We will will help you scientifically understand how an air conditioner removes heat from a building. Warning: Some of you may get flashbacks to high school chemistry and the Ideal Gas Law (PV=nRT).
Your video is straight forward, your sketch is clear, concise and specific, and your physical demonstration of refrigeration cycle is just corresponding to the sketch! Thank you!!
By far the best explanation I could find on youtube. You are super crisp in your technical explanations and now I don't need to go through a lot of literature to understand phenomena behind refrigeration cycle. Kudos to your efforts !
You explained it better than many other videos I have seen on this topic. I think all the difference was in explaining how compression reduces volume which leads to increase in temperature.
I really learned something. Being a dummy about this i always thought when i went out to my compressor outside that the thick cold pipe was going INTO the house and the thin hot pipe was coming FROM inside. It's the opposite. Very good video. Thank you.
Excellent explanation, I never could grasp the idea of why the temperature would have to get increased even more in the refrigerant, now I understand. Many thanks......
Funny you said that because Same with me couldn’t understand why refrigerant tempeture needed to be raised to get cooler, I did research other places then this video just shined a light on it
You are talented! I have watched dozens of videos on this topic and although some did a decent job of explaining the details, none of them did as well as you! I really liked the vertical line concept, where you divided the 4 components into two categories, that's not something I've seen anywhere else. That made the difference in the concepts clicking for me.
We do not know who CGP Grey is, but they must be selecting from the same library of free use music that our video guys does. (we may be a little frugal over here LOL)
I definitely thought the names for "liquid line" and "suction line" were stupid and confusing before you broke it down this way. It's easier to think about the liquid line and txv being one pair in the cycle and the suction line and suction line and compressor being the other pair.
I have a question please .. I am not native speaker so my grammar not that much good.. what is the temperature at the suction and discharge line of the throttle expansion valve TXV ? and is decreasing pressure in this valve the main reason of decreasing temperature which will be capable to absorb heat from the food inside ?
This video was based on HVAC, not refrigerated food storage, but the principles are the same. Temperatures are specific to the application and the type of refrigerant used. Yes, the decrease in pressure through the TXV decreases the temperature since this is a fixed volume. PV=nRT
@@bah920 P*V=n*R*T is only valid for ideal gasses. A refrigeration cycle expands liquid into a two state mixture, which isn't even close to an ideal gas. The process occurs as the liquid drops pressure and ends up at a pressure where it should be boiling. This causes some of the refrigerant to use the thermal energy to change its state from liquid to gas. On net, there is no heat added or removed from the system, but it drops in temperature by producing another destination for its thermal energy (i.e. the latent heat of vaporization). If you did expand an ideal gas through a valve like this, it wouldn't produce any temperature drop. Real gasses do change temperature by a small amount, and some real gasses (e.g. helium) even heat up when doing this, in an effect called the Joule-Thompson effect. But for an ideal gas, there theoretically is no temperature change, when expanding in an isenthalpic process (i.e. a frictional valve). You need a turbine or other equipment that trades thermal energy for mechanical work, in order to drop temperature as an ideal gas expands.
at which point in condensing coil the Freon will start to change from vapor to liquid ..and the evaporator from liquid to vapor ? can you answer and help me please
Nice video I think what would’ve made this video better is if you will explain everything inside of the condenser I see parts on the suction line that you’re just running your finger across and not explaining what they are or what they do
There is a refrigerator built as an application of the ideal gas law, which is called the Bell-Coleman cycle. It is the Brayton cycle (what airplanes and gas-fired power plants use) but in reverse, that uses air as a working fluid. The standard refrigeration cycle is like a Rankine cycle in reverse, while the Bell-Coleman cycle is a Brayton cycle in reverse. The essential difference is that a turbine has to replace the throttling valve, because air doesn't drop in temperature in an isenthalpic process nearly as much as refrigerant does, when expanding to a two-state mixture. So they replace the isenthalpic process with an isentropic process, and re-capture some of the backwork. With standard refrigeration cycles, the diminishing return of the turbine means that the design opts for a valve instead. A Bell-Coleman cycle isn't as common as a standard vapor-compression refrigeration cycle, because air's heat transfer properties are a lot worse than that of refrigerant, so the two heat exchangers aren't nearly as effective with air, as they are with boiling and condensing refrigerant.
Why do you use the phrase "condensor rejects heat" rather than "condensor emits heat"? The light bulbs in my house don't reject light, they emit it. Also, according to the diagram, the temperature on either side of the TXV appears to be the same (the colours are the same) - in reality, there is a drop in temperature across the TXV that matches the drop in pressure.
Rejecting heat is the common way to describe heat leaving the structure. Condensers, condensing units, and cooling towers are always referred to as rejecting heat. Terminal devices inside the structure are usually referred to as heat emitters, such as radiators, convectors, etc. Or at least that is the terminology used by the HVAC industry in the Midwest.
@@TECTubefilms P*V=n*R*T is only valid for an ideal gas, which essentially means a gas that isn't anywhere close to its liquid state. The reason the expansion valve cools the refrigerant is due to the liquid refrigerant dropping pressure to a point where it should be boiling. The refrigerant trades energy of its temperature, for energy of its phase (the latent heat of vaporization), as it passes through a frictional constriction that drops pressure with no energy exchange.
@@carultch Yes, you are correct that PV=nRT stops being the correct formula once we enter the liquid state. However there still exists a similar relationship of temperature and pressure for liquids. As you decrease pressure of a liquid, temperature also decreases, and vice-versa. However, because we have an incompressible liquid, the P/T relationship is not as linear as it is for a compressible gas. A large decrease in pressure only yields a small decrease in temperature.
I have one question,how refrigerant condenses when the its boiling point itself -40 degree C. Because outdoor temp will be 30+ degree. I know that it is because of pressure, i had read it somewhere but,can anyone explain
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Not sure what you are asking? Which specific pipe? What are you switching on in this example? A compressor, a condenser fan, an evaporator fan, or all 3?
@@TECTubefilms the two copper pipe line that from outdoor unit (compressor i supposes) to indoor unit pipes, one of them (the small pipe was icey when switch on..but only for 1 minutes)
@@tedcleveland8488 That is not normal at all. If you had ice issues develop after running for a while, that is usually either an airflow or charge issue. Not sure why you would see ice on the lines during startup, though. For ice to form, that means the pipe itself got colder than the dewpoint of the air and caused condensation AND the pipe (or the air directly adjacent to the pipe) dropped below 32 degrees.
where is the sub cooling and superheat explanation? that is also part of the refrigeration cycle I have to say is a good video but I think that you just when over a basic of the basic of the really basic of the basic cycle.
