If you thought adjusting your thermostat temperature to 75 degrees meant you would have 75-degree air coming out of...

>If you thought adjusting your thermostat temperature to 75 degrees meant you would have 75-degree air coming out of your vent, it does not.

>Changing the temperature of your AC thermostat simply determines if the “run-cycle” will be longer or shorter, based on the current temperature in the home, and what you set it to. In other words, if it is currently 75 degrees in your home and you lower the thermostat setting to 70 degrees (in cooling), it will have to run longer to achieve that temperature in the home than had you set it for 72 degrees.

Hold the fuck up. Are you telling me that these things don't even use a thermostat? It's just a timer?
How expensive is it to just put a sensor in there, to gauge the temperature. On a device people use for temperature control. Are laser/ir/whatever-the-fuck temperature gauges not an option for this? Has anyone come up with a contraption to emulate this?

Attached: Window-AC-Units-That-Heat-and-Cool[1].jpg (500x299, 20K)

I'm going to emulate the IR remote, and use some SoC bullshit to gauge the temperature of the room. Set the AC to run constantly, but the sensor would turn it on or off based on some bullshit metrics.

Just fyi.

But it accomplishes the same thing in the end.

For me, the temperature is always inconsistent. I often have to control it manually, or even in the best case, reconfigure/recalculate everytime the temperature changes. In my area, the temperature changes dramatically.
In the end, this seems like a task that could be easily automated.

With this.

Attached: cold prices.jpg (300x300, 18K)

Does this make me lazy though?

ACs are all inverter now and those can vary temperature output.

How old are you and how dumb?
ACs use a compressor.. to produce a hot/cold gradient. The hot side exhausts outside... the cold side inside. The cold temperature the gas can reach varies based on ambient conditions and how much heat it can bleed off on the outside. The most efficient operation is to try to compress as much gas as possible thus why they tend to use a consistent amount of power. So, you might get a blow temp of say 66*F .. In such a case the temp you set the AC to is indeed how long it runs blowing 66*F into your hot ass 80*F room. Eventually the temp in your room comes down to what you set it at .. Say 75*F and the AC shuts off...

What's confusing about this? Are you talking about the actual off/on functionality that a cheap version doesn't have? Yeah dude.. get a raspberry or wtvr, get an IR transceiver .. read off the codes from the remote you have for it and have it trigger it on and off based on a program you right that monitors a temp probe you have connected to the raspberry.. This is what those things are for.

Have fun !

user do you even know what a thermostat is?

>using non-SI units in 2018
you burgers are absolutely disgusting

I feel like OP might actually be a faggot this time.

Cheap ones dont.

Also who the fuck wants their room to be 70°C

75° is too cold for a sauna, maybe works as a babby sauna or for drying clothes.

he's an idiot. he thinks the output of the AC is supposed to be the temperature he sets it as.

That's the point of the knob, to keep the room at the temperature you set it to, not to output that temperature.
It's far easier to pick a room temperature than set a temperature for the AC and how long it should run manually.

Yes
That's how everything works
It uses a closed loop feedback system
The temperature you set is the target temperature
If in winter you set it to 24 degrees, it warms air
If in summer you set it to 24 degrees, cold air comes out of it
The variation in temperature in the output you notice depends on how the control system was designed

>murilard units
>doesn't know how a device she uses everyday works
>doesn't know how a fucking thermostat works

Attached: 1532326069996.jpg (700x461, 50K)

I wish my car AC had a setting to control the output temperature rather than target temperature.
Fucking hate being blasted with maximum ice cold air when starting the car in hot weather.

>Changing the temperature of your AC thermostat simply determines if the “run-cycle” will be longer or shorter, based on the current temperature in the home, and what you set it to
That's only true for old models, I'm pretty sure any decent model form current year has an inverter so you can control the output temp.

That's not what I'm implying at all, that's what the quoted article is implying. I expected the temperature to be the room's target temperature, not the output temperature.
While I didn't expect accuracy, I didn't expect a lack of gauge. As is saying
But it doesn't even keep the room at that temperature, it's a timer that uses temperature units. That's fucked up.

What would be the point of that?
The output temperature has to be well below the target temperature to cover for people/equipment heating up the room, doors opening, and poor insulation.

>2018
>Not having an inverter A/C that can run continuously at low power instead of clunking on and off every 30 seconds

Isn't that what the fan speed is for?
Plus you can direct the air flow.

