Too Cold

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bumbleberry

Member
Growing in 2x2.5 in cold garage. How can I heat or insulate this? Foam board frame? Heat mats? On a pallet? My girls need help
 
xtsho

xtsho

Well-Known Member
If they're setting on a cold concrete slab get them elevated. You can use an oil filled heater in the tent. That's assuming you are growing in a tent. If not you'll need to enclose them somehow.

I'm growing in an unheated garage. I put a raised floor on the bottom of my tent so the plants were not sitting on the cold concrete and added a heater. I also run my lights at night when it's colder and the heat from my HID keeps the tent around 75°F. The heater has a thermostat and doesn't kick on until after the lights go out and the temp starts dropping. Even with the exhaust fan running it stays around 65°F when the lights are off.


 
dbz

dbz

Well-Known Member
I use interlocking foam exercise mats for a floor.
Seems like you are going to need heat, I suggest a radiator like @xtsho posted above.
A word of caution with heaters, if you use a ceramic heater or something with a blower, be careful it isn't aimed directly at plant leaves they will die from extremely hot air being blown directly at them.
 
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bumbleberry

Member
My tent is sitting on a piece of plywood that is on top of a pallet. I would prefer not to use heaters since my goal is low power consumption and my light is only 210 watts. For such a small space I was hoping to keep a heat mat on to help but not sure if that will have any significance. I already bought a 20 watt heat mat that seems useless, maybe I should by a controller for it? What do you think of cutting foam board insulation to size around the tent or any other material to wrap around it?
 
TurboTokes

TurboTokes

Well-Known Member
You can not use that style heat mat as a garden bottom, thats a disaster.

Buy electric heat mats, you can buy smaller repltile tank type heat mats for $10 each for individual pots, they use 10-15 watts each which costs pennies to run but they keep the roots warm, or buy larger electric mats (usually soldas rv heater mats to keep there water tanks from freezing) and you can line the bottom of your floor.

Keeping the root zone warm in a cold grow is most important, if it falls below 60* in the root zone your no longer seeing any progress.

I am in Canada, with an unheated garage growing successfully throughout winter, and IMO I do it cheaply. It costs alot to run a 1500 or 750w blowing heater, just to have it be sucked out with the exhaust. I use small 6X10 electric heat mats, kicked on at lights off, and I only really need them when its really cold like -15C outside. I believe they are 10watt each, with my wet fabric pot sitting right ontop of it.

I built a custom grow box, veg chamber on the bottom 3x3 but short height, and a flower box right ontop of it. I made it out of metal to frame it, then 1" foam, then plywood shell it. Easy if your handy with custom shit. So my veg space below runs 24/7 with T5's and the heat from the lower box keeps itself at good temperature, but also radiates to the floor above it when the flower box goes lights out. I monitor temps in the root zone and at plant height and it stays above 65*, even when the garage itself is 30* Fahrenheit

Definitely get the pots off the ground, preferably some electric heat mats, and use the heat generated by the lights creatively to heat the space.
 
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dbz

dbz

Well-Known Member
TurboTokes said:
You can not use that style heat mat as a garden bottom, thats a disaster.

Buy electric heat mats, you can buy smaller repltile tank type heat mats for $10 each for individual pots, they use 10-15 watts each which costs pennies to run but they keep the roots warm, or buy larger electric mats (usually soldas rv heater mats to keep there water tanks from freezing) and you can line the bottom of your floor.

Keeping the root zone warm in a cold grow is most important, if it falls below 60* in the root zone your no longer seeing any progress.

I am in Canada, with an unheated garage growing successfully throughout winter, and IMO I do it cheaply. It costs alot to run a 1500 or 750w blowing heater, just to have it be sucked out with the exhaust. I use small 6X10 electric heat mats, kicked on at lights off, and I only really need them when its really cold like -15C outside. I believe they are 10watt each, with my wet fabric pot sitting right ontop of it.

I built a custom grow box, veg chamber on the bottom 3x3 but short height, and a flower box right ontop of it. I made it out of metal to frame it, then 1" foam, then plywood shell it. Easy if your handy with custom shit. So my veg space below runs 24/7 with T5's and the heat from the lower box keeps itself at good temperature, but also radiates to the floor above it when the flower box goes lights out. I monitor temps in the root zone and at plant height and it stays above 65*, even when the garage itself is 30* Fahrenheit

Definitely get the pots off the ground, preferably some electric heat mats, and use the heat generated by the lights creatively to heat the space.
Click to expand...
I grow plants in the winter in my greenhouse by circulating water in pipes beneath the soil that goes through an inline heater....they can take cold air much better than soil..the roots are paramount
 
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bumbleberry

Member
Right now my tent in on a pallet and plywood sheet. The 15 gal pot sits on a pot riser which is on top of a wheeled saucer. I'll post a pic soon. Where should I place the heat mats? My Light makes a bit of heat and someone recommended I place a fan above it facing down to recirculate the warm air.

TurboTokes,
I like the build idea. I want a veg space so that would be a great move for me. I'm somewhat handy, maybe you can share some parts you used for your build? What is a good product for measuring rootzone temperature that you use?

Thank you everyone!
 
xtsho

xtsho

Well-Known Member
TurboTokes said:
You can not use that style heat mat as a garden bottom, thats a disaster.

Buy electric heat mats, you can buy smaller repltile tank type heat mats for $10 each for individual pots, they use 10-15 watts each which costs pennies to run but they keep the roots warm, or buy larger electric mats (usually soldas rv heater mats to keep there water tanks from freezing) and you can line the bottom of your floor.

Keeping the root zone warm in a cold grow is most important, if it falls below 60* in the root zone your no longer seeing any progress.

I am in Canada, with an unheated garage growing successfully throughout winter, and IMO I do it cheaply. It costs alot to run a 1500 or 750w blowing heater, just to have it be sucked out with the exhaust. I use small 6X10 electric heat mats, kicked on at lights off, and I only really need them when its really cold like -15C outside. I believe they are 10watt each, with my wet fabric pot sitting right ontop of it.

I built a custom grow box, veg chamber on the bottom 3x3 but short height, and a flower box right ontop of it. I made it out of metal to frame it, then 1" foam, then plywood shell it. Easy if your handy with custom shit. So my veg space below runs 24/7 with T5's and the heat from the lower box keeps itself at good temperature, but also radiates to the floor above it when the flower box goes lights out. I monitor temps in the root zone and at plant height and it stays above 65*, even when the garage itself is 30* Fahrenheit

Definitely get the pots off the ground, preferably some electric heat mats, and use the heat generated by the lights creatively to heat the space.
Click to expand...
Under floor heating can't be used? Why not?
 
D

Driver733

Well-Known Member
Put your tent on 2" thick rigid foam board insulation, this is my tent on blue foam board:

20201005_095316.jpg

They should cost about $40 per 4'x8' piece, one piece cut in half is enough for a 4x4 tent. This will keep the floor warm and reduce the drafts coming up thru the floor, even more important if your tent is sitting on cold concrete.

They sell blue and pink foam board, the blue is R=13 and the pink is R=10, so the blue is better insulating value.

See link here: https://www.homedepot.com/p/Super-TUFF-R-2-in-x-4-ft-x-8-ft-R-13-Insulating-Sheathing-99060464/300528092
 
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bumbleberry

Member
Thanks Diver733, I'm not sure what R value I want since I'd like something to work through the entire year but don't know if that will be reasonable. My tent is currently off the ground but insulation will probably be a big proggresion for me since the tent isn't air tight like I thought it would be.
 
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