So here it fucking is. How to HVAC max and be like me. Why do electrical or plumbing and make almost twice as much when you can be like me and do HVAC witch is more brain consuming then either of those 2 trade and pay somewhere between automotive and plumbing? Well here is part of why I HVAC max. It make you in a weird way a trade Chad as in you can if you can do HVAC. You can do plumbing drunk or electrical sleep deprived. No one will admit it or agree but HVAC has a skill gap that comparing it to plumbing is like comparing COD ghosts to battlefield 4. One make you a better brained tradesman and the other gives you financial privileges. One gives you Chad like trade ability's and the other gives you Chad like pay. So if you rather have Chad like trade ability's then lets begin.
Electrical: so before learning HVAC you need to know about electrical. Don't matter weather furnace or Heat pump you need to know about electrical first since all of HVAC systems need electrically. Unless you want your compressor to run off either a exercise bike or a engine. Its used for heat pumps and controls such as a furnace mother boards, the thermometer, and safety mechanisms. if you already know about then electrical then what you need to know now is that HVAC systems in residential settings run on 2 currents. First is the 120/240E current for motors and other big stuff. The second current is the 24E current for controls/relays. between those 2 currents is gonna be a step down transformer. But also wire from the 24 to 120 for the control stuff to happen. Keep in mind most of this shit in a HVAC system is automated except for the thermometer or circuit fuckery done by a tech or home owner. Another thing to know is the wire colors for the systems. Unless someone fucked it up the colors should match with certain parts of a HVAC system in residential and probably commercial setting. Red wire is the 24E power supply(possibly the 120E supply as well but possibly not to) and is a guarantee to be seen anything involving HVAC. Green wire is the for the fan systems weather blower motor or fan in a air handler and because its connecting to a motor it will be in the 120E or should be the 120E circuit. Yellow is for the compressor or cooling system or I should say compressor motor since who the fuck uses a engine for a compressor? Yeah yellow is for the compressor. Orange should be for the heat pump or more likely the pilot switch heat pump. Blue is the common or neutral wire. basically the wire sending the current the fuck back home.
Basic: Something I should've done before electrical but my thread my rules, but how does a HVAC system work? It's really not much more then channeling heat were its either needed or not needed. For AC we need to flash back to middle school. If you weren't getting beaten by a physically abusive mom like I was in middle school you were learning in physics class how there no such thing as cold, less hot. So how does a AC system make something "cold"? Well to understand that you need to understand 3 things. First is that there's shit out there that likes to absorb heat. You went swimming? Wile getting mogged by shirtless Chad in the pool the water would be absorbing your body heat. In a AC system there is refrigerant that flows through part of the house to absorb heat. But that refrigerant channel in really only found in the garage except for ductless systems. Second thing to know is that pressure tend to fuck with heat. When something goes under high enough pressure that pressure is also a type of energy. Same with heat. When pressure builds up like in Eliot's bullets in that Glock of his, that pressure will expel the bullet but pressure can also expel heat alone and even change the state of matter of substance regardless of temperature. There's even a planet found by NASA were it has hot ice. Genuine ice you see in a freezer but its very fucking hot due to giga pressure. Lack of pressure will do the opposite witch is absorb or in the ACs case, absorb heat. The 3rd and final thing to know for this section is that ambient air that you breath can transfer heat. That factor also plays into how a furnace works. When you blow into something hot the first thing that'll happen is people will stare at you thinking your a retard. But the more important thing to know when blowing into something hot is that the air will take some of that heat with it and become warmer air. If you blow onto something cold that air will loos heat because the heat from the air you blow will go to what's cold. So the take away from this section is heat is the equivalent of what black people call a hoe, traveling to all these men/things that absorb heat.
Basics AC : Now I explain a shot load of things of how HVAC work lets talk the mechanics of a AC system. There's 4 main components to a AC system. Lets begin with the evaporator. This is were refrigerant is at its lowest pressure. Most of the time in a Evap system it'll be a low pressure vapor. As being low pressure it'll have "room" to absorb heat from the air blown on the outside of the evaporator. Then the compressor moves the refrigerant in a one-way direction for the system (exception for heat pumps). The compressor will pump the refrigerant as a low pressure vapor into a high pressure vapor into the condenser. The condenser will be smaller size then the evap due to the fact evap needs more surface area to absorb more heat. Also the fins on both the condenser and evap have these fins for increase of surface area and are usually are soft metals outside of the ACR coppers to channel heat more efficiently. The refrigerant in a condenser will go from a high pressure vapor into a high pressure liquid Right up until the 4th component. The expansion valve. This is the part that restricts the amount of refrigerant into a system. Think of it as the HVAC version of a resistor. The expansion valve comes in multiple flavors such as : Thermal Expansion Valve, Electric Expansion Valve and Capillary tube. The Capillary tube is just a funnel that restricts refrigerant flow by its shape alone and how no moving components or anything's techy. Refrigerant after passing the expansion valve of choice will be back into the evap as a low pressure liquid so the cycle can repeat. Thermal Expansion and Electric Expansion instead regulates how much refrigerant can go to the evap via computer means giving the system more effieancy but more maintenance being required.
