Hey Ty, just wanna thank your for help and shared knowledge. I finished the NTI HVAC technician course ( online) and I’m well into my trade and just wanted to thank you. I’m glad I found you on RUclips :) , I still go back and rewatch the old course videos to refresh the memory. You’re the best teacher I’ve come across.
This stuff takes me back to the late 80's! All these manufactures trying to reinvent the A/C circuit. High temp Medium temp Low temp Ultra low temp Nice videos they didn't seem this easy to find back then? 🍺🍺🍺🥃🥃🍇🏌 Stay safe. Retired(werk'n) keyboard super tech. Wear your safety glasses.
MR TY thanks for sharing your knowledge with us. You took time before and answered this little senior tech before. Dropping hats for you awesome teacher. One question I have it seems I can't find answers even my teacher at tech school really didn't answer me. When we measure the pressure at suction line and according to pt chart that represents the temperature in the middle of coil. At the same time if pressure and temperature law works accordingly. Superheated vapor at suction line has higher temperature due to absorbing heat than , now why measuring the pressure right in that suction line represents the temperature in the middle of coil. Should we use some kinda math or calculations. How is that possible the pressure at suction line which has higher temperature represents the temperature in middle of coil. According to PT chart every refrigerant has different temperature at different pressure and vs. So why does Superheated vapor higer pressure than middle of evaporate coil gives us that temperature. Shouldn't be lower. I hope didn't confuse you. Thanks for any input.
I will be adding superheat and saturation soon. I will try to answer this in text. When its vapor only, temperature and pressure are connected but it's not easily trackable. Its all superheated vapor and the molecules are bouncing around like crazy resulting in the pressure. Number of molecules, the heat and the pressure all play a part. Because its superheated vapor theres very little BTU but a lot of sensible heat change. When we add liquid saturation it changes things. With a saturation (boiling point) we can track and pinpoint it. Now as we change the pressure we change the boiling point. Having liquid boiling in the evaporator gives us startimg point. That is our PSI to temperature. That is the majority of the evaporator. As we add or remove heat overpressure that point changes but it's still our base line. Massive amounts of heat are absorbed there. Superheat vapor is a measurable sensible number bit very little but but we can measure it. Oxygen has a saturation temperature of -279f at 0 pig (14.7psia) I can pour liquid oxygen out and watch it boil. At the same time, and the same pressure I can breath superheated oxygen. Its superheated above its saturation point. In the evaporator, let's say with the conditions we have a saturation of 40⁰F in our evaporator. A lot of variables come in play to get there and a lot of things can change that. While its boiling we cant measure how much liquid is there bit it's a lot of BTU's Now after all the refregerant boils into a vapor is still low temperature so it will still absorb heat but it's only a sensible. Easy to measure but very little BTU. Superheat is sensible heat added to a vapor a above saturation. Now pressure. Residential evaporators do have a pressure drop across the evaporator but it's not much. I don't remember the number but I think it's less than 5 psig total. Where the pressure drop is happening is still saturation. Since the number does not account for much we don't adjust for it. Since the pressure is essentially the same on the suction side the pressure will balance out. The temperature from the superheat does have an effect on the pressure but it's already accounted for into the pressure pushing against the saturation. Also pressures are bouncing all the time. The old gauges had a flutterless feature and the new digital uses an averaging. Applied results, A larger evaporator coil is more effecent but worse at dehumidification. The larger coil picks up more heat, raising the saturation temperature and pressure in the coil. The higher temperature still absorbs heat but not as "cold" so less moisture condenses on the coil. A smaller evaporator picks up less heat but the less heat results in lower pressure and lower saturation temperature resulting in more condensation and this better dehumidification. Applied 2 Decreasing airflow across the coil will reduce amount of heat transfer to tue refregerant. The lower heat results in lower pressure and lower saturation temperature. More airflow results in more heat against the evaporator coil raising the pressure and saturation temperature. In all the examples the additional heat from superheat is already balanced out in the pressure and the pressure is fairly averaged across the evaporator and already affecting the saturation point.
It helps to start the course from the beginning. HVAC 00. It's in sequential order under learn HVAC playlist. There are multiple concepts to absorb And build in to get to that answer. In short it's latent or hidden heat
Hey Ty, just wanna thank your for help and shared knowledge. I finished the NTI HVAC technician course ( online) and I’m well into my trade and just wanted to thank you. I’m glad I found you on RUclips :) , I still go back and rewatch the old course videos to refresh the memory. You’re the best teacher I’ve come across.
I cannot agree more. Ty is best teacher..
I like these short to the point principals of operation.
Ty, its yet another video with lot of learning. Thnx - for your passion to teach us.
