I'm using a Thunderbolt display when in the office and often run one or two Parallels VMs concurrently, which makes the fans spin a lot. I'm worried that the 13" 2011 MacBook Air isn't being cooled enough with the lid closed so I tend to open it up - am I just being paranoid?
MacBook Air, Mac OS X (10.7.3)
when putting high demand on your mac, a vast increase in your macs fan rpm's can be expected and this is not out of the ordinary. Regarding the cooling of your mac, you can purchase a laptop cooling pad (certainly can't hurt).
One thing I really like about the Mac is that you don't need a load of extra junk to make it work - and I rate cooling pads in the same order as external keyboards / mice, USB webcams and keyboard lights etc. Don't get me wrong, these all have their place, but I'd like to think that if Apple didn't include it in the original design you don't need it.
I'm sure that when the lid of the MacBook Air is open it will get sufficient cooling to cover any processor-intensive task, my question is does the same apply if the lid is closed. (and if not, is there a thermal safety cut-out?)
The cooling of the MacBook Air is accomplished via an internal fan which draws in and exhausts air in the rear gap area below the hinge. This gap remains unimpeded whether the computer is open or closed. In fact, Apple has specifically designed the notebook to operate in a "normal" open screen configuration, as well as a closed (clamshell) mode. As long as you retain an adequate clearance and allowance for clean cool airflow at the rear of the Air, there is no recognized issue of whether the unit will adequately cool.
This does not preclude that the user can also "enhance" cooling with external conduction cooling devices designed to extract heat from the heat conductive aluminum case But in normal circumstances it is not required, nor even mentioned by Apple that it is necessary to do so. In fact, Apple even sells a stand for operating the MBA in a closed, vertical position for space savings. This does in face preclude use of a cooling pad, and still it is not a problem.
While there may be those who observe that the open case affords more surface area for direct case to atmosphere heat transfer, one must also recognize that this is probably more than offset by the fact that the device does not generate extra heat supporting a operting and lit display when closed.
Thanks for the concise reply - this sets my mind at rest with regards to heat transfer when using an external dispay, although my reason for doubting the efficiency of a closed case was more to do with lack of 'input' air vents rather than surface dissipation. I would expect the keyboard of an open Air to let more air in that a closed unit thanks to the rubber seal around the perimter ...
No real worry about "airflow" into the keyboard, as it is relatively miniscule anyway. In fact, the amount of air that "might" seep through the keyboard is minimal as compared the massive lack of resistance through the opening categorically designed to be the flow input. The internal fan "pulls" air in from the logic board cavity, wherein one side of the opening in the case rear slot is the primary route of air entry. Exhaust however is 100% through the ejection port located beyond the heat pipe radiator for the processor (also located at the rear hinge, on the other side).
I think the misconception that he keyboard is a primary exhaust comes from the fact that an open case slightly reconfigures some the exiting airflow wherein some is split off to exit the "crack" about a 1/2" above the keyboard. In some cases, warm airflow can be felt if you put a hand near the screen, in the flow of this.
In terms of cooling, is it OK to use demanding applications for extended periods with the internal display of my MacBook Air closed?