Heat Pump: So if you wonder what would happen if you reversed that refrigeration cycle then wonder no longer. You see the pressure refrigerant is under alone can be enough to heat the condenser the fuck up and pretty good. So company's found out not only can you turn the evaporator in a condenser by reversing the refrigeration cycle but its also more efficient the electrical heating. It might need assistance of electrical heating/ gas heating if cold gets to freezing but usually is a cheaper way to put the heat in housing. Another thing is that the refrigeration filters are usually gonna be in direct series with the compressor in a heat pump so that when the cycle switches between heating and cooling, the refrigerant flow doesn't push the shit the filter caught out of the filter and all over the heat pumps internals. Remember the orange wire on the electrical section? Well I bring it up now because I'm not entirely sure but it could be for only one purpose. To switch between AC and Heat Pump what the thermal stat does is send a current through the orange wire into this 4 valve system. That 4 valve system is what chooses witch direction refrigerant will be channeled to. When heat pump time comes, the signal from the thermostat will put in the current that goes to this magnetic field. It'll attract a magnet that'll block the flow of this small mini channel or refrigerant that cause a short chain reaction to change the other small channel flow that'll move the internal valve around, you know what, your probably better off searching up heat pump components on you tube. I know how it works but its a bitch to explain it.
Motors: The 2-3 hearts of a HVAC system is gonna be the motors in a system. Regardless of a compressor motor or blower motor you should know these things about motors. They work by running a current that makes the magnets inside them go ape-shit and they spin around. But short winding and ground winding (were short circuits with in the winding) will typically mean the end of a motor. The days of actually fixing them are fucking over and is replaced by replacing things like a dumbass barbarian. But if you want to find out weather or not you got short winding all you need to do is either 1 of 2 things. Both require either a multi or more likely a clamp meter since Clamp meters are more common for HVAC techs. Option one is measure the Amp with the circuit shut the fuck down (don't rope your self with current). But these motors will be running the 120/240E current in AC so if the voltage goes way lower then that, the short winding will mean less E in that motor in general since its literally taking a U-turn at the traffic light. Your 2nd option will be Measuring the ohmage. If there is very little R in the circuit then it also explains the lack of E in a circuit since you know... E=IR... As for ground shorting in a motor its a matter of using a Mego-meter. This motherfucker will shit out 10KV of DC to look for a ground shorting but is really used for compressor motors and if I'm right only really used for Hermetic Compressor Motors. On larger open style motors you'll probably need to replace bearings, I did it once in class and fucked up my finger in the process. Oh and something to note, most modern day AC/Heat-Pump systems use hermetic or sealed compressors so good luck working on one LOL. There sealed in a way were you need a angle grinder to open it up and welding equipment to close it down, literally.
Compressors: so outside of the motor part there mothing more then really pumps for the refrigerant. That's it. They do come in variety but nothing to special about the variety except for water chillers. They do need oil for lubrication and that oil and mix can in with the refrigerant and fuck things up.
EPA 608: So one major thing you need to have is a EPA certification if you wish to work with refrigerants. And there's 4 types. Plus the EPA basic that must be completed in addition to witch ever type you want to have. Type 1 is for small appliances were the system is 5 pounds and under. Type 2 is for the shit over 5 pounds aka anything that isn't a appliance or MVAC. MVAC is basically the AC system for cars and is its own thing. It allows for any AC/Heat-Pump Over 5 pounds but no less the 6. Technically the limit is 200 pounds. Type 3 is for low pressure systems. 50 to 500 pounds. But its called low pressure because the low side or the cooling side of the system is under a vacuum pressure. Low pressure systems are typically water chillers witch is a whole thing in its self. I myself got the 4th type with is universal. But to be honest Id love to work on water chillers.
