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 Johnny420
Registered: 04/21/08
Posts: 289
Last seen: 5 years, 1 month
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 HPS Dilemma 
#138166 - 10/29/08 04:32 PM (16 years, 1 month ago) |
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I know some of you people on are are very in the know when it comes to HPS lamps. So i have a couple questions.
It's a toss up between 250w (£75) or 400w (£85) for a space 2.5'(W) x 2'(D) x 5'(H).
Now i know price wise the 400w wins hands down, but what would the heat difference be between these? How hot do these lamps run?
Also whats the difference in production?
I'm swaying towards the 400w, but if it's going to cause a problem then it's best to know before laying out any money.
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  WE HIT THE TREES TILL WE LOOK VIETNAMESE
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 Magash
The Feminizer
Registered: 04/21/08
Posts: 6,634
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Re: HPS Dilemma [Re: Johnny420]
#138217 - 10/29/08 06:37 PM (16 years, 1 month ago) |
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For such a small space you could get away with the 250 but more is better when it comes to light.
If you have a way to vent the heat the 400 is the way to go. With either lamp your gonna have heat.
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All creatures tremble when faced with violence. All creatures fear death, all love life. If we can only see ourselves in others, then how could we possibly hurt another creature?
 Join us at the Growery!
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Dr. Penguin
Registered: 05/19/08
Posts: 1,036
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Re: HPS Dilemma (moved) [Re: Johnny420]
#138288 - 10/29/08 10:34 PM (16 years, 1 month ago) |
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 This thread was moved from Soil & Organic Nutrients.
Reason:
Wrong Forum, better off in general cultivation.
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t0ad
ribbit ribbit
Registered: 09/28/08
Posts: 599
Loc: FL, USA
Last seen: 15 years, 1 month
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Re: HPS Dilemma [Re: Johnny420]
#138293 - 10/29/08 11:24 PM (16 years, 1 month ago) |
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dude just like he said, seriously get s way to just vent out the warmth and go 400w, you would NOT regret it seeing your plants getting all the light they can get! 
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<img src="/forums/images/graemlins/hypnotoad.gif" alt="" />
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Dr. Penguin
Registered: 05/19/08
Posts: 1,036
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Re: HPS Dilemma [Re: t0ad]
#138297 - 10/29/08 11:28 PM (16 years, 1 month ago) |
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I have a bit smaller area than you and I run my 400w lamp in a cool tube. Temps are pretty constant, about 7o above ambient. So if the room you draw air in from stays a reasonable temperature under ~78o you will do great running the 400w.
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Johnny420
Registered: 04/21/08
Posts: 289
Last seen: 5 years, 1 month
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I'm not sure if i can afford the cool tube version. Is there a great variation in temp between a cool tube and no cool tube?
Ambient is about 50o I'd say. 3x CFL's (23w), 2x CPU fans and 6" fan give and awesome airflow and produce enough heat to sit at around 77o rising to 86o if the heaters are on in the room.
looking at it then I reckon I may be fine with the 400w. Just gotta decide on cool tube or not. All dependant on how much a non cooled lamp will bump up the temp.
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WE HIT THE TREES TILL WE LOOK VIETNAMESE
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Dr. Penguin
Registered: 05/19/08
Posts: 1,036
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Re: HPS Dilemma [Re: Johnny420]
#138433 - 10/30/08 09:16 AM (16 years, 1 month ago) |
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Wow, 27o change in temperature from three CFL's. Are you sure thats correct? If those small bulbs are putting out that much heat, a 400w might warm up your little space way to much. If price is an issue, you can make a cooltube for about 20$.
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Johnny420
Registered: 04/21/08
Posts: 289
Last seen: 5 years, 1 month
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Yeah, it's pretty insane how well the box holds heat and humidity. My humidity was 90% until I put the 6" fan in there and now it circulates the air enough the drop it from 40 - 50%. How it did that I'll never know.
The main room is the same temperature as outside, no double glazing. This weeks temps have been from around 46 - 50o and inside the box has been around 77o. I don't have any extraction/intake at the moment. it's purely what gaps are around any edges that let fresh air in.
I'll try to get a picture later.
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WE HIT THE TREES TILL WE LOOK VIETNAMESE
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Dr. Penguin
Registered: 05/19/08
Posts: 1,036
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Re: HPS Dilemma [Re: Johnny420]
#138545 - 10/30/08 02:15 PM (16 years, 1 month ago) |
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Ok, that is the temperature without any exhaust. You will definatly need to install an exhaust fan if you will be running an hps of any size. If you have a good extraction system, burning a 400w light, air cooled or not, should be fine.
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Johnny420
Registered: 04/21/08
Posts: 289
Last seen: 5 years, 1 month
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Yeah i didnt bother with exhausts, cuz it didnt really require it with CFL's.
My aim is a SCROG, so I'll affix one to the side underneath the screen (intake) and then the other above the screen (exhaust).
Not sure how well this will remove the heat, but given the ambient temp i think the box will be generally cooler with the extra holes. I can always hook up more fans if needed.
Looks like I'm on for the 400w then people. Thank you guys for your help.
Here's a pic to wet your appetite for now.
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WE HIT THE TREES TILL WE LOOK VIETNAMESE
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impgl
Registered: 04/20/08
Posts: 1,666
Last seen: 11 years, 8 months
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Re: HPS Dilemma [Re: Johnny420]
#140286 - 11/03/08 08:54 PM (16 years, 1 month ago) |
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you need a real exhaust man. dont spend your money unless you wanna do it right. also, adding a few holes (which i dont think will do much to remove heat buildup) can be inviting light leaks into your closet. you might be able to get away with it with a 250 though.
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Johnny420
Registered: 04/21/08
Posts: 289
Last seen: 5 years, 1 month
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Re: HPS Dilemma [Re: impgl]
#141792 - 11/06/08 04:48 PM (16 years, 28 days ago) |
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I'm wondering if I'll even need a 400w with a single plant. Seems over kill.
I wouldn't just be making holes. I'd be attaching fans to the intake and the exhaust holes. Reading back I realise I didn't really make that clear.
The intake wouldn't be a problem with light leak. I was looking at a cool tube with ducting to remove the heat. and i can link this to the exhaust to suck air from in the box, through the light and out of the box. The ducting should provide 90o angles to supress light leak.
I also want have 2 fans inside circulating the air inside.
I should really knock up a drawing of ideas to show what I mean.
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WE HIT THE TREES TILL WE LOOK VIETNAMESE
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impgl
Registered: 04/20/08
Posts: 1,666
Last seen: 11 years, 8 months
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Re: HPS Dilemma [Re: Johnny420]
#142381 - 11/08/08 11:55 AM (16 years, 26 days ago) |
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more light more buds -- straight up
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