Hi... I've begun round two (my second crop) already but am still working on refining and implementing the new plan. I did have a bit of a temperature problem with the first room, though I can happily report that the end result was nevertheless pretty damn good in terms of yield (by my beginner's standard anyway) and certainly in smokability. Anyway, for this next incarnation, the goal is to create a controlled environment situation. There's a ton of information out there in the form of excellent youtube vids and various other sources. Obviously the cooler is central to this way of setting up a room... but just as surely it is the most complicated decision cuz there are so many ways to go, with the cost, efficiency and complexity all being important factors. I have a question that'll make the decision for me. Here is one 'room' plan. Six 1000watt lights arranged in three parallel rows of two. These are air cooled tube lights utilizing three powerful Can-Fans to drive external air through the tubes and back out of the room again. A single fan is in series with a two foot insulated duct, an air cooled reflector tube light, a one foot insulated duct, another air cooled reflector tube light, and ten feet of 6" insulated duct that goes to an inlet duct in my work space. Care has been taken to completely seal the air in ducting and lights from the room. Let's assume for the sake of argument (not that I want to argue), that 100% of the convective heat can be removed with this air cooled light system. My question is... What percentage of a light source will be convective and what percentage radiant? It's fairly simple to run a test by operating one air cooled light for a short time and one non air-cooled light for a short time and measuring the temperature difference. I haven't done that yet. Maybe later today I'll do that. But I'm thinking that might not be an accurate analysis anyhow... as radiant heat is tricky to measure. If a considerable percentage of heat can be removed with air-cooled lights without the need for a larger scale room cooler, then it would make sense to do that. A lot of systems out there use chillers of some kind to cool the air in closed loop systems. I'd rather bring that hot air into a cool shop in winter and vent it right back outside in summer than buy and install and maintain a large cooler. I could get by with a smaller BTU unit. Anybody with experience or opinions on this... please offer it up.
First thought Simon is you're in over your head. If you haven't figured out effective air flow and cooling and are running 6000w of HID then you're well behind the curve. The most immediate flaw is forcing air through the reflectors rather than drawing it through. That's the least efficient and creates positive pressure in your fixtures and room from any possible leaks. (Yes, you have leaks. They're unavoidable) The radiant vs convective is too varied to be accurate from one garden to the other. Reflector material (if you choose to use one), size, shape, proximity to other objects, etc... There's a table floating around of cooling BTU's per 1000w HID but I'll be damned if I can find it. Some clarification on terminology. A "Chiller" in cannabis gardens is a unit that cools water. This can be for cooling lights in water cooled hoods, cooling reservoirs, cooling CO2 generators. Not for cooling entire rooms. A room cooler is an AC (air conditioning) unit. These are two separate units.
Thanks for the info Resin Rubber... I did bite off a lot with this project, you're right about that, but I'm hoping I'm not in over my head. It's all a learning process that will obviously continue to improve with each subsequent crop. My yield was about 2/3's of the optimum for 6,000 watts so yeah... I know there's room for improvement. That's what this forum is all about though... experience and wisdom being shared freely to help the newbies work it out. My goal is optimization. My background is Industrial Electrical with a fair bit of Commercial and Residential, though this is my first Grow Room. Designing electrical systems is my business and one of my passions. I guess there is some terminology to learn as well in this particular application. In the Industrial and Commercial world, 'Chillers' are very often room coolers although they can just as easily be utilized for cooling equipment. I'd prefer running a chiller (with heat exchanger) to cool the room than a conventional Air Conditioner actually as I can get a lot of cooling BTU's from the abundant and free water. My plan for this room incarnation is to line the walls with mirrors which will dramatically increase radiant heat. I neglected to mention that little detail in my original post. So a large scale room cooler (meaning A/C or chiller) will have to factor that in as well. Any comments from people with mirror lined rooms would be welcome. It's new territory for me and I like the idea of benefiting from the mistakes made before me... the experience of the people who have tried similar approaches. It's been a fascinating experience so far... Thanks again to all offering up their help.
I get you. Room coolers(stand alone AC units) can be effective but you still need to vent the exhaust hot air they create. Toss the mirrors they suck for growrooms. Mirrors reflect about 90% of usable light, are heavy, breakable and can create hotspots in your garden. 2< mil mylar reflects 90-95% of usable light. It's cheaper, doesn't create hotspots and is not breakable. Panda Film claims it reflects 90% of usable light. It's inexpensive, easy to install, easy to clean and is poly so it can handle the abuse of a growroom. Flat white paint reflects 85-87%% of usable light. It's cheap, easy, washable and effective. All of these alternatives will reflect less direct radiant heat into your canopy than mirrors. Dude.....seriously though.....click on the OverGrow FAQ link or GrowKind Grow Guide in the bottom of my signature and read them a few times. The mirror thing and the forcing air rather than drawing air for ventilation are both basic....basic.... pieces of knowledge you'll need to make your 6000w's perform like they should. Otherwise your wasting time and $$ with all that firepower. To be honest...it feels rather silly to be telling a guy running so many lights the absolute basics. Walk before you run my friend and cut back until you KNOW what you're doing. Would you take a kid who just learned to ride a bike to the local BMX track and tell him to mix it up? Of course not. That's essentially what you're doing with your garden.