Recovery: So if there is a leak or a needed major repair on a AC system. You need to do a recover on that system were you take all or most of the refrigerant into a tanks that's around the size of a propane tank. First 2 things to know: the tank should be empty with a grey body and yellow top. Second thing to know is not to exceed 80% of the tanks filling capacity. That's because the refrigerant will then expand and turn the tank into a fucking bomb. Refrigerant in general doesn't like to stay in a liquid state witch is what you'll be recovering the refrigerant as most likely. Oh and when recovering refrigerant you'll always want to do the high pressure side of a AC system. That high pressure will speed up the process ALOOOOTT. You can do low side but it'll be way slower. Also when you put refrigerant into a AC /Heat-Pump system, put it in the low side as it'll be empty and a vacuum( if you properly purged and evacuated the system with you always do before putting shit into the system) and the low side will suck that gas up the ass. There's also other terms used by the EPA 608 such as recycling, reusing with different meaning but is never really mention that much outside of 608 talk. Have a scale with you so you can tell how much refrigerant you moving somewhere. It's also one of 3 ways to prevent you from exceeding the 80% mark. Oh and one last thing for this section DO NOT MIX REFRIGERANTS!!!!! Shit will go to shit if you do so.
Other shit : Get a clamp meter and make sure its a CAT 2 meter. You can use a multi meter but sometimes you just want to use the clamp to check amperage and not risk shocking your self with the metal butt plugs that comes with the meter. Also you can hang it up one some things in times you need a 3rd arm. Get your self some quick disconnect pieces on your PSI gauges if you want to reduce the loss or refrigerant when checking the pressure of a system. Look around in a attic or crawl space before going there. It would be shitty to be bitten by a rabid animal. Remember when I said substances like water attract heat? Because the evap of a AC system will attract that heat also, water will condense on the outside of a evap system giving dripping on a system. Make sure the drainage is clear to prevent water puddles from happening. As for piping on a AC/Heat0Pump, ACR is a type of copper tubbing most commonly used for refrigerant flow in AC systems.
Super heat: so if a AC system works to well then Super heat will kick in. It basically heats up the Evap coil slightly to prevent ice from building up and turning the evap useless due to insulation gone wrong. If the fan on a evap system goes to shit then that'll also provide a risk to the evap icing up.
Super cooling: I don't know much about it but I think its supposed to cool the condenser to improve effieancy of a AC system.
Duct system: So the V in HVAC. It means ventilation. You see a evap or what ever used for heating isn't enough to change the temp of a environment. You need something to spread that temperature of that evap/ heat the room up thingy. So that were fans have the role for blowing air through it and getting that air of desired temp into were its fucking needed. So that's were ducting goes into play. A channel for air to go through and change the ambient environment into one more desirable. It don't matter weather if its AC or heating. There will be air flowing around to get the job done. Or prevent you from breathing in contaminated shit. Hence why air filters are a thing in ventilation. If the ducts get dirty witch they will do eventually then duty will call for someone to clean it the fuck up so that air can flow and do it's job.
Heating: I already bitched about heat pumps so that'll be in it's place. But there 3 other methods of heating ( also relay on ventilation) that should be talked about. The 2nd oldest method of heating is gas heating were natural gas ( what ever the fuck natural gas is substance wise) will be ignited into a burner and go through these vent tubes on the inside. On the outside will be ventilated air via a blower motor fan system to put that heated air to good use. Furnaces are old school for heating but are also the most dangerous way of heating up a house considering many things can go wrong. The next and probably most rare method of heating is oil heating. It's a rare way of heating up a house because that "oil" is actually diesel. Except that diesel is dyed red so people cant use it in diesel car(witch is illegal due to some bullshit diesel tax nothing more) but its kind of the same way as natural gas. Only difference is that there's this big ass tank to store the diesel and between the oil furnace and tank is a diesel filter. Still a dangerous heating method but in my opinion its way safer then gas heating. Now for another heating method. Before heat pumps but after gas heating was electric heating. Its nothing more then making one of those electric radiators you see from a store, having it built in the house and having built on a the room. Its the same concept as a electric stove/oven were it runs a current through high R and that causes friction amongst the amperage. For more info just look this shit up on you tube. In fact you tube will probably give you better info then what I'm giving you since I got shit memory for the whole subject on the damn thread.