>But it doesn't even keep the room at that temperature, it's a timer that uses temperature units. That's fucked up.
>Changing the temperature of your AC thermostat simply determines if the “run-cycle” will be longer or shorter, based on the current temperature in the home, and what you set it to.
>based on the current temperature in the home, and what you set it to.
So... This is the power of american education...

>it's a timer that uses temperature units. That's fucked up.

I fully agree.
Sadly not everyone on Jow Forums shares or even appreciates our autism.

I guess it's hard to measure the room temperature near the AC unit.
But then yeah it should just say low/medium/high or something.

There are people who still don’t know this?

Attached: E58C553F-197A-4375-9C34-D3921AAF57D8.png (180x180, 14K)

I can't tell if you're being sincere, it seems like you're not.
As we've discussed in the thread, this is wildly inaccurate.
Think for a moment, it polls the temperature at the start, generates a duration, and goes.
Basing it around the starting temperature, in my practical experience, does not result in a consistent temperature.

75 "degrees" is arbitrary, it doesn't even transalte into a fixed time. It's an arbitrary offset and a terrible metric.

On a related note:

>use "smart" thermostat because modern and shit
>temperature is several degrees off because it's own electronics and LCD screen heat up the temperature sensor.

This is the future we choose.

Attached: Eneco Toon update augustus 2015.jpg (600x436, 78K)

Imagine doing this with an oven.
>user, set it for 350 degrees
>>do you mean 350 Fahrenheit or 3, 1-minute heat cycles?
I expect you to reply in less than 75 degrees.

>Fucking hate being blasted with maximum ice cold air when starting the car in hot weather.
Nigga that's the best part of car AC. My car sits in the sun all day long and when I get into it at 6 PM I want that sucker to blow the coldest air it can in order to quickly go from 90ºF to a more reasonable temperature for the interior of a car.

Depends on the type, but yeah my heat is all the same temp until it reaches the desired temperature. My AC can blow our colder or warmer though

Here's an acute reply

What in the fuck are you retards talking about? If you were autistic you would at the very least research how a fucking thermostat works instead of saying this shit. I should know, I have fucking asperger's myself.
No, what you read is an oversimplified version of how a thermostat works designed for americans. You see, a thermostat's contact is either on or off. What you set with the knob is the temperature it turns on at. Meaning: if your room is hotter, it'll be harder to cool down and thus the AC will have to run for longer until the thermostat reaches 75 amerimutt units and clicks off. If your room is colder, it'll take less for the thermostat to turn off. It's as simple as that.
YOUR OVEN WORKS IN LITERALLY THE SAME WAY YOU PIECE OF SHIT

>not setting the hondo on four hondo for everything
You suck at cooking.

So to get this straight:

- it's 30C in your room
- you set the AC to 20C
- it goes "hmmm, 10 degree difference so better work hard".
- after a while room is lowered to 25
- for some reason you decide to switch the AC off temporarily, and then back on again (still at 25)
- now the AC goes "ahh, only 5 degree difference, must not be a very hot day, so no need to do much"

If that's really how it works then this is indeed retarded.

>What in the fuck are you retards talking about? If you were autistic you would at the very least research how a fucking thermostat works instead of saying this shit. I should know, I have fucking asperger's myself.

I also have asperger's.
But I only have a shitty mobile AC which I only ever run at "turbo" setting since it never gets even close to getting the room down to a dialed in temperature anyways.

The ones I have keep going until that temperature is achieved. If it can't reach it, it stays going. If it reaches it, it cycles between on and off depending if it warms up again.
Also
>fahrenheit

So the problem is just that thermostats are garbage and need to be deprecated?
I understand that this was good enough for most things at a time, or a controlled environment like an oven, but how anyone could in this modern time apply this to air temperature control of a dynamic room, is beyond me. When sensors exist for this.

How hard would it be to put an IR beam on it that gauges the temperature of the wall across the room, even that seems like a better metric than this.

WHERE THE FUCK DID YOU DERIVE THAT GODDAMN CONCLUSION FROM YOU FUCKING RETARD?
Okay, I'm done with this thread. I'm fucking done. You americans keep thinking your AC somehow has an intelligent system that would cost tens of dollars to implement instead of a bimetallic strip that costs five cents. I'm outta here.
No. There isn't a fucking problem here. It's working as intended.
>a dynamic room
Say what now?
>When sensors exist for this.
Exactly, they're called THERMOSTATS.
That's it, I'm closing the tab. Fuck you all crossbred creaturas.

