Completely sealed grow room ventilation help.

And before I go purchasing bare build reflectors does anybody see 8 1000 watt lights to be too much heat for a 30,000 btu 18 seer Ac unit. I know that rule of thumb is 3500 btu per 1000 watts making 28000 btu but I just want to make sure no body has objections before I continue with non venting shades.

Any body have any opinions on the adjusts wings or the grostar parabolic reflector?

Hey Eleconnect,

If you dont want to make the investment in the hoods.. Which I know darn well how much these rooms cost to build and the stress the old wallet feels (or credit cards) then maybe you should go vertical and just hang the bulbs from the mogul sockets.. Then if it gets too hot, then buy the appropriate hoods... Just a thought.... Donutpunched..

I agree with donutpunched on the mini split. Every sealed grow I've run has used this A/C with great success. Here's the deal on having a tech come to the site. Just connect the fan coil units (the ones in the room) yourself and run everything to the compressor, but don't hook it up. I assume the compressor is on roof or outside somewhere. The tech can nitro flush the lines, vacuum them down, and charge everything right at the compressor. He doesn't need to do anything in the grow. I have done this 3 times, and will be doing it again this spring when I seal my current 20k watt grow. Most of the larger split systems don't come with pre charged lines, so a tech is needed. Shop around and you'll find a good deal on a mini split. I'd shoot for 2 - 18,000 btu systems for your wattage. That will handle bare bulb lights and a CO2 burner easily. Undersizing the A/C will cause the unit to run 24/7 and possibly burn out early. If $$$ is an issue, start with 4 lights and 1 - 18,000btu split A/C. Then add lights and another A/C.

okay thanks for the advice. I have on order a 30,000 watt 18 seer lg mini split heat pump system and i am gonna be running 8 light not vented with a co2 cylinder and dehumidifer. do you think that the unit i bought is big enough for no light venting? the room is 24Lx14Wx8H.
would really appreciate any input before i go ahead and decide which reflectors to get.

Stay away from water cooled systems unless you have alot of BTU headroom within your setup.....

Eleconnect said:

okay thanks for the advice. I have on order a 30,000 watt 18 seer lg mini split heat pump system and i am gonna be running 8 light not vented with a co2 cylinder and dehumidifer. do you think that the unit i bought is big enough for no light venting? the room is 24Lx14Wx8H.
would really appreciate any input before i go ahead and decide which reflectors to get.

Click to expand...

I think it will be close. But it sounds like you don't have much choice with only 4" ducting outlets available. Water cooling isn't really a choice...it kind of sucks. Bare bulbs tend to grow a little better because glass gets dirty and robs light. I would move forward with un vented lighting. Worse case, you run 6 lights for a while, and then add more A/C.

i have heard the rule 3500 btus per 1000w light. but i like to go with 5000 btu per 1000w. the reason for this is because you dont want your ac just running ot. you actually want it to cycle on and off like it is designed to do, which also saves big in energy costs over the long run. straining an ac unit only costs you more money in the end.

Mrfootball420 said:

i have heard the rule 3500 btus per 1000w light. but i like to go with 5000 btu per 1000w. the reason for this is because you dont want your ac just running ot. you actually want it to cycle on and off like it is designed to do, which also saves big in energy costs over the long run. straining an ac unit only costs you more money in the end.

Click to expand...

Keep in mind BTU's can be subjective. Portable units don't even come close to their rating. A 12,000BTU ductless mini split is more powerfule than 3-10,000BTU portables. I know this because my last grow I started with portables and moved to the split system. I agree with footbal that the A/C will last longer if it's sized big enough to cycle, and not need to run consistantly. I've only had one grow with all bare bulb lighting. Most of my ops have been air cooled lights...and with good reason. But, you don't have that option. My bare bulb grow was 4 - 1000 watt lights in Adjustawings (fantastic reflectors). I had an 18,000btu Fujitsu Mini Split in a 100% sealed room. The A/C unit MORE than handled the lights and a CO2 burner. In fact, I once wanted to see how cold I could get the room with lights on. Running full time, the A/C got the room down to 71F. Not too bad. At 78F the A/C was probably running around an 80% duty cycle.

