You can check the results from our tests on the tables below.

Legend:

(1) With side duct and side window opened and rear fan turned on.
(2) With side duct and side window opened and rear fan turned off.
(3) With side duct and side window closed and rear fan turned off.

With adequated casing and cooling everything was between the specs, even with the high temperatures achieved.

Without the rear fan the temperature increased 5º F (3º C) while the CPU was idle comparing the results obtained with the rear fan turned on. When the CPU load was at 100% the temperature increased only 2º F (1º C) when we turned the rear fan off, but this small difference only occured because we were using a power supply with very good cooling system (120 mm fan that change its speed depending on the power supply temperature). If we used a regular power supply certanly the results would be worse.

On our third test we simulated our system installed on an innadequated case. We removed the side duct and closed its hole and the side window with paper and tape (see Figure 9).

Figure 9: We closed all side holes from the case.

Without the side duct and with the rear fan turned off, the system heated a lot and on the very first minutes of testing with the CPU at 100% processing load the Intel Active Monitor alarm started beeping, indicating that both processor and system zone programmed temperatures alarm were reached (122º F/50º C for system zone and 156º F/69º C for CPU). As for the system zone, Intel recommends to increased the default alarm temperature from 122º F (50º C) to 140º F (60º C). As for the CPU temperature, the results were disturbing: only 7º F (4º C) below the trigger when the Thermal Throttling overheating protection comes in action. During this condition the power supply fan was spinning at 2,000 rpm trying to keep the system temperature as cool as possible and the air that came out of the case was very hot. A computer working in a situation like this would have problems for sure, as the high inner temperature also affects other components like hard disks.