This stuff takes me back to the late 80's!
All these manufactures trying to reinvent the A/C circuit.
High temp
Medium temp
Low temp
Ultra low temp
Nice videos they didn't seem this easy to find back then?
🍺🍺🍺🥃🥃🍇🏌
Stay safe.
Retired(werk'n) keyboard super tech.
Wear your safety glasses.
really , so interesting lecture. Thanx a lot
Start the Learn HVAC playlist in sequential order here
ruclips.net/p/PLc7QlzR-srBgknwzlXjoESxNbzHQJ-TIq
🙏👏🏼
MR TY thanks for sharing your knowledge with us. You took time before and answered this little senior tech before. Dropping hats for you awesome teacher. One question I have it seems I can't find answers even my teacher at tech school really didn't answer me.
When we measure the pressure at suction line and according to pt chart that represents the temperature in the middle of coil. At the same time if pressure and temperature law works accordingly. Superheated vapor at suction line has higher temperature due to absorbing heat than , now why measuring the pressure right in that suction line represents the temperature in the middle of coil. Should we use some kinda math or calculations. How is that possible the pressure at suction line which has higher temperature represents the temperature in middle of coil.
According to PT chart every refrigerant has different temperature at different pressure and vs. So why does Superheated vapor higer pressure than middle of evaporate coil gives us that temperature. Shouldn't be lower. I hope didn't confuse you. Thanks for any input.
I will be adding superheat and saturation soon. I will try to answer this in text.
When its vapor only, temperature and pressure are connected but it's not easily trackable. Its all superheated vapor and the molecules are bouncing around like crazy resulting in the pressure. Number of molecules, the heat and the pressure all play a part. Because its superheated vapor theres very little BTU but a lot of sensible heat change.
When we add liquid saturation it changes things. With a saturation (boiling point) we can track and pinpoint it. Now as we change the pressure we change the boiling point. Having liquid boiling in the evaporator gives us startimg point. That is our PSI to temperature. That is the majority of the evaporator. As we add or remove heat overpressure that point changes but it's still our base line. Massive amounts of heat are absorbed there. Superheat vapor is a measurable sensible number bit very little but but we can measure it.
Oxygen has a saturation temperature of -279f at 0 pig (14.7psia)
I can pour liquid oxygen out and watch it boil. At the same time, and the same pressure I can breath superheated oxygen. Its superheated above its saturation point.
In the evaporator, let's say with the conditions we have a saturation of 40⁰F in our evaporator. A lot of variables come in play to get there and a lot of things can change that.
While its boiling we cant measure how much liquid is there bit it's a lot of BTU's Now after all the refregerant boils into a vapor is still low temperature so it will still absorb heat but it's only a sensible. Easy to measure but very little BTU.
Superheat is sensible heat added to a vapor a above saturation.
Now pressure.
Residential evaporators do have a pressure drop across the evaporator but it's not much. I don't remember the number but I think it's less than 5 psig total. Where the pressure drop is happening is still saturation.
Since the number does not account for much we don't adjust for it.
Since the pressure is essentially the same on the suction side the pressure will balance out. The temperature from the superheat does have an effect on the pressure but it's already accounted for into the pressure pushing against the saturation.
Also pressures are bouncing all the time. The old gauges had a flutterless feature and the new digital uses an averaging.
Applied results,
A larger evaporator coil is more effecent but worse at dehumidification. The larger coil picks up more heat, raising the saturation temperature and pressure in the coil. The higher temperature still absorbs heat but not as "cold" so less moisture condenses on the coil.
A smaller evaporator picks up less heat but the less heat results in lower pressure and lower saturation temperature resulting in more condensation and this better dehumidification.
Applied 2
Decreasing airflow across the coil will reduce amount of heat transfer to tue refregerant. The lower heat results in lower pressure and lower saturation temperature. More airflow results in more heat against the evaporator coil raising the pressure and saturation temperature.
In all the examples the additional heat from superheat is already balanced out in the pressure and the pressure is fairly averaged across the evaporator and already affecting the saturation point.
@@love2hvac
Thank you so much for your time and answering my questions. I really truly appreciate it 🙏
If refrigerant is absorbing heat when it pass through the evaporator. Why is it cold as it leaves?
It helps to start the course from the beginning. HVAC 00. It's in sequential order under learn HVAC playlist.
There are multiple concepts to absorb And build in to get to that answer.
In short it's latent or hidden heat
Hello Mr.Ty what is the temperature inside line the evaporator coil when the refrigerant change it’s state from liquid to vapor in R410a? Thank you.🌹
At what pressure ?
If we know the pressure we know the boiling/saturated temperature.