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AC Boxes Made Easy (to understand and build)
- Thread starter hoosierdaddy
- Start date
S
SCROG McDuck
I've only read thru page 4 and have no idea where it ends and it doesn't matter because it has helped immensly already, but...
I must, first thank you 'daddy' for the tute. I'm getting tired of portables and 2nd to G33k Speak for asking questions that ultimatly leads you, 'daddy', to say Funny how it seems to function properly when it is hung outside in 95 degF weather isn't it?..
I have been wrestleing with the same delema or non-delema.
Having an AC unit that is controlable with a timer is what I
need. You turned on the light.
EDIT: Now I see you are bannned, I hope to see you back.
echo_chamber
Active member
I made an A/C box very similar to the ones showed here. Everything was fine til I installed the A/C. Now that its hanging, the compressor turns off after running for 5 minutes. Worked fine during the building of it.
Several times i had to tilt the unit on its side, and had to tilt it on it's back to get it into the flower room. Is it possible that i broke the unit by tilting it? Any help would be really appreciated. Nothing like a weeks worth of hard work with failure as a result...
Several times i had to tilt the unit on its side, and had to tilt it on it's back to get it into the flower room. Is it possible that i broke the unit by tilting it? Any help would be really appreciated. Nothing like a weeks worth of hard work with failure as a result...
anything with a compressor like an AC, refrigerator, freezer, etc should not be tilted. If they are, they need to sit in the proper position for roughly 24 hours I believe. The reason I believe is the compressor has oil in it and tilting it puts the oil in the wrong spot, and it needs time for the oil to drain to the right spot.
So maybe it is overheating cause of oil.
On a previous design in a different spot, (not the one I posted in this thread), my unit would shut off due to overheating. I was not removing enough heat from the box
BTW the box I posted a few pages ago is still running great
R
RedRain
ya you probably starved your compressor of oil. the compressor has a reserve of oil in the bottom, but if you tilt it, or place it on its side and turn it on while its tilted you risk damaging the compressor.
Marshall is correct, if the heat is no removed from the refrigerant and transfered to the air, the head pressure of the unit goes up and will cause damage to the compressor or possibly a burst in the coil.
Marshall is correct, if the heat is no removed from the refrigerant and transfered to the air, the head pressure of the unit goes up and will cause damage to the compressor or possibly a burst in the coil.
echo_chamber
Active member
Here is my 5000BTU project i just completed. Just mounted the A/C in a box separating the air intake and output. A 435 CFM Centrifugal fan is pulling the heat out of the box, no more A/C sitting in the widow.
Lessons i learned:
Dont tip the A/C on its side while building the box and use insulated ducting for all heat exhaust output. Also put the A/C as close to the ceiling as possible to condition the warmer air at the top of the room.
Lessons i learned:
Dont tip the A/C on its side while building the box and use insulated ducting for all heat exhaust output. Also put the A/C as close to the ceiling as possible to condition the warmer air at the top of the room.
G
GMax
man sucks hoosierdaddy gone
So what size air conditioners are you guys using for how much light ???? i have heard that 3500btu per light, but what per 1000w???
i am currently running 2000w ( 2x600w & 2x400w) uncooled barebulb in a 12x14 basement. the room has one window but is one of those basement ones that fold inside and wouldnt even hold the smallest AC. I built a box around the window outta dow corning.
Before summer started i was able to keep temps in check with just active intake but now that summer has started i have added a old used 12000btu and sealed the room 98% w Co2.
i use 10in insulated ducting for the outake w a 8in windtunnel ducted to the window box and 6in instulated duct with 4in 265cfm squirrel cage fan for intake from a seperate room.
my AC blows cold and i have checked for heatleaks but during the hot summer i have hit a all time high of 86. this doesnt seem right, if it is 3500btu per 1000w i should be able to get away with 7000 btu and even uncooled they should be sufficient with 10000btu
is my setup not sufficient ???
is my AC too small ??
is my AC too old ??
how big is your AC??
i dont know exaclty how old it is but it is old enough to have woodgrain design lol but like i said it is blowing cold but i have never owned a AC this large and really dont know how cold it supposed to be and my temps are hitting 86
I am about to buy a brand new one and i just want to know how big to buy i would rather go overkill but i am kinda budgeting. i dont want to buy one too small and try to box it up and it not work and not be able to return it. i thought 12000btu was already overkill....
input from people with similar setups would be awesome
So what size air conditioners are you guys using for how much light ???? i have heard that 3500btu per light, but what per 1000w???
i am currently running 2000w ( 2x600w & 2x400w) uncooled barebulb in a 12x14 basement. the room has one window but is one of those basement ones that fold inside and wouldnt even hold the smallest AC. I built a box around the window outta dow corning.
