Setup for growing in cool temperatures

1212ham

Well-Known Member
Growing in cool temperatures is a problem for many, but I haven't seen much to deal with it. I have some ideas and hope others can contribute.

I'd like to make a grow box of foil faced foam insulation. I'm hoping to get by with minimal air exchange to keep the heat and humidity inside, but have little info on this.

I expect air exchange to be the biggest obstacle to retaining heat. I think one site said three times a minute and that seemed crazy to me. Maybe it was 3 times/hour, but that wouldn't have seemed so crazy to me.
So, is there any good info on the amount air exchange needed?

I guess the next thing is to research and calculate the heat loss through insulation.
 

Lordhooha

Well-Known Member
Growing in cool temperatures is a problem for many, but I haven't seen much to deal with it. I have some ideas and hope others can contribute.

I'd like to make a grow box of foil faced foam insulation. I'm hoping to get by with minimal air exchange to keep the heat and humidity inside, but have little info on this.

I expect air exchange to be the biggest obstacle to retaining heat. I think one site said three times a minute and that seemed crazy to me. Maybe it was 3 times/hour, but that wouldn't have seemed so crazy to me.
So, is there any good info on the amount air exchange needed?

I guess the next thing is to research and calculate the heat loss through insulation.
With my leds cob or qb I can keep my room around 77-79 degrees constantly venting 24/7
 

Rocket Soul

Well-Known Member
Growing in cool temperatures is a problem for many, but I haven't seen much to deal with it. I have some ideas and hope others can contribute.

I'd like to make a grow box of foil faced foam insulation. I'm hoping to get by with minimal air exchange to keep the heat and humidity inside, but have little info on this.

I expect air exchange to be the biggest obstacle to retaining heat. I think one site said three times a minute and that seemed crazy to me. Maybe it was 3 times/hour, but that wouldn't have seemed so crazy to me.
So, is there any good info on the amount air exchange needed?

I guess the next thing is to research and calculate the heat loss through insulation.
If it is a small place you could look into 850 infrared leds. You could theoretically run them at night aswell to help with lights off freeze but im not sure what it would do with your plants. Check steves led for reasonably priced infrared, but you would have to solder them.
 

Nutria

Well-Known Member
If it is a small place you could look into 850 infrared leds. You could theoretically run them at night aswell to help with lights off freeze but im not sure what it would do with your plants. Check steves led for reasonably priced infrared, but you would have to solder them.
I am of exactly the same opinion: IR.
I grow inside an attic and it's damn cold during winter, hella hot in summer. Energy consumption is important for me so an electric heater isn't a valid option.
Styrofoam could work, I am going to place a layer of foam between the tent and the floor. Btw I am also looking to make some rigid strips with IR leds.
 

doctordetroit

Well-Known Member
The white foil backed foam is only 5-7.5 r value theres 2inch pink stuff thats like 10 r. Roll insulation would be much better. As for the air exchange maybe do some kind of Co2 add on. Im in a detached garage on a single 15amp breaker so I'm in the same situation.
 

Moflow

Well-Known Member
Growing in cool temperatures is a problem for many, but I haven't seen much to deal with it. I have some ideas and hope others can contribute.

I'd like to make a grow box of foil faced foam insulation. I'm hoping to get by with minimal air exchange to keep the heat and humidity inside, but have little info on this.

I expect air exchange to be the biggest obstacle to retaining heat. I think one site said three times a minute and that seemed crazy to me. Maybe it was 3 times/hour, but that wouldn't have seemed so crazy to me.
So, is there any good info on the amount air exchange needed?

I guess the next thing is to research and calculate the heat loss through insulation.
All they need is a bit of insulation and they grow away nicely
20181123_145418.jpg

That and a block of polystyrene on floor with a heatmat.
I'd say off hand the garage temps right now are ~ 7 - 8°c 46F
Here they are last night
20181125_212654.jpg
I've a small extractor fan on an sms fan speed controller.
There's a 12v pc fan that pulls warm air from top of tent and dumps warm air to plants below too.
Looks a mess but doesn't look like a grow tent lol
 

Moflow

Well-Known Member
A bit of an insulation sandwich and it's ready to rock
20181126_120600.jpg 20181126_121041.jpg
That's the root zone sorted. I might need a timer on it though
 

1212ham

Well-Known Member
I forgot to mention, I'm looking at a 2x2 or 60x60 with LED and aiming for efficiency, trying to minimize power used for heating. More later.......
 

doctordetroit

Well-Known Member
In my opinion id get rid of a exhaust fan and run a cheap co2 bag/2 litter bottle thing if needed (and if possible), tap into the bathroom exhaust fan ducting as a intake for fresh air and warmer air, then wrap in roll insulating till it stayed warm enough inside.
That leaves just your lights, inside fan for air movment, and maybe a booster fan from the bathroom exhaust as power consumption. Im no expertbut the only thing i can think of that would be a problem is humidity when taking a shower but some DIY calcium chloride (its available in bulk at home improvment stores as ice melt) humidity traps.
 

Humple

Well-Known Member
With my leds cob or qb I can keep my room around 77-79 degrees constantly venting 24/7
What nutes do you use, and how heavy do you feed? Seeing a few growers here who manage to do well under LED without getting their temps over 80°F, and I suspect the feeding regimen has a lot to do with it. I can tell you that growing in ROLS, if my temps drop below 80, things go to shit right quick-like.
 

Humple

Well-Known Member
All they need is a bit of insulation and they grow away nicely
View attachment 4238926

That and a block of polystyrene on floor with a heatmat.
I'd say off hand the garage temps right now are ~ 7 - 8°c 46F
Here they are last night
View attachment 4238927
I've a small extractor fan on an sms fan speed controller.
There's a 12v pc fan that pulls warm air from top of tent and dumps warm air to plants below too.
Looks a mess but doesn't look like a grow tent lol
You still feeding them the magic tomato food? Must be damn good stuff, because your plants are always rocking.
 

Lordhooha

Well-Known Member
What nutes do you use, and how heavy do you feed? Seeing a few growers here who manage to do well under LED without getting their temps over 80°F, and I suspect the feeding regimen has a lot to do with it. I can tell you that growing in ROLS, if my temps drop below 80, things go to shit right quick-like.
I use worm tea with recharge added and megacrop. My night time temps never go under 70 and day time temps even with me currently using 2 315 cmh lights never go past 77.
 

Moflow

Well-Known Member
You still feeding them the magic tomato food? Must be damn good stuff, because your plants are always rocking.
Yea, thanks mate, I bought a new bottle yesterday.
I ran out so I was using a 1 part bloom this go. Tomatorite is great.
 

1212ham

Well-Known Member
Thanks for all the ideas. The blankets look strangely familiar. ;) I also had thought about c02 if ventilation removes to much heat. I'll have more time to get back to this on the weekend....
 

Nutria

Well-Known Member
Last summer it reached 30c/86f ambient temp and I got large yield while quality wasn't good.
When temps go below 20c/68f I can't really manage to get the quantity even if the VPD should be on point with a RH between 30% and 40%.
 
Top