Water chillers: I don't know much about the setting of were you can find water chillers witch is a shame since its the system I want to work on the most. I know there mostly used in either commercial or industrial settings. What there good for is cooling down a big ass space with better effieancy then a big ass high pressure AC system but they come at 2 costs. 1st cost of a water chiller is because they use water as a secondary refrigerant, they cannot freeze jack shit, give it thought and you'll understand why. 2nd cost is they are complex. I only really know of 1 type of water chiller and that is called a centrifugal compressor. Air ventilation does play a role in a water chiller but most of it is gobbled up by water circulation. The AC system in a water chiller has low pressure on the high side and vacuum pressure on the low side. Instead of the Evap/Condense coils having air go around them its water. And there's 2 water channels for the water chiller. Low side geos through the Evap and goes to were it's needed. High/Condense side will absorb heat from the condenser and then flow through what's called a cooling tower witch acts like a giant expansion value and is located on the roof of a building. And the reason to go through all this trouble is for effieancy. If you wanted to accomplish the same with a industrial AC system it would be way way more refrigerant then what's in a water chiller for its own AC system. Also water is way more cheaper then refrigerant so should a big ass leak happen, then it would be as much of a shit show. In fact most leaks in a water chiller have the opposite effect of a normal AC system. Instead of shit getting out. Shit gets in the system and in response the centrifugal device will have purge units to clean out the refrigerant. Leak testing is also done differently as you need to heat up the water to test the leaks though I don't know how or why you do so. Same thing for recovery/evacuating a chiller. You need to heat up water to get more refrigerant out and speed up the process. But if I had to guess a lot of the times when a Water chiller leaks its due to a shit gasket. These systems use a decent amount of gaskets not found on normal AC systems. Unfortunately I don't know jack shit about the motors for water channeling or how water is even moved in the first place. That's something I'll have to figure out in the future.
Hazards: Outside of nails sticking out in either the attic or crawl space alone( got my head scratched by these nails, not good since I'm 15 years late for my tetanus shot) with a rat that wants to rip your balls off, there's 2-3 hazards I can think of for AC/Heat pumps. One is electrical. Know how to safely handle electricity. In fact you should know electrical before HVAC to keep bad shit at bay. Other is what I like to call refrigerant surprises. Either pressure gets too big and explodes or enough leaks and gets on your skin and eats it up. If shit show #2 happens then use Luke warm water to ease off the cold burn. Furnaces. Now the thing with furnaces is that the gas supply will go on and off but the ignition switch is time based. If enough of that natural gas leaks into the house and that switch goes off. BOOM. When screwing/ unscrewing pipes, use a new batch of thread sealing stuff( IDK if you would use plumbers tape or thread lock in that case). You don't want gas building up in a home just so a switch can ignite on a bunch of leaked up gas and jihad a house(unless its a woman's house then you probably will... And a Chads house). Another not so known hazard will be CO2 leak. After the natural gas is burnt it turns into CO2 and need to be ventilated. Failure to ventilate can either resulting of a automated shut off switch in some furnaces( that activated when it doesn't sense oxygen) or CO2 into the ventilation gassing the poor fuckers to death. Diesel... At worst it can start a house fire but chances of a explosion are super rare. CO2 are not a exception to diesel furnaces. Electric heating can start a fire but if its surrounded by not so conductive metal and not wool/ flammable shit then chances are rare. Incase your too retard to ignore the electrical advice, Do not wear loose clothing or jewelry. Especially gold as gold is the equivalent to amperage that a free way is to the VTEC of my Truck-kun. In fact copper and gold are very conductive ( gold is more conductive) so don't fuck with either of them. Have a 2nd person with you if your doing dangerous shit. Especially when going in a crawl space to prevent you for being left for dead if shit goes bad. A second person with you is literally cock blocker for the grim reaper. And your not gay so use it. Watch out for booby traps. Some cases the costumers you serve are probably victims of scam trades man. Typically company's that hire non licensed individuals for a job. They wont know what the fuck there doing and will leave something dangerous for someone to be a victim to. In other cases it'll just fuck up someone's house like seen on my "PLUMBERS GONE WILD! DRAMMA EDITION!" thread. Someone might not have properly sealed up the gas pipeline and left a gas leak. Someone might have put the wrong fuse and a AC system has gone to shit. Another hazard though not to you but weirdly enough is traffic victims. There is this youtuber named Rodger Wakefield who made a video on how to spot human traffickers in a house. Apparently tattoo markings are common on victims. See his video for more info. Driving. Weather residential, commercial or industrial, you will have to drive to get the job done. You cant drive like a black person who watches too much Vin Diesel movies. You need to be observant and careful. Go a little slower. You would rather see a accident on you tube then in your life. Also stay clean. As for any trade if the company finds out you have drugs in your system, your chance of working in a lot of trades are bye bye. Same with a criminal record.
End: As I type this. I have universal on my 608 despite forgetting a whole bunch of the content I was taught. And I'm a month away from entering my final quarter for HVAC and getting the certificate. If I do land a job and don't jump ship to doing electrical (since the pay is Chad tier) then I'll be able to re-learn all I was taught the hard way at my job. Despite never going to plumbing school I still have a much better time understanding plumbing then anything else with the only plumbing thing I ever did was flush my moms water heater. I hope after this final quarter that one of these days I can move to Utah(and pray I don't face a ERPO order despite not doing anything threatening or dangerous with my guns), get the fuck out of WA state before I get mauled by a fucking tweaker. Work on water chiller despite the struggle I'll face. Own a 2nd gen CRV with a manual. Mod the fuck out of that CRV. Who knows what fate await my virgin ass. But I do hope this gives you guys some trade fuel along with the other trade threads I made. I might put in another section in the comments for what ever important things I miss. Merry Christmas. And happy new year.
