Cooling a sealed room within a room?

[MPL]

I have an extra bedroom I can grow in for some experiments and I am going to be running C02. I plan on enclosing the flowering room within half of this bedroom and sealing it. I do not want to use fans to vent the sealed area at all, so it requires I have a cooling unit and a dehumidifier within. I need the units to NOT share air from the inside sealed room to the bedroom, so single duct portable ACs won't work.

What kind of options do I have to cool and dehumidify the sealed room? Would it be possible to install a small window AC and have it exhaust into the bedroom? My central AC could take care of the heat produced. Not very efficient, I know...

Otherwise I'm stuck getting an uber expensive C02/temp/humidity/fan/everything controller and I'll have to exhaust the C02 from the room periodically to cool things off, which I don't want to do as I want to maximize the time the plants are supplemented with high levels of C02.

Thanks!

 

[the gnome]

window unit leaks and smell will go out along with your Co2.
get a mini split, this is your best cooling option for what
your doing imo.
it has it's own temp controller,
the ac should handle the Rh in daytime.

use a dehuey at nite on a photo cell @lites out
I use 2-50pt units and never a prob with the nite time Rh spike.

then all you need is the co2 controller,
I'd use a tank/Co2 for a bedroom sized gro.

this is what i use(except I use a gas Co2 gen)and it works great,
my room is 14 x 20ft, i do no exhausting at nite.
your will be much small probably,

I have a room with a room too, much larger though.
size you AC properly and you should be good to go.
what the expected size of the sealed room?
how many lites/wattages?
open hood or air cooled?

 

[MPL]

Mini split is a no go. I can only do the most simple and basic modifications to the room. It's also on the second floor do double no-go for a mini split. Otherwise that's exactly what I'd do.

I thought about just filling the whole room with C02 but a 10x13x9 room would use up a 50# tank in like a week, if that.

I do have central AC. I should be able to put the register for this bedroom directly into my grow, then all I need to worry about is a small dehuey... C02 shouldn't go out the register since it is heavy. Hmm this might be what I have to do. I'll have 6k BTU in gavitas with no air cooling so might be interesting... This might be my only option.

window unit leaks and smell will go
out along with your Co2.
get a mini split, this is your best cooling option for what
your doing imo.
it has it's own temp controller,
the ac should handle the Rh in daytime.

use a dehuey at nite on a photo cell @lites out
I use 2-50pt units and never a prob with the nite time Rh spike.

then all you need is the co2 controller,
I'd use a tank/Co2 for a bedroom sized gro.

this is what i use(except I use a gas Co2 gen)and it works great,
my room is 14 x 20ft, i do no exhausting at nite.
your will be much small probably,

I have a room with a room too, much larger though.
size you AC properly and you should be good to go.
what the expected size of the sealed room?
how many lites/wattages?
open hood or air cooled?

 

[ElusiveQuark]

Unless the thermostat for your central a/c is in that bedroom you will not cool 6k of lights. With one in there it will be running whole time lights are on. You need a 20k btu a/c at minimum directly into that room. I have similar setup inside my garage. I cool garage with evap and pull air from there into bloom rooms. I also have window a/CSS as backup that vent outside of garage. You might consider dialing in your environment b4 CO2. FWIW I see my CO2 levels raise significantly from me just working in the room.

 

[MPL]

The thermostat isn't in the grow area, but I keep my house at 62F most of the time anyway. I was even running the AC when it was 0F outside last winter. It's not 6000w of lights, it is 6000btu of heat from the lights. If it were 6kW of lights I wouldn't be able to grow here at all lol Definitely would need 20k+ btu of cooling in that case.

It won't take me long to dial in the room. I'll run it dry for a week and that should dial it in for me. It's not my first room. I had a thriving business selling AAA weed to dispensaries in Sacramento a couple of years ago. I won't build anything until everything is designed on paper properly and then a few days to iron out the kinks and I'm set. It's never taken me more than a week to dial in a well-designed grow.

I don't mind compensating the temp setting on the thermostat to account for my grow. I love it cold. Worst case I will try to find a 12k btu portable AC with a separate fresh air intake and vent out a window.

Thanks for the reply

Unless the thermostat for your central a/c is in that bedroom you will not cool 6k of lights. With one in there it will be running whole time lights are on. You need a 20k btu a/c at minimum directly into that room. I have similar setup inside my garage. I cool garage with evap and pull air from there into bloom rooms. I also have window a/CSS as backup that vent outside of garage. You might consider dialing in your environment b4 CO2. FWIW I see my CO2 levels raise significantly from me just working in the room.

 

[the gnome]

like the quark said, no way your ac is cooling 6000ws
even if the thermastat was in the bedrm it wouldn't work with the 1 or 2 small ac registers feeding the room

6000w open bulb requires minimum 5000btu cooling, I prefer to hedge that a tad for comfort.

