a VRF system the pressure difference will make the refrigerant flow easily within the system. Thank you for watching.
Great video and a great teacher.
Can you descripe the controll of the compressor a little bit more in detail? You said, that the speed of the compressor depends on the active units. So, is there a related speed for every amount of active units? Or is the compressor controlled by the suction pressure?
The speed of the compressor is controlled by the demand. With these new units they have sensors and those sensors will tell the compressor what it needs to be doing by converting the pressure to temperature. Of course there are different types of units so one may be slightly different than the other asked how they control the speed of the compressor. I'm sorry I cannot be more specific. I'm glad you like the video! Thank you!
Is there a video for how does the control box work? Is it heat exchange or refrigerant in and out when one of the evaporators needs it? What is the best refrigerant to use in this system? Thanks boss you’re amazing 👍🏽👍🏽
Thank you!!! these boxes are just refrigerant in and refrigerant out. They have solenoids inside that will direct the flow of refrigerant to which ever evaporator is calling for cooling. For right now it is mostly R410a that is being used in the systems. Soon 410a is going to be replaced and we will see other refrigerants in these systems. At the moment it is hard to know exactly which refrigerant will take the place of 410a, it may be 454b? but we are not sure at the moment. thank you for your comment!!!
Julio your presentation was easy to follow. What's the recommended size of VRF condensing unit for 4 bedroom apartment w/ 1x14k & 4 x 9k evaporators?
That is a tough question to answer. There are a lot of variables to think about. I just recently put a 2 1/2 ton unit in a cabin that should have only needed a 1 ton. The insulation is not that good and the windows were awful. I did a 1 ton on one side of the living room, another 1 ton on the other side and a half ton in the dining room/kitchen area. Because of the different units they can control how much cooling or heating they will be needing. This way they can dehumidify and cool as needed. Also in the winter time they will have plenty of heat. What you gave me might work but it all depends on how big the rooms are and how the evaporators will be placed. I wish I could be more specific but there are a lot of variables that go into something like this. You are looking at about a 3 1/2 ton unit but with these VRF units you can also set them to dehumidify so that might be enough?
@@AirConAcademy Julio the reason I asked this question is the contractor for the project had installed 2 ton condensor for all the units and many had condensation problems at the indoor air handlers. The LG company on island did not carry the indoor air handlers (special order) so we went with another company that completely changed out 2 unit's systems with a 4 ton condensor with no issues.
We had the LG company upgrade the condensor and they installed a 3 ton which did not fix the condensation issue.
Mahalo for your tutorial and reply. We live in Guam which is high humidity and these apartment units are only 1.5 years old.
@@brucewilliams1924 when you say that they were having condensation issues, what do you mean? Does it mean that it was generating too much condensate? Was the condensate leaking out of the hanging wall units? Was it not dehumidifying? I am trying to understand exactly what your issues are to see if I can help. I'm sorry I'm asking so many questions. I was thinking that, if you have condensate leaking out of the air handler's check the drain line. I have seen it that when the drain line is not completely straight and at a downward angle the condensate will back up into the air handling unit that is hanging on the wall. This will cause the condensate to come out of the air handling unit. If you are having an issue with condensate coming out of the unit please check your drains even if it has the smallest dip in it it will back up. These units do not use traps so that drain must be straight and without any low spots in it. Please let me know if this helps and what other problems it is that you're having. My son was stationed in Guam for three years and he used to tell me how humid it was there. So I am thinking you have too much humidity.
@@AirConAcademy Julio the condensation is at the air handler. The drains are not plugged. Per the other AC company that replaced 2 units the condensor is too small, they are using 48BTU, where as the original condensors are 24BTU.
I’m an old timer. Been in sales for a while so when I left the field VRF wasn’t really a thing to concern myself with. I have sold them but it’s just really a high-level view is all I need for sales to be honest
I go and help people a lot of times. I retires a few years ago and VRF's were not around when I was doing more work. BUT I still like to learn as much as I can so I can pass it on. I hope you enjoy the videos!!!
pls need help ! i have Samsung 48k vrf outdoor unit pressure is good , NO ERRO CODES , i have 2 indoor units 2x24k ducted , both indoor units workd fine for last couple years ! but last 2 weeks im having problem with only 1 indoor unit it blows 78 deegress on the cool setting 64 degrees ( while other indoor working fine 64 deegres , when i shutoff good working indoor unit my outdoor compressor start freezing up, can you pls explain what it is the issue can be? I try to call samsung customer serves no help on they behave
I am not sure if I understand, I think you're saying that the one evaporator works well when you shut off the other one? Also I think you're saying that the compressor starts to freeze when you have that one evaporator working? Or is it on both when it freezes? I would suggest making sure you have enough refrigerant, make sure that you have plenty of sub cooling because that could be starving one evaporator. If that is not it you might have a restriction on that one evaporator that's not working right. It may have to be replaced. I would first start by checking my charge and making sure I have enough refrigerant, and do that by making sure you have plenty of sub cooling. I would say 15 to 20° F of sub cooling. I hope this helps. Good luck!
