newworldicon
Well-Known Member
Every grow space is different but you can bank that with that bulb in there you would need ventilation. Passive intake so zero cost, a 4 inch fan that pushes out from the top and boom you are smiling..
Moving Up From CFLs To HPS!
- Thread starter leeak47
- Start date
leeak47
Active Member
well ive now been considering doing a 250 watt cool tube but with those you have to run ventilation from both sides of the lamp correct? because the one i was looking at...http://cgi.ebay.com/250-WATT-250W-HPS-MH-GROW-LIGHT-E-Ballast-COOL-TUBE-/190463564995?pt=LH_DefaultDomain_0&hash=item2c58835cc3 dosent look like it has open air flow on the side where the light is so could you just suck the warm air out to the attic and that be fine?
newworldicon
Well-Known Member
If the closed hood does not have a open end on each side then it will certainly be able to suck from one end and out. The point is to draw cold air over and away from the around the bulb, whether its inline or not is besides the point. Cool tubes are IMO more effective and cheaper than hoods at this act. Hoods depending on type will give you more versatility in how you use your light spread. Considering you are in a smallish space a hood directing down mostly will be more productive.
newworldicon
Well-Known Member
I would shop around first, and I'm british so US pricings mean little to me, I dont know if thats a good deal or not. A 6 inch cool tube here is £40.
Brick Top
New Member
A 250 watt HID light does not put off intense heat. If someone is growing in a closet or cabinet normally a circulating fan blowing into the closet or cabinet is sufficient to keep temperatures under control.
There is also a bit if a fallacy of CFL's being so much cooler than lower wattage HID lighting. Multiple CFLs are used and while each one feels cool to the touch there is an accumulation of heat from the combined multiple CFLs and all the heat from one HID light comes from one bulb so it seems there is a much larger differential in overall temperatures than there actually is.
CFLs put off more heat per watt used but people use such pitiful low amounts of watts and each source of heat is spread out so they seem to be much cooler than they actually are.
HID lighting far out produces CFL lighting. HID lighting produces more grams per watts used and with that means larger denser buds.
To give an example of light efficiency equivalency, to equal the light put off by one single 400 watt HPS bulb it would take 5.3 125 watt actual 'horticultural' CFLs, that is actual wattage, not equivalent wattage, and not the Lowes, Home Depot Wal-Mart pig tail home lighting bulbs that most CFL growers use and swear by. To get an equal amount of light you would burn more wattage and the combined heat from the multiple bulbs would not be cooler, it would only seem cooler when placing your hand near each individual CFL bulb.
If you go with a HID light, if it is not one with a switchable ballast allowing you to use both a metal halide bulb for the vegetative growth stage and a hps bulb for the flowering stage of growth it would be well worth purchasing a metal halide conversion bulb that you could use with your HPS ballast. That would give your plants more of each light spectrum that they need during the different stages of growth.
Something else to consider is light penetration. Just because a light is a HID light do not expect uber-penetration from lower wattage HID lighting. A 250 watt HID light will only give you about 18 inches of adequate light penetration. If you veg to a height of more than about 8 to 10 inches you are wasting your time because your plants will outgrow your lighting capability. The result will be your lower branches with the tightest nodal spacing will not receive enough light and will likely die out before harvest time and if they do not die out the most you will have is a small amount of sparse popcorn buds.
If you have the funds to work with I would suggest a 400 watt digital ballast/switchable that can run both metal halide bulbs and high pressure sodium bulbs and add ventilation. A Cool Tube might be the best way to go to keep temperatures down. Roughly $350.00 to $375.00 should cover a basic setup, though your situation/conditions/needs may vary somewhat. A magnetic ballast and using a metal halide conversion bulb, with the rest the same, should be able to be purchased for roughly $320.00 to $345.00.. but for the small difference in price I would suggest the digital ballast. (prices do not include shipping)
In either case if odor will be a factor/problem a carbon filter can be purchased or built inexpensively following online plans and added to your ventilation system.
You could do without the Cool Tube and use a basic, but still good, reflective hood and save between $35.00 and $75.00 (depending on what you used instead) but a ventilation system would be needed. The Cool Tube is a better option if you are or will be running CO2.