>an IR beam on it that gauges the temperature of the wall across the room

Or just put the temperature sensor in the remote control and add bluetooth.

Wow so angry.
Must be very hot in his room.

>what are open loop control systems.

>Turn on AC
>Set temp
>Thermostat tells unit it's above temp
>Unit runs until it is a bit below temp
>Unit shuts off compressor
>Room warms up
>Temp goes a bit over the target
>Compressor turns back on

They work just fine as they are now. If your system is struggling, you need a more powerful unit.
An air conditioner attempting to calculate how much cooling a room needs is going to barely work, at best. You have to take in to account outside temp, insulation, is the sun hitting the wall, airflow, doors opening, etc.

Welcome to basic control systems.

Literally all air conditioners and heaters use this system. Set a desired temperature, turn on thing until it heats up/cools down to desired temp, turn off thing, turn on again when temperature goes above set point. Rinse and repeat. Ideally add some hysteresis so the device doesn't rapidly cycle on and off again as soon as you go a fraction of a degree above the set point.

ACs, heaters, even ovens all use this system. As for why ACs can't just simply put out 75 degree air, it's basically just a compressor and a big-ass heatsink. The temperature of the air coming out of the AC is dependent on the power the compressor is drawing and is also depending on external factors like the ambient in door and outdoor heat (for window mount units anyway) as well as humidity so it's not as simple as whacking a thermistor in there and it'll magically output the temp you set it to. Also consider that let's some you come home to a room that's 90F as you were out all day and had the AC off. You don't really want that unit putting out 75 degree air. You'll cool the room off faster if the AC pumps out 60 degree air and simply turns off when it hits 75 degrees.

But cars havea variable air temps. The knob that had the red and blue line is you temp. Blue is cold, red is hot, and somewhere in the middle is warm.

>There isn't a fucking problem here
I don't see how a device aimed at controlling air temperature, being unable to gauge the temperature of the air accurately, isn't a problem. It may work well enough for your case or even most cases, but that doesn't change what is being said. It's the logical equivalent of being right on accident, except it's not even right 100% of the time. It's guessing a range as best it can, and sometimes that works well. That guess could be more accurate, the margin of error lower.

>Say what now?
Doors open and close, people come and go.
If we poll the room when 1 person is in the room, initiate the chill process, then add 3 more people. It's not going to be sufficient. It's already decided some duration and/or strength. It's not dynamic.

Unrelated, I suggest you calm down. You display 0 patience which is likely going to impact your blood pressure.

Basically what I'm going to do with mine Either emulate the IR signals or use the board it came with.

What kind of car is that?? Most of them have a mode where you can just adjust the air itself.

ACs do measure the air temperature. They have to in order to know when to turn off when the air hits the temperature the user sets.

The issue you are having is that the AC makes no attempt to regulate the temperature of the air it outputs. It just outputs cold air until the indoor ambient temperature hits the set point. It doesn't have to though, that's the thing. This kind of control system works perfectly well.

Re-read the OP.

That is NOT how it works.
That's only how you'd EXPECT it to work.

>They have to in order to know when to turn off when the air hits the temperature the user sets.

Exactly: They HAVE to....but they CAN'T.
So they can't actually make the room the temperature the user selected, making the temperature setting meaningless.

I'm sorry, I did skim the OP and I basically completely missed the point, that said, I can't imagine every air conditioner is like that. Probably only the really cheap bargin bin models.

I meant to quote I think the concern is in the datapoint, or really it seems to be the data point in this case.
Even just having multiple temperature sensors at different areas, seems like it could drastically improve things if you just averaged them and polled them during operation. I wonder how costly something like that would be. Imagine little antennas you drop around the room that signal back.

People seem to be implying differently. That a temperature is measured and a timer is set based on that temperature. It does not turn off when a temperature is reached, it is simply a duration based around it.
i.e.
someaverage cycle time + ambient temperature offset value = next cycle duration

>This kind of control system works perfectly well.
I strongly disagree for this specific case. Again, I think it's fine for controlled environments but not for something that changes.
Even if nothing else in my room changes, the ambient temperature can and does.

>I think the concern is in the datapoint, or really it seems to be the data point in this case.
I'm on a roll.
datapointS plural, and "data point" singular.
The single sensor, single poll seems to be the root of the issue.
I understand that you probably can't get an accurate reading by just polling again since you'd only be getting the temperature of the air immediatly around the unit, not the room.
But if they're going to be arbitrary with their initial value, I suppose you could do the same fuzzy math on the subsequent polls.

