AC Boxes Made Easy (to understand and build)
- Thread starter hoosierdaddy
- Start date
I'm not clear on the "blowing through" part of the fan.
If you are going to Y to another line, you really need to have the fan sucking the air from the exit end.
Even then, if you do not add an additional fan for your AC exhaust, the line you Y into may not help your AC line much, although it is an option for a path out.
Tell me about the line you are Ying into....what sort of fan is it on that line?
What is that line doing?
If you are going to Y to another line, you really need to have the fan sucking the air from the exit end.
Even then, if you do not add an additional fan for your AC exhaust, the line you Y into may not help your AC line much, although it is an option for a path out.
Tell me about the line you are Ying into....what sort of fan is it on that line?
What is that line doing?
my plan was to have a 10 inch max fan like this..... outside>>>>>ducting>>>>lights>>>>ducting>>>>10 inch max fan>>>> ducting>>>>y duct>>>ducting>>> exit. hows that sound? or what if i had a 10 inch max fan also pulling the ac box so i would have a fan blowing through both legs of the y duct and being shot ou the ducting to outside..... or what if i had a 12 inch max fan pulling air from both the air cooled lights and the ac? any of those 3 sound swell?
You will be better off if you can keep from Ying the two lines together. You create a bottleneck that only hampers optimal flow. Could you just run two lines to outside (or wherever you exhausting to)? If you can, then I think that a 10" with an inline fan would be sufficient to exhaust the AC. Run a piece of 12" to the intake box part of the AC for passive air intake (getting air from outside?), and then run 10" out of the exhaust box to the exhaust port (attic, outside?) that has the fan at the last (or nearly the last) of the run.
Not sure how many lights you have, but normally a clean 6" line will take care of multiple hoods. You can just 6" in and out for lights, and have the fan at the end of the run at the exit port. OR..tie that 6" into your AC exhaust 10" line. You can always rig an adapter to make that happen. The larger 10" line will probably help the 6" line out.
Not sure how many lights you have, but normally a clean 6" line will take care of multiple hoods. You can just 6" in and out for lights, and have the fan at the end of the run at the exit port. OR..tie that 6" into your AC exhaust 10" line. You can always rig an adapter to make that happen. The larger 10" line will probably help the 6" line out.
i have 4 1k lights right now and will eventually have 8. i can only have 1 exhaust because of the neighbors. the ac intake is from the living room but it stays around 65 F in there. so are you thinking i should have my ac intake and exhaust hooked up to a fan and exhausting outside? and i should be fine hooking my lights up to that? especially if i step the light ducting up to 8 or 10 inchs?
You need lots of air. More than what your central air system is designed to provide. I can almost guarantee you the living room won't stay at any 65f when you are sucking the air out with those fans. You need to get your air from outside, and exhaust it back outside, or into an attic or crawlspace.
what do you mean more than what my central air is supposed to provide? the ac will be 25000 btu and i only have 4 air cooled lights for now and will later step it up to 7 or 8 1k but i feel that should still be enough btu to keep it cool all year but if i can only run 6 or 7 lights with it at max then so be it. the living room might get colder than 65 from all the negative pressure but i dont see it getting any hotter than that because of my climate, incase thats what you meant by it not staying at 65?
The central air system that cools your house is sized to move the air needed to keep up with the volume of air needed.
If you run a fan inside your house and exhaust the air outside, you are removing a certain volume of air from the intake supply...which from what you said is the living room, which is kept at that 65f by the central cooling system.
Your fans are going to be pulling in air, and it will be air that the central air system has cooled down to 65f. Which is fine, for a short while. There will be a point real quick that you will be removing more of the cool air from your living room that the central air system can keep up with. It will not be able to cool as efficiently as before and the system can actually labor. You could see the cold lines freeze up when they are overworked like this.
When this happens, good luck at keeping your house at 65f without the central air running constantly.
If you draw in air from a separate intake that comes from outside, you are not infringing on the air volume that the house uses.
Remember that if you push air out, it has to come from somewhere to start with. If you were in a garage with the doors closed and no vents, it would suck the air from every nook and cranny it could trying to satisfy the volume. You would see it suck the doors shut with ease when it is starved for air like that.
A room similar to the garage would need an intake from somewhere to satisfy the volume needed. Much better and cheaper to make that intake from outside instead of from the very, very expensive air inside the house.
Hope you are grasping this.
If you run a fan inside your house and exhaust the air outside, you are removing a certain volume of air from the intake supply...which from what you said is the living room, which is kept at that 65f by the central cooling system.
Your fans are going to be pulling in air, and it will be air that the central air system has cooled down to 65f. Which is fine, for a short while. There will be a point real quick that you will be removing more of the cool air from your living room that the central air system can keep up with. It will not be able to cool as efficiently as before and the system can actually labor. You could see the cold lines freeze up when they are overworked like this.
When this happens, good luck at keeping your house at 65f without the central air running constantly.
If you draw in air from a separate intake that comes from outside, you are not infringing on the air volume that the house uses.
Remember that if you push air out, it has to come from somewhere to start with. If you were in a garage with the doors closed and no vents, it would suck the air from every nook and cranny it could trying to satisfy the volume. You would see it suck the doors shut with ease when it is starved for air like that.
A room similar to the garage would need an intake from somewhere to satisfy the volume needed. Much better and cheaper to make that intake from outside instead of from the very, very expensive air inside the house.
Hope you are grasping this.
ohhh ok i see what you're saying. i dont have central air conditioning so thats where we got confused. i just live in a slighty cooler climate. i just keep atleast 1 window open in the living room. it only hits 85 max outside during the summer on the hottest day and gets to about 60 or 55 at night. during the winter the climate probably ranges from 30-50 F.