There is also a bit if a fallacy of CFL's being so much cooler than lower wattage HID lighting. Multiple CFLs are used and while each one feels cool to the touch there is an accumulation of heat from the combined multiple CFLs and all the heat from one HID light comes from one bulb so it seems there is a much larger differential in overall temperatures than there actually is.
CFLs put off more heat per watt used but people use such pitiful low amounts of watts and each source of heat is spread out so they seem to be much cooler than they actually are.
HID lighting far out produces CFL lighting. HID lighting produces more grams per watts used and with that means larger denser buds.
To give an example of light efficiency equivalency, to equal the light put off by one single 400 watt HPS bulb it would take 5.3 125 watt actual 'horticultural' CFLs, that is actual wattage, not equivalent wattage, and not the Lowes, Home Depot Wal-Mart pig tail home lighting bulbs that most CFL growers use and swear by. To get an equal amount of light you would burn more wattage and the combined heat from the multiple bulbs would not be cooler, it would only seem cooler when placing your hand near each individual CFL bulb.
If you go with a HID light, if it is not one with a switchable ballast allowing you to use both a metal halide bulb for the vegetative growth stage and a hps bulb for the flowering stage of growth it would be well worth purchasing a metal halide conversion bulb that you could use with your HPS ballast. That would give your plants more of each light spectrum that they need during the different stages of growth.
Something else to consider is light penetration. Just because a light is a HID light do not expect uber-penetration from lower wattage HID lighting. A 250 watt HID light will only give you about 18 inches of adequate light penetration. If you veg to a height of more than about 8 to 10 inches you are wasting your time because your plants will outgrow your lighting capability. The result will be your lower branches with the tightest nodal spacing will not receive enough light and will likely die out before harvest time and if they do not die out the most you will have is a small amount of sparse popcorn buds.
If you have the funds to work with I would suggest a 400 watt digital ballast/switchable that can run both metal halide bulbs and high pressure sodium bulbs and add ventilation. A Cool Tube might be the best way to go to keep temperatures down. Roughly $350.00 to $375.00 should cover a basic setup, though your situation/conditions/needs may vary somewhat. A magnetic ballast and using a metal halide conversion bulb, with the rest the same, should be able to be purchased for roughly $320.00 to $345.00.. but for the small difference in price I would suggest the digital ballast. (prices do not include shipping)
In either case if odor will be a factor/problem a carbon filter can be purchased or built inexpensively following online plans and added to your ventilation system.
You could do without the Cool Tube and use a basic, but still good, reflective hood and save between $35.00 and $75.00 (depending on what you used instead) but a ventilation system would be needed. The Cool Tube is a better option if you are or will be running CO2.
newworldicon
Well-Known Member
I agree that multiple CFL's can produce immense heat, I used 7x 250W HO CFL's in a 8x4 tent and the heat was plenty.
leeak47
Active Member
well i would like to just get the 250 watt hps with a hood but from what some people are saying is that i could be ventilated and be ok with a fan in the closet, the setup im using now is 10 25watt and 27watt cfls right now and its being ventilated fine with a fan blowing in the closet pointed out the door and im not sure if thats close to the amout of heat a hps puts off or not. ive heard so many options now im confused of what i want to do haha
Brick Top
New Member
Depending on your budget you could use almost any wattage. All you would need is a CoolTube and adequate ventilation through the CoolTube and temperatures would not be an issue.
goodeye2113
Well-Known Member
agreed! i just switched up my setuo from growing with 200+- watts of cfl to a 400w hps in my closet with just a dual window fan for ventalation and it gets as low as 65 when lights are on to 80 with lights on. it takes maybe 4 hours of the 400w and cfls being on, with my door closed, to raise the temp of my room from ~65-75. but even cracking the window can bring temps down 10 degrees
Chelseys Man
Active Member
Maybe a 150w hps that has 16,000 lumins
leeak47
Active Member
haha goodeye2113 sounds like you have almost the EXACT same setup as me i have 257watt of CFLs running right now being ventilated by a dual window fan! haha so from your setup a 250 watt HPS would be fine really considering the 250 noww the 400 im afraid would just pull to much power as i have a seperate veg box with cfls