I run 6000w and a have a 32,500 mr slim.
you need 3o,ooobtu to cool 6000w effectively

drop to 4000w and you can install a friedrich breeze minisplit 20,000btu,
it has quick connects-no havc tech needed
you can put the condenser unit in the outer room
BUT
you'll have to vent the excess heat produced from the condenser and its a lot of heat but can be done
I dont see you having much inn the way of options,
you can get those big chiller/res combos and help cool the lamps like that, but you need air cooled hoods, with gavita's it won't work.

btw, if your room is sealed that tank will easily last over 4 weeks

 

[the gnome]

ok just read your not running 6000w of light,
sorry...
so whats the wattage are you going to run?

 

[MPL]

2kW, roughly 3k btu per open lamp (Gavita 1k DE fixtures).

This is a flower room for genetic hunting only. I have hundreds of seeds I gotta pop and see if I get anything unique. This is an extra bedroom that I'm using for flowering out seeds and to test out the Gavita fixtures to see if I like them.

ok just read your not running 6000w of light,
sorry...
so whats the wattage are you going to run?

 

[Mister_D]

Mini split run through the wall you intend to build (requires no modifications to the actual house beyond what you already intend to do). Put the outside unit of the mini in the half of the room you're not growing in so the heat is taken care of by your central a/c. This will insure you have no smell/co2 leaks, help with humidity, and use much less power than a window banger. Window banger would work also, but you will have some level of leakage (smell & co2). That can be minimized, but it will still exist. In either case you will also need a dehumidifier to take care of lights off humidity.

 

[MPL]

I don't have much experience with C02. I calculated I would need roughly 1.00# of C02 to initially fill a 13x10x9 to 1100ppm C02. That's before any plant usage or leaks. I don't see how 50# would last over 4 weeks. Am I calculating something wrong?

Thanks!

btw, if your room is sealed that tank will easily last over 4 weeks

 

[MPL]

The last mini split I installed required a concrete slab for the heat exchanger. How would I set that up in a bedroom? Don't think that's doable. I'd also have to tap into the power lines and I'm restricted to one 240v 30a outlet and 2 15a 120v outlets. Unless I am missing something here I don't think a mini is a good option.

I do think a portable AC with a separate fresh air intake could work. 12k btu should only use about 12a of power so can just run it off one of the standard outlets.

Thanks!

Mini split run through the wall you
intend to build (requires no modifications to the actual house beyond what you already intend to do). Put the outside unit of the mini in the half of the room you're not growing in so the heat is taken care of by your central a/c. This will insure you have no smell/co2 leaks, help with humidity, and use much less power than a window banger. Window banger would work also, but you will have some level of leakage (smell & co2). That can be minimized, but it will still exist. In either case you will also need a dehumidifier to take care of lights off humidity.

 

[the gnome]

Ive read many posts about portable AC's.... like a window unit, they leak.
get a breeze 12,000btu mini split, it runs off 110V
and as D said, you'll save a lot of $$ on the elec bill.
my 32.5Kbtu mr slim runs me $115 monthly in 12hr bloom.
I have an 8000btu window unit that runs 24/7 in summer, $75 a month

forget the concrete slab,
its for outside use
my 20,000btu breeze comes with a plastic *slab* to sit on.as
long as your on solid level anything your good to go.
also with the breeze quick connects, you can also disconnect and move, no refill or havac tach needed again.

 

[the gnome]

I don't have much experience with C02. I calculated I would need roughly 1.00# of C02 to initially fill a 13x10x9 to 1100ppm C02. That's before any plant usage or leaks. I don't see how 50# would last over 4 weeks. Am I calculating something wrong?

Thanks!

third coast has a room about your size w/4ooow of Gav's
he said his tank lasts...?? 6 wks... something like that.
maybe he'll drop in.

 

[MPL]

Very nice. I have not ever seen one of those units. I do know the window bangers and portables are inefficient as hell and leak. The only mini splits I've worked with have required the concrete slab, but to be fair I have not worked with many.

Thank you for the advice

Ive read many posts about portable AC's.... like a window unit, they leak.
get a breeze 12,000btu mini split, it runs off 110V
and as D said, you'll save a lot of $$ on the elec bill.
my 32.5Kbtu mr slim runs me $115 monthly in 12hr bloom.

forget the concrete slab,
its for outside use
my 20,000btu breeze comes with a plastic *slab* to sit on.as
long as your on solid level anything your good to go.
also with the breeze quick connects, you can also disconnect and move, no refill or havac tach needed again.

 

[MPL]

Ok I think I found it.

Mini Splits

That particular one does do exactly what you described. Looks EASY. Can even plug it into a standard outlet. lol Is that the one you are referring to? If it is that's crazy awesome.

How loud is your heat exchanger?

 

[Granger2]

So you're looking at about 5x13x9 with 2k lights not air cooled, right?

The central AC isn't going to work like you want. And you certainly do not want the outdoor unit of a mini split in the bedroom. WAY to much heat plus other problems.

