What's new
  • As of today ICMag has his own Discord server. In this Discord server you can chat, talk with eachother, listen to music, share stories and pictures...and much more. Join now and let's grow together! Join ICMag Discord here! More details in this thread here: here.

Sealed room question 1) insulation 2) hood

tact1

Member
Hello, I am having an estimate to 'finish' my grow room to a sealed state. I am located in the river-valley of the midwest, along the Missouri/Illinois border (reference for weather). The summers are humid and hot. My existing grow room is not sealed it is located in a cool basement with concrete floors. It is approx 6' below the ground level outside, two walls are cinder block construction foundation. The room is 8'x6' (with lower basement ceiling of a 100 year old house). One wall is the back of a closet that opens on the other side of the basement, the wall of this closet is horizontally nailed in wooden boards (about as far as sealed as you can get, with the final wall being a door entry, in a framed partition wall. The room has 2 xl mag 1k hoods that are air-cooled with air ducted in from the basement (outside the room) pushed over the light and then outside the house. I planned on ditching the air-cooled ducting, and have them seal those entries to the outside, though I could just cap it and tape it? I have a two hole sin the partition drywall door entryway. One had been used for for an active exhaust blowing hot air out of the room through a filter mounted on the wall (high on the wall) with a passive (slightly larger) vent in the opposite corner of the door partition to allow passive-air in a positive pressure air exchange. Obviously that too will be closed up.

I have a 12k btu mr slim going in, and a dehuey for evening. One note: this is a PERPETUAL flowering room only. I have read a lot saying that is slightly problematic with sealed room as co2 needs are different for plants in different flowering stages. So should I at very least be setting an appropriate ambient for a perpetual flowering room, s opposed to the 1300 ppm growth range, but that may be too high for late flower ladies?* (bonus question)

So my questions:

1) Insulation: So blown in will give me the best seal, I had a buddy suggest r45-r50 insulation, how much VOLUME would that take up? Keep in mind three walls will need framing put up for the insulation to go within, the ceiling which is drywalled needs to be insulated above the room as well. So what should I tell the guy coming to give an estimate in regards to insulation, blown in, r50 rating? I will probably lose what, 3" on all sides with a frame/insulation with drywall over it and finally panda film over that, so the room dimensions become more like 7'6"x5'8", making things a bit more tight.

2) I have those two huge xxl mag 6" 1k hoods. Should I consider ditching these altogether so the AC is more functional in terms of eliminating a hot metal object above my plants? Like cooltubes with no glass would be better? I am fearful of barebulbs as my ceilings are quite low as an old basements ceiling are (in the midwest anyway). i could totally see myself splashing or coughing shit on them/touching them inadvertently.

Thoughts?
 
Last edited:

the gnome

Active member
Veteran
1) Insulation: So blown in will give me the best seal, I had a buddy suggest r45-r50 insulation, how much VOLUME would that take up? Keep in mind three walls will need framing put up for the insulation to go within, the ceiling which is drywalled needs to be insulated above the room as well. So what should I tell the guy coming to give an estimate in regards to insulation, blown in, r50 rating? I will probably lose what, 3" on all sides with a frame/insulation with drywall over it and finally panda film over that, so the room dimensions become more like 7'6"x5'8", making things a bit more tight.

seeing how your putting the room in the basement where it is by your words comparatively *cool*
your at an advantage there and don't need a super hi R value and your only running a couple thousand watts.
you haven't specified exactly what type of insulation is to be blown in?
I think using something like isocyanurate will give you good bang for your buck. I believe it's R value is like 7.8-8 pr inch
and the nice thing with iso is R value increases exponentially the thicker it's applied.
there's kits you can get for a DIY application,
so talk to your pal..... you/he can spray this or if not call a insul. co.
with a wall stud thickness of 3.5" this would be suitable for your need and you could probably get close to R30 .
another option is go to your local roofing supply and they have or can get iso panels from 1/2" ---6" thick.
they cut easily with a reg. circular or table saw and can be fit between the studs and attached to the ceiling and clock walls.
the ceiling can be sprayed or foam panels used.
something to consider is insul. foam can be quite flammable so think about about how cover it.
the framed walls are easy, you said it will be sheet rocked.
speaking of wall board get the greenboard if it's available.
its made for hi moisture applications like bathrooms etc etc