Electrical: so before learning HVAC you need to know about electrical. Don't matter weather furnace or Heat pump you need to know about electrical first since all of HVAC systems need electrically. Unless you want your compressor to run off either a exercise bike or a engine. Its used for heat pumps and controls such as a furnace mother boards, the thermometer, and safety mechanisms. if you already know about then electrical then what you need to know now is that HVAC systems in residential settings run on 2 currents. First is the 120/240E current for motors and other big stuff. The second current is the 24E current for controls/relays. between those 2 currents is gonna be a step down transformer. But also wire from the 24 to 120 for the control stuff to happen. Keep in mind most of this shit in a HVAC system is automated except for the thermometer or circuit fuckery done by a tech or home owner. Another thing to know is the wire colors for the systems. Unless someone fucked it up the colors should match with certain parts of a HVAC system in residential and probably commercial setting. Red wire is the 24E power supply(possibly the 120E supply as well but possibly not to) and is a guarantee to be seen anything involving HVAC. Green wire is the for the fan systems weather blower motor or fan in a air handler and because its connecting to a motor it will be in the 120E or should be the 120E circuit. Yellow is for the compressor or cooling system or I should say compressor motor since who the fuck uses a engine for a compressor? Yeah yellow is for the compressor. Orange should be for the heat pump or more likely the pilot switch heat pump. Blue is the common or neutral wire. basically the wire sending the current the fuck back home.
Basic: Something I should've done before electrical but my thread my rules, but how does a HVAC system work? It's really not much more then channeling heat were its either needed or not needed. For AC we need to flash back to middle school. If you weren't getting beaten by a physically abusive mom like I was in middle school you were learning in physics class how there no such thing as cold, less hot. So how does a AC system make something "cold"? Well to understand that you need to understand 3 things. First is that there's shit out there that likes to absorb heat. You went swimming? Wile getting mogged by shirtless Chad in the pool the water would be absorbing your body heat. In a AC system there is refrigerant that flows through part of the house to absorb heat. But that refrigerant channel in really only found in the garage except for ductless systems. Second thing to know is that pressure tend to fuck with heat. When something goes under high enough pressure that pressure is also a type of energy. Same with heat. When pressure builds up like in Eliot's bullets in that Glock of his, that pressure will expel the bullet but pressure can also expel heat alone and even change the state of matter of substance regardless of temperature. There's even a planet found by NASA were it has hot ice. Genuine ice you see in a freezer but its very fucking hot due to giga pressure. Lack of pressure will do the opposite witch is absorb or in the ACs case, absorb heat. The 3rd and final thing to know for this section is that ambient air that you breath can transfer heat. That factor also plays into how a furnace works. When you blow into something hot the first thing that'll happen is people will stare at you thinking your a retard. But the more important thing to know when blowing into something hot is that the air will take some of that heat with it and become warmer air. If you blow onto something cold that air will loos heat because the heat from the air you blow will go to what's cold. So the take away from this section is heat is the equivalent of what black people call a hoe, traveling to all these men/things that absorb heat.
Basics AC : Now I explain a shot load of things of how HVAC work lets talk the mechanics of a AC system. There's 4 main components to a AC system. Lets begin with the evaporator. This is were refrigerant is at its lowest pressure. Most of the time in a Evap system it'll be a low pressure vapor. As being low pressure it'll have "room" to absorb heat from the air blown on the outside of the evaporator. Then the compressor moves the refrigerant in a one-way direction for the system (exception for heat pumps). The compressor will pump the refrigerant as a low pressure vapor into a high pressure vapor into the condenser. The condenser will be smaller size then the evap due to the fact evap needs more surface area to absorb more heat. Also the fins on both the condenser and evap have these fins for increase of surface area and are usually are soft metals outside of the ACR coppers to channel heat more efficiently. The refrigerant in a condenser will go from a high pressure vapor into a high pressure liquid Right up until the 4th component. The expansion valve. This is the part that restricts the amount of refrigerant into a system. Think of it as the HVAC version of a resistor. The expansion valve comes in multiple flavors such as : Thermal Expansion Valve, Electric Expansion Valve and Capillary tube. The Capillary tube is just a funnel that restricts refrigerant flow by its shape alone and how no moving components or anything's techy. Refrigerant after passing the expansion valve of choice will be back into the evap as a low pressure liquid so the cycle can repeat. Thermal Expansion and Electric Expansion instead regulates how much refrigerant can go to the evap via computer means giving the system more effieancy but more maintenance being required.