If you want to use water chillers to remove heat in your room then water cooled lights like the fresca sol would be more efficent then iceboxes.
We must respectfully disagree. He is not "IN" over his head, - BUT, he is damm sure giving it his best shot to try to get in over his head. But we understand the excitement, it is a big deal when that first crop comes in. Simon, if you had a room setup and funtioning well with 6-1000 watters going, you are either a licensed caregiver providing meds, or you are on your way to prison for sale. No way you need that much firepower for personal use, even if, you with your skills could get it up and running. :-welcome-: Slow Down...........:F-A-Q: Keep asking for help, its all good
Yes, I am in fact a licensed designated medicinal grower and have thus far only taken advantage of half of the license allotment. Therein lies my interest in optimization and in trying to run before I can walk. That method has worked for me in various endeavors. As long as the information is out there, I'll do what I can to assimilate it and make it work. As for the basic push-pull for air flow, I did read the FAQ's but have decided that in my application pushing with a high speed fan is better than pulling because if I'm drawing outside air and exhausting the same air back outside the room, any leaks in the ducting or light tubes would simply leak fresh air into the room rather than sucking aromatic and incriminating air out from the room. I am operating under a license but discretion is still a good idea. There's enough hot air blowing into my work space from two lights with a push fan to almost keep it up to temp in winter so it's got to be working fairly well I'm thinking. I've put a whole lot of effort into this garden, including construction of the building itself. I haven't thought of everything but it's been working pretty darn good so far. I'm planning on increasing production, and optimizing production... not slowing down and optimizing. Thanks again for all your comments.
I've got a bit of a silly question. I am not trying to cool the air in my lights but simply direct it... recycle it into my work space so the electric heater doesn't have to come on in the winter. In the summer the air can either be ducted outside or into the workspace at night time depending on temperature in the workspace. On a night time light cycle, the summer air being drawn in will be ample to cool the convective heat within the light tubes. The air to cool the lights is coming from outside. Why are closed looped systems more prevalent? I mean I can't see any downside to a system like this. Water cooled fixtures become unnecessary as well as iceboxes in a closed loop duct because that hot air is not in a closed loop. It's going right out of the room. I'd sooner put a bit of effort into completely isolating the cooling air from the room air than installing and having to maintain any kind of cooling aside from a fan. Is there something I'm not considering that makes it a bad idea to [KISS] with this system?
A closed loop light exhaust? Huh? The typical set-up draws either outside or ambient room air into the garden, through a reflector/hood, then out of the garden to the outside. A dedicated light exhaust draws outside or room air into the duct, past the reflector and exhausts outside. Neither is a closed loop system. If you choose to direct the exhaust into a room....who cares? As long as it maintains the garden temp you need it's a moot point where you send it. Seriously my friend you have some profound misunderstandings. If you read the guides....please reread them. How is your garden itself breathing? A dedicated light exhaust implies either a CO2 system, a separate fresh air ventilation system, or, completely inadequate airflow through the garden.
yeah, a closed loop lighting cooling system (not my chosen system but one that is out there utilizing inline icebox chillers. Check out youtube and the icebox) .... and yeah, a fan pushing the air through light tubes rather than pull... Here's a link (one of few I've found) that discusses this option. http://nugmag.com/2010/08/building-a-grow-room/ "Always air cool your lights to keep them closer to the plants without burning them. Using a 6” Vortex fan at 447 CFM will cool two 1000 watt lights with 6” air cooled reflectors, as long as there is not too long a run of ducting and not too many 90 degree bends. An 8” vortex fan at 747 CFM can cool up to four 1000 watt lights with 8” air cooled reflectors. These fans should be drawing fresh cool air from outside the room, and pushing the air through the reflectors and back outside the room again. This should be its own independent ventilation system and not be tied into the room exhaust." and yeah, a chiller to cool the room and not an A/C... You can use chillers or A/C's. For a moderator you're pretty stuck on one way of doing things dude. You need a chiller for your brain. An important purpose for a site like this, I might remind you is to encourage and offer positive criticism to people just venturing into a new horticultural adventure. You should be saying something like... 'way to go. Congratulations on your first grow. I remember my first grow and this and that... blah, blah, blah...' Not 'you're in over your head' or 'that stuff is basic basic basic, go read the FAQ's again.' If you're gonna talk shit like that, without anything positive to say at all... then please take it somewhere else 'kay. I'm reading grow mags... I'm doing Internet research... I have been talking with a couple of pretty experienced people... I spent the money, read the book... etc... etc... My first yield was pretty darn good at about 66% of what I've been told is a realistic maximum. It's killer smoke too. Give me a little credit.