Before summer started i was able to keep temps in check with just active intake but now that summer has started i have added a old used 12000btu and sealed the room 98% w Co2.
i use 10in insulated ducting for the outake w a 8in windtunnel ducted to the window box and 6in instulated duct with 4in 265cfm squirrel cage fan for intake from a seperate room.
my AC blows cold and i have checked for heatleaks but during the hot summer i have hit a all time high of 86. this doesnt seem right, if it is 3500btu per 1000w i should be able to get away with 7000 btu and even uncooled they should be sufficient with 10000btu
is my setup not sufficient ???
is my AC too small ??
is my AC too old ??
how big is your AC??
i dont know exaclty how old it is but it is old enough to have woodgrain design lol but like i said it is blowing cold but i have never owned a AC this large and really dont know how cold it supposed to be and my temps are hitting 86
I am about to buy a brand new one and i just want to know how big to buy i would rather go overkill but i am kinda budgeting. i dont want to buy one too small and try to box it up and it not work and not be able to return it. i thought 12000btu was already overkill....
input from people with similar setups would be awesome
echo_chamber
Active member
5000 BTU per 1000Watt just barely keeps me under 85 on those HOT days, but keeps things in the low 70s on a regular day.. After experimenting with AC's the past few months, i'm going 10K BTU per 1K for now on..
BlueGrassToker
Active member
Gmax, the 4" fan is the bottleneck in your system. With it in the line, the whole thing will flow like a 4" line no matter how big the rest of the ducting is. The fan may seem like it is a helper, but it is hurting your whole system. No need for a fan at intake anyway. Much better to use a fan of proper diameter at exhaust to help the AC fan.
I suggest doing away with the 4" fan, and intake with the 10" duct, while using what you have for exhaust.
I bet the moment you change the intake to one 10" run, your whole world will change.
I suggest doing away with the 4" fan, and intake with the 10" duct, while using what you have for exhaust.
I bet the moment you change the intake to one 10" run, your whole world will change.
G
GMax
thanks you for the input
I have a 6in 440 cfm inline fan that i could swap the 4in out for but the intake comes from a 6 in register vent that is upstairs, so that is maximum, width i can pull
my only other option is i could cut another 10 in hole in the window box but it would be using hot summer air mixed with HOT exhaust air for intake. would that work ???
also those larger units are pretty heavy . anyone have any luck hanging them with chains ????
thanks
I have a 6in 440 cfm inline fan that i could swap the 4in out for but the intake comes from a 6 in register vent that is upstairs, so that is maximum, width i can pull
my only other option is i could cut another 10 in hole in the window box but it would be using hot summer air mixed with HOT exhaust air for intake. would that work ???
also those larger units are pretty heavy . anyone have any luck hanging them with chains ????
thanks
BlueGrassToker
Active member
You don't want to use hot exhaust air for intake whatsoever.
It is hard to visualize your system, and it would help if maybe you gave a sketch?
All I can tell you is that the smallest orifice in the system is the bottleneck and no matter what you do before it or behind it, it will only flow as a 4" system.
The AC has a fan, and an enclosure that surrounds it. Measure that and it will tell you the size of duct it requites for full flow. If it is a 10" enclosure, it means that the system is looking for about a 10" duct worth of air.
I think the first few pages of this explains it all quite well.
It is hard to visualize your system, and it would help if maybe you gave a sketch?
All I can tell you is that the smallest orifice in the system is the bottleneck and no matter what you do before it or behind it, it will only flow as a 4" system.
The AC has a fan, and an enclosure that surrounds it. Measure that and it will tell you the size of duct it requites for full flow. If it is a 10" enclosure, it means that the system is looking for about a 10" duct worth of air.
I think the first few pages of this explains it all quite well.