Heat Pump: So if you wonder what would happen if you reversed that refrigeration cycle then wonder no longer. You see the pressure refrigerant is under alone can be enough to heat the condenser the fuck up and pretty good. So company's found out not only can you turn the evaporator in a condenser by reversing the refrigeration cycle but its also more efficient the electrical heating. It might need assistance of electrical heating/ gas heating if cold gets to freezing but usually is a cheaper way to put the heat in housing. Another thing is that the refrigeration filters are usually gonna be in direct series with the compressor in a heat pump so that when the cycle switches between heating and cooling, the refrigerant flow doesn't push the shit the filter caught out of the filter and all over the heat pumps internals. Remember the orange wire on the electrical section? Well I bring it up now because I'm not entirely sure but it could be for only one purpose. To switch between AC and Heat Pump what the thermal stat does is send a current through the orange wire into this 4 valve system. That 4 valve system is what chooses witch direction refrigerant will be channeled to. When heat pump time comes, the signal from the thermostat will put in the current that goes to this magnetic field. It'll attract a magnet that'll block the flow of this small mini channel or refrigerant that cause a short chain reaction to change the other small channel flow that'll move the internal valve around, you know what, your probably better off searching up heat pump components on you tube. I know how it works but its a bitch to explain it.
Motors: The 2-3 hearts of a HVAC system is gonna be the motors in a system. Regardless of a compressor motor or blower motor you should know these things about motors. They work by running a current that makes the magnets inside them go ape-shit and they spin around. But short winding and ground winding (were short circuits with in the winding) will typically mean the end of a motor. The days of actually fixing them are fucking over and is replaced by replacing things like a dumbass barbarian. But if you want to find out weather or not you got short winding all you need to do is either 1 of 2 things. Both require either a multi or more likely a clamp meter since Clamp meters are more common for HVAC techs. Option one is measure the Amp with the circuit shut the fuck down (don't rope your self with current). But these motors will be running the 120/240E current in AC so if the voltage goes way lower then that, the short winding will mean less E in that motor in general since its literally taking a U-turn at the traffic light. Your 2nd option will be Measuring the ohmage. If there is very little R in the circuit then it also explains the lack of E in a circuit since you know... E=IR... As for ground shorting in a motor its a matter of using a Mego-meter. This motherfucker will shit out 10KV of DC to look for a ground shorting but is really used for compressor motors and if I'm right only really used for Hermetic Compressor Motors. On larger open style motors you'll probably need to replace bearings, I did it once in class and fucked up my finger in the process. Oh and something to note, most modern day AC/Heat-Pump systems use hermetic or sealed compressors so good luck working on one LOL. There sealed in a way were you need a angle grinder to open it up and welding equipment to close it down, literally.
Compressors: so outside of the motor part there mothing more then really pumps for the refrigerant. That's it. They do come in variety but nothing to special about the variety except for water chillers. They do need oil for lubrication and that oil and mix can in with the refrigerant and fuck things up.
EPA 608: So one major thing you need to have is a EPA certification if you wish to work with refrigerants. And there's 4 types. Plus the EPA basic that must be completed in addition to witch ever type you want to have. Type 1 is for small appliances were the system is 5 pounds and under. Type 2 is for the shit over 5 pounds aka anything that isn't a appliance or MVAC. MVAC is basically the AC system for cars and is its own thing. It allows for any AC/Heat-Pump Over 5 pounds but no less the 6. Technically the limit is 200 pounds. Type 3 is for low pressure systems. 50 to 500 pounds. But its called low pressure because the low side or the cooling side of the system is under a vacuum pressure. Low pressure systems are typically water chillers witch is a whole thing in its self. I myself got the 4th type with is universal. But to be honest Id love to work on water chillers.
Recovery: So if there is a leak or a needed major repair on a AC system. You need to do a recover on that system were you take all or most of the refrigerant into a tanks that's around the size of a propane tank. First 2 things to know: the tank should be empty with a grey body and yellow top. Second thing to know is not to exceed 80% of the tanks filling capacity. That's because the refrigerant will then expand and turn the tank into a fucking bomb. Refrigerant in general doesn't like to stay in a liquid state witch is what you'll be recovering the refrigerant as most likely. Oh and when recovering refrigerant you'll always want to do the high pressure side of a AC system. That high pressure will speed up the process ALOOOOTT. You can do low side but it'll be way slower. Also when you put refrigerant into a AC /Heat-Pump system, put it in the low side as it'll be empty and a vacuum( if you properly purged and evacuated the system with you always do before putting shit into the system) and the low side will suck that gas up the ass. There's also other terms used by the EPA 608 such as recycling, reusing with different meaning but is never really mention that much outside of 608 talk. Have a scale with you so you can tell how much refrigerant you moving somewhere. It's also one of 3 ways to prevent you from exceeding the 80% mark. Oh and one last thing for this section DO NOT MIX REFRIGERANTS!!!!! Shit will go to shit if you do so.
