Where it sits
Wind recordings carry most of their energy at the low end, like brown noise, with a slow movement on top that keeps it from feeling synthetic. That makes it a good choice for people who find pure brown noise too flat and rain too busy.
What it covers
Air conditioning, a server fan, traffic, and the general hum of a building. It covers speech moderately well, better than sea or forest, less well than brown noise.
Use
Long blocks. Wind is undramatic, which is the compliment. Ninety-minute sessions with wind and a written task are how several of the people who tested Kiri now work.