I'm glad it worked out for you.
AC Boxes Made Easy (to understand and build)
- Thread starter hoosierdaddy
- Start date
somebody041
Member
i have a question for anyone with knowledge on the subject:
right now i have my 5000btu ac hooked up with 8" ducting. i looked in the ac before i started building my box and saw the fan was 10". when i feel my exhaust ducting it feels HOT. even the area around my box/exhaust vent is hot. the exhaust air is really hot coming out but at a slow rate. right now the AC is keeping the room temps in check with a max of 85 but it's cranked up at max temprature and it's running all the time (i have an older model with no thermostat but i just installed a thermostat for it today). max 85/min 71.
feel like i should supplement my system with a booster fan between the ac and the exhaust vent. would there be any benefit to this besides reducing the vent duct heat? would it make my ac run more efficiently?
right now i have my 5000btu ac hooked up with 8" ducting. i looked in the ac before i started building my box and saw the fan was 10". when i feel my exhaust ducting it feels HOT. even the area around my box/exhaust vent is hot. the exhaust air is really hot coming out but at a slow rate. right now the AC is keeping the room temps in check with a max of 85 but it's cranked up at max temprature and it's running all the time (i have an older model with no thermostat but i just installed a thermostat for it today). max 85/min 71.
feel like i should supplement my system with a booster fan between the ac and the exhaust vent. would there be any benefit to this besides reducing the vent duct heat? would it make my ac run more efficiently?
M
micro gro
Yes. In fact I believe just about everyone on this thread uses an inline fan to extract the hot air from the box...
somebody041
Member
didn't even realize that you had already addressed my question.looks like i will be purchasing a 8" 250cfm duct booster fan
phattybudz
Member
I posted a new thread about this but maybe someone in here can help me out,
"I'm running 6 lights (only 4 are on right now because of the A/C problem,) in a 10x13 room with a 24,500 btu a/c.
Built a box from the DIY tutorial on here, and was trying to vent it with two 6'' vortexes, one pushing air from outside to the intake, and one sucking out the exhaust to my attic. The problem is the A/C gives me cool air for a while, and then gets warmer and warmer... right now I'm aircooling my lights with a 10'' vortex, but I am thinking about buying a 12'' can-max fan and running it at 50% (noise is another issue I have to fix, I need to soundproof a wall or two for sure,) and then using my 10'' vortex to exhaust the air conditioner.
Does it sound like I need a bigger exhaust? Will a 10'' be big enough if so?
Thanks!"
"I'm running 6 lights (only 4 are on right now because of the A/C problem,) in a 10x13 room with a 24,500 btu a/c.
Built a box from the DIY tutorial on here, and was trying to vent it with two 6'' vortexes, one pushing air from outside to the intake, and one sucking out the exhaust to my attic. The problem is the A/C gives me cool air for a while, and then gets warmer and warmer... right now I'm aircooling my lights with a 10'' vortex, but I am thinking about buying a 12'' can-max fan and running it at 50% (noise is another issue I have to fix, I need to soundproof a wall or two for sure,) and then using my 10'' vortex to exhaust the air conditioner.
Does it sound like I need a bigger exhaust? Will a 10'' be big enough if so?
Thanks!"
foolish fool
Member
I read through this whole thread, thanks a lot hoosier, great stuff. It may be a stupid question but are there reasons not to run a window a/c sitting any other way than normal? like could you run it with the hot side facing up and cold side down? or any other way? I'm trying to figure out how to cool a small tent and I'm trying to figure out my options. any advice?
phattybudz,
The 10" would be better for your exhaust, but no matter what, you need to open up the intake. It needs to at least be the size of the exhaust duct.
ff,
I have heard it said that you cannot run them in any other position than normal, but I have no idea why not.
The 10" would be better for your exhaust, but no matter what, you need to open up the intake. It needs to at least be the size of the exhaust duct.
ff,
I have heard it said that you cannot run them in any other position than normal, but I have no idea why not.
foolish fool
Member
alright thanks man, if i end up trying it I'll let everyone know how it works out. Not sure what I'm going to do right now.
I can't imagine a situation that can't be worked out. Some details and sketches and I will help you all I can.
phattybudz
Member
Hoosier wrote: "The 10" would be better for your exhaust, but no matter what, you need to open up the intake. It needs to at least be the size of the exhaust duct."
So, would I be good with a passive intake coming from the outside then? or do I need another fan pushing into the box? I was originally told to pull through a scrubber with a 6 inch and push that into the intake...
So, would I be good with a passive intake coming from the outside then? or do I need another fan pushing into the box? I was originally told to pull through a scrubber with a 6 inch and push that into the intake...