Other shit : Get a clamp meter and make sure its a CAT 2 meter. You can use a multi meter but sometimes you just want to use the clamp to check amperage and not risk shocking your self with the metal butt plugs that comes with the meter. Also you can hang it up one some things in times you need a 3rd arm. Get your self some quick disconnect pieces on your PSI gauges if you want to reduce the loss or refrigerant when checking the pressure of a system. Look around in a attic or crawl space before going there. It would be shitty to be bitten by a rabid animal. Remember when I said substances like water attract heat? Because the evap of a AC system will attract that heat also, water will condense on the outside of a evap system giving dripping on a system. Make sure the drainage is clear to prevent water puddles from happening. As for piping on a AC/Heat0Pump, ACR is a type of copper tubbing most commonly used for refrigerant flow in AC systems.
Super heat: so if a AC system works to well then Super heat will kick in. It basically heats up the Evap coil slightly to prevent ice from building up and turning the evap useless due to insulation gone wrong. If the fan on a evap system goes to shit then that'll also provide a risk to the evap icing up.
Super cooling: I don't know much about it but I think its supposed to cool the condenser to improve effieancy of a AC system.
Duct system: So the V in HVAC. It means ventilation. You see a evap or what ever used for heating isn't enough to change the temp of a environment. You need something to spread that temperature of that evap/ heat the room up thingy. So that were fans have the role for blowing air through it and getting that air of desired temp into were its fucking needed. So that's were ducting goes into play. A channel for air to go through and change the ambient environment into one more desirable. It don't matter weather if its AC or heating. There will be air flowing around to get the job done. Or prevent you from breathing in contaminated shit. Hence why air filters are a thing in ventilation. If the ducts get dirty witch they will do eventually then duty will call for someone to clean it the fuck up so that air can flow and do it's job.
Heating: I already bitched about heat pumps so that'll be in it's place. But there 3 other methods of heating ( also relay on ventilation) that should be talked about. The 2nd oldest method of heating is gas heating were natural gas ( what ever the fuck natural gas is substance wise) will be ignited into a burner and go through these vent tubes on the inside. On the outside will be ventilated air via a blower motor fan system to put that heated air to good use. Furnaces are old school for heating but are also the most dangerous way of heating up a house considering many things can go wrong. The next and probably most rare method of heating is oil heating. It's a rare way of heating up a house because that "oil" is actually diesel. Except that diesel is dyed red so people cant use it in diesel car(witch is illegal due to some bullshit diesel tax nothing more) but its kind of the same way as natural gas. Only difference is that there's this big ass tank to store the diesel and between the oil furnace and tank is a diesel filter. Still a dangerous heating method but in my opinion its way safer then gas heating. Now for another heating method. Before heat pumps but after gas heating was electric heating. Its nothing more then making one of those electric radiators you see from a store, having it built in the house and having built on a the room. Its the same concept as a electric stove/oven were it runs a current through high R and that causes friction amongst the amperage. For more info just look this shit up on you tube. In fact you tube will probably give you better info then what I'm giving you since I got shit memory for the whole subject on the damn thread.
Water chillers: I don't know much about the setting of were you can find water chillers witch is a shame since its the system I want to work on the most. I know there mostly used in either commercial or industrial settings. What there good for is cooling down a big ass space with better effieancy then a big ass high pressure AC system but they come at 2 costs. 1st cost of a water chiller is because they use water as a secondary refrigerant, they cannot freeze jack shit, give it thought and you'll understand why. 2nd cost is they are complex. I only really know of 1 type of water chiller and that is called a centrifugal compressor. Air ventilation does play a role in a water chiller but most of it is gobbled up by water circulation. The AC system in a water chiller has low pressure on the high side and vacuum pressure on the low side. Instead of the Evap/Condense coils having air go around them its water. And there's 2 water channels for the water chiller. Low side geos through the Evap and goes to were it's needed. High/Condense side will absorb heat from the condenser and then flow through what's called a cooling tower witch acts like a giant expansion value and is located on the roof of a building. And the reason to go through all this trouble is for effieancy. If you wanted to accomplish the same with a industrial AC system it would be way way more refrigerant then what's in a water chiller for its own AC system. Also water is way more cheaper then refrigerant so should a big ass leak happen, then it would be as much of a shit show. In fact most leaks in a water chiller have the opposite effect of a normal AC system. Instead of shit getting out. Shit gets in the system and in response the centrifugal device will have purge units to clean out the refrigerant. Leak testing is also done differently as you need to heat up the water to test the leaks though I don't know how or why you do so. Same thing for recovery/evacuating a chiller. You need to heat up water to get more refrigerant out and speed up the process. But if I had to guess a lot of the times when a Water chiller leaks its due to a shit gasket. These systems use a decent amount of gaskets not found on normal AC systems. Unfortunately I don't know jack shit about the motors for water channeling or how water is even moved in the first place. That's something I'll have to figure out in the future.
