# Growbox in my shop building - heating question



## spuddzrmeandyou (Dec 28, 2008)

I had hopes of using an unfinished walkin shower in my home for a grow chamber, but my wife is uncomfortable with me growing in the house, (and I am giving up trying to convince her otherwise) so my only option now is a grow box built in my shop.

I have a (unfinished) bathroom in the shop I think I can use... and build a box into that which measures 4 ft wide by 32" deep by 5 ft tall (or could go as tall as 9 ft). There is already a vent in this space to the outside so I could flush the air from the box direct to the outside. My only challenge I see with this location is HEAT... its winter here (temps in 20s to 30s, sometimes lower) and my shop is currently unconditioned, so I will have to add a small oil filled heater in the grow box with a thermostat.

- Would a 600W HPS with a cool tube be okay in this space? (53.2 CF)? As this will be out in the detached shop away from the house, I figure I can use most any fan I want, not concerned about noise. 

- Could I run a duct from the outside > cool tube and into the grow box and use the heat from the HPS bulb to warm the air as it comes in? ... and then the air is sucked out the top of the box through the fan and out the vent?

I plan to order my seeds tonight from Attitude (some NLxBB) so I hope with patience I will eventually have a crop (with some luck)!


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## Vegs (Dec 28, 2008)

> Could I run a duct from the outside > cool tube and into the grow box and use the heat from the HPS bulb to warm the air as it comes in?


 
That's exactly what I was going to recommend. Just pick up a "Y" joint or extension or two from the local hardware store to help take from the light to the grow chamber. I would recommend making a separate box for your light so to be able to draw directly all that heat and funnel into your grow chamber and then out etc...

You will have to think about summers as well and a setup that will allow you to no longer vent hot air from the light into the grow chamber.

All of this can be done with a single 265 CFM squirrel cage fan. I am actually using this same kind of setup minus venting hot air back into the grow chamber. I use two box setup divided by a sheet of 1/4 inch non-UV glass with separate ventilation for each chamber (grow and light) using one fan and a Y split. Temps in my grow room are never an issue because of it. But then again I don't have to worry about below freezing temps.


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## METALMOVER420 (Dec 29, 2008)

Go with a propane portable heater inside they emmitt co2 and can be set on a thermostat of course,also if its that cool dont forget about good insulation 600watt would be ok in that area but if you could go a little larger and get a 100 they produce much more heat, good luck and watch for light leaks.


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## blancolighter (Dec 29, 2008)

You have enough space that I would go with a 1000 watt setup if I were you, it'll cover that area better and in this winter weather it'll give a little heat. Also I would work on removing that 5 foot vertical limit you have and get as much head room as you can. Best to have more room for your plants to grow into than not enough. Also with a small ceiling like that, your grow box will turn into an oven in the summer, no matter if you choose 600 or 1000 watt lighting. Sounds like you've got the airflow and heating ideas worked out pretty well. Good luck!


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## aeroman (Dec 30, 2008)

This is just me, and I do thing different then a lot of people but I still get decent yields.  I'm in cold temps right now and I'm not bringing in any out side air.  I make CO2  If your shop is unfinished, I bet it isn't air tight.  It that bathroom drafty.  If so, there's your fresh air.  I would cool that bulb.  That would be my heat source.  
    You need a digital thermometer that saves the high and low temps.  Walmart sells them for about 12 bucks  You need to know how cold it gets by your plants when the lights off.    I'm going to post a thing on how I make CO2 soon.  A string dripping vinegar into baking soda makes co2.  CO2 is heavier then air so it will drop over your plants.  vinegar will burn them if it drips on them so be careful.  my replies are way to long


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## spuddzrmeandyou (Dec 30, 2008)

Thanks Areoman and everyone else on this thread!

I figure it will be trial and error to see what venting does to the temps with the light on. I thought of picking up a small space heater, like this one: 
walmart. com /catalog/product.do?product_id=7768641

and mount it near the bottom of the cab and pull the colder air (from inside the shop) through it, wiring it to a thermostat inside the box to come on only when temps drop too much. Once summer comes of course I will have to reduct this thing accordingly. (Hopefully by then I will have the shop conditioned and the temps constant inside).

I have attached a drawing, see what you think. Since I am trying to keep warmer air in the box while the HPS is off, maybe it would be better to pull the air out from the bottom of the box instead of the top? ALthough with your suggestion of a CO2 maker, that might not work of the CO2 settles to the bottom. I haven't given any thought to supplental CO2 production, was hoping that just keeping a constant supple of fresh air from the shop into the box would get me by. I also plan on adding a little oscillating fan inside to blow over the plants.

I have some NLxBB seeds on the way... my plan is to start of germinating say just 5 of the 10 seeds and cross my fingers for a female... and just veg these in the one area under the HPS... if more than one plant I hope I can switch them both over to 12/12 at the same time and not have to worry about a seperate veg chamber for now. But I figure at some point (soon) I will have to figire out how to add a veg area inside this for  seedlings/clones etc. Many thanks for any advice.




			
				aeroman said:
			
		

> This is just me, and I do thing different then a lot of people but I still get decent yields.  I'm in cold temps right now and I'm not bringing in any out side air.  I make CO2  If your shop is unfinished, I bet it isn't air tight.  It that bathroom drafty.  If so, there's your fresh air.  I would cool that bulb.  That would be my heat source.
> You need a digital thermometer that saves the high and low temps.  Walmart sells them for about 12 bucks  You need to know how cold it gets by your plants when the lights off.    I'm going to post a thing on how I make CO2 soon.  A string dripping vinegar into baking soda makes co2.  CO2 is heavier then air so it will drop over your plants.  vinegar will burn them if it drips on them so be careful.  my replies are way to long


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## METALMOVER420 (Dec 30, 2008)

I would probably veg.24 hours a day now that I think about it that would probably get you into march and use a propane portable heater on a thermostat for supplemental heat.IMO


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## aeroman (Dec 30, 2008)

Yeah I thought you were a little further a long.  You'll want to start you your seeds in side.  once you germinate the seeds You might want to buty a heating pad to start the seedlings on.  Use the lowest setting and put a towel over the pad.  That way when the plants are the weakest they'll stay warm.  
   You put the co2 generator behind your fan.  As the fan oscillates, it blows co2 over the plants.  I'll put a pic of mine up soon
  I can't see much on your pic, but you pretty much always want your  exhaust at the top and you may want to be able to move your intake around your room, but have it come into room as low as possible.  and if you can have it draw the air from an area that will be cool in the afternoon and evening.  If you do use a propane heater I think they put of co2.  i would look into it.  might be carbon monoxide


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