so, you'll have a 3 framed walls and existing basement concrete block walls,
I'm assuming they're exterior walls... if so prob with this is I doubt you have any type of vapor barrier.
do the walls sweat now? or do they leak?
regardless, you may have issues with condensation probably be an issue when your temps-RH at at grow levels.
you'll need to seal the block walls.
there's stuff like dryloc you can get at the orange place if it's not too bad.
depending on the severity you may have to get a commercial products available at masonary supply outlets.
you can even spray iso foam
 

the gnome

Active member
Veteran
2) I have those two huge xxl mag 6" 1k hoods. Should I consider ditching these altogether so the AC is more functional in terms of eliminating a hot metal object above my plants? Like cooltubes with no glass would be better? I am fearful of barebulbs as my ceilings are quite low as an old basements ceiling are (in the midwest anyway). i could totally see myself splashing or coughing shit on them/touching them inadvertently.

Thoughts

any heat issues you have won't be with your AC.
if your hood has glass take it out and you'll get another 10-15% of lite from your bulbs.
i don't think those bid azzed big hoods like magnums/raptors have glass.
of course if you've been wanting to go with another hood now's a good time I guess

there's all kinds to choose from and its personal taste.
personally I use the old school parabolic reflectors because they give you a very large uniform footprint compared to
square hoods that have all kinds of briter and darker areas.
para's also diffuse the heat very evenly under the hood over a larger area eliminating hots spots and keeping the canopy cooler.
I recommend the vertizontal and std. parabolic hoods
 

tact1

Member
Word, thanks gnome. I will check out the insulation types and ask the guy, he is a legit construction company project manager or whatever, comes in and say what you want to do and he gives an estimate an some other dudes come do it. My first room was a 'kiln' room, as my cover for why I asking for 6" insulated ducting to run from outside, inside the room, out of the room, and then out of my house. I told him I had a kiln going in there. Makes no sense most likely, but he didn't seem to give a shit, he just wants that money like everyone else.

Quick question: I have two dedicated 20 amp quad-outlets in that room, while its emptied, and before the room gets sealed do you think I should add more power to the room? I am limited by the 12k btu mr slim, lol just returned the 17.2k. Just a thought. The room is already broken down. Anyway I figure, each dedicated 20 amp circuit (2) has a 1k light on it, + fans, +dehuey, +heater/winter. Was contemplating having them throw another 2 20 amp dedicated in there.
 

the gnome

Active member
Veteran
you'll want a dedicated 20A 110V line for the AC.
btw, don't need a heater, the 12Kbtu breeze has a heatpump.

dunno if you've decided on a dehuey yet but friedrich makes a couple great units
the D50BP and D70DB models.
i run 2 of the 50pt units and they are solid work horses with built in pumps,
you just need a drain to dump the water or you can catch in 5 gall. buckets and use to water your plants.
btw...the 70pt unit is on sale right now for a killer price $259 delivered


if you run a 220V 2-pole breaker you can run both your ballasts on that line
and pull just under 10A

and yeah for sure, Id run some extra elec into the room while you can,
no telling what you may want to do down the road.....
because you'll have a bit of extra overhead on your AC may be you want to run
an extra 400W bulb or 2 for "enhanced" lighting for a blind spot

forgot to add this about iso foam will offgas.
i used mostly panels in my room but also used a few dozen cans of great stuff.
i had no issues with it,
but it was a good 30-45 days after the last cans of great stuff were use before plants went in.
I doubt you will but don't worry if you have some phantom issues with your plants for a while
your room may have to cure for a while if your having it blown in fresh, also caulks, paint and other things
need some time to cure out.
 

tact1

Member
I meant that my reflector hoods are the big metal object. I actually have that dehuey saved from an icmag convo where people were suggesting it in sealed rooms. The AC I have is a mitsu mrslim, it is cooling only btw, I saved a chunk and got it at just under $1k shipped (when I move I was going to use it in a veg room where lights would be on 24 hours/not get cold). The AC is powered directly from the outside unit, which will hook right into my circuit breaker box. So the AC won't be a load on the rooms electrical load. The notion of an extra 400k that would meet my AC load made me thinking about 4x600s being more spread out over the same space as the 2x1000s.

Anyway. So what is the insulation that has sealing properties (expands I guess), that does not offgas? Or do they all. Is there one that everyone agrees is better for an enclosed grow space/non-toxic longterm?

BTW I checked out your room, that is fucking crazy. Dream room. I can see the labor of love. The electrical setup and organization of unsightly wires was clean as all get out. The door thing was genius as well, I have an absolute shit door on this grow space. In my future home I will simply tell the same dude I am now a hunter and need a cooler to store my game in, and have them put in a roughed out cooler w/door.
 
