The fixtures produce very little heat as far as I can tell. My greenhouse is heated with a radiant floor set to come on at 42F. The source of the hot water is a small furnace that also makes hot water for domestic use. There’s a ridge vent that closes at 50F. I felt that the heat should not open the vent. I set a buffer between the two actions. On cold sunny days the ridge vent moderates the temperature at around 46-48F without heat coming on. Arnold Sent from the all new AOL app for iOS On Thursday, February 24, 2022, 3:31 PM, XYZ2 in Virginia <867ykcor@cox.net> wrote: Thanks Arnold, Do your light fixtures put out much heat with the LED bulbs? Do you ever use supplemental heat mats during the winter? Or, I presume your greenhouse is heated for when the days are overcast. Thanks again, this is great info for me. I appreciate it. Regards, Bern -----Original Message----- From: pbs [mailto:pbs-bounces@lists.pacificbulbsociety.net] On Behalf Of Arnold Trachtenberg via pbs Sent: Thursday, February 24, 2022 2:35 PM To: pbs@lists.pacificbulbsociety.net Cc: Arnold Trachtenberg <arnold140@verizon.net> Subject: Re: [pbs] Supplemental winter lights Bern Yes it's two 4 ft fixtures end to end. The bench is 12 feet long. Each has 4 LED tubes. Timer set to go one at 8 AM and off at 5 PM. Fixture is about 20 inches above the bench. I haven't used a light meter. The fixture is a Sun System Sun Blaze T5 HO 44. Rated at 4600 lumens. Arnold -----Original Message----- From: XYZ2 in Virginia via pbs <pbs@lists.pacificbulbsociety.net> To: 'Pacific Bulb Society' <pbs@lists.pacificbulbsociety.net> Cc: XYZ2 in Virginia <867ykcor@cox.net>; 'Arnold Trachtenberg' <arnold140@verizon.net> Sent: Thu, Feb 24, 2022 2:23 pm Subject: Re: [pbs] Supplemental winter lights Hi Arnold, Are you using the Agromax T5 light bulb that is 4 feet long? How many of them to you have in your fixture? And how many total? Finally, how high do you have them above your plants? Do you use a light meter to help you adjust the height for brightness, lumens? Thanks, Bern in Williamsburg -----Original Message----- From: pbs [mailto:pbs-bounces@lists.pacificbulbsociety.net] On Behalf Of Arnold Trachtenberg via pbs Sent: Thursday, February 24, 2022 12:02 PM To: pbs@lists.pacificbulbsociety.net Cc: Arnold Trachtenberg <arnold140@verizon.net> Subject: Re: [pbs] Supplemental winter lights Sorry 41 watts at 6400 K 411 is the old telephone number here for directory info. Arnold -----Original Message----- From: Arnold Trachtenberg via pbs <pbs@lists.pacificbulbsociety.net> To: pbs@lists.pacificbulbsociety.net <pbs@lists.pacificbulbsociety.net> Cc: Arnold Trachtenberg <arnold140@verizon.net> Sent: Thu, Feb 24, 2022 11:59 am Subject: Re: [pbs] Supplemental winter lights Martin: I'm using AgroMax T5 LED. 411 watts at 6400K. On whenever the sun is up. Rimmer suggested not letting them run into night time and I think it has helped. Plants need a dark period. Arnold -----Original Message----- From: Garak via pbs <pbs@lists.pacificbulbsociety.net> To: Arnold Trachtenberg via pbs <pbs@lists.pacificbulbsociety.net> Cc: Garak <garak@code-garak.de> Sent: Thu, Feb 24, 2022 11:48 am Subject: Re: [pbs] Supplemental winter lights Hi, I've also prolonged my lighting hours from year to year and at least think I get better and better results here at 48° - one question though: What type of light are you using? LEDs or something more on the heating side? -- Martin (pronoun: he) ---------------------------------------------- Southern Germany Likely zone 7a _______________________________________________ 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> _______________________________________________ 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> _______________________________________________ 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>