@@AirConAcademy when I shut off one of the working unit & let bad unit running only then compressor freeze, but when both units are running no problem, but ones again only 1 indoor unit cooling, freon good pressure
@@Ray-wr2wr have you been able to check the superheat on that one unit when the compressor is freezing? Also have you checked the airflow and that one unit? If you have too much refrigerant going through that unit, It is possible that the compressor would freeze? If you don't have enough airflow I could also affect it. Is that fan working like it should?
thank you sir pretty good explanation!
Thank you, and thank you for watching!
Superb explanation...👍
Thank you!!!! glad you liked it!!!
Great video, can you run one unit on cooling and another on heating? Does the branch box have a reversing valve on each circuit?
On most of these units they all have to run in the same mode, either the heating or the cooling. If you have three lines going from your outdoor unit to distribution box then yes, they can each run independently of each other. But you would have to purchase a unit that is specifically made to do that. And yes, those work very well! Thank you for watching!
So I’m doing a job right now that has 25 units. But 2 of those units have to run cooling all year (electrical rooms). Those 2 units have their own outdoor units, while the rest of the VRF system (the other 23 units) run off of two massive outdoor units
Hello sir,
Your videos are very helpful to understand the concepts. I have been working as service engineer in VRF system.
Could you please help me what could be the possible reason of higher temperature of liquid refrigerant entering into evaporator?
Typically when you have high temperature of liquid refrigerant entering the evaporator that would mean that you do not have enough sub cooling. That a lot of times means that you are low on refrigerant and you need to add more refrigerant. Of course I do not know the type of system you're working on but if you have enough refrigerant in the system the sub cooling will increase and your units will work more efficiently. I hope this helps.
I need an expository explanation on the VRF units installation and how it works
That would be a long explanation I will have to see if I can make a video of that! Thank you for your comment!
How to recover refrigerant on a VRF Daikin system??? Wondering if you offer a video about it. Thanks!!
I do not have one for that but let me see if I can do one for that for you!!! Thank you
When you install that control box you mentioned, what would be the best optimal location to place: nearest place to all evaporators or nearest place to the condenser (outdoor) unit?
So it’s been 8 months and no ones answered you, so I’ll answer, honestly, I’ve run 120 ft runs to a branch box and it didn’t matter. So that answer is, it doesn’t matter since it’s a pressurized system, for the most part, the distance doesn’t matter
Thank you for the explanation!
I have a VRF system
Of Toshiba
The upper units in the rooms produce ice while operating on cooling (It can be one unit or several units together)
What could be the reason?
My guess would be that the unit may be low on refrigerant. You may need to add refrigerant to it because of the length of the lines add or you may have a leak. There are a lot of variables but I would be my first guess.
Thank for your video sir
I am glad you liked it and thank you for watching!!!!
Thanku sir and I need more information obout Veribele speed compressor and that input voltage AC and DC ⚡ both
@@rudramuniah6002 ohh ok. good suggestion Thank you!!!
so, if the Compressor speed slows down, it will just make the AC Cools less, and not something dangerous, because the expansion valve is the one adjusting the point where the refrigerant is superheated? so we could attach the Compressor to any energy source?
because I'm thinking if we could make a infra-subwoofer doubles as a compressor to cool the amplifier
making the amplifier still *cool while quiet*
On these VRF's sometimes they will adjust the speed of the compressor and the fan at the same time. if you are using a TXV the TXV will make sure that you do not flood the compressor. By slowing the compressor down you're such impress will increase and do less cooling. I hope this helps! Thank you for watching!
If we were to charge this system would I have to take superheat readings at each individual evaporator or is it okay taking it at the suction line 'systemSuperheat'
With the systems typically you add refrigerant according to the length of pipe you are adding. Because the metering devices in these systems adjust you would not do a superheat reading. You would do sub cooling but the manufacturers want you to weigh the charge in according to the length of pipe.
