Heat is an issue, 630 cmh vs 1000w de

Hey all, I'm looking to pull the trigger on some lights for about 144 sq ft grow space with 8 foot ceilings. I have always grown with hps, either se or de In my mind they were always the best yielding bulbs. I'm hearing alot of talk about cmh now and they may work for me, my biggest interest being the ease of cooling less heat. So the choice for me is basically 4 1000w de (gavita) or 4 630w nanolux cmh. Doing sog on 1 4x4 table per light. Some questions:

1: for anyone who changed or has experience with hps vs cmh what are your thoughts
2. What's the heat out put on nanolux cmh 630w, I tried looking but I cant seem to find anything.
3. Yeild and quality changes, I dont mind a little less yeild for less stress of worrying about heat and power.
4. Distance to light. How far should I put the cmh to the canopy. I know 5ft with gavita but hoping to get the cmh a little closer.

I hope someone can answer these questions thanks!

I think 630 cmh produce around 2700 btu

Kushandjams said:

Hey all, I'm looking to pull the trigger on some lights for about 144 sq ft grow space with 8 foot ceilings. I have always grown with hps, either se or de In my mind they were always the best yielding bulbs. I'm hearing alot of talk about cmh now and they may work for me, my biggest interest being the ease of cooling less heat. So the choice for me is basically 4 1000w de (gavita) or 4 630w nanolux cmh. Doing sog on 1 4x4 table per light. Some questions:

1: for anyone who changed or has experience with hps vs cmh what are your thoughts
2. What's the heat out put on nanolux cmh 630w, I tried looking but I cant seem to find anything.
3. Yeild and quality changes, I dont mind a little less yeild for less stress of worrying about heat and power.
4. Distance to light. How far should I put the cmh to the canopy. I know 5ft with gavita but hoping to get the cmh a little closer.

I hope someone can answer these questions thanks!

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Sorry can’t help. Maybe can help me I’m an outdoor grower looking to start indoor. Have a 1000w hps was going to setup in my shed am a lil worried about heat tho although it’s getting colder out It’s only a flowering room think i would be ok on temp

Babbagoots said:

Sorry can’t help. Maybe can help me I’m an outdoor grower looking to start indoor. Have a 1000w hps was going to setup in my shed am a lil worried about heat tho although it’s getting colder out It’s only a flowering room think i would be ok on temp

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From what I've seen with shed grows, it really pays to add some insulation and poly if you have the time and budget. It helps with possible light leaks, pest resistance (lay mice traps!) and more consistent temps. I've done about 10 grows and been around many more commercial sized ones. I'm no expert but I think plants can run ittle hot or a little cold but not both, a huge temperature range always leads to problems imho. Happy growing!

Babbagoots said:

Sorry can’t help. Maybe can help me I’m an outdoor grower looking to start indoor. Have a 1000w hps was going to setup in my shed am a lil worried about heat tho although it’s getting colder out It’s only a flowering room think i would be ok on temp

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A standard 1000 watt hps is around 4000 btu including the ballast I believe, if you can calculate the volume of your room you could get a rough estimate of the temperature in their on paper. I forget what the formula is

If it's height/radiated heat that's the problem try a parabolic reflector with hps or cmh, the heat gets thrown around the bulb like a doughnut as opposed to vertical where the radiated heat is directed at your canopy, distance is a enemy!
660w @10/12 inches from the canopy, going on the lighting distance/power that makes my 660w @ 1ft = much better than a 1000w @5ft???
This is the best photo I can find to convey just how close you can get a parabolic reflector.

It might not be the most reflective surface ever made or computer designed or any other stuff but it's ability to get close trumps all the shinny surfaces and computer designed shapes...
that don't cause hot spots lol.

5ft away would leave me 2ft to grow in lol

Beautiful, on average what do you pull with a single 1000 watts hps and that style reflector?

Kushandjams said:

Beautiful, on average what do you pull with a single 1000 watts hps and that style reflector?

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When I was growing in a traditional style with a 1k 1.2/1.5 gpw since using the screen I've only used a 600w +10% boost = 1.5/1.8gpw if I put the time into the prep.

Star Dog said:

When I was growing in a traditional style with a 1k 1.2/1.5 gpw since using the screen I've only used a 600w +10% boost = 1.5/1.8gpw if I put the time into the prep.

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Wow those are some pretty wild numbers. And just to clarify this is with single ended hps? Were you running co2 and at which concentration?

Kushandjams said:

Wow those are some pretty wild numbers. And just to clarify this is with single ended hps? Were you running co2 and at which concentration?

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Yes just a regular se 600/1000w lamp with no co2, fwiw I do have a dimmable 1100 de parabolic but I find the distance from the canopy negates any benefits the 400v De brings.

Kushandjams said:

I know 5ft with gavita but hoping to get the cmh a little closer.

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Its not 5 foot for DE fixtures, especially trying to cover a 4x4. Ive had mine as low as 29 inches. DE's are awesome nothing in the world beats it.

2520w is 37% less wattage than 4kw. If you have everything dialed you would probably only yield ~20-25% less.

What hoods do you have for your SE HPS?

They have conversion kits like this. You could turn each SE HPS hood into a 315w CMH for around $200/ea.

NukaKola said:

2520w is 37% less wattage than 4kw. If you have everything dialed you would probably only yield ~20-25% less.

What hoods do you have for your SE HPS?

They have conversion kits like this. You could turn each SE HPS hood into a 315w CMH for around $200/ea.