Tag
I may be a litttle dense but why not use the exhaust air for intake to the A/C? That air ultimatly ends up 'outside'. If the unit were mounted in a window, it would be useing the hot air from outside. What am I missing? or forgot. This is funny because I am, right now, debating putting the unit thru the bedroom wall, exhausting (and intaking) to/from my garage. or build a box and exhaust to the garage thru 8" ducting (that laready exists), taking the air from the room in which my tent is set up. it is basically taking ambient ACd household air (72F) and shooting it out into the garage via the AC unit. no? the tent is exausted into the attic.
BlueGrassToker
Active member
When the unit is hanging out of a widow the hot air gets shot out the back of the unit and as hot air rises it immediately seeks a higher level than where it came out. Basically the hot air exhausted gets carried away by the wind or by rising above the unit.
Closer to the window the vents are taking in ambient air (whatever the temp of air is outside) and is really unaffected by the hot exhaust air.
If you exhaust into a garage, the hot air will continue to heat up the air in the garage, and as a result the air used by the intake vents will continue to get hotter and hotter.
If you can vent out some of the garage air, the idea you have may work. But if not like I said, it will keep getting hotter and hotter as the exhaust air has nowhere to go.
I would suggest doing what you are thinking about, but box in the very back and duct the hot air out of the garage somehow. If there is an attic space above the garage, cut a hole for the duct and run the hot air up there. Or run it out a window.
If you do box up the back and have the unit hanging in the garage, remember that there needs to be a way for air to get into the garage,,,because you are going to be pushing hot air out. If pumpin out air through an 8" duct, you need to have 8" worth of air coming in.
Closer to the window the vents are taking in ambient air (whatever the temp of air is outside) and is really unaffected by the hot exhaust air.
If you exhaust into a garage, the hot air will continue to heat up the air in the garage, and as a result the air used by the intake vents will continue to get hotter and hotter.
If you can vent out some of the garage air, the idea you have may work. But if not like I said, it will keep getting hotter and hotter as the exhaust air has nowhere to go.
I would suggest doing what you are thinking about, but box in the very back and duct the hot air out of the garage somehow. If there is an attic space above the garage, cut a hole for the duct and run the hot air up there. Or run it out a window.
If you do box up the back and have the unit hanging in the garage, remember that there needs to be a way for air to get into the garage,,,because you are going to be pushing hot air out. If pumpin out air through an 8" duct, you need to have 8" worth of air coming in.
I'm talking put a virtual window in the wall and use it like it was hanging out a window, no box. I understand taking cooler air, from the grow room, into the AC and exhausting into the garage being inefficient (but affecive). I'm in Fla and in the summer the garage runs typically 110F, or more, w/o any input of hot air. You're saying that that garage air could go up to ??? 130F from the exhaust of the AC? When I lived in Pheonix they used swamp coolers, saying that AC didnt work as well because of high temps (and maybe low humidity?). At what temperature would the air be 'too hot' for the unit to be ineffecive?
BlueGrassToker
Active member
Go back and look at the pics at the start of this thread.
I would not use the air from the grow side of the AC for anything. The cool air only gets recirculated through the cold side of the unit and back into the grow room. The air intake and exhaust are separated from the grow room and are both in the garage. You need to have some air vented into the garage, and ducting it right in to the intakes would be the best way to go. You could then exhaust the hot air into the garage without effecting the units efficiency.
Get the ambient temp air from outside the garage, not the grow room. (roof, attic, whatever) Get a good grasp of what the pics show on how to feed the unit.
I would not use the air from the grow side of the AC for anything. The cool air only gets recirculated through the cold side of the unit and back into the grow room. The air intake and exhaust are separated from the grow room and are both in the garage. You need to have some air vented into the garage, and ducting it right in to the intakes would be the best way to go. You could then exhaust the hot air into the garage without effecting the units efficiency.
Get the ambient temp air from outside the garage, not the grow room. (roof, attic, whatever) Get a good grasp of what the pics show on how to feed the unit.
So I am about to build one of these and want to make sure I understand what I need to do to do this correctly.
I need two seperate boxes, one enclosing the intake vents with a passive intake from outside, and a box around the exhaust section of the window unit and a strong fan pulling that and blowing it outside
This sound right?
I need two seperate boxes, one enclosing the intake vents with a passive intake from outside, and a box around the exhaust section of the window unit and a strong fan pulling that and blowing it outside
This sound right?
