AC Boxes Made Easy (to understand and build)

[bdomina]

who knows anything about baseboard heater thermostats. they take a full 120v AC input and i am not sure about what kind of a load they output. Wondering if one could be spliced into a heavy guage extension cord and used to power off and on the window unit. I have my ac unit ouside my box and ducted the cold air in. i pulled the tstat wire from my ac unit into the box but it leaves me with like a 15-20 deg window. temps swing from 72 to about 85 if i tweak the dial just right....I am thinking that the temp range of a different tstat may be better

 

[Danknuggler]

Thanks for that HD.I guess I wont be going a big as I was gonna.I'll save some $$.nuggler

 

[Gold123]

Great post HD! The sharing of ideas is what this is all about. That Cool-N-Save looks intriguing. However I have a problem with it. Evaporating all that H2O mist will leave a considerable amount of build up of disolved solids from the H2O, same as you would get in a humidifier. I suppose you could clean it off the AC coils but it probably would also be corrosive. I wonder how long before it would become a problem if at all. Sure is a cheap way to save on electricity. I'm not asking for an answer just some thoughts. My next plan is to under-ground a shipping container it will stay way cool down there.

 

[Yes4Prop215]

What if you need an AC but dont have a reasonable place to exhaust that hot air?

I have one exhaust hole drilled into my closet that is attached to a vortex fun, could i just run my AC exhaust ducting up there instead? it might be kinda hard considering how my room is attached, or maybe run my AC exhaust into a ducting that runs to the vortex fan that eventually exhaust?

 

[hoosierdaddy]

I would run another duct to an additional hole to the attic. Use an additional fan for this new run.
If you use a small 5000-8000 btu unit, 6" duct and fan will do the job. Any larger and you may need to use 8".

 

[Green Mama]

The tutorial looks really well explained. But I'm wondering if by the time I bought a window air conditioner and all the supplies to make it. would I be saving any money than buying a portable unit for $300 -$400? plus considering all the time and energy to build it. Does anyone have any insight on this?
Green Mama

 

[hoosierdaddy]

500btu AC $100
6 x 4 sheet of insulation board $12
25ft duct $30
Nice fan $150
Replacement ac if one goes $100 total
Using an AC unit without manual controls (DIY or portable) and the power goes off....$your whole grow

 

[Brastaman]

the portable units work well. BUT they take so much floor space, whether its in your grow or outside your grow, they need floor room.

the window a/c conversion that hoosier is suggesting can "float", even though there will be some space needed for it as well.

 

[Vegan]

very nice tutorial indeed

 

[sneaky_g]

Thank you for an awesome thread !!!
I'm new to ac units and growing for that matter, and as a very visual learner this is the best thread i've seen on the net so far relating to ac units and how they actually work.


A couple questions. This is the first time i've attempted a grow in the summertime in a garage for that matter in california. In the summertime , it gets hot here. I'm concerned as I should be.
specs are as follows
3x5 grow space. With a 400 watt air cooled MH/HPS switchable. ( Nice exaust fan with 6" ducting goin to attic)
It's studded and sheeted on the 3 foot returns, and plastic on the front ( zipper opening)
A few fans to circulate the air inside

Now as for the AC unit, if I set the cool side in the grow space, and the hotside + ambient out, will it be bad for the AC unit to suck garage temperature heat through the ambient and push out through the hot coil exaust into the attic?
Than the inside should do its job of circulating the air in the room and cooling it correct? I'm thinking anything over 6000 BTU would be overkill..

Do all the AC units come with a ducting opening to pump your hot air out?

I'll snap some picture of what i've got so far later in the day, but any advice help would be greatly appreciated.


Thanks !

 

[micro gro]

Nice thread. Took the A/C box concept to the next level using a 3.5 ton A/C

 

[somebody041]

i just picked up most of the supplies to make one of these today. one question: where can i find things like 10" ducting or large duct vents?

 

[micro gro]

Home Depot / Lowe's. Or a HVAC supply shop.

 

[somebody041]

Home Depot / Lowe's. Or a HVAC supply shop.

home depot and lowes only had vents up to six inches and ducting up to 8 inches. i'll look for a hvac store or heating and air place and hopefully they don't ask too may questions


hey hoosierdaddy, or anyone who knows for that matter,

you mention in the original guide that calculating the size of the vent or the CFM/fan size you'd need was for another guide. i am some trouble deciding if i need an extra fan.

there is a 10" fan inside my AC so i was going to use 10" ducting and a 10" vent to exhaust, but i'm not sure that will be enough. could i just get 6" ducting/venting and use a fan to pull air and push it right before the vent?

if anyone could point me in the right direction to find the answer to my questions i would greatly appreciate it.



edit: forgot to add that the ac unit i am experimenting with is most likely too small i am just using it because i had it lying around to test the system before i dump several hundred on a nice new unit. i would like my ventilation to be adaptable to a bigger system if needed.

 

[micro gro]

I've seen Home Depot's around here that carry up to 10", and some that carry up to 12", but never smaller. I guess it's a regional / distribution / demand thing.

 

[hoosierdaddy]

somebody, yes you can use a lesser sized duct to exhaust the AC, if you incorporate a fan to help pull that air out. My 5050btu AC unit is exhausted to my attic via 6" ducting and a 250cfm fan.

 

[somebody041]

thanks hoosierdaddy and micro gro!

 

[micro gro]

My last setup used a 6" Vortex to cool a 14,500 BTU window mount A/C and a 1000w air-cooled hood (and 7 1000w ballasts in the room).

 

[apartmentblower]

do you just use glue to put the insulation board together?

im using a 24k btu window a/c. so by my understanding, i should be fine with just a 8" passive intake and 8" output with 8" fan?

 

[somebody041]

to anybody who is considering this:

i had a spare 5000btu window ac laying around and decided to buy the parts to see if it would work. couldn't find the insulation recommended but i just used thick styrofoam with R-11 i think. cut the pieces to the size of the box i wanted to build and just used foil tape to make everything stick. i bought a couple of elbow pieces to stick the intake/exhaust. i used 8" ducting and don't have any supplemental fan... i think the fan in the AC is 10".

this thing cooled my grow room over 20 degrees! from 107 max's with lights on and 87 minimums, to 85 max with light on and 70 with light off!

i've been considering getting a supplemental 8" booster fan to increase the efficiency but right now it's working when i run everything at max temp so i may just let it do it's thing.


thanks micro gro for answering my questions and hoosierdaddy for also answering my question and posting this awesome guide! instead of spending $550 on a portable ac i spent $45 and got the same results!