Thoughts On My Cold Weather Indoor Grow Setup Please

[giannid]

Here's my setup I'm planning on putting together. Keep in mind the tent will be mind the tent is in a building that is climate controlled to 44 degrees fahrenheit.

The tent will be a 3' by 3' by 6' high. I'm going to put the tent up against a wall and put some rigid foam insulation around it on 3 sides and underneath. The door side will probably have a blanket or something draped over it but I figure I'm going to have the venting and heat come in there and want to have access to get it without moving a bunch of shit.

The heating is going to be the hardest part but right now I plan on putting the tent next to the furnace which will give me a little heat coming off of it also which will help. I'm going to leave some vents open around the tent for some passive venting but don't want too much cold air coming in. I have two ways planned for heat. I think I'm going to drill a 4 inch hole off of the furnace outlet and take a 4 inch dryer vent into the tent for some heat. Should give me a good boost in temperature in the tent I just need to bring the heat in where it doesn't fry the plants or leaves.

For external heat I'm thinking I want to run a small ceramic heater on the outside of the tent with a 4 inch tube going int the tent. Something like this-https://www.amazon.com/Blu7ive-Portable-Personal-Oscillation-Protection/dp/B07JMZPJLZ/ref=as_sl_pc_tf_til?tag=-20&linkCode=w00&linkId=&creativeASIN=B07JMZPJLZ

I'm thinking this over the oil filled electric heater because the tent is going to be tight on the inside with 4 plants. I also need to make sure I put the heat where it doesn't damage the plants. I'm thinking of controlling the heater with this type of thermostat device which I will also use as an exhaust temperature controller if it gets to warm when lights are on.
https://www.amazon.com/Inkbird-Pre-...&linkCode=w00&linkId=&creativeASIN=B01FTYRORS

This device will be connected to the heater to turn on if the temperature gets below say 65 degrees. I will also have a discharge fan at the top of the tent that will blow hot air out when if the temperature gets above say 85 degrees. I'll put the pbe on the thermostat controller somewhere in the middle of the tent so it gets a good reading.

I'm going to probably use an 4 inch internal blower and charcoal filter inside the tent that will just recirculate and move the air around. Might not use the carbon filter at first until the plants start to produce odor. I think this will keep the air moving around inside the tent well and scrub the air.

For lights I think I'm going to go a 315 watt cmh light with a 3100 k bulb like this.
https://www.amazon.com/Replace-4X30...&linkCode=w00&linkId=&creativeASIN=B06WVFZZHF

I think this is going to be a better option over the timber led light I can get my buddy. The led is 400 watts and will probably not create as much heat as the cmh bulb. I think the cmh bulb might be better for the plants and I imagine I could use it for veg and flower. Obviously the lights will be on a timer as i'll be using photo plants in soil.

One thing I'll have to do is monitor the humidity and have to change things up it I have a problem. What should be the optimum humidity in my grow environment? I'm afraid a combination of the low humidity in the winter months and heated air from the heat, will make it too dry in the tent. Just have to wait and see. What would be the best way to add humidity to the tent? I know it gets really dry in my house without a humidifier.

Let me know your thoughts and recommendations. I'm new to the indoor growing world and want to avoid as many problems as I can. Thanks in advance.

 

[goingtoguano]

I have a 4 inch can (blower) and I can tell you that will probably be too much to recirculate inside the tent. It blows pretty hard. IMO, a small fan would be a better choice. If you exhaust the air to outside the tent but keep the flaps mostly closed it restricts the flow quite a bit. I sometimes only use one flap with a piece of furnace-filter tucked in to help keep heat in the tent.

The combination of too much air flow combined with really low RH will probably be too much for the plants. I use a small clip-on fan and not pointed directly at the plants, just enough to move air around. -and only during lights-on.

 

[giannid]

I really want to scrub the air on the inside of the tent so it doesn’t stink? I imagine you have a blower constantly blowing air out of the tent sucking from a charcoal filter to keep the smell down? I could get a speed controller on the fan and run at a very low speed.

 

[goingtoguano]

Yes, I keep the air going out 24/7 but you can get by for a while without it. I have waited a month before running it but, I tried to open the tent at least once a day to let in some fresh air. For the first month from seed, the plants are really small and don't require much or smell much but like to stay warm.
Just one other thought, if you went with something like a 600watt mh/hps you would have the hottest option of the light choices available. Nothing against CMH (I may be going there soon) but, hps does make more heat and it does grow big buds (and is cheap to buy). You may not need as much external heat source as you think with either hid although I haven't tried to grow as low as 44f . I now keep my basement heated to 61 at lights-off (I have gone down into the 50's on previous grows without much problems). Plants will be slower at colder temps but they still grow.

 

[xavier7995]

I am growing in the cold atm. I run plain old 1k's and the post above is accurate, you can use the heat to your advantage. It is probably down in the lower 40s at lights off. Not going to yield well and they are slow, very nice shades of purple though so meh.

One thing to watch is they dont seem to drink as much/transpire so watch for soggy bottoms and root issues. I water with warm water right at lights on to try and get the roots back to a reasonable temp as quickly as possible.

 

[giannid]

Yeah, I know the hps lights make more heat but really want to use the newer technology lights. Regardless of which lights I use, I know I'm going to need supplemental heat at lights out so I figure I'll save the money on wattage and use it to heat. JMO.