Cooling cyle questions

Discussion in 'MacBook Air' started by Kanunu, Dec 30, 2016.

  1. Kanunu, Dec 30, 2016
    Last edited: Dec 30, 2016

    Kanunu macrumors 6502

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    Hawaii
    #1
    I recently bought a 13.3 Macbook air, current model, to replace my 2010 iMac which needed repairs beyond it's value (hard drive, screen, and on-off switch which may be integral to the motherboard.) As the iMac had cooling issues, I had both Temperature Gauge.app and smcFancontrol.app installed and I installed them on the Air as well. I notice watching the temperature control window, that without the Fancontrol loaded the Air exhaust fan will cycle from the base level of 1200 RPM to the maximum near 6500 RPM as soon as the CPU temperatures reach a little over 100C. The CPU cools fairly quickly, about a minute, and the fan drops down to normal. The fan doesn't seem to run at intermediate speeds in response to lower temps of let's say 80C but waits for the turn on point then maxes out again.

    1) Is all this normal for the Air?

    2) Also, as I can boost the minimum fan speed using smcFancontrol.app, would people recommend a higher minimum to avoid reaching that 100 C level at all?

    3) I sense that the exhaust is near the hinge but where is the air intake? Is it through the keyboard and if so would a keyboard skin be a bad idea?

    Thanks
     
  2. Rok73 macrumors 65816

    Rok73

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    #2
    And you don't think you're overthinking this? Apple designed the MacBook Air to run just fine without messing around with fan tools. And when does the CPU reach 100°C? Not in a normal use case. A lot of heat is conducted away through the aluminum body, it's a perfect cooling material.

    Hell, I even played a couple of hours of L4D2 and CS:GO with a 24" monitor connected and the lid closed. In the rare case the MBA would get too hot it would turn itself off anyways before any serious damage would be done.
     
  3. Boyd01 macrumors 68040

    Boyd01

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    Feb 21, 2012
    Location:
    New Jersey Pine Barrens
    #3
    I agree and have never felt any need to mess with the regular operation of the fans. When I do something intensive like encoding video, they kick into high speed almost immediately. Within less than a minute of completion, they slow back down. But for ordinary everyday stuff, I would never even know that the MBA had a fan; it's silent.
     
  4. Kanunu thread starter macrumors 6502

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    Hawaii
    #4
    My MBA CPU sensors are reaching 100C with light web browsing and spreadsheet work, definitely not CPU intensive work. The other components including the SSD remain normal. As I indicated, they do cycle down fairly quickly after the fans kick in but I was curious if this up/down cycle was normal. I may be a little over sensitive as my iMac had definite issues with cooling, but of course the primary heat source was the screen which is not a factor with a laptop.
     
  5. Boyd01 macrumors 68040

    Boyd01

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    #5
    Well I have no idea what the CPU temperature is. But my fans don't make any noticeable noise with "light web browsing and spreadsheet work." I have a 2013 11" i7/8gb/512gb MBA and would expect it to be even more sensitive than your 13" MBA, due to the i7 CPU and smaller case. If your fans are running on high with this kind of light usage, that does not sound normal.

    However, since you are in Hawaii, what is the ambient temperature/humidity? When they get high, the MBA fans will kick in sooner.
     
  6. Kanunu thread starter macrumors 6502

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    #6
    Temperatures in Hawaii only rarely exceed 32C. Humidity can be high in places but not where I live. I suspect that if you had an app like Temperature Gauge or a widget like iStat Pro, you would find that your fans are cycling more than you realize. The fan is definitely nice and quiet. If there is any ambient noise you probably won't hear it.
     
  7. Boyd01, Jan 3, 2017
    Last edited: Jan 3, 2017

    Boyd01 macrumors 68040

    Boyd01

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    #7
    Well 32º Celsius is 90º Fahrenheit. If it's that hot in the room where you are using the MBA, the fans are going to be running. I start noticing them when the ambient temperature rises somewhere above 80º F (27º C), especially if the humidity is over 50%.

    If I had an app like that, I could also sit around and worry about my CPU temperature. The point is, I don't worry and have been using MacBook Airs (often with demanding software) since 2012 with no problems.