I wouldn't involve my AC exhaust air with the grow air at all. So, no I would not run through the scrubber first. The scrubber itself is restrictive enough to cause you problems trying to feed the AC with it.
Yes, create a passive intake for the AC. It needs to be adequate to feed plenty of air to the unit. If the unit has plenty of air available, then your fan set-up at the end of the AC exhaust will be fine.
Yes, create a passive intake for the AC. It needs to be adequate to feed plenty of air to the unit. If the unit has plenty of air available, then your fan set-up at the end of the AC exhaust will be fine.
Great thread, thanks!
I have a window unit with the hot side sitting inside my garage. It works great in the winter, spring, and fall since the ambient air, even with the hot exhaust never gets very warm. It's actually nice in the winter, since the garage can get very cold. Although in the summer it is a minor nightmare.
Before I read your thread, I didn't understand that the hot side has both an intake and exhaust. I almost attempted to box the entire hot side including the intake, and exhaust it into the attic. Now that you enlightened me, I am super excited about boxing off only the exhaust of the hot side, and allow the passive intake to come from within the garage.
Got two questions, if you don't mind.
1) If I use 14 inch insulated ducting to duct the AC box into the ceiling, a relatively straight shot of ducting; think I can get away without adding a fan to help it exhaust. I think the AC is around 15kbtu or so, it looks as if the internal exhaust fan is around 14 inch or smaller.
2) Where can I find the aluminum insulated foam board at? Do they sell it at Home Depot? I am a pretty decent carpenter, but the foam board seems a lot easier and lighter to put together.
Thanks again, great info.
Mr^^
I have a window unit with the hot side sitting inside my garage. It works great in the winter, spring, and fall since the ambient air, even with the hot exhaust never gets very warm. It's actually nice in the winter, since the garage can get very cold. Although in the summer it is a minor nightmare.
Before I read your thread, I didn't understand that the hot side has both an intake and exhaust. I almost attempted to box the entire hot side including the intake, and exhaust it into the attic. Now that you enlightened me, I am super excited about boxing off only the exhaust of the hot side, and allow the passive intake to come from within the garage.
Got two questions, if you don't mind.
1) If I use 14 inch insulated ducting to duct the AC box into the ceiling, a relatively straight shot of ducting; think I can get away without adding a fan to help it exhaust. I think the AC is around 15kbtu or so, it looks as if the internal exhaust fan is around 14 inch or smaller.
2) Where can I find the aluminum insulated foam board at? Do they sell it at Home Depot? I am a pretty decent carpenter, but the foam board seems a lot easier and lighter to put together.
Thanks again, great info.
Mr^^
MedResearcher,
Your situation will work fine by exhausting the hot to the attic.
This graphic is what I envision you doing.
And with a set-up like this, a fan at the exhaust end is probably a good thing.
If your exhaust ducting is as large as the internal AC fan, then it may be enough without an additional fan. The restrictions in your duct will dictate if you have enough exhaust air flow or not. If the4 unit starts to cycle continuously and won't cool, then a helper fan is called for.
If you were to use the foam board and duct from the back of the unit, you could essentially run it anywhere you wanted to and no additional fan would be needed. This graphic shows the back end boxed up, and could be going right into the attic above. Instead of the bottom of the box squared off, it would be better if I showed a 45 deg rise. It would be less pressure to push if it 45'ed out of the back. If you don't follow that, I can do a graphic of it.
Basically just raise the back end of the floor the box up 45 degrees.
Boxing the exhaust end of the AC unit is a breeze using the DowCorning insulation board. Use aluminum tape to fix it together. The board is not always carried at all Lowes or Home DePot stores, but many I have seen do.
You could ask for it and see if they will order some. It shouldn't be a problem because I know it is on their buy list. It may be an area thing too.
Runs about $12-$16 a 4x8 sheet.
Your situation will work fine by exhausting the hot to the attic.
This graphic is what I envision you doing.
And with a set-up like this, a fan at the exhaust end is probably a good thing.
If your exhaust ducting is as large as the internal AC fan, then it may be enough without an additional fan. The restrictions in your duct will dictate if you have enough exhaust air flow or not. If the4 unit starts to cycle continuously and won't cool, then a helper fan is called for.
If you were to use the foam board and duct from the back of the unit, you could essentially run it anywhere you wanted to and no additional fan would be needed. This graphic shows the back end boxed up, and could be going right into the attic above. Instead of the bottom of the box squared off, it would be better if I showed a 45 deg rise. It would be less pressure to push if it 45'ed out of the back. If you don't follow that, I can do a graphic of it.
