Thermal Insulation of Grow room - Problem with lights off temps

[ridgelind]

So I am having a hard time keeping the lights-off temperature of my grow room anywhere near the acceptable 17C range.

The room is about 1.2m x 1.5m x 1.8m

I have two 500 W Oil heaters inside and still get temps max 13C. I have a fan blowing the air around as well. The fan has an option to heat as well, but I heard that those dry out the air too much, plus its a power draw of 1000W to heat!

During lights on temperatures are fine. Its a 400W Dual Grow/Bloom light. Exhaust fan is a 220/280 m3/hour fan with a filter that is rated from 240/280 flow.

What can I do to improve the temps during the night but not to boil my plants during the day?

The room is in a basement of a small shed that i have out in the backyard. Since this is a shed, there is almost no thermal insulation on any of the walls or on the slab, except for a thin layer of mastic/tar to keep the water out - this was basically a place for storing preserves in the winter, like a fridge.

During the summer its nice and cool down there and during the winter, when temperatures drop below freezing outside, inside there would be temps above 0.

I divided this basement part in half - placed and OSB wall with a door to gain access, with a small grille for intake air. This wall is insulated inside with about 7.5cm styrofoam, plus OSB on both sides. All other walls within the growroom are not insulated against the ground.

I was thinking about maybe just gluing styrofoam boards to the inside walls/floor of the room, but I'm afraid about condensation/mold between the wall/floor and styrofoam. And I'm afraid that it will be too hot during lights on.

Anyone can give me any advice on how to improve this? Anyone had the same issue?

 

[_tessarecting]

Insulating your room has advantages. Heat while lights on can be controlled by pulling the air thru an inline fan outside. Attach the cable to a dimmer to control temps.

 

[ridgelind]

Insulating your room has advantages. Heat while lights on can be controlled by pulling the air thru an inline fan outside. Attach the cable to a dimmer to control temps.

I know insulation is good but will placing it on the inside be more helpful or more problematic ie maybe i should just get another space heater instead and run them on a thermostat.

 

[DoubleTripleOG]

Insulate, and use a dehumidifier in the flower room during lights out. Is your veg area nearby? You can always pump warm air form the veg area into the flower area during lights out.

 

[ridgelind]

Insulate, and use a dehumidifier in the flower room during lights out. Is your veg area nearby? You can always pump warm air form the veg area into the flower area during lights out.

Hehehe im not that much of an advanced grower my friend ☺ This is my first grow which isnt in a tent in my closet, dont have a separate veg/flower room just gonna veg then flower in the same space and scrog it

 

[Mikell]

Unless that styrofoam is space age stuff, the R value is shite. Replace it with pink or Roxul.

Are you flip flopping light cycle? Re: running lights at night.

 

[ridgelind]

Unless that styrofoam is space age stuff, the R value is shite. Replace it with pink or Roxul.

Are you flip flopping light cycle? Re: running lights at night.

Yeah im going to run lights at night but it wont make a big difference though as daytime temps are still pretty low and it gets cold down there.

I dont think minerall wool is the best idea for such a small space plus it tends to dust and is absorbent (moisture)

What do you mean by R value? Is that the same as the U value?

I guess the most important for me right now is will mold grow if i put insulation on the walls....

 

[ridgelind]

What do you mean by R value? Is that the same as the U value?

.

Ok i see R is the inverse of U. What would be ab acceptable value/thickness?

 

[queequeg152]

I was thinking about maybe just gluing styrofoam boards to the inside walls/floor of the room, but I'm afraid about condensation/mold between the wall/floor and styrofoam. And I'm afraid that it will be too hot during lights on.

Anyone can give me any advice on how to improve this? Anyone had the same issue?

you can furr out the space between the wall and foam insulation with any number of products, it just depends on the severity of moisture... ingress? how much moisture is coming through the walls i mean.

if its a small amount you can just furr it out with regular wood furring strips and glue. then put down foam board over the wood, tape seams, then put drywall over the foam. you do the same more or less with the floor. when you get a bad rainfall event, the little bit of water runs down the wall, down onto your floor, and into your sump. the gap between the foam and concrete then allows the cavity to dry to the outside or inside space depending on how you detail the wall.

