Fun stuff: Basic air conditions + why not to run A/c lower than 70 - General

[highlight]I will answer any questions you have about air condition to the best of my knowledge.[/highlight] Hello. I am gerbile4. I am a student at a vocational school. I take the Heating, Ventilation, Air conditioning, and Refrigeration shop, also known as HVAC. I learned alot this year, so I decided to share some of my learning with you. First, Lets learn knowledge on the basic A\C or refrigeration system. [img]http://www.whfin.net/modules/Green_Energy/300px-Heatpump.svg.png[/img] Terms to know: [B]Refrigerant:[/B] A refrigerant is a compound used in a heat cycle that reversibly undergoes a phase change from a gas to a liquid. Traditionally, fluorocarbons, especially chlorofluorocarbons were used as refrigerants, but they are being phased out because of their ozone depletion effects. Other refrigerants are ammonia, sulfur dioxide, carbon dioxide, and non-halogenated hydrocarbons such as methane.[1] There are 4 basic components in an Air Conditioning system. I will use the numbers on the diagram to identify them. 1. Condenser. 2. Metering device. 3. Evaporator. 4. Compressor. I should mention there is one more. and it seems to not be mentioned in the diagram above. It is the filter drier. The path of flow in an A/C system is: Compressor Condenser Filter drier Metering device Evaporator Compressor [B]Compressor[/B] Let's start with the heard of the system. The compressor. This is a hermetic piston compressor. [img]http://img.diytrade.com/cdimg/927727/9086747/0/1242800100/hermetic_compressor.jpg[/img] Here is a very simple GIF on how the piston compressor works. [img]http://www.actechelp.com/pics/comprani.gif[/img] In an A/C system, low temp, low pressure vapor come in through the left. The compressor compresses that vapor, making the temperature of that vapor go up since pressure and temperature are directly related, and then the vapor leaves through the right pipe. Piston compressors are very, very common in the household setup. A fact to throw in here is that compressors can not compress liquid. As far as I know, the force needed to compress liquid is too great to be achieved with anything that is feasible for any setup we have in the human society right now. Other types of compressors include: Scroll Centrifugal Rotary Piston Screw [B]Condenser.[/B] From that gif, I explained the refrigerant leaves to the right pipe. It just doesn't go off into space. It goes into a device called the condenser. Most of you actually know what a condenser is already, but you probably associate it as "That magic box that has a fan and is hot outside when the A/C is on." Here is a picture of one. [img]http://www.imaginehomessa.com/images/about-green/condenser.jpg[/img] That is just one type of compressor. But since I am educating you guys on a standard A/C system, I will only show this one. The definition given in my class for a condenser is "Device that rejects heat absorbed into the refrigerant into an unobjectionable location (such as outside or into an attic)." The way it does it is via condensation. For the refrigerant traveling through it to condense, the refrigerant must give off heat. (I bet you can figure the rest out) My condenser is outside under my porch. The sizes of these units range from small to huge. Small being the one on the right in this picture [img]http://ingramswaterandair.com/images/2Haiermodel.jpg[/img] larger ones being [img]http://www.lonestaronline.com/fullsize_thumbs/946578289.jpg[/img] They do get way bigger though, but I can not find a good picture at the moment. [b]Filter drier + Metering device[/b] The filter drier is very self explanatory. It filters and dries the refrigerant. To dry refrigerant means to remove moisture (water vapor) from it. Water is a very big enemy of refrigerant. Inside a filter drier, shown here. [img]http://liquidicestore.com/images/alcofilterdrier.jpg[/img] are little beads, called "Beaded desicant". These adsorb water vapor in an A/C system. Pretty much every A/C system on earth has one of these. Metering devices. By definition the metering device is "Device that creates a pressure drop in a refrigeration system". The drop in pressure helps with the process or boiling off, which takes place in the evaporator. There are many types of metering devices. A widely used metering device used in a household A/C system is the fixed orifice metering device. This is a type in which the pressure drop is fixed, and the diameter of the device can not be changed without removing the device and replacing it with a new one. Usually, fixed orifice devices are capillary tubing, shown here [img]http://www.easybizchina.com/picture/product/newpic/tcjinxin_F64112FB00C168C1.gifp[/img] The diameter of these pipes are very small. An example of a commonly used diameter is .039 inside diameter. Lets get on to our last component. [B]The Evaporator[/B] The evaporator is a device that absorbs heat by boiling off the refrigerant. In today's modern systems, the Evaporator coil, shown here, [img]https://www.keysecure.com/bestbuyheatingandairconditioning.com/Merchant2/graphics/00000001/Coil%20Half%20Upflow.gif[/img], is usually combined with the same ventilation system the heat uses. The outlet of the evaporator goes back to the compressor, allowing the cycle to repeat. Now we get on to this. [b] WHY YOU SHOULD NOT PUT YOUR A/C UNDER 70 DEGREES FAHRENHEIT[/b] If you learned anything above in the paragraph about the evaporator, it's that you need heat to boil off refrigerant. Since the A/C system pulls heat from the rooms of the house, and pushes it through the evaporator, you need a certain temperate to allow for all the liquid to boil off. As the air temp in the house gets lower, there is less heat to help the refrigerant boil off. That means the liquid creeps closer to the compressor. When the system is set to only cool the house to 70, there is plenty of heat energy to boil the refrigerant off with. When you get down to 69, 68, there is less, which means it takes longer to boil off the refrigerant. If it takes too long, the liquid will slug into the compressor. Your household compressor can only pump liquid once, and then it dies. The only way to avoid the liquid slug is a "Suction line accumulator", Which accumulates extra liquid refrigerant and allows it to boil off before entering the compressor. I hope you enjoyed this information and learning about the basic A/C system. Fun fact: Sulfer (Or it might have been sulfur dioxide) used to be used as a refrigerant. When a leak occurred in a large system, people were evacuated for miles. [highlight]I will answer any questions you have about air condition to the best of my knowledge.[/highlight] Edit: [img]http://img156.imageshack.us/img156/6934/66043169.png[/img] Fucking pokeporn

