the actual temp of lights

[fishboybug]

right now i am running 8 26w cfl's in my grow box. i was wondering if anyone knows the heat temp differences in bulbs. i am putting out 12,800 lumens and want to know if i were to buy 2 150w cfl's would they run cooler than my 8 26w? also, would 1 250w hps run cooler than 2 150w cfl's? i'm trying to find the best light to decrease the temps in my box. i have a friend that will give me the hps and ballast but don't know if it is worth the trip to go get it. i really don't want to put it in my box and have the temps hit over 100 degrees. the 8 cfl's are running around 100 degrees without any venting

 

[Hick]

you "have" to have venting, fresh air exchange, for healthy plants. OR a rather expensive and complicated c02 induction system.
You should shoot for 5,000 lumen per sq ft. and work out your ventilation system to be compatible with 'that', rather than trying to limit your light in an enclosed space to control temp's.

 

[fishboybug]

all of those things i understand. i have venting and air flow set up in my box already. i just want to know which lights put off less heat. LED's put off no heat but i just don't have the funds for them.

 

[Hick]

the 8 cfl's are running at almost 100 without any venting

:confused2:... this confused me.. I reckon..
watt per watt, lumen per lumen, the hps is superior in both effiviency and performance. As far as 'heat' goes, the amount of energy consumed id going to be the most prevalent factor, wether it's 200 watts of cfls or 200 watts of hps. The heat produced is going to be very similar, with "less" efficiency/lumens per watt consumed, from the cfl's.

 

[BlueNose]

not sure about the heat differences between 8 26w CFL's and 2 150w CFL's but I use 42w CFL's and they put out a fair amount of heat.

Does the HPS have a vented hood or just a reflector? That will affect how much heat buildup you get.

 

[ozzydiodude]

" the 8 cfl's are running at almost 100 without any venting"

If by this you mean 100 degrees F then your grow area is way to hot. You need ventalation to drop the temp down.
IMO a 250 watt light would be less heat than 2-150 watt lights. The more electric used, the more heat that is produced

 

[fishboybug]

sorry, 100 degrees. so hick, ur saying that 1 250w hps should be close to the same heat temp as my 8 26w cfl's? is there any formula to calculate heat temp per watt? my cfl's bring the temp in my box to 105 degrees. that means that my lights are putting off about .5 degrees per watt. do all lights put off close to the same amount of heat? not counting LED's

 

[The Hemp Goddess]

You can put a smaller wattage HPS into a Pyrex tube and have a cheap cooltube that is easy to vent and cool.

 

[pcduck]

If you have an a/c reflector and good ventilation for the reflector. I would say the temperature the light gives off is nil b/c most the heat is getting expelled. I would opt for good reflector and ventilation. Make the drive if the light is usable.

 

[zipflip]

i was running 26 count 26watt 2700k cfls prior to gettin a 400 hps.
with teh 26 cfls i had and the heat tehy werre putting out wit the ventillation i have(tho not top notch) still i had to keep my door to the grow open half way wit fan blowing into the grow room. but i was able to get my lights all within 3inches of the tops which i pretty much had even canopy cross the board.
my room is only 2.5x3 roughly 7.5 sq feet and 3.5-5ft high wit slanted ceiling. (space/closet under steps)
and when i got my 400 hps remote ballast even wit an open reflector(not aircooled) but wit still same fan in the door open when lites on, and i can even get my 400 bout 8 inches from my tops so far now without burning them and with the double in lumen output but also figurin the loss of lumens from distance form plants and all other factors and teh fact that teh 400 is bout 4-6 degrees cooler in there tahn the 26 cfl's i now finnally will say that i was foolish for even doin one plant under CFLs
so imo if i was you go wit any size hps your space will allow while keepin temps etc in mind.
cuz when i lok back if i had paid new price for all my stuff for all my cfls includin sockets splitters wire connectory chords etc.. i really think i spent close to 150-175$
and my hps was only 100 tho refurbished but still 100 times better than teh prior lights i was running.

i'd say if you got 8 cfl's runnin now that you could prolly get away wit a 150 hps in there dependin on how good ya exhaust and how high you can keep the light from canopy for the most part. but if at all possible (i can finally say this now from experience LOL) go wit HPS

 

[fishboybug]

You can put a smaller wattage HPS into a Pyrex tube and have a cheap cooltube that is easy to vent and cool.

in that case, could i just put up a plexi glass shield to create a heat barrier between my lights and plant. i could build up the height of my container and lower it as the plant grows instead of changing the height of my lights.

 

[Hick]

sorry, 100 degrees. so hick, ur saying that 1 250w hps should be close to the same heat temp as my 8 26w cfl's? is there any formula to calculate heat temp per watt? my cfl's bring the temp in my box to 105 degrees. that means that my lights are putting off about .5 degrees per watt. do all lights put off close to the same amount of heat? not counting LED's

thats eggzactly what I'm saying.. and the hps is sooooo much easier to build a cool tube for, or a vented/air cooled hood. In addition, more useable light from the hps..

 

[The Hemp Goddess]

in that case, could i just put up a plexi glass shield to create a heat barrier between my lights and plant. i could build up the height of my container and lower it as the plant grows instead of changing the height of my lights.

No, not the same at all. You don't just need a heat shield (not sure how light penetrates plexiglass since I have never seen it used as a light heat shield), you want to contain and expel the heat. In a small space, it is better, IMO, to draw cool air from outside your grow space via ducting and expel the hot air outside your space via ducting. I like to suck the air through my lights rather than push it through.

 

[Hick]

No, not the same at all. You don't just need a heat shield (not sure how light penetrates plexiglass since I have never seen it used as a light heat shield), you want to contain and expel the heat. In a small space, it is better, IMO, to draw cool air from outside your grow space via ducting and expel the hot air outside your space via ducting. I like to suck the air through my lights rather than push it through.

good points hg.... I've used plexi as a cover for my humidity domes under flourescent tubes, but it might be a bit much asking it to contain the heat from an HID. It "needs" to be tempered glass, ordinary sheet glass, window glass won't take the heat, "I know".. from experience.