Can this work.
- Thread starter Hood420
- Start date
it might not be enough to keep it cool. some people will probably pop in and say you can't do this, you can't do that... blah, you can do what you want!
try to find the bigger thicker pc fans. you might pay a little more for them, but they are worth it. the thicker ones spin slower and are quieter, but still move a lot of air. try to pull the heat away from the bulb and out of the box as soon and fast as you can. this is the biggest heat source in the box, so should be focused on. also, the room you're pulling fresh air from should be kept cooler if possible. if the room is to warm, it will make the box that much more hotter.
Florida Girl
Well-Known Member
No, a pc fan will not be enough to keep the heat from a HPS light in check.
You might think about cutting two 6" circular holes and adding 2 of these these High Tech Garden Supply (one for intake and one for extract).
here's my argument. a computer with one of the more efficient modern cpu's would put off about 80 watts of heat, just from the cpu, not including anything else. if they can keep the heat down in such a small confined space down to around 80f, then why can't you do the same with a bigger box with probably less heat?
I don't know what your light housing looks like, but I was thinking, try to duct the heat away right from the source.
Florida Girl
Well-Known Member
1. The CPU fan (you reference) sits right on top of the CPU and delivers a constant blast of air at point blank range. If that same fan did not sit on top of the CPU... but instead was off to the side pushing air across the CPU... it would NOT be enough to keep the CPU cool.
2. For a grow closet you need to move/replace a significant amount of air. The smaller the cabinet... the quicker the air heats up and the quicker it needs to be moved out and replaced with cooler air.
3. Typically Computer fans move about 40 CFM (some of the higher end ones move 80 CFM) ... the fans I linked to above move 250 CFM. The more air you can move/replace quicker...... the better of you will be with keeping the heat in check.
4. The fans I linked to are only $25.00 and move 250 CFM whereas the higher end CPU fans run around $30 - $40 and only move about 80 CFM. It's a no brainer.
You were correct in your previous post.... it's his/her grow.... he/she can do whatever they like.
It's just my opinion that the poster will be dissappointed with the performance of Computer Fans against a HPS light.
Florida Girl
Well-Known Member
I'm not saying you are fibbing.... but I'm hard pressed to believe ^^^.
I run a 400 Watt HPS in a 48" x 48" x 78.5" grow tent and my temps SOARED into the high 90s... sometimes over 100 F. There is no way in hell 2 computer fans would have cooled the space. Even with 250 CFM intake and extract fans I had to add a stand alone air conditioner to get the heat in check.
My grow room is upstairs.... which tends to be warmer in my house so that may have contributed to the heat.... but even with my setup downstairs I know 2 computer fans would NOT be enough to cool my 400 Watt HPS.
My HPS ballast is also magnetic, which tends to run hotter then the new digital ballasts so that may be a factor as well.
I live in FL and keep my inside home temp at 74 F. With my stand alone A/C in my grow room I'm able to keep the temp in there at a constant 74 - 76 F.
the cpu fan pulls heat off the cpu and circulates it around inside the case. the power supply fan and any other 4 inch or bigger fans would take care of removing it from the case. this is what is more similar to removing the heat from a grow box. the bulb temperature doesn't matter so much. it's the air temp around the plants, same as case temp, not cpu temp.
true, the quicker it would heat the air inside the case/room. but, 80 watts of heat inside a computer case is the same amount of heat as 80 watts of heat inside a closet, it just takes longer to heat the entire room, and more surface area on the walls would also help remove more heat then in a smaller computer case.
could be. all we can do is give advice and with them luck. there are a lot of variables that could change the outcome. it could work ok, or it could be a complete and total flop. I just think it "could" be made to work. just gotta pull the heat away from the source as fast and efficiently as you can, and hope it keeps the rest of the box cool enough.
Florida Girl
Well-Known Member
You got me there... I misspoke about the direction the air moves on a CPU... but even so... the fan sits right on top of the CPU and pulls air from close range and it would not do the job adequately if it were not directly on top of the CPU.... such as if it were mounted on the side of a grow cabinet.
The poster said 150 Watt HPS... not 80 Watt. Regardless.... the heat from a HPS light is going to be significant in a small place. The more air you can move the faster the better. The fans I linked to come pre-wired with a plug so you only have to plug them in. I just don't get why anyone would opt for a fan that costs about the same or more, moves less air and has to be wired. Doesn't seem logical to me.
True. I've already done battle with heat and solved the problem for my scenario. I've given my input here .... and I stand by what I posted... and wish the poster well with whatever he/she chooses to do.
Padishah
Well-Known Member
i agree the fans you linked would be much better then pc fans but the poster didnt ask what can i buy to move air he asked if pc fans would work to vent his light and i believe that if he keeps the ballast out of the room it will with no problem 150 hps doesnt build alot of heat a good pc fan can move 133 cfm Scythe Ulta Kaze 120 x 38mm Case Fan (45.90dBa, 133.6CFM)
as for my room with 2 pc fans the abient temp in my basement is 65 ° f i keep the magnetic ballast outside of the room and the 2 fans keep the room with a 400 watt mh light at 75°f if the abient temp outside raises 5° so does the room
as for my room with 2 pc fans the abient temp in my basement is 65 ° f i keep the magnetic ballast outside of the room and the 2 fans keep the room with a 400 watt mh light at 75°f if the abient temp outside raises 5° so does the room
Florida Girl
Well-Known Member
I wish I had a basement... maybe I could have saved the $300 I spent on a stand alone A/C
this is something I'm unsure of. how much heat does a 150 watt hps really put off? no where near 150 watts. they are using a smaller bulb them what most people use, so that helps. I'd like to see someone successfully grow in a dresser with a 600 watt hps and computer fans, and not start a fire. there's a good time.. or just a head ache. lol
Padishah
Well-Known Member
a good pc fan can move 133 cfm Scythe Ulta Kaze 120 x 38mm Case Fan (45.90dBa, 133.6CFM)
some people do that as a quick fix, yes. but you might want to do some odor control once you go into flowering.