When growing purple strains, you can crank down the nightime temps to 60F and really bring out the color. You'll also find that the split units do a great job at removing humidity. I've never needed a dehumidifier with a mini split A/C. The room was a constant 78F and 40% - 50% RH.

I think your 30,000 BTU unit will come really close to doing the job. If you have to, just lose a light. You'd be better off with 7 lights and perfect temps, than 8 lights and a hot room. I can't help but thinking there must be a way to get a couple 8" ducts routed to the outside. Keep brainstorming it. If, in the future, you could air cool your lights, the A/C will be running way less and save you some $$$ in power. Probably enough to cover whatever construction costs are needed to get the ducts in.

In the meantime, take some pics of your build. For 20 years I've dreamed of having a basement grow op. Here in California there are no basements, though. So I became the 2 car garage grow op building guru...6 of em! The most lights in bloom I ever ran was 4. That's why we moved up to a warehouse. I still dream of the ultimate basement op. Warehouses are a pain in the ass.

I dont know if i overlooked something. But have you considered using some cooltubes on your lights. Intaking from one of the 4" pipes and exhuasting out the other. It would be a closed loop so your CO2 and conditions would not be effected. The 4" of course would not cool the lights down to be touchable etc, but the exhuast air would contain a crazy amount of heat. Over the 12 or 18 hour lights on period. This would be significant and would majorily help your AC handle the loads.

theTinker said:

I dont know if i overlooked something. But have you considered using some cooltubes on your lights. Intaking from one of the 4" pipes and exhuasting out the other. It would be a closed loop so your CO2 and conditions would not be effected. The 4" of course would not cool the lights down to be touchable etc, but the exhuast air would contain a crazy amount of heat. Over the 12 or 18 hour lights on period. This would be significant and would majorily help your AC handle the loads.

Click to expand...

You can't daisy chain 8 lights with a 4" duct. The last lights will be hotter than with no ventalation. I never daisy chain more than 3 lights with a 6" duct and 500 cfm.

If the new 30,000btu unit is not enough, you could divide the room in 2 and run a flip settup. One room is on from noon to midnight, and the other from midnight to noon. Then just figure out a way to divert the A/C to the operating room. Solonoid ducting is available. A flip settup has several advantages: Half the amp draw (twice the time), no 12/12 electrical usage pattern (worries some people), half the cooling needs (again, twice the time), and half the amount of ballasts needed (but you need to purchase a flip box).

I was thinking about using just four inch exaust for the lights but CG makes a good point on the last light being hotter than the first. As for bringing 8 inch ducts into the room I think that it will be a no go. I need to keep construction to a minimum. The house needs to stay as is as requested by the owner. The house was built 3 years ago and new furnace systems only have those 2 4inch pipes for intake and out take and a ventilation switch which turns on the furnaces blower and sucks air from the basement and spreads it out throughout the house. There is also two medium sized windows that I considered for ventilation but I really wanted to keep this a very secret room so I built half inch wooden covers painted black on the inside and made them deep with blinds on the window so from the outside you cannot see a glimpse of light. I will get pictures up as soon as possible for sure. I never realized that cali had no basements. That seems odd coming from a Canadians perspective hah. And as for the split room with the ballast switcher I think that would be a great idea for flowering but what do you do for the 18 hour cycles? Another question for you straying a little off topic, this is my second opp and I have stuck with sog rockwool technique and I have left 15 inchs diameter and 3 feet heigh for each plant with a total of 12 plants per 1000 watts. Do you forsee any problems I might encounter? As always I really appreciate everyone's opinion!!

Okay so I was slightly confused on sog. I can't start from clones. So I was wondering if I start from seeds is it possible to go from flouros directly to a 12 hour cycle and do you think that my canopy will be really un even starting like this?

