I'm using this to understand boiling point of refrigerants in HVAC industry.Please if able look for refrigerants PT charts in relationship to their boiling point and break it down for me as I am struggling at this area.Many thanks
Thank You for watching the BP and VP videos! I have a fundamental understanding of HVAC refrigerants, however, I will further investigate the function and application with regard to BP and VP today and hopefully be able to break it down for you... no promises for an explanation that meets your needs, but I will do my best.
The pressure-temperature chart for refrigerants shows the temperatures at which refrigerant is liquid or gas. And temperature and pressure are directly related, meaning as temperature of the refrigerant increases, pressure of the refrigerant increases, and as temperature and pressure of a liquid increases, the attractive bonds (intermolecular forces) between the molecules in the liquid break (absorbing heat helps break bonds), allowing the molecules to separate from each other into individual molecules (when the molecules are broken free from each other, they become more mobile and start vibrating and moving around and colliding with each other causing great pressure in the liquid). When the pressure of the liquid reaches or surpasses atmospheric pressure, the individual molecules start escaping the liquid and float out of the liquid into the air as gas molecules-essentially the molecules become just like the atmosphere… gas. So, back to the pressure-temperature chart, if the boiling point of freon is approximately -41˚C, then at any temperatures below this (more negative/colder), the refrigerant would have lower pressure than atmospheric pressure and thus be in liquid form. At temperatures above -41˚C (more positive/warmer), the refrigerant would have same or higher pressure as atmospheric pressure and be in gas form… like the atmosphere itself. To help thoroughly understand this-think of a crowd of people forming, and as more and more people join the crowd, the more they start bumping into each other until it gets to be too much and individuals start leaving the crowd, escaping the cramped crowd…. like at a Metallica concert! Boiling Point and Condensation (Dew) Point of a commonly used refrigerant (freon) is exactly the same temperature, meaning freon evaporates (boils) into gas just as it surpasses -41˚C and it condenses into liquid just as it drops below -41˚C. -41˚C is an extremely cold temperature and generally not in the standard ambient temperature range, meaning it’s generally not a temperature that humans inhabit, however, what this means for freon and using freon as a coolant is it becomes gaseous in even cold temperatures, unlike many/most other substances, which further means it is gaseous in all temperatures above -41˚C… and thus very useful in AC units or refrigerators. So how does refrigerant (freon) help an AC unit cool the house? Freon is kept inside of a closed system and is transported back and forth between the condensing coils and the evaporator coils. The condenser unit cools and keeps freon below -41˚C which is when freon is liquid. This cold liquid freon is transported to the evaporator unit coils. The evaporator unit sucks warm air in from the house, cycling the warm air across the evaporator coils where the heat from the warm air is absorbed by the cold liquid freon causing the freon to heat up surpassing its boiling point (-41˚C) and evaporating (boiling) into gas. The now-cold air in the evaporator unit continues to cycle into the house cooling it. This warm freon gas is then transported back through the compressor and to the condenser unit. The compressor applies pressure to the gas helping condense it back into a liquid which forces the heat out of the freon gas. (Do not confuse this pressure with the pressure discussion in the first paragraph-“pressure of the liquid”. Applying “pressure to a gas” compresses it, in a way, squeezes it forcing the molecules to get closer to each other and form attractive bonds between each other… forcing it back into liquid form.) The condenser has a fan that blows the warm air that was released from the condensing gas out of the AC unit and cools the freon gas back down to below -41˚C. I believe the the compressor and condenser units simultaneously cool the freon gas back down converting it back into a liquid, because applying pressure to a gas, compresses it which forces the heat out of it and the fans in the condenser unit would have to remove the warm air immediately so it is not reabsorbed by the now-liquid freon. But you would know about the AC units better than I… correct me if I am wrong. Same/similar concepts can be applied to other types of refrigerants or the refrigerator.
@@PraxisAcademic That's a very thorough explanation and an outstanding effort of you to help .Thank you very much and I am definitely subscribing to your channel and will always recommend it to my fellow trainees.
I am glad this helped. I hope it helps on more BP-VP Qs... they can be a bit tricky on MCAT. I appreciate your feedback; all my videos, except Significant Figures... lol... are MCAT and DAT geared! Thanks for watching!
Atmospheric (gas) pressure is constant (ie: 1atm at sea level). The vapor pressure of liquids and solids are lower than atmospheric pressure (solids are lowest). When the surface molecules of a liquid or solid reach 1atm, usually due to temperature increase, the surface molecules of the liquid or solid will become gaseous. Liquids or solids reaching 1atm does not cancel out atmospheric pressure since that is constant (cannot be changed); liquid or solid molecules that reach 1atm vaporize into gas molecules--think of this as, if gases have a vapor pressure of 1atm, then any liquid or solid that obtains a vapor pressure of 1atm will become one with the atmosphere gas.
I'm using this to understand boiling point of refrigerants in HVAC industry.Please if able look for refrigerants PT charts in relationship to their boiling point and break it down for me as I am struggling at this area.Many thanks
Thank You for watching the BP and VP videos! I have a fundamental understanding of HVAC refrigerants, however, I will further investigate the function and application with regard to BP and VP today and hopefully be able to break it down for you... no promises for an explanation that meets your needs, but I will do my best.
