I'vent got a 600 watt mh/hps light. My mh light at 100% and 10"away never broke 81 degrees. I switched bulbs this morning and the hps after an hour was reading 93 degs. I moved the light to 15" and turned it down to 75% and my temp is ranging 82-84 degrees. How is my mh light running 100% cooler than the hps running at 75% 5 inches further than the mh light was.
Switched bulbs and temp jumps
- Thread starter Grower899
- Start date
Walterwhiter
Well-Known Member
Need a cool hood or tube
captainmorgan
Well-Known Member
HPS has a red shift and IR.
SPLFreak808
Well-Known Member
@Grower899 this is why.
Walterwhiter
Well-Known Member
What's your air intake lookin like? My 600w mh runs at 75 and I have a much weaker fan than you
Intake is just the 3 flaps on the bottom and I leave the bottom of the door unzipped so the intake holes are def 3x the size of my fan.
Walterwhiter
Well-Known Member
Damn well I hope my shot don't burn up when I put my hps in
Got the temps down to 82 at 75% guess that's gonna have to do. Hate that I'm not gonna be able to run it at 100%. Yeah like I said I was expecting a small difference in heat not 13+ degrees
Thanks man. Any idea what more I need to keep the temps down some? I have an air-cooled hood with an ipower 6" fan (400 something cfms), a twin window fan blowing under the light, but above the plant tops, and a desk fan underneath the plants. Maybe a bigger extraction fan?
MeJuana
Well-Known Member
This spectrum of light raises temps very efficiently. Even when using a hood we have a known amount of heat btu added to the grow space. The only option is to counter this and it is in fact what we do. I exhaust my hood light air from outside, through my hoods and then back outside again. During the winter I run my lamps at night, it is lower than 50F and I have heating problems not cooling problems. (This can affect the spectrum of your lamp they say, but I do fine and I don't cool the room).
When I first started growing this was one of my struggles, managing the cooling bill. But now I shut down for the summer and I only do a little cooling at the beginning/end of the seasons. The rest of the time it's not economic to grow where I live so I plan around it.
When I first started growing this was one of my struggles, managing the cooling bill. But now I shut down for the summer and I only do a little cooling at the beginning/end of the seasons. The rest of the time it's not economic to grow where I live so I plan around it.
It's the end of summer here and temps don't get to high anyway. The tent is in the closet in a spare bedroom. My fan pulls air from the hood and blows it through the wall into another closet, which is sealed up. The room the tent is in stays around 68 degrees. Idk thought I'd be able to pull it off with this equipment, guess not.
MeJuana
Well-Known Member
When the ambient temps drop it will be a completely different story. For example say your house is 68F right now because you run an air conditioner, it doesn't bleed heat well because the temps outside aren't impressively low. But on the contrary if you kept your home 72F in the winter by using the heater your room will bleed off heat extremely well, likely too well, because it is impressively cold outside. When your home or structure cools down in entirety it vents off the heat rapidly and as a matter of fact you may need a heater depending how cold it gets there.
Hang in there and keep trying but always use the rule of investing very little in your grow if you can't control the environment. In time you will learn your grow room and the basics of working in your areas ambient temps. Soon you will have a surplus on hand to help through the less than ideal times of year to grow.
Hang in there and keep trying but always use the rule of investing very little in your grow if you can't control the environment. In time you will learn your grow room and the basics of working in your areas ambient temps. Soon you will have a surplus on hand to help through the less than ideal times of year to grow.
Yeah I guess I'll see what happens come fall, and winter. I don't have much in it only like 350ish. Think I'm just gonna try a bigger fan on the light for the time being. An 8 or 10" instead of a 6.
Problem solved. Seems if you use common sense when positioning your exhaust fan it works a lot more efficiently. The ducting between my hood and fan wasn't level and there was a large 90 degree bend. I moved the fan back so it's 12" away from the hood and straight and temps dropped drastically. Got my light up to 600 watts so I'm happy