Hello Sir, can i do VRF course online
Hi! I am sorry to say that I do not have a class on VRF. I really do not know who might have one online. I sure wish I could help you! All I have is the videos that you saw online for now. Thank you for watching, and good luck!
Superb Elaboration
Thank you!!!!
Thanks Julio
You're welcome! I'm glad you enjoyed the video! And thank you for watching!
Sir please tell me 2 ton rotary and 2 ton reciprocating or 2 ton screw compressors efficiency same? They are working and will give same result. Can I replace ich and another type comp. Not same example can i change hermetic except screw compressor compressor ?
as long as you are removing a 2 ton and putting in a 2 ton, or taking out a 4 ton and replacing a 4 ton. it should not matter and it has not mattered in the past replacing a reciprocating with a scroll. I hope this helps
Very informative 👍
Thank you!!!
thanks sir please show the connection to condenser about the pipe system.
I am making a note on that and will try to get a video on that. Thank you
Gracias ...! Don Julio !
Gracias!!!!
Julio, can you please help me to choose a good super market refrigeration book or at least get my to me with an answer? Thanks.
What about vrf subcooling
Thank you! I guess that's another video I need to make! And thank you for watching!
Thanks !
Thank you!!! I am glad you liked it!!!
Exelent Julio. Gracias bro.
De nada!! You are welcome!!!! thank you!!!!
Thanks
If you could explain VFD
Hi sir is DVM work the same as VRF or VRV whats the difference between them
Very good question!!!! VRF (Variable Refrigerant Flow), VRV (Variable Refrigerant Volume and DVMs are basically the same. They will control the flow of refrigerant so you can have several mini-splits doing or performing what it is needed. With a DVMs you can cool one room and heat another room with the same outdoor unit. In most mini-splits you can only cool or heat with all of the units at the same time you cannot have them independently of each other like with Some of these DVMs.
What is the name of this "box" that speaks to the compressor to control the refrigerant flow?
Do units have sensors in them and they are actually sensing the pressure, plus the communication cable that goes from the evaporator unit/section to the condenser section will communicate all of that plus the the branch box or the branch distribution box is what will be controlling the flow of refrigerant. Thank you for watching and thank you for your comments!
Sir how many ton compressor in used the outdoor
ohhh that is hard to say. In some places you only need a 2 ton compressor for a small space and at other places you may need a 5 ton compressor or unit for a larger space. We have to do a heat low calculation to see what the capacity of the compressor and or the system needs to be. I hope this helped. Thank you
Thanks sir
Phew... To paraphrase The Wizard of Oz, "We're not in residential anymore."
I thought you were going to talk about TXVs... they're "variable refrigerant flow" aren't they? (Lot to learn here. Don't mind me - for us residential students, this is like county boys going to the city for the first time. )
Thanks for making!
PS: I have to wonder about the speed of the condenser fan - is that variable too, like the compressor? (Lot to learn here. Thanks for an excellent, "user friendly" intro to the subject.)
Here's how VRFs are talked about "out in the market":
th-cam.com/video/vie4kHN_iYU/w-d-xo.html
Have to start a separate playlist for this, HVAC - VRF.
.
Thank you so much for your comments. And with these units yes everything is variable. The indoor fan, the outdoor fan, the compressor and sometimes the metering device is an electronica expansion valve. These units are a totally different animal as you stated, and one of your funny comments that you made! Yes, there is a lot to learn and a lot to say about them I just wish I had the time to make more of these videos. Thank you for sending that link!
Can this heat aswell? In the same way or even cooling and heating at the same time?
Glasgow Scotland UK
You can have both heating and cooling VRF system simultaneously. So what that means is Air handler a.k.a. cassette can be heating while another one is cooling.The systems can be huge one condenser to 60 to 70 evaporators
What is cheaper: 5 single split or one VRF ???
I would guess that the VRF will be cheaper and you will have better control!
Do you recommend any dealership here in Brazil?
@@rogernevez5187 I am not too familiar with Brazils economy but I have had students that have gone back to the country were they were from and started their own business there. This industry will do well everywhere as long as the government does not tax you to death and you can easily start a business.
> "as long as the government does not tax you to death and you can easily start a business."
This is not the case here in Brazil. kkkk
varey god tehare
so, if the Compressor speed slows down, it will just make the AC Cools less, and not something dangerous, because the expansion valve is the one adjusting the point where the refrigerant is superheated? so we could attach the Compressor to any energy source?
because I'm thinking if we could make a infra-subwoofer doubles as a compressor to cool the amplifier
making the amplifier still *cold while quiet*
**bass**