The problem must be that any temperature sensor attached to the AC unit gets severely impacted by the cold air coming from the AC and/or the heat generated by the AC.

Even standard room thermostats are quite shitty because they only measure the temperature next to one wall. usually in the corner near the door.
Which can give a wildly different reading than near the windows where people like to sit.

>usually in the corner near the door.
>Which can give a wildly different reading than near the windows where people like to sit.
This is triggering angry winter memories where you had to decided between too hot or freezing because there was 0 insulation to keep out the draft.

>I wonder how costly something like that would be. Imagine little antennas you drop around the room that signal back.

I think keeping them all powered will be the biggest challenge.
Nobody likes to swap batteries.

What the fuck kind of air conditioner do you have that measures the temperature and tries to guess how long to run?
Why not just run until it is the proper temperature?

Okay, OP, serious answer time I think. AC units are often quite old, and are built on the cheap. So fancy anything is not going to be present. BUT! they DO have a feedback loop, in the form of a cheap thermistor, which is a resistor engineered to change its value with temperature. All that needs to be done, then, is check if the voltage is above or below where it's supposed to be.

If the temp is high, the thermostat voltage will be lower than expected and, it turns on the fan, and blows -40 degree CELSIUS air all over your room until the thermostat voltage is too high, and it's too cold in your room. At this point, the AC shuts off entirely, assuming that your house will heat itself back up, as warm air slips in from outside.

The trick is figuring out the proper threshold voltage for the thermistor given a temperature. You could use a 75 cent microprocessor, but you can do it completely analog, by putting a adjustable resistor behind the dial calibrated to roughly match the thermostat.


IR temp sensing units accurate enough to matter are waaaay too expensive. Controlling the output air temp means controlling the compressor speed. Look up how much control units cost for a 1 horsepower motor.

Well, consider the opposite case, right. Take the AC and put it on one wall and then put the temperature sensor that controls the AC on the opposite side of the room as far from the AC as possible. Now you've created a temperature gradient where the side of the room near the AC is much colder than the set temp and the side near the thermostat is correct. There's no good way to evenly heat the room assuming a reasonably large room. You'd need a fan to help distribute the air. Putting the temp midway between the AC and opposite wall in a symmetrical room is probably best but it'll still leave a thermal gradient.

You could have a contact pad on top of the unit.

>What the fuck kind of air conditioner do you have that measures the temperature and tries to guess how long to run?
According to the quote in the OP and responses in the thread, that's how it works.

>Why not just run until it is the proper temperature?
I'd like to know!

And of course we all know all unsourced quotes on the internet must be true!

Depends on the sauna, some stoves give off good steam at 75C and if you're after the moist löyly then 75C is pretty good

I appreciate the response and insight.

It's why I'm inquiring about it.

>-40 degree CELSIUS
A/C or cryogenic storage?

>not putting a heartbeat sensor in your A/C so that the moment you die the cryo-insurance plan kicks in

>it's a timer that uses temperature units
except its not at all a timer. unless you consider it one, a thermostat will literally "turn on or off" if it goes beyond a certain temp. usually there is a range for a thermostat. For example. On comercial fridges that I worked on, the thermostat range is between -2F and 20F, and it will kick on or off depending on the temperature that it measures (in a mechanical way). If you want to call that a timer, be my fucking guest, you can call it a waifu if you want, it doesnt make it one.

A temperature sensor and low power transmitter could draw as little as 5mA, probably. You could power it with one of those indoor solar panels, like they use on calculators, or those weird faucets.

Attached: 611AcbfRTLL._AC_SL1500_.jpg (824x1189, 50K)

I'd be open to believe that cheap units or old units might regulate temperature the way OP suggests but I doubt all or even most ACs do these days.

Indeed my own AC appears to reduce power to the compressor and fan when it hits the target temp assuming it's not in energy saving mode, you can hear the hum of the AC get quieter when this happens. When in power saving it appears to turn off at the right temp however my main gripe with it is its implementation of hysteresis as it will shut off for literally a minute and pop right back on again. I'd be okay with the room heating up 5-6 degrees before it kicked back on but it doesn't do that. That said, I've never made any measurements of the actual room temp and compared it to the set point to see if the AC actually tries to regulate the temp to what I set so I don't have any quantitative data.

I think the origin of the discussion is based around, the possibility that air conditioners are using their thermostats state as a metric once, not continuously. However there seems to be disagreement on this. I suppose it's implementation specific.