Prism Lighting Science 315W CMH Light Conversion Kit

Now you can use a 315W CMH Lamp in your existing reflector with a standard mogul socket! CMH conversion kit including 315W ballast, CMH to MOG lamp adapter. (Not included in price of Kit: Your choice for options of 4200k or 3100k 315W CMH Lamp.)

growershouse.com

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Sorry for he miscommunication, currently I have 2 de 1000 watt gavitas in one room and they are being cooled with a 12,000 btu portable ac unit. I'm also building another room that will house 4 lights, I have yet to purchase these 4 lights, I am concerned that heat will build up in this room beyond the point of control if use 4 1000 watt gavitas in this room and have a negative effect on efficacy/safety. I could cool the room with 2 individual 12,000 btu ac's but that's starting to pull alot of power. I'm not opposed to doing it but basically I'm weighing the yields/quality/powerconsumption and ease of mind with all of this in determining the 2nd room.

Kushandjams said:

Sorry for he miscommunication, currently I have 2 de 1000 watt gavitas in one room and they are being cooled with a 12,000 btu portable ac unit. I'm also building another room that will house 4 lights, I have yet to purchase these 4 lights, I am concerned that heat will build up in this room beyond the point of control if use 4 1000 watt gavitas in this room and have a negative effect on efficacy/safety. I could cool the room with 2 individual 12,000 btu ac's but that's starting to pull alot of power. I'm not opposed to doing it but basically I'm weighing the yields/quality/powerconsumption and ease of mind with all of this in determining the 2nd room.

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Ahhh I see. What about LED? You could do 480w of quality LED per 4x4. It also costs less to cool since you run LED rooms 82-85F or 85-89F if supplementing CO2 not to mention it’s half the wattage of 4 1kw’s.

They definitely cost more initially but you can DIY some nice lights for ~$1/watt and they will pay for themselves in electricity/heat savings and not having to replace bulbs.

LED/CMH is also a great combo.

NukaKola said:

Ahhh I see. What about LED? You could do 480w of quality LED per 4x4. It also costs less to cool since you run LED rooms 82-85F or 85-89F if supplementing CO2 not to mention it’s half the wattage of 4 1kw’s.

They definitely cost more initially but you can DIY some nice lights for ~$1/watt and they will pay for themselves in electricity/heat savings and not having to replace bulbs.

LED/CMH is also a great combo.

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That's something I thought about as well, the price and the complete lack of knowledge on my part about them makes me want to stay away, atleast for now.

Kushandjams said:

That's something I thought about as well, the price and the complete lack of knowledge on my part about them makes me want to stay away, atleast for now.

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If you can connect a few wires, cut aluminum angle and drill a few holes it’s a piece of cake. You don’t even necessarily have to build a frame to mount them too but it makes it easier to raise and lower the lights.

4x HLG QB 96’s Wired to an HLG-480H-54A driver would kill a 4x4 and cost about $500.

NukaKola said:

If you can connect a few wires, cut aluminum angle and drill a few holes it’s a piece of cake. You don’t even necessarily have to build a frame to mount them too but it makes it easier to raise and lower the lights.

4x HLG QB 96’s Wired to an HLG-480H-54A driver would kill a 4x4 and cost about $500.

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Sorry for the late reply, I initially was more weary of led as for so many years everyone I knew seemed to perpetuate they were very weak. I have since been doing alot of research . What would one pull with a lamp like you mentioned?

Kushandjams said:

Hey all, I'm looking to pull the trigger on some lights for about 144 sq ft grow space with 8 foot ceilings. I have always grown with hps, either se or de In my mind they were always the best yielding bulbs. I'm hearing alot of talk about cmh now and they may work for me, my biggest interest being the ease of cooling less heat. So the choice for me is basically 4 1000w de (gavita) or 4 630w nanolux cmh. Doing sog on 1 4x4 table per light. Some questions:

1: for anyone who changed or has experience with hps vs cmh what are your thoughts
2. What's the heat out put on nanolux cmh 630w, I tried looking but I cant seem to find anything.
3. Yeild and quality changes, I dont mind a little less yeild for less stress of worrying about heat and power.
4. Distance to light. How far should I put the cmh to the canopy. I know 5ft with gavita but hoping to get the cmh a little closer.

I hope someone can answer these questions thanks!

Click to expand...

CMH - Less Heat - Mainly because it has less infrared output than HPS. HPS is something like 60% of the light output is in IR! IKR? People talk about the BTU/watt and say that 1 watt = 3.4 btu/hr. But people also say the "california rule" for DE HPS is 5000 - 5500 BTU/hr for a 1kW DE. This is because of the IR output heating the surfaces it hits. This of course is something we need to account for if switching to LED for example. No IR output to warm the leaf surface temps means you require a warmer canopy temperature to get the metabolic rate up otherwise plant growth slows to a crawl and yields suffer greatly.

I run 1kW DE HPS and gave 600 DE CMH a stab and was not impressed with yields. Definitely dropped off from the HPS lights (side by side). The quality was great on the CMH but the flower lacked the bulk.

If I wanted to switch things up from HPS to combat heat I would be aiming for LED. Perhaps a mix. I would entirely skip the CMH.

Kushandjams said:

Sorry for the late reply, I initially was more weary of led as for so many years everyone I knew seemed to perpetuate they were very weak. I have since been doing alot of research . What would one pull with a lamp like you mentioned?

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1GPW up to 2GPW if you have things dialed and a good yielding strain. So between 1-2lbs.