    I'm in a quiet room (I live out in the country, my house is back in the woods and can't even be seen from the road). It's 73º F with 48% humidity right now. I just put my ear right up to the MBA and can't hear anything at all. Am only running Safari at the moment, but was just using excel and filemaker pro a little while ago.
     
  8. Kanunu thread starter macrumors 6502

    Joined:
    Apr 18, 2009
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    Hawaii
    #8
    I don't really want to get into contention with you over this. I simply had made observations about how the cooling cycle seemed to work and asked if someone had made similar observations. My observations were from software that actually works off of the sensors and not subjective. I appreciate that your MBA may work fine, but please accept that my iMac was basically killed by heat.

    By the way, right now Honolulu at midday is 76F and 54% humidity. 32C is a very rare hot day in summer.

    Can anyone answer my question about the intake?
     
  9. cruisin macrumors 6502a

    cruisin

    Joined:
    Apr 1, 2014
    Location:
    Canada
    #9
    If you have two computers in a row with light loads and cooling issues, then your location might be too warm. For light loads the fan should be at minimum speed (and stopped on the newest MacBook Pro) as the body does most of the cooling, so it's not normal. Occasionally the speeds will go up, but it shouldn’t be much.

    While you can fiddle with the fan speed, you will be treating the symptoms and not the cause. If something is broken with the cooling, take it in and have Apple fix it while it is still under warranty.

    What happens in the morning when your location is cooler? If you take the Air to a location with air conditioning, does it still reach 100ºC? Do you use the Air on a hard surface or a soft surface?

    The cooling on the Air uses the grill by the hinge. One side takes in air and the other side blows it out. For my Mac, if the fan is at high it will stay there until I close the app that is using all the energy. A warm day will cause the fan to occasionally run at medium speed.
     
  10. Rok73 macrumors 65816

    Rok73

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    #10
    My CPU temp reaches about 80-85 °C max when it is under heavy load aka playing a 3D multiplayer FPS with external display connected and the lid closed. I am living in central Europe where the temperature usually isn't very high in summer, well at least not on average with the occasional day with 30 °C. Private houses and flats don't have AC in 99% of the cases. Normally the room I am using the MBA in mostly has a temp of around 21-22 °C which can rise to 27-30 °C in summer with medium humidity.

    I'd say that the climate you're living in surely can have an influence on your CPU temps. I'd also say that I wouldn't worry too much about it. 100 °C is a lot but the CPU that is built into the MBA can withstand temps of up to 105 °C. Surely, the average life expectance of computer components is less the higher the average temp is. But the MBA definitely would turn itself off before any serious damage is done. That's about all I can say.

    If you still feel insecure talk to Apple and let them have a look.
     
  11. kohlson macrumors 65816

    Joined:
    Apr 23, 2010
    #11
    We have several MBAs in our family. The fans get noticeable when using Handbrake (video encoding) or code compiling. Occasionally there are ill-behaved apps, such as web pages and Spotify. IMHO, 100C CPU temp, on an otherwise non-explainable basis, is too hot - certainly to keep on you lap.

    I would check Activity Monitor, as high CPU usage is usually what drives high fan activity. If you can't isolate the issue, engage warranty and/or AppleCare.
     
  12. bhayes444 macrumors 6502a

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    Jul 13, 2013
    #12
    First off I will state I don't have a MBA to directly compare with yours, but I do own a rMBP and the fan control behavior you describe seems normal to me. I will notice that my computer essentially waits until temperatures start getting over 80C, then it slowly ramps up fan speed. It makes me a bit nervous when it hasn't hit full throttle yet, and the CPU sensor reads 103C, but it soon cools it down to appropriate levels. As cruisin mentioned, the venting is don't all in the hinge area of the laptop.

    For your case, what I would be concerned with is why the cycling is happening. Myself, and others in this thread, have the fans ramps up with, high CPU temps, only when under more intense and sustained workloads. Yours seems to be acting strangely for whatever reason and should be diagnosed by yourself or Apple.

    Using a fan control app to keep the fan spinning at a faster rate than stock is fine, but generally not needed.
     

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