The Evaporator Operator and Super Heat - HVAC Online Training and Courses
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- čas přidán 26. 08. 2024
- In this video, I will give you a brief explanation why superheat is so important and why you should always take superheat readings.
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Thank you, Julio. I've been thinking about your awesome classes. We have a lot of air conditioning work going on these days: our local weather temperature is 113 F!
Thank you! I am glad you liked my classes! Local temperature 113°F? Where are you? Texas? Thank you for watching!
Southern Mexico
@@jaimeguillermo1908 I guess you moved there!?!?! Good luck I am so glad to hear from you!!!!
Thanks so much for the tutorial. I wish I had access to the books you got your knowledge from
You're very welcome! Books? Well let me tell you most of this I have learned from being out in the field and working. Yes I have taken several courses and I have gone to several classes, but most of this comes from putting all of those little bits of information together, condensing it and putting it out for you guys! I'm glad you enjoyed the video and thank you for watching!
You’re the gift that keeps on giving! Thanks so much for the videos I’m learning a heap!
Thank you!!! I am glad I can help you guys out there!!!!
Amazing, so informative and helpful.
regarding the evaporator coil and compressor equilibrium operating point. If you elaborate little more on that.
Thanks
I will try to do that! I need to get on here and make some more videos for you guys! Thank you!
Thanks a lot for this video. You mentioned that as the flow rate of air reduces from 400 to 300, the PDP point is going to move towards the compressor and the suction pressure would decrease. I could not understand the reason behind the decrease in suction pressure. Can you please explain why the suction pressure would decrease upon reduction in air flow rate and why would it increase when the air tempeerature increased from 75F to 80F.
That is a good question. When you reduce the airflow you have less heat going to the evaporator. Yes the air would be warmer but you have less airflow so the amount of heat would decrease. The refrigerant is not going to boil as fast as it should in evaporator so it will make less vapor. The compressor only runs in one speed so it will still draw in the same as before, because of that the pressure will drop. The compressor is pulling in more vapor than the evaporator is making and the pressure drops. I hope this answers your question. Good luck!
@@AirConAcademy Thanks, it is more clear now. Really appreciate your help.
@@puravpatel5511 thank you! And keep learning out there.!
@@AirConAcademy Hi Sir, in above answer you told that "The compressor only runs in one speed so it ............" . So my question is what would happen when it comes to variable speed compressors ? same thing will happen?
@@chamilanawaratne6629 most compressors will only run and one speed so they pump only a specific amount of refrigerant. You do have variable speed compressor's and these will increase, and decrease the volume metric efficiency of the compressor. Meaning that they will pump more or less depending on the need. One problem with this is that by adjusting how much the compressor is pushing through the pressures are going to change and if the pressure drops too much on the low side the evaporator coil could start to freeze. Sometimes manufacturers will use two or three metering devices to control the flow of the refrigerant as the compressor speeds up or if it has unloaders as the unloader loads up. The mini splits that you see everywhere now the Compressor motor and fan motors are all variable speed so they can adjust the speeds as needed to help maintain proper pressures.
Hi, this is an fantastic video that can clear everyone's doubt about charging and recovering refrigerant without any actual need.
can you please make us understand also the case which you explained along with real lack of refrigerant and overcharged system.
It will be more helpful, thanks in advance for your great work and support to the community through teaching...
Thank you, Thank you and I will try to see if I can make some other videos soon and explain that about the lack of refrigerant. Thank you for your suggestion.
Perfectly said
Thank you!!!!
Tanks for sharing
And thank you so much for watching!
Good detail
Thank you so much! I really appreciate your comment and I'm glad you like the video!
Best ever
Thank you very much! Thank you for your comment and thank you for watching!
Gracias . Muy buen consejo e importante chequear súper heat .. 👍👍 es un detalle q no sabía .. profe julio .. algún método práctico y sencillo para chequear súper heat ? Porfavor
Perdone que asta hoy vi su mensage. gracias por ver el video. si es muy importante el super heat!!! mire este otro video y esplico sobre el super heat mas. si tiene otra pregunta mandeme mensage. gracias. czcams.com/video/LckKofURNkE/video.html
Thank you sir additional learn again to me
Thank you and I am glad I could help!!!
Sir,
I like your explanation. Very good.sir I have if when u try to collect refrigerant in receiver and u find it less, does it mean that refrigerant in system is less.
Some of the refrigerant is not going to go into the receiver, some will be stored in the condenser. So what is in the receiver will be less because of the condenser. If you have a receiver in a system most likely you have a TXV as the metering device. When you have a TXV you charge the system by weight or by sub cooling. It is very important to check the sub cooling. Remember, the receiver is only there to store refrigerant while the unit is running and when the refrigerant is not being used. I hope this makes sense. And thank you for watching!
Sir,
Thanks for your reply. We had a condenser cum receiver so there was no separate receiver as such in our case. Sometimes when we used to pump down that time we used to not get back any refrigerant back so we used to charge again. We also cud not trace any leak during such times. So I cud not figure out as where refrigerant gone?
great man ,,, thanks a lot ,,,
Thank you!!!! I am glad you liked it!!!!
Tnx for new lesson
mark yukiteru I am glad you liked it! And thank you!