Basically just raise the back end of the floor the box up 45 degrees.
Boxing the exhaust end of the AC unit is a breeze using the DowCorning insulation board. Use aluminum tape to fix it together. The board is not always carried at all Lowes or Home DePot stores, but many I have seen do.
You could ask for it and see if they will order some. It shouldn't be a problem because I know it is on their buy list. It may be an area thing too.
Runs about $12-$16 a 4x8 sheet.
Thanks for your time and help Hoosier^^
I actually found the board at my local store, although it was 30 bucks a sheet for 1 inch thick. Got 2 sheets, couple rolls of aluminum tape, carpet knife, and a nice big square.
Hopefully 2 sheets will be enough to duct it straight into the attic, like you explained. Ill put the bottom piece on at a 45 degree angle, thanks for that tip, it makes perfect sense.
Thanks again, almost time to get to work. Ill let ya know how it turns out, this heat wave at the moment is horrible. This should really help me a lot.
Mr^^
I actually found the board at my local store, although it was 30 bucks a sheet for 1 inch thick. Got 2 sheets, couple rolls of aluminum tape, carpet knife, and a nice big square.
Hopefully 2 sheets will be enough to duct it straight into the attic, like you explained. Ill put the bottom piece on at a 45 degree angle, thanks for that tip, it makes perfect sense.
Thanks again, almost time to get to work. Ill let ya know how it turns out, this heat wave at the moment is horrible. This should really help me a lot.
Mr^^
Three hours later and all done. It would have been a lot faster, but it turned out my attic access door was in the way of the duct. So instead of going 45 degrees off the bottom then going completely vertical; I went 45 degrees off the bottom in a straight line all the way into the ceiling.
Funny cause I am always saying how all the advanced math classes I took were worthless. Well, they came in handy today figuring out the measurements since everything was at a 45 degree angle.
The ambient temp in the garage has dropped an incredible amount, it doesn't even feel like the same room. This was very key to me because the ambient air also feeds the cooling for my flower lamps, as well as it is used to ventilate my veg room. My veg room had been way overheated and growth was suffering, now it feels great and the leaves are already looking better.
Normally the metal on the AC would be very hot, now it is cool to the touch; so I figure it should be working a lot more efficiently now. When I was done with the installation my flower room had hit an all time high of 87 degrees, last few nights the peak was 86. An hour later it had dropped to 83 and the air from the AC on the cool side felt very cool. Tomorrow I think it wont even peak to 83, once everything cools off completely. I'll post once I get a full days high and low temps with the new ducting.
Have to say, working with that aluminum coated foam board and aluminum tape turned out excellent as well as an easy job. If I would have tried to make it out of wood, that would have been a full day of work and probably wouldn't have turned out half as nice. It looks like a professional duct.
Thanks again Hoosier, you da man.
Mr^^
Funny cause I am always saying how all the advanced math classes I took were worthless. Well, they came in handy today figuring out the measurements since everything was at a 45 degree angle.
The ambient temp in the garage has dropped an incredible amount, it doesn't even feel like the same room. This was very key to me because the ambient air also feeds the cooling for my flower lamps, as well as it is used to ventilate my veg room. My veg room had been way overheated and growth was suffering, now it feels great and the leaves are already looking better.
Normally the metal on the AC would be very hot, now it is cool to the touch; so I figure it should be working a lot more efficiently now. When I was done with the installation my flower room had hit an all time high of 87 degrees, last few nights the peak was 86. An hour later it had dropped to 83 and the air from the AC on the cool side felt very cool. Tomorrow I think it wont even peak to 83, once everything cools off completely. I'll post once I get a full days high and low temps with the new ducting.
Have to say, working with that aluminum coated foam board and aluminum tape turned out excellent as well as an easy job. If I would have tried to make it out of wood, that would have been a full day of work and probably wouldn't have turned out half as nice. It looks like a professional duct.
Thanks again Hoosier, you da man.
Mr^^
You don't know how good it feels to me that it worked out for you. The whole reason I offered up this thread. (well, that and I saw other threads setting folks up for disaster)
I have read over this thread many times. I finally got around to using the info and pics that you posted to build a box for the 8k that i got, i built the full box a little differnt than yours. I've had it turned on for about the last 36 hours, and i just noticed that i have water dripping out of the front of the unit. the unit has drain plug in the back of the unit which i attached a drain line to. I'm not sure if this was due to the unit not being level, it was angled forward a slight bit. I shimmed the unit so that it is now tilting backward slightly.
what are your thoughts?
what are your thoughts?
I had the same issue with a window unit. They're designed to sit with the back end a bit lower, you shouldn't have any problems now.