I am not a big fan of them, Medgirl. Not very efficient for the money, and the type you are looking at will draw in air from the grow/cool area to use for an exhaust. That means odor will escape with the hot air. If you can figure out how to rig the intake of one to be separate from the grow room air, it would probably work out...
But by the time you did all that, you might as well save money and build a box around a window unit.
But by the time you did all that, you might as well save money and build a box around a window unit.
portable a/c
portable a/c
Yeah but it would be less conspicuous because there would not be a a/c unit sticking out of the box, not to mention you would not hear it running all the time or have to deal with condensation as the unit does not need the water emptied.
I'm thinking smell will not be a problem if I'm venting it outside via an attic vent 15' in the air. This is a small grow.
I am considering it for those reasons.
My concerns are if I can run a 400w light (electronic ballast), a couple small fans and an A/C unit on the same 2 outlet box.
portable a/c
Yeah but it would be less conspicuous because there would not be a a/c unit sticking out of the box, not to mention you would not hear it running all the time or have to deal with condensation as the unit does not need the water emptied.
I'm thinking smell will not be a problem if I'm venting it outside via an attic vent 15' in the air. This is a small grow.
I am considering it for those reasons.
My concerns are if I can run a 400w light (electronic ballast), a couple small fans and an A/C unit on the same 2 outlet box.
The WeedChucks
Member
Great thread!
T
Tr33
Thanks hoosierdaddy, I finished my inside AC box and it runs great, temps evened out to where I need them in my sealed room.
I was thinking about building an a/c box. But instead of having 2 boxes on the back, just having one box for the hot exhaust, and then the hot intake just pulls in from the same room air the cool intake is pulling from. here is a diagram explaining. The a/c is located in the room that a grow room is built into. so it cools the air that is passively intaked from the outside, which is then passively intaked into and actively exhausted out of the grow room.
Will this work? If it has to have an intake tube then the intake tube would just run to the passive intake for the outer room, so it would be pulling from the same source right? Or is this wrong?
Will this work? If it has to have an intake tube then the intake tube would just run to the passive intake for the outer room, so it would be pulling from the same source right? Or is this wrong?
I was thinking about building an a/c box. But instead of having 2 boxes on the back, just having one box for the hot exhaust, and then the hot intake just pulls in from the same room air the cool intake is pulling from. here is a diagram explaining. The a/c is located in the room that a grow room is built into. so it cools the air that is passively intaked from the outside, which is then passively intaked into and actively exhausted out of the grow room.
Will this work? If it has to have an intake tube then the intake tube would just run to the passive intake for the outer room, so it would be pulling from the same source right? Or is this wrong?
Not sure I really understand your drawing, but it seems that the main downside to your design is it'd be highly inefficient since it's taking the air that it just worked so hard to cool and shooting it out the exhaust of the room at a very high rate (eventually faster than it can cool). If you're exhausting your light's heat too, it'll be even more profound.
Also, obviously any smells in that outer room would go out the exhaust too. I smoke in my "outer room" and so this is a concern of mine.
So, my recommendation is that for the most efficient use (resulting in less $$), you want 1 "hot" intake & exhaust pair which both duct outside of whatever space you're cooling and then of course the 1 "cool" intake & exhaust pair which is inside the space you're cooling. Certainly variations on that may work to different degrees and may work for you, but I don't think it'd be worth it to me to do it so it works @ 50-99%.
DB
Duct size recommendations? 10k BTU Frigidaire
Duct size recommendations? 10k BTU Frigidaire
I just picked up this unit today. I doubt I need 10k btu, but I figured I should double the BTU sizing on the box since they don't account for the 400 watt HPS, the 100+ degree temps outside and that I work from home in the same room I grow in. I was thinking of using 6" ducts and setting the unit right next to the outer wall it will exhaust through (relatively straight duct run of maybe 18").
Anyone with similar experience able to share if they think the 6" ducting will be sufficient? I don't want to install any duct-fans in addition to the AC if I can help it.
Thanks,
DB
Duct size recommendations? 10k BTU Frigidaire
I just picked up this unit today. I doubt I need 10k btu, but I figured I should double the BTU sizing on the box since they don't account for the 400 watt HPS, the 100+ degree temps outside and that I work from home in the same room I grow in. I was thinking of using 6" ducts and setting the unit right next to the outer wall it will exhaust through (relatively straight duct run of maybe 18").
Anyone with similar experience able to share if they think the 6" ducting will be sufficient? I don't want to install any duct-fans in addition to the AC if I can help it.
Thanks,
DB
If you are going to exhaust the AC straight out the back, it would be best if you don't squeeze it down to the size of a duct pipe. If you can just make a box (18") that leads from the back of the AC to the wall to outside.
The intake needs to come from somewhere besides the grow area or the unit will be inefficient. You can duct from ambient to the AC intake, but I would suggest two 6" or better two 8" pipes to feed it. You don't want to starve the AC for intake air.
Keep the cool air in the grow recirculating as it does in the house, best not to have the other parts of the AC in there at all if you can help it.
I have sketches in the first pages that shows this.
The intake needs to come from somewhere besides the grow area or the unit will be inefficient. You can duct from ambient to the AC intake, but I would suggest two 6" or better two 8" pipes to feed it. You don't want to starve the AC for intake air.
Keep the cool air in the grow recirculating as it does in the house, best not to have the other parts of the AC in there at all if you can help it.
I have sketches in the first pages that shows this.
