Which T bulb gives off the mist heat - t5,t8 or t12
 

Which of these lights us the hottest to run. Right now I am using t12 lights and my room is quite hot.

T12's are the most inefficient. For the same lumen output, T5's will be the best.

I don't know about regular T5's but HOT5s (High Output T5s) get very hot. VERY hot.

My lights heat up so much that my furnace doesn't run when the lights are on...in the dead of winter. Granted, I have an entire room of lights and the thermostat is in the grow space...but the heat from lights keep the room around 72-74 during the winter. Until it gets really cold outside I usually keep a couple of windows cracked so the room doesn't get too hot.

MY HOT5s are much warmer than the T8s in the phal area.

Yes, but do your T8's give off the same amount of light as the T5's? Measure and find out.

Of course the 5s are more intense than the 8s but the question was regarding heat output not light intensity.

FWIW - I wouldn't want to be w/out my HO T5s...the 8s are really only good for lower light plants. At least that's been my experience.

I thought someone said that t5 is not as t12. Is this true

---------- Post added at 11:29 AM ---------- Previous post was at 11:29 AM ----------

Oops not as hOt

---------- Post added at 11:34 AM ---------- Previous post was at 11:29 AM ----------

So here is my problem. We live in Arizona and I grow in a small room. I have three 48 inch light fixtures that hold four bulbs each. I am planning on using the t5 fixture for catts. Etc. and using t8 fixtures for my Phals and mini catts. Yes I am trying to get more light for the orchids, but am trying to reduce the amount of heat my t12s put out in my orchid cart

Alla is right, for a given amount of wattage or light, T12 is going to produce the most heat because of the inefficiency. But if you compare 2x 54W T5HO vs 2x 32W T8, T5HO obviously produces more heat even though the efficiency between T5HO and T8 is similar.

If your electricity is not cheap, some high-end LED will be cheaper in a long term (this may not be true for low efficiency LEDs). I've been gradually migrating to LEDs over T5HO and T8 because of the heat issue inside of a grow tent.

I went with the T5's and I really like them. I have three fixtures (four foot, four bulbs) and it does get uncomfortably warm when the outdoor temperatures are in the upper seventies. For me, this is okay because our house is cooler in the winter and the orchids will probably love the warmth. I would caution you that cool-growing orchids might suffer--my Anguloa seedling bit the dust when it became warm again last week and I forgot to move it to the window. :(

Because of living in Arizona and growing under lights you can forget cool growing plants. Moving here from New Jersey I lost about half of my orchids because of the heat.

---------- Post added at 03:08 PM ---------- Previous post was at 03:04 PM ----------

Since I have three shelves on my cart, I will use one with t5 lights for catts., etc and the other two use t8s.
Hopefully this won't be as hot as three shelves using all t12