Last edited:

the gnome

Active member
Veteran
Anyway. So what is the insulation that has sealing properties (expands I guess), that does not offgas? Or do they all. Is there one that everyone agrees is better for an enclosed grow space/non-toxic longterm?


tbh, almost everything made offgasses to a point.
because of your space requirements the amt of isocyanurate that will fit in your 3-1/2" of wall space will give you close to R30,
it's a closed cell foam so it's pretty well airtite as it is.
like i said, you can cut-n-fit iso panels into your wall.
these have been off gassing for while whereas fresh sprayed will off gas for a while.
if your sheetrock is facing the inside of the room the foam will be spray on the back side and any offgassing with go into the basement, i really don't think you'll have those probs by the time your ready for plants. i experienced zero issues and my room was packed with it.
you can also paint it after its sprayed to further seal it.

as far as 1000w lamps vs 600w lamps I wouldn't touch that one with a 10ft shitstick.
there's probably still a huge fight going on somewhere about whats best :D
 

queequeg152

Active member
Veteran
1) Insulation: So blown in will give me the best seal, I had a buddy suggest r45-r50 insulation, how much VOLUME would that take up? Keep in mind three walls will need framing put up for the insulation to go within, the ceiling which is drywalled needs to be insulated above the room as well. So what should I tell the guy coming to give an estimate in regards to insulation, blown in, r50 rating? I will probably lose what, 3" on all sides with a frame/insulation with drywall over it and finally panda film over that, so the room dimensions become more like 7'6"x5'8", making things a bit more tight.

2) I have those two huge xxl mag 6" 1k hoods. Should I consider ditching these altogether so the AC is more functional in terms of eliminating a hot metal object above my plants? Like cooltubes with no glass would be better? I am fearful of barebulbs as my ceilings are quite low as an old basements ceiling are (in the midwest anyway). i could totally see myself splashing or coughing shit on them/touching them inadvertently.

Thoughts?

dense pack cellulose yields around r4 per inch, so you need between 10 and 12 inches of wall cavity.

closed cell spray foam ( very expensive) is around r6 per inch so... 8-10 inches.

r50 is EXTREEMLY hard to justify outside of like... north dakota.

r30 could be achieved in an 8" gap, and could be built from regular dimensional lumber quite quickly.

if you already have say... a 2x4 wall in place, you could simply furr out the space with a modified larson truss. if you have nothing in plsace at all, you will need to first furr out a level surface, then build out the wall.

denspack cellulose is not a DIY job, you need a guy who has the correct feel for it, and a good machine.
i couldnt estimate cost, it varies area to area.

the only problem i see with big metal light fixtures... is that they block air flow. i suppose you could argue that they emit more heat when air cooled... being that they have a larger surface area, but im not sure that is the case.

what do these things cost anyway? i dont imagine you will see any return on investment in smaller hoods.

regarding off gassing, unless you are using old building materials... most of the new shit is pretty safe with respect to formaldehyde, and voc's etc. anyway, all of this will be behind drywall, with a latex paint barrier.
 

tact1

Member
dense pack cellulose yields around r4 per inch, so you need between 10 and 12 inches of wall cavity.

closed cell spray foam ( very expensive) is around r6 per inch so... 8-10 inches.

r50 is EXTREEMLY hard to justify outside of like... north dakota.

r30 could be achieved in an 8" gap, and could be built from regular dimensional lumber quite quickly.

if you already have say... a 2x4 wall in place, you could simply furr out the space with a modified larson truss. if you have nothing in plsace at all, you will need to first furr out a level surface, then build out the wall.

denspack cellulose is not a DIY job, you need a guy who has the correct feel for it, and a good machine.
i couldnt estimate cost, it varies area to area.

the only problem i see with big metal light fixtures... is that they block air flow. i suppose you could argue that they emit more heat when air cooled... being that they have a larger surface area, but im not sure that is the case.

what do these things cost anyway? i dont imagine you will see any return on investment in smaller hoods.

regarding off gassing, unless you are using old building materials... most of the new shit is pretty safe with respect to formaldehyde, and voc's etc. anyway, all of this will be behind drywall, with a latex paint barrier.

