here we have our basic refrigeration cycle powerpoint for new students to understand and we have this side in red and that side on blue because this is the high pressure high temperature side and the other side is a low pressure low temperature side and you have two components in any system that separate the high and low pressure sides and that's the compressor and the metering device so the compressor's job is to increase the pressure of the refrigerant in order to increase the temperature the metering device's job is to lower the refrigerant pressure in order to lower the temperature of the refrigerant and so you have your low pressure low temperature vapor refrigerant enters into a refrigerant compressor in this case it's a reciprocating compressor that's what that looks like right there and then you have on the outlet of the compressor high pressure high temperature vapor refrigerant and so what happens is the high pressure high temperature discharge gas is entering into the condenser coil where the refrigerant is going to reject its heat at and so the refrigerant traveling through a refrigeration cycle the whole object is it's moving heat it absorbs the heat energy over at the indoor coil or the evaporator and it rejects heat energy at the condenser coil that's the job and you are manipulating the refrigerant because you have a pressure increasing device and a pressure decreasing device you're using air across the condenser coil in order to reject the heat from the refrigerant into the outdoor air and you are absorbing heat energy by blowing the indoor air across that indoor coil and then you have low temperature air on the other side you have air then you have a coil and then you have the refrigerator inside and so you have those three things happening so you have high pressure high temperature discharge gas traveling into the condenser coil and then it comes out of the condenser coil as a high pressure high temperature liquid refrigerant so this is going to be sub cooled refrigerant because it's going to allow the refrigerant to lower in temperature between here and here so it's going to be sub cooled liquid fully in the liquid state as it travels through the liquid line surface valve as it travels through the filter dryer and so the filter dryer's job is to absorb any water vapor in the system and it's trying to collect that and store that so that the water vapor in the system does not mix with the refrigerant oil which could damage the compressor electrical windings so you got to think about that refrigerant oil are traveling through any refrigeration system that compressor is hermetically sealed and so there's an electrical motor on the inside of there with electrical windings that are exposed to the refrigerant because the refrigerant's job is not only to do this whole loop but it's to also lower the temperature of the motor inside it's to cool the motor and so you can take a pressure reading right here at this surface valve you can also shut down this surface valve up here at the top the filter dryer is just to trap any moisture but it has a limited capacity so basically you have sub cooled liquid traveling through here it remains unchanged so then you have the refrigerant entering into the metering device so it's a high pressure high temperature sub cooled liquid refrigerant entering the refrigerant is forced to go into the inside of the piston metering device and then it's going to lower in pressure so then it's going to be in the low pressure liquid state but really as you can see there's a little bit of light blue at the top that is your little bit of vapor refrigerant so what's happening is you're reducing the pressure so much that the refrigerant has a chance to expand and so you have eighty percent liquid twenty percent flash gas as the refrigerant enters into the coil it's already saturated and saturated means liquid and vapor both exist at the same time anytime the refrigerant is saturated you have a phase change occurring and the phase change is the big secret to allowing the refrigerant to absorb heat energy from the air crossing the coil and that is because any time that the refrigerant is saturated where liquid and vapor exist it's always the same temperature as it travels through the coil until in this case becomes a vapor state in the fully vapor state once it becomes vapor it can then increase in temperature as the hot air is blowing across the coil it's going to the refrigerant is going to absorb heat energy a low pressure low temperature vapor refrigerant exiting the indoor evaporator coil and then you have the low pressure low temperature vapor refrigerant re-entering into the compressor and then the cycle starts all over again it's also important to make sure that you also have vapor refrigerant entering in order to have vapor refrigerant exiting so you got to remember that that compressor is a vapor compressor you shouldn't have saturated refrigerant entering into that compressor saturated means there's going to be a little bit of liquid in the refrigerant right that would damage the compressor so if that indoor blower motor was broken maybe the capacitor was bad or whatever the blower motor stopped working that refrigerant is not going to be able to absorb any heat energy at that indoor coil and so you're still going to have saturated refrigerant entering into that compressor and that's going to damage the compressor that's the basic refrigeration cycle if you want to learn more make sure to check out some of the resources we have over our website at acservicetech.com we also have our refrigerant charging and service procedures for air conditioning books so this is everything i want you to know about air conditioning systems and preparing a system for refrigerant checking the charge and also troubleshooting a system and then we also have our thousand question workbook and so this has a self-study guide so you can check your own answers in order to see you know if you're retaining the information there's a thousand questions in this and then we also have quick reference cards and we have refrigerant weights on these pt charts we have the uh checking the charge methods of total super heat and sub cooling we've got the step-by-step directions on here so make sure to check all this out over the website at ac servicestick.com and we also have these resources available over on amazon so you can read the reviews there hope you enjoyed yourself we'll see you next time at ac service tech channel