Eleconnect said:

I was thinking about using just four inch exaust for the lights but CG makes a good point on the last light being hotter than the first. As for bringing 8 inch ducts into the room I think that it will be a no go. I need to keep construction to a minimum. The house needs to stay as is as requested by the owner. The house was built 3 years ago and new furnace systems only have those 2 4inch pipes for intake and out take and a ventilation switch which turns on the furnaces blower and sucks air from the basement and spreads it out throughout the house. There is also two medium sized windows that I considered for ventilation but I really wanted to keep this a very secret room so I built half inch wooden covers painted black on the inside and made them deep with blinds on the window so from the outside you cannot see a glimpse of light. I will get pictures up as soon as possible for sure. I never realized that cali had no basements. That seems odd coming from a Canadians perspective hah. And as for the split room with the ballast switcher I think that would be a great idea for flowering but what do you do for the 18 hour cycles? Another question for you straying a little off topic, this is my second opp and I have stuck with sog rockwool technique and I have left 15 inchs diameter and 3 feet heigh for each plant with a total of 12 plants per 1000 watts. Do you forsee any problems I might encounter? As always I really appreciate everyone's opinion!!

Click to expand...

Flip grows require a second veg room. I just assumed running 8000 watts that you had a seperate veg room. I would seriously consider breaking that room up into a veg and bloom room(s). You yearly yield will be WAY more running seperate veg and bloom rooms. There's just no other way, in my opinion...especially with your space/wattage. running two 1000 watt lights in veg and 6 in bloom will give you 6 harvests/year with 6 lights...or 36 harvests per light. If you use 8 lights to veg and bloom you get MAYBE 4 harvests per year...or 32 harvests per light maximum. And that's if you can squeeze your veg into 4 weeks. I just can't see running an op this size using seeds. I picture a clone table, a veg table, a space for a couple mothers, all feeding a big fucking bloom room.

Your sog plan is almost the same as ours. We run 50 plants in each 8 x 8 table covered by 4 - 1000 watt lights. We use 4" rockwool blocks set on top of 6" rockwool blocks. However, I'm switching to the Big Mama 8" blocks for more water retention. We hand water once per day

okay thanks for the help, i seriously over looked the actual process of starting and was so concentrated on table size and atmosphere. As you can see the set up would be difficult to convert into a multi room setup so i would like to stick to sog and get some mother plants going to feed it. i too am using 6inch slabs with 4 inch blocks and i have got the trays set up so if needed i can switch slabs around, turning the room into a 2 room setup would mean re designing everything up to this point. Any suggestions on the amount of mother i should shoot for.I was thinking 1 1000 watt and 6 mothers in soil. Any other suggestions now that you can see my situation

Eleconnect said:

okay thanks for the help, i seriously over looked the actual process of starting and was so concentrated on table size and atmosphere. As you can see the set up would be difficult to convert into a multi room setup so i would like to stick to sog and get some mother plants going to feed it. i too am using 6inch slabs with 4 inch blocks and i have got the trays set up so if needed i can switch slabs around, turning the room into a 2 room setup would mean re designing everything up to this point. Any suggestions on the amount of mother i should shoot for.I was thinking 1 1000 watt and 6 mothers in soil. Any other suggestions now that you can see my situation

Click to expand...

I'm a little confused. You say you're getting some mother plants going. So they're going to be in a different room I assume. What do you mean when you say "I'm going to stick to sog"? A Sea of Green just refers to numerous small plants.

If you plan to have 36" tall plants you'll need some veg time...probably a month from a rooted cut. If I'm hearing you right, you'll do that veg in the main room under 18 hrs of light, then switch bulbs and turn the lights back to 12/12? That's the only option I see without a decent sized veg room.

