On 12 Oct, 20:14, Derek Geldard wrote:

Meanwhile on a new school roof in Cleckheaton (All right, all right.
get it over with, it's not *that* funny) is adorned with the things
like candles on a birthday cake.

The rebuilt primary school behind our house has planning permission
for a small low-mounted vertical axis machine - small, but a quite
reasonable installation that should work well enough (within its size
limitations) on that site.

However the usual cost-cutting half-way through the project has
switched this for a cheaper horizontal axis machine. Which is more
sensitive to disturbed airflow, and so will be a waste of time and
effort.