Automotive A/C Systems Explained: Learn How It Works! Best/Easiest Explanation!

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[@francoistombe]

Very conveniently laid out and accessible in this Subaru. My vehicle......every thing stashed where some dissembly is required to access any part.

[@nowiecoche]

Interestingly, what interested me in learning the AC system in cars is Rainman Ray’s work with fixing broken car ACs. Now with your video, it is one more knowledge received in how to potentially service my Subaru’s AC if it needs one. Very easy to understand. Thanks for the video.

[@hesneyk1]

Excellent articulation. However, the geeky proper terms are: evaporators "absorb" the heat & condensers "reject" heat. Nonetheless, absolutely well explained.. Next time, please cover high & low pressure safety switches & the crappy evaporator thermistor that is problematic in most every older subaru! Maybe show how ohms go up & down with a meter depending on exposure to different Temps & how it shuts off the a/c clutch. Thanks again.

[@JenniLudes]

Thanks. Enjoyed the refresher. Back in the "old days" my dad and I would service our own a/c's. Very crude to what's done today. When my dad passed away a few years ago and we were cleaning out his garage and found several cans of unused R12. Yep, that was a while back! (1970s and 80's) Not sure why he hung on to it because by then, things had moved on to R134a. Don't think he had any car new enough to get to the newest/R-1234yf or whatever it is now. Haven't really kept up. I think my 2019 STI and 2016 Crosstrek are still the 134.

[@mrphiscal]

R12 that stuff was cold

[@mansalaija]

Hi, I’m having trouble with my 2007 Subaru Forester and while trying to troubleshoot the problem I came across your channel. I have never worked on automotive AC before but giving how expensive the repair can turn out to be I’m willing to give a DIY repair a try. The problem I’m having is that the AC system is not sending cool air into the passenger compartment and I noticed the clutch in the compressor is not engaging. I checked the AC relay inside the fuse box in the engine compartment and it’s ok. That is pretty much all I’ve done so far, I did it by swapping the AC relay with another one just like it within the fuse box. The rest I have done is just watching videos. For what I have seen I know I have to get a multimeter to check the AC pressure switch to see if it’s closed for continuity. For what I’ve seen these switches open when they sense higher pressure than normal inside the high pressure line or lower pressure than normal inside the low pressure line. Do you know if my Subaru has these two switches by chance? Can you help me find this switch? Also I need to see if the compressor is getting any voltage but I’m assuming it does as the AC relay is working properly. Summer is around the corner and I need to fix this asap. I hope you can guide me through the process and keep up the good videos 👍

[@BMMEC2009]

I repaired the a/c system in my old outback. And in my antique Chevy convertible. So easy. The a/c shops quotes were nuts.

[@timbrown9731]

I'm glad you explained the "heat pump " Robert! A lot of people don't understand it!

[@davidhannum9017]

would love to see a video on replacing a condenser on older Subaru's if you haven't already made one. love your videos and have learned a lot from them helping me with my 2010 Forester

[@vincentlee2460]

It does not dump heat onto the condenser!! The condenser removes heat from the high pressure and high temperature gas refrigerant after the compressor has done its job. The condenser turns refrigerant gas to a liquid throught heat removal at the High pressure side

[@ErlingGrey]

Thanks for clearing that up!

[@mckoylach1622]

Very elaborate and meticulous explanations on top of that, very accurate, thanks for your video

[@jessiehead6525]

Oh man, this is SO helpful! Thank you!

[@jojopojo9516]

Good stuff as always, Mr. Subaru. If time permits, you can go deeper still into the theory. As in why do we need the refrigerant to change states why it needs to enter the TXV as a high pressure liquid, etc. I remember learning about HVAC back in the day COULD NOT wrap my head around how a closed circuit "absorbs" heat. 😅 As ever, this video was good and I look forward to your new content.

