Nice, I run my Pi2 and Pi3 with tiny heatsinks and a couple of small noctua fans I had laying around, I got some USB to 5V fan cables and used those, the 5V is sweet because it keeps the fan speeds low for totally silent operation.

I also run Gridcoin on the Pi3 besides BOINC.

Here is a picture of my Pi2 in my electricity cupboard, running BOINC, and logging solar PV generation data to the SolarCoin blockchain, yes all my kit is solar powered :)