What you're saying is how most people expect it to work, but in actually it may not be the common case for A/C units, just for other things that also utilize a conventional thermostat.
This is my understanding at least.

Neat.

I'll say in my own experience it seems very inaccurate in both directions.

Sometimes it will stay on despite it being freezing and almost certainly below the target temperature for several minutes. And other times, it won't turn on despite being under the target for several minutes.

If I don't switch it to manual mode, but stay on energy saving/economy/whatever, and jack the temperature down until it starts, I notice it almost always runs for longer, DESPITE resetting the temperature.
That is to say
75 (off) -> 72(on) -> 75(on) = runs for a long ass time compared to clicking on at 75 normally.

While it may or may not be typical, it seems possible that mine is configured this way. Although this is far from an accurate study. I'm not going to pretend like the most common phrase out of my mouth has been
>there's no way it's x degrees in here
again in both direction, too hot, too cold.

The low temp side of a AC unit drops to the boiling point of the refrigerant being used. For R22, and others like it that are used in home AC units, that's -40 degrees. Take one apart, and you can see frost forming on all cold side pipes instantly. Some even ice up half the radiator when left on too long. I once tried to tape a leak shut, and it froze duct tape to the point that the tape snapped like a cracker when I tried to wrap it around the pipe.

>it may or may not be typical
Actually, reconsidering this maybe it is the common case, and maybe for this reason.

there is usually a little thermistor or thermocouple in the front vents to gauge the temp of air entering and it uses that. I just pull that little thermistor out and put it in front the vents a good ways and it seems to regulate the temp better. my .02

Don't forget some thermostats show the temperate of what you "feel" it is and not the exact temp.

One brand does this, so it throws off the temp 2-3f. Meaning you could have it set to 78 but it could be set to 80.

What kind of dogshit device DOESNT have a thermostat

Even my cheap $20 room heaters have a thermostat and cycle about temp

large scale ac systems do blend the cooled air with uncooled air or outside air to create the desired temperature and humidity air while also taking into consideration zone thermostats and thermal loading

>go to Europe
>temperature value is an offset that starts at 0 for fans only
I like it.

Good to know.

if you pumped 70 degree air into a room, it would take forever for the average room temperature to reach 70.

Air conditioners pump as cold air as possible into the room until it reaches the desired temperature, you reach the desired temperature much faster

What if I pumped 70 degree air into you?

Attached: 1450822079298.gif (400x524, 215K)

>implying using Celsius even makes sense
Scalar values aren't supposed to go negative and yet here C is being just as retarded as F with "below zero" bullshit.

Wake me up when the rest of the world starts using Kelvin. Until then, fuck off.

Attached: 1528687505111.png (797x715, 734K)

You can gather the cold air in a large refrigerator box, then using a pi, some fans, and some actuated vents, create a device that outputs air at a preset temperature.

>Computer fa/g/s talking real engineering
Hilarious

>Hold the fuck up. Are you telling me that these things don't even use a thermostat? It's just a timer?
No, they have a thermostat, they just always spit out as cold air as possible, the temperature is not based on what you set. That is what your quote is saying.

We're so nice to you /diy/ and here you are being mean.

>2018
>still believing that burgers are the only ones using non-SI units

Attached: 1519282049160.jpg (784x519, 157K)

>Using Celsius
>Americans

God I hate Rajeev-Jow Forums, this board turned into a bunch of underage tranny democrat 3rd worlders bashing Americans.

No, they don't.

Oh good another thread of "I dont understand how AC works"

It would never mean you get 75 degree air coming out of the vent, it means it attempts to adjust the temperature of the air in the room to 75 degrees, most likely meaning the air coming out of the vent has to be a lot cooler.

Fahrenheit's superior for air temperature

i think its gotta have time between running compressor and such because idk pressure or something. i recall being told not to turn the window ac on and off in rapid succession because of that

It literally works like that though

With an aircon, usually inverter based systems say if internal temp is 30c, you set it to 20, it'll be putting out air within a roughly +/-6 degree celsius delta (sometimes slightly greater) of your set temperature (depending on whether heating or cooling and the power of the unit itself) This is from what my father has told me and he's done literally thousands of air conditioner installs over his working career. This applies to inverter style AC's though not window units which can't ramp down and reduce the temperature delta as they get closer to the set temperature. Usually they'll output air warmer/colder than your set temperature for obvious reasons, to get the temperature up to your desired one, as basic thermodynamics is that greater the temperature delta, faster the heating/cooling.