On Monday, September 19, 2016 at 11:02:42 AM UTC-4, TomR wrote:
Are circular fluorescent lights dimmable?

A friend of mine just called me and asked me this question? I told him that
I think they are not dimmable, but I am still checking.

He said someone has him putting up a flush mounted circular fluorescent
light in a kitchen ceiling, and she wants to have it put on a dimmer switch.

Then he should have the specs and/or installation instruction for
the actual fixture which will have the information. A typical one is
not dimmable, but apparently there are some that are.