Since my NAS is located in the basement along with my server, router and other equipment, I actually am happy to see teh fan running all the time. I use the setting low/high as it keeps the temp @ a constant 100 degrees compared to 107-114 if the fan is off.
Fan off/low/high:
Wed, 24 Feb 2010 19:00:24 EST NAS Temp:111°F(44°C) Capacity:915GB Free:319GB [34%] 6 days 3 hours 9 minutes
Wed, 24 Feb 2010 20:00:23 EST NAS Temp:109°F(43°C) Capacity:915GB Free:319GB [34%] 6 days 4 hours 9 minutes
Wed, 24 Feb 2010 21:00:24 EST NAS Temp:111°F(44°C) Capacity:915GB Free:319GB [34%] 6 days 5 hours 9 minutes
Wed, 24 Feb 2010 22:00:25 EST NAS Temp:109°F(43°C) Capacity:915GB Free:319GB [34%] 6 days 6 hours 9 minutes
Wed, 24 Feb 2010 23:00:26 EST NAS Temp:109°F(43°C) Capacity:915GB Free:319GB [34%] 6 days 7 hours 9 minutes
Thu, 25 Feb 2010 00:07:12 EST NAS Temp:109°F(43°C) Capacity:915GB Free:319GB [34%] 6 days 8 hours 16 minutes
Thu, 25 Feb 2010 01:00:23 EST NAS Temp:113°F(45°C) Capacity:915GB Free:319GB [34%] 6 days 9 hours 9 minutes
Thu, 25 Feb 2010 02:00:23 EST NAS Temp:113°F(45°C) Capacity:915GB Free:319GB [34%] 6 days 10 hours 9 minutes
Thu, 25 Feb 2010 03:00:25 EST NAS Temp:113°F(45°C) Capacity:915GB Free:319GB [34%] 6 days 11 hours 9 minutes
Fan low/high:
Thu, 25 Feb 2010 04:00:24 EST NAS Temp:100°F(38°C) Capacity:915GB Free:319GB [34%] 6 days 12 hours 9 minutes
Thu, 25 Feb 2010 05:00:23 EST NAS Temp:100°F(38°C) Capacity:915GB Free:319GB [34%] 6 days 13 hours 9 minutes
Thu, 25 Feb 2010 06:00:24 EST NAS Temp:100°F(38°C) Capacity:915GB Free:319GB [34%] 6 days 14 hours 9 minutes
Thu, 25 Feb 2010 07:00:24 EST NAS Temp:100°F(38°C) Capacity:915GB Free:319GB [34%] 6 days 15 hours 9 minutes
Thu, 25 Feb 2010 08:00:24 EST NAS Temp:100°F(38°C) Capacity:915GB Free:319GB [34%] 6 days 16 hours 9 minutes