With some shelving it may be possible to use that little nook with the window as a dedicated veg room. You could settup a bunch of T-5's on shelves. If you ran a perpetual harvest on a 30 day cycle you would only need to be veging enough clones to fill half the bloom room. I think you could get 6 - 24" x 48" T-5's on 2 sets of shelves. That could easily veg 50 plants to about 15" in height. Depending on the strain, that could be enough to finish at 36".

I would do whatever it takes to keep that bloom room on 12/12 and just feed it with plants ready to bloom.

yea i want to keep the big room for bloom and use that nook for the mothers and the veging. how many mothers do you recommend for 50 trimmings at a time and do you think that i would have enough room for the mothers on the ground and the shelves on top of them? previously i was thinking of running the room on a veg and bloom cycle switching out the bulbs from his to mh and starting with seeds for the first crop before taking some clippings for a mother before blooming. I guess not the best plan.

Eleconnect said:

yea i want to keep the big room for bloom and use that nook for the mothers and the veging. how many mothers do you recommend for 50 trimmings at a time and do you think that i would have enough room for the mothers on the ground and the shelves on top of them? previously i was thinking of running the room on a veg and bloom cycle switching out the bulbs from his to mh and starting with seeds for the first crop before taking some clippings for a mother before blooming. I guess not the best plan.

Click to expand...

What are the dimmensions of the nook? From what I can see, you can pull it off. I would even consider 3 sets of shelves: 2 for the veging plants, each one with 3 - 2' x 4' T-5's...and maybe 1 shelf with 2 - 400 watt MH's for the mothers. Once the mothers have had a few rounds of clones srtatigically cut from them they can produce an amazing amount of clones. I've taken 50 cuts from a ball shaped 24" mother. I would just shoot for 4 mothers. Since a 1000 watt lights works best in a 4 x 4 foot area, two smaller lights on shelving may take better advantage of the limitted space. Or, you could try 8 mothers under T-5's. Not having any MH would reduce your heat load...the issue that started this thread in the first place. Our partner grow op uses only T-5's in veg for veging and mothers. They grow pre-98 Bubba and veg the plants big enough to yield 3ozs ea. You'll also need a couple 48" floros for rooting the cuts. The top shelf works well for this because the heat helps rooting. If it were mine, I'd use three shelves and all T-5's. One shelf for mothers and the other 2 for veging. Clones would be on top of every shelf.

I take cuttings 40 days before I want them in bloom. 10 days to root and 30 days of veging. They can stay in the 4" blocks until they go on top of your slabs in bloom. Get the tall 4" blocks. Since you're probably growing 60 day plants, the max veg time will be 30 days...and the veg lights always have plants in them. Every veg batch fills half the bloom space. You'll harvest half the room once per month. It will take a few months to develope your mother stock and get the routine down. Once you're rolling it should be a very efficient system. I would always veg 30 days and adjust your plant count to provide optimum density in the bloom room.

I f you're starting from seed, make sure to number each plant, take cuts with same numbers, bloom the original plants, decide which plant number you want for mothers, and grow those clones into your mother stock. Never just assume the seeds will all be the same. They will vary a bunch. This eats up time, but is the only way to assure you're growing the best possible phenos from that batch of seeds. Of course, the better way is to start from a known cutting.

Okay I like your idea with the shelves. The space not including the bulk of the window cover is 80" x 100".
Do you think I would have enough room to pump out 100 plants ready to bloom every 40 days with that space. The 2' x 4' 4000 lumen 6500k t5 setup says a growing area of 4' x 4' can be covered. With 4" rockwool cubes would that be sufficient enough coverage to grow 100 cuttings ready for bloom? and get another 2' x 4' t5 setup for rooting the cuttings?

I know this is getting really off the forum topic but I really appreciate all the advice everyone is giving me. Especially you CG. What do you think about having 6 mothers under 3' x 4' of t5 and then on the opposite wall have 3 shelves. 2 of them with 2'x4 of t 5's for veg and one of them with 1'x4' t5's for cuttings to root. Do you think that would be sufficient enough to pump out 96 plants ready for bloom every 40 days