I can be an opinionated prick. Admitted openly. And I do give you credit...in fact I think it was one of my posts that first congratulated your first harvest but I believe in talking straight when seeing a gardener "in over his head". Anything else just prolongs failure or less than ideal returns on effort and $$$ spent by the particular gardener. I been growin pot, reading about growing pot, talking about growing pot, watching films about growing pot, on the internet looking for more ways to grow pot for quite a few years now and understand these things because I've been putting them into actual practice. Tron has been growin pot for a long freakin time and understands these things because he's been doing them. You been growin pot for one cycle of below average yield, reading some magazines and talking to folks.....who's opinion on the "correct way" to do things in a cannabis garden is more valid? Mine and Tron's or yours? When two experienced growers say you're not ready.....might want to listen. Honestly...it takes a good deal of experience to do what you want to do. To be really blunt. In no way shape or form are you prepared to fully utilize 6000w of light. You don't have the requisite knowledge about cooling your garden, your lights, wall coverings..I can only guess where else there are errors. I see a trainwreck and was hoping to guide by being direct rather than feeding ego. I know you'll be able to put it all together eventually, that seems to be your personality. Jump in and flounder until you get it right by perseverance and trial and error. Was simply hoping to kick you in a direction that got you to the finish a little more efficiently and earlier. I'll be going now. Have fun and good luck. cheers,
Chillers.... You CAN use a chiller to cool your room. I DO. ALL large commercial buildings provide AC via the use of chillers and not conventional AC units. The reason is the savings in electricity. After a certain size of building is realized, the initial cost of the chiller style cooling is negligent in comparison of the cost of electrical usage. In fact I am developing a garden specific cooling unit that cools the room far more effectively and efficiently than any similarly sized AC. I have a portable 12k BTU AC and a 12k BTU chiller. Both will maintain the room at the same temperature but my chiller only runs about 40% of the time, whereas the AC run continuously. And this is only using one 6" icebox heat exchanger. Tommorrow I will be building a much larger air handler with a 12"x12"x3.5" heat exchanger. I am confident with my previous experience with the small icebox that I can cool my room far more than necessary. Now one thing you MUST have with this system is a dehumidifer. Anything over 50%RH and you get serious condensation issues. Also your dehumidifer will become a significant source of heat. This decreases the performance of the system as will any other source of heat in the garden. However with an adequately sized chiller mated to a large enough heat exchanger these problems are solved. As to your initial question regarding radiant heat. You should KNOW just how much radiant heat comes out of a 1kw. A shit load. So when you are designing your cooling system it is important to supply cool air directly below and across the lens of your hood. That's where it's hottest and also where it's closest to the plants. If your room temp is 85 degrees you can bet your ass that it's 100 or better just below your bulbs. Now RR is absolutely correct in stating that you should pull air through your hoods instead of pushing. It just works better. Period. You do not want outside air leaking into a sealed room. This creates positive pressure inside your grow room and forces any odors out. If you are running a sealed room then supp CO2 is a must. If you have this then you do not need or want any exchange of air whatsoever. Any air exchange is just wasted CO2. It sounds like you've got some good ideas. Keep playing with them and make diagrams. Put them on paper and they will evolve. IMHO sealed grows are the way to go. Good Luck Retiree
Im sorry but......Im still lost as to what your trying to do Simon Could you not write it in 1k words......simple and to the point please
4000 BTU per1,000 watts You do not need air cooled hoods If you have plenty of fans blowing air around Good sealed room For co2. Just an AC that has the required 4,000btus per light. I have two K's in a 6 1/2 by 9 foot room open reflector ajusta wings and the 8,000 BTU AC keeps them below 80° even when its hot out. the ajusta wings are the most efficient light reflector available if used correctly SIX LBS IN THAT SPACE WITH TWO Ks IS A GOOD YIELD And I do it consistently The worst yield I've got out of there is 2.25 pounds per light And that's With 1 year old light bulbs
Thanks for the information. The best way to learn anything is through first hand sharing of information with the people who have the experience. I appreciate the interest in helping me to optimize things. I am okay with moving the fan in the light tube ducting to the outlet end. I understand the reasoning behind it... making sure the room won't pressurize if there are any light tube duct leaks. My strategy was going to be putting the effort in to making sure there were no leaks in that duct, but I will change my plan there. Although if the fan is sucking and there is a leak it'll draw the aroma outside anyway. I was under the impression that a pound per K of light was a very respectable goal. You're saying you typically get three times that much!!!??? Did I understand you correctly? There's something to strive for it that's the case. I only got a little over four pounds with six lights. So you're yield works out to four and half times what my first one did? I was thinking that a big reason for my smaller than ideal yield was the high temperatures in the room. It's a good thing that I did it through the cold winter months. I had lots of air movement with 747 cfm Can-Air fans on the intake and the exhaust. I had three oscillating fans set up to blow across the area between the lights and the canopy top (which had to be fifteen inches away minimum). I vented the air continually in this first attempt. Am in the process of setting up an entirely controlled environment second attempt though. High up on the list of things I've learned from my first garden is just how important temperature control is. Got some real and useful information out of this discussion. Thanks again for all your help. for reacting RR. I should have counted to ten before writing that last post.