Hazards: Outside of nails sticking out in either the attic or crawl space alone( got my head scratched by these nails, not good since I'm 15 years late for my tetanus shot) with a rat that wants to rip your balls off, there's 2-3 hazards I can think of for AC/Heat pumps. One is electrical. Know how to safely handle electricity. In fact you should know electrical before HVAC to keep bad shit at bay. Other is what I like to call refrigerant surprises. Either pressure gets too big and explodes or enough leaks and gets on your skin and eats it up. If shit show #2 happens then use Luke warm water to ease off the cold burn. Furnaces. Now the thing with furnaces is that the gas supply will go on and off but the ignition switch is time based. If enough of that natural gas leaks into the house and that switch goes off. BOOM. When screwing/ unscrewing pipes, use a new batch of thread sealing stuff( IDK if you would use plumbers tape or thread lock in that case). You don't want gas building up in a home just so a switch can ignite on a bunch of leaked up gas and jihad a house(unless its a woman's house then you probably will... And a Chads house). Another not so known hazard will be CO2 leak. After the natural gas is burnt it turns into CO2 and need to be ventilated. Failure to ventilate can either resulting of a automated shut off switch in some furnaces( that activated when it doesn't sense oxygen) or CO2 into the ventilation gassing the poor fuckers to death. Diesel... At worst it can start a house fire but chances of a explosion are super rare. CO2 are not a exception to diesel furnaces. Electric heating can start a fire but if its surrounded by not so conductive metal and not wool/ flammable shit then chances are rare. Incase your too retard to ignore the electrical advice, Do not wear loose clothing or jewelry. Especially gold as gold is the equivalent to amperage that a free way is to the VTEC of my Truck-kun. In fact copper and gold are very conductive ( gold is more conductive) so don't fuck with either of them. Have a 2nd person with you if your doing dangerous shit. Especially when going in a crawl space to prevent you for being left for dead if shit goes bad. A second person with you is literally cock blocker for the grim reaper. And your not gay so use it. Watch out for booby traps. Some cases the costumers you serve are probably victims of scam trades man. Typically company's that hire non licensed individuals for a job. They wont know what the fuck there doing and will leave something dangerous for someone to be a victim to. In other cases it'll just fuck up someone's house like seen on my "PLUMBERS GONE WILD! DRAMMA EDITION!" thread. Someone might not have properly sealed up the gas pipeline and left a gas leak. Someone might have put the wrong fuse and a AC system has gone to shit. Another hazard though not to you but weirdly enough is traffic victims. There is this youtuber named Rodger Wakefield who made a video on how to spot human traffickers in a house. Apparently tattoo markings are common on victims. See his video for more info. Driving. Weather residential, commercial or industrial, you will have to drive to get the job done. You cant drive like a black person who watches too much Vin Diesel movies. You need to be observant and careful. Go a little slower. You would rather see a accident on you tube then in your life. Also stay clean. As for any trade if the company finds out you have drugs in your system, your chance of working in a lot of trades are bye bye. Same with a criminal record.
End: As I type this. I have universal on my 608 despite forgetting a whole bunch of the content I was taught. And I'm a month away from entering my final quarter for HVAC and getting the certificate. If I do land a job and don't jump ship to doing electrical (since the pay is Chad tier) then I'll be able to re-learn all I was taught the hard way at my job. Despite never going to plumbing school I still have a much better time understanding plumbing then anything else with the only plumbing thing I ever did was flush my moms water heater. I hope after this final quarter that one of these days I can move to Utah(and pray I don't face a ERPO order despite not doing anything threatening or dangerous with my guns), get the fuck out of WA state before I get mauled by a fucking tweaker. Work on water chiller despite the struggle I'll face. Own a 2nd gen CRV with a manual. Mod the fuck out of that CRV. Who knows what fate await my virgin ass. But I do hope this gives you guys some trade fuel along with the other trade threads I made. I might put in another section in the comments for what ever important things I miss. Merry Christmas. And happy new year.