[@ussenterncc1701e]

Edit: sorry, I misread, didn't catch that you've gone through HVAC school, sorry. I'll leave this up anyway in case someone else is wondering. It doesn't "need" to change state, you could accomplish this type of heat transfer with just a gas. But, during phase change, substances go through a change in internal energy, the latent heat, without changing temperature. Two substances placed in good thermal contact will reach thermal equilibrium when their temperatures are equal. For each substance, there is a heat requirement to change temperature, called the specific heat. If I place a substance with a high specific heat in contact with a substance that has a lower specific heat, the higher one will experience a greater change in energy, relative to the temperature change, but a smaller change in temperature. If one of those substances must undergo a phase change, then that's a change in energy without a change in temperature for that substance. For this reason, water at 32°F will absorb less energy from your drink than ice at 32°F, meaning ice will bring the temperature down further. This means the phase changes in the exchanger and condenser result in more heat transfer to and from the refrigerant.

[@joseventura5271]

IM A RESIDENTIAL HVAC TECH AND WATCHING THIS VID TO TROUBLESHOOT MY CAR'S AC😂😂😂

[@MrSubaru1387]

Same same but different lol

[@isd605]

Frickin' awesome! I NEEDED that level of explanation that it seems mechanics don't want or know properly "how" to explain what you so thoroughly did! Now, I can more confidently replace all the parts mentioned. I have the orifice tube and accumulator setup in my 1999 Ford Mustang GT. The discharge hose has a small canister on it. When I asked ChatGPT, it said it's the pressure relief valve, but I see no hole to release any pressure. Though, it would be environmentally detrimental to release refrigerant, so maybe, somehow, it releases excess pressure internally somehow, without actually "releasing" it into the environment. I guess that's why it's called "relief" rather than "release" valve? Maybe I answered my own question, ha! Again, thanks for the perfect explanation. Like you said, understanding the basis of how the AC system operates goes a long way in aiding in any troubleshooting one may need to go through!

[@lakshmandalpadado9066]

Simple - works same as a refrigerator .. with very few changes

[@randalfuentes6953]

Watching this while using the A/C on my impreza

[@jessehernandez2215]

Wow well put!

[@wuerzelburg]

Could you show us how access and check the a/c drainage to see if it us clogged. And also how to access the evaporator to clean it. Thank you. I have 14 years a Subaru. How on earth I missed your great channel?

[@kidwelldavid6136]

Thanks. I did learn some information on this.

[@MichaelSvenson]

Do you have a video that explains, locates, and diagnoses the pressure switches for the ej25 ac system? I'm looking all over and can't find a single video that even talks about them.

[@alexysaguilar3455]

Just failed my ac ase bu 2 questions, and i come to find this video😕 great video 👍🏽

[@MrSubaru1387]

Oh no! 😱

[@OutsideTheTargetDemographic]

OK, but where does the NONrecirulating air come from? My dad says from the bottom of the windshield, under the top of the hood. 🤔

[@Pulse0153]

Very helpful knowledge. Thank you!

[@JoMamasHouse]

“Pulls heat out of the car.” With that, is the most effective way to cool the cab to use the button that circulates the air inside the cab?

[@MrSubaru1387]

Yes

[@Spacegoat92]

Is there a way to test the compressor off the vehicle to see if it has a fault? The a/c on my SH Forester stopped working and i want to know if it's the compressor or something else.

[@GlycerinZ]

years ago I learned from an HVAC tech that cold air isn't simply cold, it's air with a complete lack of heat

[@ussenterncc1701e]

When you understand thermodynamics, AC systems are just ridiculously cool (heh). You're making slow stuff go slower by making the fast stuff go faster through squeezing and stretching the stuff in the middle.

[@take1one]

Both my 14 and 16 Imprezas have no A/C this summer. Kinda crazy, 70k and 52k miles and no a/c. I'm super disappointed in Subaru quality.

[@mhm925]

Your Local dealer should take care of you. Subaru directly will may, even if you bought used. Its worth a try.

[@juanvargas8546]

Have you replaced the seals at the compressor? I was on the same boat for my 2017 Crostrek at 80k miles. Now it’s good after replacing seals, vacuuming the system and refill. Also needed to compressor oil to help with an ugly noise from the compressor

[@devindevin1746]

High side line o-ring seepage at compressor

[@timbrown9731]

Robert, it be cool if you cracked open a subaru compressors!

