They provide some heat, but less than fluorescents and much less than incandescents. By definition, the increased efficiency is at the expense of heating ability. It is not zero though, my top shelf of lights is warmest...if I enclosed it, I would want to provide ventilation or circulation. Robert in frosty San Francisco with radiational frost the last couple mornings, no apparent unhappiness so far among the geophytes. On Fri, Feb 25, 2022 at 7:07 AM Jim Barton via pbs < pbs@lists.pacificbulbsociety.net> wrote: > I am still using T12 Grow lux fluorescent lights for starting my summer > vegetables in my unheated garage. > > They provide some warmth which is most useful as well as light. Do the LED > bulbs provide any warmth? > > You can also use the old incandescent Chriatmas lighe strings for light > frost protection on outdoor plants. > > Jim Barton > > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > http://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> > _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>