New grower, need help in a challenged environment-cold

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giannid

Member
Hello to all and I'm a new member. This will also be my first indoor grow. Michigan has just legalized recreational use so I'm going to give it a shot this winter. Unfortunately it's cold in the Northeast and the only place I have to grow is in my commercial building I use for my business. It's a large building and am only able to keep the temperature around 44 degrees in the winter. I have to do this as we have equipment and supplies that have to be protected from freezing.

I want to set up a small grow tent in the building. I'm thinking a 4 by 4 tent will be sufficient for 4 to 6 plants. A friend of mine has this Timber LED light he will give me which is a Models 4vs and puts out 400 watts with 3500k bulbs. It may be a little undersized and I'm worried that the LED'S might not produce enough heat. I'd really prefer to use an led as I feel it'll be better in the long run as far as maintenance and longevity. I could down size the tent to a 3 by 3 if I needed to. The floor is concrete so I'll probably set the tent on some 2 inch foam insulation. This is the tent I'd like to use as it seems like it has decent reviews Vivosun 4' by 4' by 80".


I'm not going to be using autoflowers so I'll probably have to ad some supplemental heat which I'm thinking of just putting in an oil filled heater in the tent with a thermostat. I know this isn't the most ideal situation but it's all I got. Heating the entire building isn't an option and I don't have the room to build a dedicated grow room.

Ventilation I'm still trying to figure out. Not sure how bad the plants will stink up the shop so I'm not sure I need a carbon filter. I may just add a carbon filter when the plants start to stink. Recommendations on a good ventilation system would be appreciated also. I'm not sure I need to vent outside but I can if I need to as I'll be next to a wall.

Looking for people who've grown in similar environments and have had the same challenges. I'm new to this and could use all the help I can get. Locally, I have an HTC supply and some other indoor grow shops I can buy supplies from. I'm going to get the plants started in the next couple of weeks. Thanks for the help in advance :)
 
Herb & Suds

Herb & Suds

Well-Known Member
I bet you find space for a dedicated grow room once you get the bill for heating a tent 24/7 in a 40 F environment , but good luck and welcome to RIU and legally growing
 
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giannid

Member
I'm hoping you're wrong. It can't be that expensive to heat a 4' by 4' grow tent 16 degrees for 12 hours.
 
Herb & Suds

Herb & Suds

Well-Known Member
giannid said:
I can definitely insulate it on the outside it it helps. Could use rigid foam insulation as we have that material already.
Click to expand...
Why do you even need a tent then ? I would build a little room out of the foam ...all the tent is giving you is a frame to hang light and fans
 
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giannid

Member
I don’t have room for a shed inside the building unfortunately. No public access to the building as we just use it for storage for our tools, trucks and equipment. This is the only place I have that I can set up to grow at. We may need to get a filter if the smell gets really bad.
 
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Digger47

Well-Known Member
I'd build whatever size you can have in there. Frame it up, fiberglass insulation with foamboard on the inside and out. Tape the seems.
 
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giannid

Member
Don’t I need to bring in fresh air and keep it circulating in there? I always thought sealed wasn’t good. Figure if I use a tent I can insulate it good enough and still leave some open vents to bring in some air.
 
1

1212ham

Well-Known Member
giannid said:
Hello to all and I'm a new member. This will also be my first indoor grow. Michigan has just legalized recreational use so I'm going to give it a shot this winter. Unfortunately it's cold in the Northeast and the only place I have to grow is in my commercial building I use for my business. It's a large building and am only able to keep the temperature around 44 degrees in the winter. I have to do this as we have equipment and supplies that have to be protected from freezing.

I want to set up a small grow tent in the building. I'm thinking a 4 by 4 tent will be sufficient for 4 to 6 plants. A friend of mine has this Timber LED light he will give me which is a Models 4vs and puts out 400 watts with 3500k bulbs. It may be a little undersized and I'm worried that the LED'S might not produce enough heat. I'd really prefer to use an led as I feel it'll be better in the long run as far as maintenance and longevity. I could down size the tent to a 3 by 3 if I needed to. The floor is concrete so I'll probably set the tent on some 2 inch foam insulation. This is the tent I'd like to use as it seems like it has decent reviews Vivosun 4' by 4' by 80".


I'm not going to be using autoflowers so I'll probably have to ad some supplemental heat which I'm thinking of just putting in an oil filled heater in the tent with a thermostat. I know this isn't the most ideal situation but it's all I got. Heating the entire building isn't an option and I don't have the room to build a dedicated grow room.

Ventilation I'm still trying to figure out. Not sure how bad the plants will stink up the shop so I'm not sure I need a carbon filter. I may just add a carbon filter when the plants start to stink. Recommendations on a good ventilation system would be appreciated also. I'm not sure I need to vent outside but I can if I need to as I'll be next to a wall.

Looking for people who've grown in similar environments and have had the same challenges. I'm new to this and could use all the help I can get. Locally, I have an HTC supply and some other indoor grow shops I can buy supplies from. I'm going to get the plants started in the next couple of weeks. Thanks for the help in advance :)
Click to expand...
Welcome to the cold club. o_O
I plan on using making a grow box with 1" thick foil faced foam insulation. I'll tape it together, and maybe use some dowels or screws. I think losing heat AND humidity through air exchange could be the biggest problem. I wish someone could tell me how much ventilation is really needed! I ran no forced ventilation part of last winter and it didn't seem to bother the plants at all. I know nothing about co2, but I think it might be an option rather than losing heat through air exchange.