[@pmdmk1422]

Good video, question if i install a bigger compressor will it help with cooling?

[@great2c4me]

I've got both... Subaru forester and a duramax like yours you displayed. I'm surprised the air drier accumulator is post evaporator, as I thought the accumulator needed to be in between the condensor and the evaporator... Apparently not so on our chevy Silverados. That was my question to see if it's backwards, but Apparently it doesn't matter what position it's in, so long as it in the system before the compressor. Correct?

[@jamesbruno5896]

Good explanation!

[@JZMartinez]

My 2017 A/C just stopped blowing cold. 😢 This helps. Cluth not engaging when AC turned on... down the 🐇 hole I go.

[@iristan4917]

I need your expertise MrSubaru. I have 04 forester XT, it has been acting up lately. The car won't start as if the battery is dead, the battery is new 2022, it would start when boosting and won't die after a drive so the alternator is good, starter is good, ignition is good. I check around the battery 2 weeks ago when it that the negative terminal was loose, I fixed that all is tight and secure. Now the problem is happening again, same thing boosting will start the car and would remain running, I assume I may have ground problem, there is power, but sometimes won't start, I had it happen today, but by noon it start without boosting. Any thoughts? Or if my assumption of the ground is correct. 12 volt reading alternator and 14 when running, battery is the same 12 volt reading. Getting good connection on ground tho is tricky.

[@jccars9400]

Mr subaru. what would cause my outback xt to stall at idle when using a/c. also doesn't idle smoothly when it's 80+ degrees outside

[@davidgriffin14]

I want to know what the pressure gauges I bought should read. Aka.... how to use them.

[@MrSubaru1387]

Coming up in another video.

[@danielguerra626]

It depends on the refrigerant and temperature.

[@johnreese3762]

Good, good! I think I've got it!!😆

[@Medevicerep]

Thanks for the explanation!

[@antonioorozco4896]

Great video!!! Do you have a playlist with the other, more in depth videos?

[@77felixthecat]

Great job again

[@user-dq8wg8kn4o]

Hello sir , do you have any wiring diagram from ac compresor to outside fuse box , go to under dash fuse box then go to off on ac swith in the middle of the dash . Thank you for your response 🫡🙏🙌🫵🫶

[@peter-mf5lh]

You are awesome thank you thank you for making this video👍🏻

[@krisx2S]

I keep having issues with AC in my Audi A3. Everything works fine until car's left in a very hot spot. AC won't turn on then - it just blows back a hot air (hotter than the air i get when AC is off). I did service it twice already - first they've replace the condenser and some filters. It didn't help. Then they replaced some temperature sensor (interior one, as they said there are two). I though that fixed since the AC was running fine for a while. Now I left it on a sun and the temparatures were rather high and the AC stopped working again. I don't know if the service is unproffessional or it's a very strange case that's hard to diagnose/replicate...

[@GODsSPECTRE]

So if my ac is blowing hot, could it be my evaporator not working right? I've checked the refrigerate and it's good. It's just blowing cool on the passenger side and hot on the driver side.

[@mojikarimi5717]

Wow, amazing explanation

[@irisbaez1972]

Ok. When we need to replace the drier on the condenser at the right side, once we change it do we need to add any oil? How we add oil if we don't disconnect it? we just remove from the bottom and then install the new one, but how to add the oil in it? We have to remove the stupid condenser in order to add any oil?

[@David-kp4gx]

Some small airplanes have the same system as a vehicle

[@MonthlyBoys]

how funny, i was looking to fix a problem with my crosstrek. It lags in acceleration when pushing the pedal from a stop while using the AC. After a few seconds it picks up again. It only happens when coming to a full stop and then accelerating. Its bugging me so much because it looks like my crosstrek is having transmission problems.

[@lizard2425]

Clear explanation ! Thanks!

[@HYPERBEAST31]

You can upsell a brake flush

[@a7xfanben]

Nice explanation, thank you

[@Fred-xo3ku]

Excellent instruction.👍

[@theghosts6887]

Hello dear, please correct me, or any one else, if we increase the size or the volume of the condenser then this lead to make the car A/C cooler?? Is this good idea?