Sir,
I am very thankful to u for your nice explanation, I have learned a lot from your videos. I have a question regarding txv.we had refer system on board ship. We have provision which r kept at -18,-18 and +5 degree centigrade. We have 3 rooms veg room, meat room and fish room maintained at 5,-18 -18 degree centigrade. We faced problem of temp not maintaining. Also refrigerant leakage. Leak part was sorted out by brazing leakage portion. Then when we tried to bring down the temp it was coming only to 10,-1, -2 centigrade. We charged refrigerant we changed txv still no improvement. Can you please advise as to what may be the problem?
They are a lot of variables that I do not know. But let me ask you this since it is a TXV system when you added refrigerant did you check the subcooling? When you have a system with a TXV to charge the system you check the sub cooling. If you do not have the proper sub cooling the evaporator will not cool down like it should. Did you guys pull a deep vacuum? Down to 500 µm? Air and noncondensibles could keep it from pulling down. Since you are on board the ship I am sure you are using salt water for the condenser like we used to use when I was in the U.S. Navy. Are your condensers clean and or are your strainers clean? You need to make sure you have a good heat exchange there. I hope this helps and thank you for watching. If you have other questions send them to me.
Thanks for your reply. In our case a workshop attended to address the refrigerant leakage. They first put nitrogen and found out the leak .then they rectified the leakage part. Then nitrogen was taken out and refrigerant was put. After that the system was put in use. From your advise I can make out that may be due to air ingress and non condensibles present as the system was not vacuumed prior putting back the system in use we were facing the issue of room temperature staying high.
Sir i m Nisarullah trom pakistan, I watched your this video. You told that we should measure the super heat, so my question is that how can we measure the superheat. ?
To measure superheat you need to get the suction line pressure, convert that to temperature using your PT chart and you get the actual temperature at the outlet of the evaporator. And subtract the two numbers and the result is your superheat. A lot of times rule of thumb says that superheat should be somewhere between 8 to 12°. So 10° of superheat would be good. But it depends on what the manufacturer suggest. I hope this answers your question. And thank you for watching.
how can l check my saturated pressure in the system so that the compressor doesn't lock up
To check the saturation temperature in the evaporator you first need to take the suction line pressure convert that to temperature and that will give you the evaporator saturation temperature. After that you would want to check the temperature of the suction line as it leaves the evaporator and subtract the saturation temperature from the suction line temperature and that will give you the superheat. You must have super heat because if you do not have superheat, liquid refrigerant will go back to the compressor and lock up the compressor. The compressor will not run anymore and it will need to be replaced. So that means you must have superheat. I hope this explains your question. I have a video on figuring out super eight. You may want to look for that and in the video and explain that step by step. Thank you for watching!
How to calculate Orefach
I am not sure what you mean? I believe you mean how to calculate the size of the office? For that you need to check with the manufacturer and see what size orifice you need for the evaporator. When I have done installations there are several pistons/orifice that come with a unit and I have to match the orifice to the tonnage of the unit. I hope this helps and thank you for watching!!!
sir superheat is directly proportional to pressure?thanks
I am sorry I just saw your message. the pressure affects the temperature but not really directly proportional. specially if you have a TXV.
Julio, hola de Kiev
Alexander Bondar hola. Cómo va hasta allá bien lejos?
@@AirConAcademy Ya hace frio
Got a question for you, I was trying to charging a very old AC, no label for its metering device type, I don't know what to use, superheat or subcool, finally, I tried subcool, it reaches 12.xx, but low pressure shows 30 psig in the meantime and superheat is around 58, what your suggestion is ? How can I tell if I should use superheat or subcool ?
I forgot to mention the refrigerant was R422B, low pressure 30 was too low, temperature was around 10~15 F, cannot be right.
If you have a TXV then you should charge by sub cooling. If you have a capillary tube or a piston then you should charge by superheat. You need to look at the type of metering device that is installed and that way you can tell which way to charge the system. I hope that helps but that is how you can tell how to charge a system. It should not matter how old it is but the type of meter a device. Thank you for watching!
@@AirConAcademy thanks for reply, I know that principle but cannot take apart in evaporator outside case, it is in a narrow attic, hard to turn. I assume it is based on sub cool, when i reach 12 at sub cool, I found suction side pressure is very low, only about 25, such that I wonder if I should go by super heat, which means, I have to add more refrigerant until it reaches 10 of super heat.
Hello sir, can i ask some question
Ilmi Febry yes
@@AirConAcademy i have some problem with my compressor bitz
, refrigerant oil also circulates until it runs out until the oil level alarm
What possible not work
Ilmi Febry I understand that the oil leaves the compressor. And then the oil alarm sounds. What does the site glass on the compressor look like? Do you see the oil? Do you see a lot of movement in the oil? If you can, can you send me a video of the so glass on the compressor.
@@AirConAcademy oil see glas is empty, only in +- 12hours oil empty from max levels to alrm
Also, what are the pressures on your high and low side?
Very good explanations thanks bro I an so far what is super heat the hot air that returns let me know please God bless
The superheat is the heat that is added to the refrigerant after it has boiled inside of the evaporator. The basic definition is racing the temperature of the gas above the boiling temperature/temperature at which it changes temperature. It is easy to misunderstand that it has nothing to do with it being hot or it has nothing to do with the air. Thank you for watching!