Damn, that was pretty well put together.

This is one of the most informative threads I have read in a while. I never really new how my AC worked.

True men use peltier elements.

[img]http://ingramswaterandair.com/images/2Haiermodel.jpg[/img] She can park her ass on my condenser any day.

[QUOTE=evilking1;22124175]True men use peltier elements.[/QUOTE] -snip- [quote=wikipedia]Thermoelectric junctions are generally only around 5–10% as efficient as the ideal refrigerator (Carnot cycle), compared with 40–60% achieved by conventional compression cycle systems (reverse Rankine systems using compression/expansion)[/quote] This system in which I am describing here, or more or less education you guys on is way more efficient.

I usually put my A/C no lower than 76 or 75, and I live in a place where triple digit temperatures are norm in summer. It blows out [i]freezing[/i] cold air.

[B]Cool[/B] thread. :rimshot:

this thread taught me nothing, my AC runs fine on 65

[QUOTE=teh pirate;22124324]this thread taught me nothing, my AC runs fine on 65[/QUOTE] And I have mine on 62 right now. It's not what WILL Happen. It's just one of those things that could.

let's have an air conditioner contest I turned mine down to 54. bet you can't go lower. :smug:

[QUOTE=teh pirate;22124367]let's have an air conditioner contest I turned mine down to 54. bet you can't go lower. :smug:[/QUOTE] 38 :smugissar:

22! [editline]03:53PM[/editline] holy shit oh fuck so cold

[QUOTE=evilking1;22124175]True men use peltier elements.[/QUOTE] True men use their own sweat to cool the air.

[QUOTE=teh pirate;22124379]22![/QUOTE] Excuse me sir but standard US Fahrenheit A/C thermostats only go down to 35 deg f. You are a liar sir. I declare myself the winner.

oh fuck oh fuck ok you win oh my god i'm going to have goosebumps for weeks

Hello. I am Anteep1. Mention that the temperature is Fahrenheit, because the standard is now Celsius. Thank you.

[QUOTE=gerbile4;22124410]Excuse me sir but standard US Fahrenheit A/C thermostats only go down to 35 deg f.[/QUOTE] i actually took it down that far out of curiosity

Hey is the condensation coming out of an AC unit ever anything other than relatively pure water?

[QUOTE=GunFox;22124461]Hey is the condensation coming out of an AC unit ever anything other than relatively pure water?[/QUOTE] Well.... Yeah. The outdoor unit should not be cool enough to allow for the condensation of water though. However, I know the evaporator coil, which is indoors, "sweats" because water vapor hits it and then it condenses into a liquid and drips off. In the case I am talking, pretty much yeah.

OP should include something about absorbtion refrigeration. I'm too lazy but shit's off the hook.

[QUOTE=WhatTheKlent;22124698]OP should include somthing about absorbtion refrigeration. I'm too lazy but shit's off the hook.[/QUOTE] We learned the very basics of it in class but I don't know enough to make a thread expansion on it.

[QUOTE=Anteep1;22124421]Hello. I am Anteep1. [/QUOTE] We can see that, thanks though.

[QUOTE=gerbile4;22124193]Actually only rich fags do since This system in which I am describing here, or more or less education you guys on is way more efficient.[/QUOTE] It costs a lot less to make though.

[QUOTE=WhatTheKlent;22125198]It costs a lot less to make though.[/QUOTE] How much lower? If that method is 5-10% of ideal, and the system in the OP is 40-60% of the ideal, is it 80% or so less in cost to do?

I ran the AC in my dorm room at 60 pretty much all the time and nothing happened to it.

[QUOTE=MaverickIB;22125474]I ran the AC in my dorm room at 60 pretty much all the time and nothing happened to it.[/QUOTE] It's something that can happen. And windows units =\= house systems

[QUOTE=gerbile4;22125376]How much lower? If that method is 5-10% of ideal, and the system in the OP is 40-60% of the ideal, is it 80% or so less in cost to do?[/QUOTE] They are generally much cheaper to buy, though they do cost more to operate in the long run.

You push a button and cold air comes out. [editline]10:24AM[/editline] There's penguins inside to do that, right?

[QUOTE=Upgrade123;22125989]You push a button and cold air comes out. [editline]10:24AM[/editline] There's penguins inside to do that, right?[/QUOTE] Yes. By passing warm air over penguins magical dust is formed which cools any oxygen it comes in contact with to absolute 0