if your basement wall is straight and you have very little moisture, there are drainage plane materials you can fasten directly to the wall, some as thin as 1/4". they do the same thing, but are quicker to install. most people are furring basement walls anyway though owing to irregularities inherent in cast in place wall + footer construction. the drainage plans are usually directed into the perimiter drain or under the slab into some sort of french drain things.

if you have a bone dry basement you can just lay foam against the walls, or lay a stud wall against the wall and pack it full of batts as you would any other exterior wall. in this case the moisture is going to have to be able to dry to the outside.



if this basement is collecting serious amounts of water, requiring sump pumping all the time etc, you really need a better system to deal with the moisture before you do any wall construction. a perimeter drain, or some earth work done to facilitate drainage around the basement walls and maby even a french drain type system around the footing.

if you need more r value... you can hang studs right off these furing strips, and install fairly serious insulation, however basements typically dont need this. the heat gain is more or less moderated by the soil temperatures. humidity is always a problem though. especially in a basement thats not engineered to be a 100% livable space... IE no membrane on the exterior wall, no perimiter drain, no air sealing no ventilation( lol radon), etc.

 

[ridgelind]

you can furr out the space between the wall and foam insulation with any number of products, it just depends on the severity of moisture... ingress? how much moisture is coming through the walls i mean.

if its a small amount you can just furr it out with regular wood furring strips and glue. then put down foam board over the wood, tape seams, then put drywall over the foam. you do the same more or less with the floor. when you get a bad rainfall event, the little bit of water runs down the wall, down onto your floor, and into your sump. the gap between the foam and concrete then allows the cavity to dry to the outside or inside space depending on how you detail the wall.

if your basement wall is straight and you have very little moisture, there are drainage plane materials you can fasten directly to the wall, some as thin as 1/4". they do the same thing, but are quicker to install. most people are furring basement walls anyway though owing to irregularities inherent in cast in place wall + footer construction. the drainage plans are usually directed into the perimiter drain or under the slab into some sort of french drain things.

if you have a bone dry basement you can just lay foam against the walls, or lay a stud wall against the wall and pack it full of batts as you would any other exterior wall. in this case the moisture is going to have to be able to dry to the outside.



if this basement is collecting serious amounts of water, requiring sump pumping all the time etc, you really need a better system to deal with the moisture before you do any wall construction. a perimeter drain, or some earth work done to facilitate drainage around the basement walls and maby even a french drain type system around the footing.

if you need more r value... you can hang studs right off these furing strips, and install fairly serious insulation, however basements typically dont need this. the heat gain is more or less moderated by the soil temperatures. humidity is always a problem though. especially in a basement thats not engineered to be a 100% livable space... IE no membrane on the exterior wall, no perimiter drain, no air sealing no ventilation( lol radon), etc.

I guess its something to consider. I think ill place some rigid xps styrofoam on the floor first cause that thing is the lowest/coldest point and see after a while if anything is growing underneath. I got a second mixer fan yesterday and temps have started to improve - i guess before they would all just rise to the top

 

[ridgelind]

Just to clarify i dont exactly have water dripping down the walls..its not water ingress im concerned about...its just with the temp differences between day night and cold walls im afraid condensation will occur at the contact point of the styrofoam and bare wall.

 

[Asslover]

Insulate, and use a dehumidifier

 

[stoned-trout]

tek foil from farmtek....its like reflectix but has more options like way thicker and 6 ft tall rolls....yeehaw..its like sriracha I put that shit on everything...farmtek rules

 

[queequeg152]

Just to clarify i dont exactly have water dripping down the walls..its not water ingress im concerned about...its just with the temp differences between day night and cold walls im afraid condensation will occur at the contact point of the styrofoam and bare wall.

you may not have water running down walls, but you likely have moisture constantly moving through the walls, into the air, then out of the building via natural air exchanges.

if you slam something impermeable onto the wall, this moisture has nowhere to go, and has to either dry to the outside, or condense and collect inside.

just lay a level over your walls. you probably need to furr it out regardless of how dry the basement is.

do not buy that reflextix radiant barrier shit. its just a radiant barrier on bubble wrap. ive gone over this a number of times here. its already close to worthless on most attic installs. its absolutly 100% worthless in a a basment application witout an air gap.

you are going to want foam board insulation or batts(if you have the space to spare) or spray foam. foam boards are going to be easiest and cheapest . spray foam kits are about a dollar a cubic foot.