That timber is a good light, but maybe a little small, 35 watts/square foot is a common recommendation for good LED. OTOH, it certainly is a good start and plenty for veg, especially if it's free. You can always add some HPS for more light and IR heat. Plants under LED like higher air temperature due to the lack of direct, infrared heating from the lights. With LED, leaf temperatures are usually about 2°C cooler than air temp due to transpiration, leaf temp will be higher than air temp with hid/hps due to the infrared heating the plants directly, but not the air. A carbon filter will remove the smell.

I started a couple threads...
https://www.rollitup.org/t/setup-for-growing-in-cool-temperatures.980362/
https://www.rollitup.org/t/growing-in-cool-temperatures.980364/

There's another thread about growing in a cold garage, I'll see if I can find it for you.
 
raratt

raratt

Well-Known Member
I would recommend against the oil filled heaters, my friend had one and said it was highly inefficient. I have a 6'X6.5'X8' room in my unheated garage in Nor Cal. Not the same weather I know but it gets below freezing often. I picked up a little heater from Wally that has 3 heating wattages and the middle one works fine. As opposed to a tent if you have a corner in the building (hopefully insulated) you could build two walls with a door for less than $200 easy with insulation all around. You could lag bolt the walls together so it would be removable. I am limited to 6 plants also but it is nice to have room to move in there. I just set the pots on milk cases to get them off the floor and keep them warmer.
 
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giannid

Member
1212ham, thanks for the links as they've been helpful. Glad to see I'm not the only guy who has this cold weather growing problem. Looks like you and others have it kind of figured out. I understand it's less than ideal and you probably won't get the yield as a warmer environment. I'm sure we'll do alright though.

Raratt, do you keep your heater in the tent? Do you have your box/tent constantly circulating air from the cold room or do you have minimal venting? Seems kind of counterproductive to bring cold air in when your trying to heat the inside of the tent?

I may try and build a grow box out of some foam board. It may be more work than it's worth since I can get a grow tent for $100 or so and just surround it with insulation.

I'm wondering if anyone has ever put an intake fan and heater on a timer so that the fan and heater run only when the lights are off to warm the tent? Would almost be nice if someone made an inline heater that could be put in the tube. Anyone have a set up like this?
 
raratt

raratt

Well-Known Member
giannid said:
1212ham, thanks for the links as they've been helpful. Glad to see I'm not the only guy who has this cold weather growing problem. Looks like you and others have it kind of figured out. I understand it's less than ideal and you probably won't get the yield as a warmer environment. I'm sure we'll do alright though.

Raratt, do you keep your heater in the tent? Do you have your box/tent constantly circulating air from the cold room or do you have minimal venting? Seems kind of counterproductive to bring cold air in when your trying to heat the inside of the tent?

I may try and build a grow box out of some foam board. It may be more work than it's worth since I can get a grow tent for $100 or so and just surround it with insulation.

I'm wondering if anyone has ever put an intake fan and heater on a timer so that the fan and heater run only when the lights are off to warm the tent? Would almost be nice if someone made an inline heater that could be put in the tube. Anyone have a set up like this?
Click to expand...
I built a room, actually two walls using the existing exterior walls as the other walls, I had insulated them already. I do have a return air vent into the room, but I need it to keep the smells down so I have a carbon filter away from the return vent. I have no problem keeping the low temps in the mid 60's. I also run my LED's at night to help heat, though they don't put out much. Heater is small and in the room.
 
fragileassassin

fragileassassin

Well-Known Member
IMO, your best bet is going to be to frame out a small room and insulate it and grow in that space instead of using a tent or build a slightly larger room around the tent and control that room. It's fairly easy and materials arent going to cost too much more than a tent will.
Itll cost a bit more up front, but you will save a lot of money on heating cost in the long run and itll be a lot easier to control.
Every bit of extra cost and effort you put into it now will pay off in the end.
You have to have some kind of air exchange unless youre running co2. Youre going to struggle keeping temps up with those outside temps. I have a heated basement and I have accidentally dropped the temps inside my tent with the lights on nearly 10F by leaving a window open for an hour when it was in the low 40s outside. Even with a space heater blowing at my air intakes, my tent gets several degrees below ambient when the lights are out.
I had originally planned out rooms that I was going to build and insulate. I ended up finding a great deal on a big tent so I got that instead. Now I wish I would have just built the rooms.

They make fairly inexpensive environmental controllers that will turn your heaters or fans on and or off at set temps.
A big thing people seem to agree on is that you dont want hot air blowing right on your plants and this will make it difficult to heat a poorly insulated space with low ambient temps. If you make a room you can grow in like 2/3 of it and use the empty space to safely heat up the rest.
 
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raratt

raratt

Well-Known Member
I used "hardboard" from Lowes for the wall covering, less than $8.40 for an approx 4X8 sheet. I did frame it with 2X4's so I could put R-13 insulation in the walls, and a bunch on the ceiling to hold in heat. The exterior I used up stuff I had laying around already.
 

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