Anybody still using a 2010 Macbook Air (with Intel Core 2 Duo Processor)?

My 2010 Macbook Air is almost 3.5 years old. It is a 13.3" model with 1.86GHz Intel Core 2 Duo processor and 4GB RAM.

The computer is still fast for the most part (it is slightly slower now to wake up from sleep and such), but it really seems to struggle when playing videos on Youtube and Netflix. The fan invariably comes on (loudly at that), anytime I start playing a video. If the video is HD, the fan noise is even worse.

Anybody else have the same issue? I don't have any problem with the computer except this fan issue. I have already cleaned the fan completely and did a clean install of Mavericks. But it didn't help much. I wonder if the computer has reached the limits of its hardware capabilities?