I have inches, like the space in a framed wall along a basement that is being finished. before you put the sheetrock/drywall over it.
 

queequeg152

Active member
Veteran
yea that is furring out a wall... but why in the fuck are they laying that against a finished wall? that picture makes zero sense.

oh or they are making an accent wall?

anyway... so your drywall is hung on furring strips like this? you will absolutely need to build out an actual wall in order to hold any insulation what so ever.


all you can do with a wall that thin would be to lay some 2inch foam boards across it horizontally, then hang drywall ontop of that. thats only going to be like... r8-r10 depends... iso boards being the higher of the two after a year or two.

if you are not comfortable building out a new wall then the foam boards might be your best bet here. not cheap tho. like 2 bucks a square foot if i recall correctly.
 

tact1

Member
yea that is furring out a wall... but why in the fuck are they laying that against a finished wall? that picture makes zero sense.

oh or they are making an accent wall?

anyway... so your drywall is hung on furring strips like this? you will absolutely need to build out an actual wall in order to hold any insulation what so ever.


all you can do with a wall that thin would be to lay some 2inch foam boards across it horizontally, then hang drywall ontop of that. thats only going to be like... r8-r10 depends... iso boards being the higher of the two after a year or two.

if you are not comfortable building out a new wall then the foam boards might be your best bet here. not cheap tho. like 2 bucks a square foot if i recall correctly.

lmao, the pic, no clue. Yeah the space is enclosed already, so 3 walls of studs/the bottom (sole?) and top pieces the studs go into, then drywall over that. So whatever that depth is. The room is only 8'x6', so there is not much room to remove interior sqft for furr volume, yeah? Like the notion of stacking 2 foam boards for r-20?
 

queequeg152

Active member
Veteran
two foam boards will add up to quite a lot of money.

do the math here, you might want sacrifice space to save like a thousand bucks.

cellulose costs like... 25 cents per lb. dens packing at like 3.5lbs per cubic foot. will yield around r4.

inside a 4 inch cavity you can get r-16. where as the foam boards could hit r20. do the math.
 

tact1

Member
two foam boards will add up to quite a lot of money.

do the math here, you might want sacrifice space to save like a thousand bucks.

cellulose costs like... 25 cents per lb. dens packing at like 3.5lbs per cubic foot. will yield around r4.

inside a 4 inch cavity you can get r-16. where as the foam boards could hit r20. do the math.

Well yeah 4", that should work, but not 8" or whatever, and beyond. Get that shit all done and I can put a 250w with a topsy-turvy in there or some shit. Say uhh 6" due to the 4" of foam.. and drywall and whatever else. So all 4 walls will lose 6".

Now, the 8'x6' is, what, 7'x5', yeah, I think. Hows that space for 2k? I think I will have hood issues. You see what I am getting at. Just trying to get my head around it.

Edit: So cellulose (specifically soy perhaps, even though sounds like mice would eat it), closed-cell, spray foam, is what I will be asking about. I found a company here that does just that, so I will ask them as well if this guy does not have that equipment, it shows people in like ebola gear applying it, so it may be more involved. It look like 4" would give you high r20s, which should be good for the function in a cool/concrete basement below ground level. Will lose some height on top and on all sides.
 
Last edited:

queequeg152

Active member
Veteran
use half inch light weight drywall.

not shure about the space. someone else will have to chime in on that issue.
 

tact1

Member
Just looked up what a larsen truss is, never knew what that was. Interesting, deff going to use that to create the space for insulation for my next grow space.
 

queequeg152

Active member
Veteran
the larsen truss is almost always used for retrofit applications.

if you are building something from scratch, i suggest you google the double stud wall, or staggered stud wall. they are easier and less time consuming to build.

some prefer to just install engineered floor joists in place of the larsens... owing to the time required to fabricate and install.
 

queequeg152

Active member
Veteran
ic


here... this looks like a new build, but i think you get mypoint.

http://www.jlconline.com/Images/493583053_12112012-3_tcm96-1725926.jpg?width=600


notice how he stagers a full joist every other. this saves lumber, and allows him to densepack that big ass ... 48" cavity in one go.
 

tact1

Member
View Image

here... this looks like a new build, but i think you get mypoint.

http://www.jlconline.com/Images/493583053_12112012-3_tcm96-1725926.jpg?width=600


notice how he stagers a full joist every other. this saves lumber, and allows him to densepack that big ass ... 48" cavity in one go.

Id like to think that you quee, just threw some shit together, side of a house and all. Hanging off your woodwork like a sailor in the straits of Gibraltar. You son of a gun.

Thanks for the knowledge man, I know shit.
 
Top