The pressure-temperature chart for refrigerants shows the temperatures at which refrigerant is liquid or gas. And temperature and pressure are directly related, meaning as temperature of the refrigerant increases, pressure of the refrigerant increases, and as temperature and pressure of a liquid increases, the attractive bonds (intermolecular forces) between the molecules in the liquid break (absorbing heat helps break bonds), allowing the molecules to separate from each other into individual molecules (when the molecules are broken free from each other, they become more mobile and start vibrating and moving around and colliding with each other causing great pressure in the liquid). When the pressure of the liquid reaches or surpasses atmospheric pressure, the individual molecules start escaping the liquid and float out of the liquid into the air as gas molecules-essentially the molecules become just like the atmosphere… gas. So, back to the pressure-temperature chart, if the boiling point of freon is approximately -41˚C, then at any temperatures below this (more negative/colder), the refrigerant would have lower pressure than atmospheric pressure and thus be in liquid form. At temperatures above -41˚C (more positive/warmer), the refrigerant would have same or higher pressure as atmospheric pressure and be in gas form… like the atmosphere itself. To help thoroughly understand this-think of a crowd of people forming, and as more and more people join the crowd, the more they start bumping into each other until it gets to be too much and individuals start leaving the crowd, escaping the cramped crowd…. like at a Metallica concert!
Boiling Point and Condensation (Dew) Point of a commonly used refrigerant (freon) is exactly the same temperature, meaning freon evaporates (boils) into gas just as it surpasses -41˚C and it condenses into liquid just as it drops below -41˚C. -41˚C is an extremely cold temperature and generally not in the standard ambient temperature range, meaning it’s generally not a temperature that humans inhabit, however, what this means for freon and using freon as a coolant is it becomes gaseous in even cold temperatures, unlike many/most other substances, which further means it is gaseous in all temperatures above -41˚C… and thus very useful in AC units or refrigerators.
So how does refrigerant (freon) help an AC unit cool the house? Freon is kept inside of a closed system and is transported back and forth between the condensing coils and the evaporator coils. The condenser unit cools and keeps freon below -41˚C which is when freon is liquid. This cold liquid freon is transported to the evaporator unit coils. The evaporator unit sucks warm air in from the house, cycling the warm air across the evaporator coils where the heat from the warm air is absorbed by the cold liquid freon causing the freon to heat up surpassing its boiling point (-41˚C) and evaporating (boiling) into gas. The now-cold air in the evaporator unit continues to cycle into the house cooling it. This warm freon gas is then transported back through the compressor and to the condenser unit. The compressor applies pressure to the gas helping condense it back into a liquid which forces the heat out of the freon gas. (Do not confuse this pressure with the pressure discussion in the first paragraph-“pressure of the liquid”. Applying “pressure to a gas” compresses it, in a way, squeezes it forcing the molecules to get closer to each other and form attractive bonds between each other… forcing it back into liquid form.) The condenser has a fan that blows the warm air that was released from the condensing gas out of the AC unit and cools the freon gas back down to below -41˚C. I believe the the compressor and condenser units simultaneously cool the freon gas back down converting it back into a liquid, because applying pressure to a gas, compresses it which forces the heat out of it and the fans in the condenser unit would have to remove the warm air immediately so it is not reabsorbed by the now-liquid freon. But you would know about the AC units better than I… correct me if I am wrong.
Same/similar concepts can be applied to other types of refrigerants or the refrigerator.
Sorry that was such a long response, but I love connecting fundamental science concepts to complex systems!
I hope it helps at least a little. ☺
@@PraxisAcademic That's a very thorough explanation and an outstanding effort of you to help .Thank you very much and I am definitely subscribing to your channel and will always recommend it to my fellow trainees.
This makes so much more sense than when we learned this in school. thanks
Thank you so much, you just helped me understand this mcat q!
I am glad this helped. I hope it helps on more BP-VP Qs... they can be a bit tricky on MCAT. I appreciate your feedback; all my videos, except Significant Figures... lol... are MCAT and DAT geared! Thanks for watching!
Oh Thank God....... Nicely explained.....
Thank You! I am glad this helped!
What a teacher.Thank you
Thank You!
Thanks
Thank You for watching!
If vapou pressure becomes equal to atm pressure dont they cancel out each other?if it happens then how ?please reply😢
Atmospheric (gas) pressure is constant (ie: 1atm at sea level). The vapor pressure of liquids and solids are lower than atmospheric pressure (solids are lowest). When the surface molecules of a liquid or solid reach 1atm, usually due to temperature increase, the surface molecules of the liquid or solid will become gaseous. Liquids or solids reaching 1atm does not cancel out atmospheric pressure since that is constant (cannot be changed); liquid or solid molecules that reach 1atm vaporize into gas molecules--think of this as, if gases have a vapor pressure of 1atm, then any liquid or solid that obtains a vapor pressure of 1atm will become one with the atmosphere gas.
@@PraxisAcademic now i feel better thank you btw example was great ❤️