Make the bedroom a lung room. You could get a serious window unit and put it in the room window. Check the Friedrich site. For a mini-split, Friedrich has a thru the window option so you don't have to cut thru the wall. A quality window unit will leak very little smell or CO2 because they are comprised of 2 closed systems. I have been using Friedrich thru the wall units for 8 years. Before I did a room make over I would get a very slight smell from the condensation water. You could only smell it if you were standing outside right next to the unit. I simply put a small jar of ONA where the unit exhausted and it did the job. I get no smell since my room make over. Mini splits are the best option.

I have closed stalls [like tents made of wood] that are exhausted thru carbon filters into the rest of the room, which becomes a lung room with AC, dehum, CO2. Entering the room with stalls closed there is NO smell even in primetime. So there is no smell in the AC condensation water outside.

You can use the thermostat on the AC, the humidistat on the dehum, and avoid buying a beefy controller. CO2 is workable using timers, which can later be upgraded to a controller.

I have a large Phresh filter in the lung room that intakes from the room and exhausts into the stalls. CO2 is injected directly into the stalls to get best use, then what's left is exhausted into the lung room, cooled, dehumidified, and circulated thru the carbon filter back into the stalls. The smell is completely under control. You could make a similar sealed stall, sealed lung room system in your bedroom.

My room is 7.3'x11.3' and the bloom area is 3x9. Keeping CO2 at about 1000 ppm during lights on, a 20 lb tank lasts over 5 weeks. Good luck. -granger
http://www.hydrofarm.com/resources//co2calc.php
http://growershouse.com/co2-calculator-for-grow-rooms

 

[MPL]

That is correct. Completely sealed. Never done a sealed grow supplemented with C02 before.

I might be able to put the outdoor unit of the mini split on a patio outside. It's 50dB so it's too loud to keep inside even if it didn't generate too much heat.

I thought about making the entire bedroom into a lung room, but I cannot install a window unit into the windows. I can't do anything with the windows except open or close them. I would also go through C02 like mad I imagine...

I use the same stalls you describe for my other grow. In fact my set up sounds a lot like yours.

Money isn't really the issue. I'm not trying to cheap out, but I don't want to spend something if I don't need to. I definitely don't want to spend twice. If I need a C02 controller I'm just going to buy one instead of buying a placeholder now and then buying one later. I know I will need it.

The problem is I'm extremely limited in the modifications I can make. If I weren't worried about C02 and a sealed flower area this would be a breeze.

thank you

So you're looking at about 5x13x9 with 2k lights not air cooled, right?

The central AC isn't going to work like you want. And you certainly do not want the outdoor unit of a mini split in the bedroom. WAY to much heat.

Make the bedroom a lung room. You should get a serious window unit and put it in the room window. Check the Friedrich site. For a mini-split, Friedrich has a thru the window option so you don't have to cut thru the wall. A quality window unit will leak very little smell or CO2 because they are comprised of 2 closed systems. I have been using Friedrich thru the wall units for 8 years. Before I did a room make over I would get a very slight smell from the condensation water. You could only smell it if you were standing outside right next to the unit. I simply put a small jar of ONA where the unit exhausted and it did the job. I get no smell since my room make over.

I have closed stalls [like tents made of wood] that are exhausted thru carbon filters into the rest of the room, which becomes a lung room with AC, dehum, CO2. Entering the room with stalls closed there is NO smell even in primetime. So there is no smell in the AC condensation water outside.

You can use the thermostat on the AC, the humidistat on the dehum, and avoid buying a beefy controller. CO2 is workable using timers, which can later be upgraded to a controller.

I have a large Phresh filter in the lung room that intakes from the room and exhausts into the stalls. CO2 is injected directly into the stalls to get best use, then what's left is exhausted into the lung room, cooled, dehumidified, and circulated thru the carbon filter back into the stalls. The smell completely under control. You could make a similar sealed stall, sealed lung room system in your bedroom. Good luck. -granger

 

[the gnome]

yeah man... thats it
its very quit as far as the conderser units go,
55DBs, about what my 50 pint dehuey makes on the hi setting.
compared to a standard split ac-heat, no comparison.
if your in the deep south, go to a strip mall and ride behind it.
here in fl they are everywhere,
take a look, if you see one you'll know it,
you won't hear it unless you either see the fan blades running
or get about 15-20ft from it

 

[the gnome]

I might be able to put the outdoor unit of the mini split on a patio outside. It's 50dB so it's too loud to keep inside even if it didn't generate too much heat.

keep in mind the lineset to connect the mini is only 25ft.
if your run is longer you'll need the hvac tech to add more line
vac, add 410 etc etc,
if thats the case I think your better off using another minisplit,
you pay more for the quick connect option
itll be cheaper and let the hvac install it.

 

[moses wellfleet]

4k btu per 1kw of light is what I work on!... Don't cut corners with a sealed room, do it right the first time and you will be among the elite, sealed rooms are some other level shit...

Listen to Gnome and Granger they know what's going on!

Wazzup Gnome? good to see you man!