[@bol8lod]

We suffer here in hot countries, in summer the ac does not cool efficiently. Im reading about insulating car ac pipes . Can you make or test if this works or does it go against car ac working principles.

[@yhyaalree6661]

Dear I have an AC sensor evaporator problem. What would happen if I put a 10k resistor in place of the sensor? My Hyundai is a compressor without a clutch

[@michaelweatherhead9470]

Thanks

[@papag7296]

Hi Mr Subaru my AC is blowing warm air and then blowing cold after a certain time is that normal? Am I low or refrigant?

[@MrSubaru1387]

Could be a couple reasons, but low refrigerant is likely.

[@eminye1]

@@MrSubaru1387 Thanks for your explanations, I have a subaru exiga 2012, the ac blows cold for few minutes then stops cooling completely, would that be the same issue as above?

[@coarsegoldkid]

My car's A/C properly charged by mechanic is intermittent. Mechanic is going to do more diagnostics. Does my 2005 LL Bean H6 outback have a computer circuit that tells a relay to provide power to the electromagnetic clutch? Thanks in advance

[@mick9419]

Does anyone know if I salvaged an aircon system from a Peugeot can I retrofit to another car?

[@Nes_2k]

Great video 👍

[@denisriod5383]

It’s a good thing you are a Mechanic and not a Teacher

[@victorpleitez1273]

Good job 👍👍

[@itsSpecialSteve]

Ty teacher. Sifu.

[@lntercooler]

now my question is: what could cause a car to start overheating with the ac on when city driving or at idle? i've been chasing this issue for a week or two now i just don't know what it could be.

[@BombsAwayLP]

My AC only works for a few minutes , I hooked up gauges and when I rev my engine the low side drops to almost zero and this cause the compressor to shut off, then I have to wait a few hours before the compressor will go back on, any ideas?

[@AodhMacRaynall-dr1sf]

good stuff

[@davidporter6578]

Thanks ❤

[@glassman3333]

So I get that it’s a heat pump. I’m not sure I understand the misconception about air being cooled though. Isn’t any scenario where air is getting cooler having its heat absorbed by the surrounding environment? Meaning, it’s just a different word to describe the same process.

[@richardview1281]

Great video since my 14 Forester looks exactly like this. My AC runs cold for about 10 minutes and then goes warm. The compressor and clutch seem to be working from what I could see. I checked the pressure with the recharge kit and it said it was fine, so I didn't use it. Any idea of what the problem could be?

[@MrValderka]

If it's still a problem for you and you have measuring gauges for spark plugs - check that between the compressor pulley and a clutch in disengaged position is the correct gap, it should be more than 0.3mm but less than 0.6mm. Good luck.

[@jstample]

The 2019 should be 1234yf but the 2016 is probably 134a

[@aggabus]

Drunk cam

[@chrysny413]

Hey MrSubaru, ppl are tagging you on my matco balljoint press video. How about unblocking me and do your thing? 😃

[@nathanyoung7587]

If you look at the life cycle of refrigerant it aligns perfectly with DuPont's patents. R12 was the best refrigerant.....but the Dupont patent was about to expire so we had to say it "hurt" the ozone.....so I came R135a which isn't as efficient but we were told it protected the Ozone but when the R124a patent was about to expire R134A was discovered to "hurt" the environment so we magically got R1234yf which as of now doesn't hurt the environment but in another 25 years from 2017 it will ....oh and R1234yf is combustible......yes your refrigerant post 2017 is combustible so be careful.......but the best most effective refrigerant is R12...... Dupont has some very effective lobbyists in Washington!

[@RATCHETMAN1001]

have you did a more advanced video, i would love to see it. for a basic video it was fantastic so many utubers are butchering compressors because of their lack of knowledge and its just a viscous cycle. i learned from tom lech, love2hvac, hvac school. they no how to do ac.,best teachers out thier ,check them out ,they changed my way of doing ac 100 percent

[@morrissabi5170]

Thanks 🙏 🙏 well explained