AC Boxes Made Easy (to understand and build)

DIGITALHIPPY · Aug 1, 2008

nice sketch... my box encompases the whole back, hot and cool. whereas u properly seperate the two. if i were running a 10,15,or 25k a/c this would be a CRUCIAL point where my design would over-heat things. atleast someone took time to properly draw the airflow of an a/c... just looking at it should be obviouse, but your colored lines are clean and concise for thoes who are less adapt at mentaly deconstructing things.
you could probably skip the 'ambiant air in' box if the vents are surounded by decently cool 'ambiant air' for the unit to push out the back. either way its a well writen naritive, just wondering what thread i missed with the ego-war.

hoosierdaddy said:
I know that many have done that, and it works for them. But I guarantee it is not performing as efficiently as it could with separation of air flows.

clarify??

the extra duct is adding drag and increasing pressure, decreasing fan efficiancy... one could probably get-away without boosters if they didnt have so much pressure...

hoosierdaddy · Aug 1, 2008

When we introduce the two air flows, the heated exhaust will heat up the air being used to cool itself. Thus less efficiency.
The only way you can get by without an additional fan is to keep the ducting sized correctly throughout the system. This would include accounting for the type of duct, resistance from turns, etc...
We must also be careful not to use the air the unit creates to cool the exhaust due to oder issues.

Not sure what ego war you are talking about?

hoosierdaddy · Aug 11, 2008

Yes, you can use whatever size ducting as long as you can keep up with the demand of the AC unit fan.

You should be getting air to cool the condenser coils with air other than what you have cooled with the AC. That sort of defeats the purpose of the lung room, yes?
And you also want to make sure the air is not coming fro the grow area unless you plan on scrubbing the air.

The heat of the exhaust should not be a concern, as it will be no where near that hot when it gets to the fan.

hoosierdaddy · Aug 11, 2008

If you have a 10" fan, then going to 8" has already choked down the pathway from what it was. This in itself would say that you would need some additional air flow to make up for what you choked down in dia. Also, you have to take in account how long the run is to the exit port, as it creates some resistance, especially using flex duct.

Where is your hot air going now? I would think the ideal situation would be for the "lung" room be completely separate from the grow, with an exhaust from the AC that goes outside of the room. If you have that, just pull the air through the duct with an 8" fan, or rig up a $40 Stanley blower..which will do the job.

When you say "out my ambient AC'd air in the lung room", I have to wonder if you are in fact cooling your lung room? If you don't have things set up properly, the size of the fan and ducting will be less important. If you are using the air that the unit cools, to cool the coils, then you will have problems.

hoosierdaddy · Aug 11, 2008

That will work, but you need to keep in mind that it all has to do with the size of your duct. The larger the duct, the less the air has to labor to get out of the duct, and the need for a fan is less.

Same with the box covering the intakes...if it is a small duct leading to them, it will only choke down the amount of air that can get in there. If you keep the ducting large, it will function better.

When you put a fan pushing air into the intakes, and another pulling out the exhaust, you basically have a single air path from start to finish. It would be better to have both fans, or even one larger fan, on the exit end pulling through this air path.

The whole deal with additional fans is, if you choke down the air path that the factory has put into the unit, then you need a fan to get you back to par.
If you keep the ducting large enough, you will need no additional fan(s), and the fan in the AC unit will do it's job.

hoosierdaddy · Aug 12, 2008

In the blue area...is that the cold air intake vents we see?

Is your box in red surrounding the intake vents? Where is the back of your unit, where the red and blue lines meet?

Just a little FYI...a 12" fan turning at 1100 RPM will create about 740 CFM.

motofox16 · Aug 12, 2008

Thanks!

Thanks!

Thanks a bunch for the tutorial. that was great info.

hoosierdaddy · Aug 13, 2008

CFM is a unit of measurement related to how much air can pass through a given space in a specific amount of time.

Let's assume that your exhaust fan is 12" in diameter.
No matter what size motor you have turning the fan, the CFM is all relevant to the RPM the fan is turning, and the size of the opening the air it is pulling has to go through.

A 12" fan turning 1100 RPM will pull 740 CFM no matter what motor is making it turn.
I don't see anything on your motor tag stating the RPM, but it is more than likely up in the 1800 range.

I could maybe buy that the cool side is only recirculating 150 CFM, I would still think that pretty low for that sized unit.

hoosierdaddy · Aug 13, 2008

Without hacking into the internal electronics of the AC, I would simply plug the AC into a receptacle strip and control the strip with the thermostat.

hoosierdaddy · Aug 13, 2008

You really do not have a lung room. It is merely an ambient atmosphere room when taking in air from your living space. And what you are doing is trying to bandaid a situation that is outside of the box, so to speak.

If you can exhaust air, why can you not get air for your AC, or your 'lung room' for that matter, from outside instead of from your living space?

G33k Speak · Aug 13, 2008

never mind.

hoosierdaddy · Aug 14, 2008

G33k Speak said:
never mind.

By you removing all of your posts, it has made a mockery of this thread. Thanks alot, pal.

It would have been better for you to have left things alone, and simply learned about how to do things the proper way, instead of working so hard to find a bandaid for the obviously screwed up situation you had.
It would have been a great tutorial on how to not do newbie things, and how to fix them even if you do. Maybe not great for you, but for those who want to do things as close to proper as possible.

G33k Speak · Aug 15, 2008

hoosierdaddy said:
By you removing all of your posts, it has made a mockery of this thread. Thanks alot, pal.

It would have been better for you to have left things alone, and simply learned about how to do things the proper way, instead of working so hard to find a bandaid for the obviously screwed up situation you had.
It would have been a great tutorial on how to not do newbie things, and how to fix them even if you do. Maybe not great for you, but for those who want to do things as close to proper as possible.

I wasn't going to say anything- but since you whine like a gurl about making a 'mockery' of your thread;

I deleted the posts, because after four fucking postings, and then going and even shooting pictures for you- you still couldn't give a straight explanation!

i'd put up photos so that other people could see examples and maybe learn from it- but you couldn't get the shit right, so I deleted it.

hoosierdaddy · Aug 15, 2008

Well, my brother, it was you that was trying to figure out a way to keep the AC exhaust from sucking out your ambient air that was actually your central air cooled living space air.
And it was you that wasn't connecting that you need to get your intake air from somewhere besides your living space, not to mention your having only a vague understanding of the term CFM, motors, fans, ducting, etc..etc...

So, no, I don't think it was me that "couldn't get the shit right", it's you pal.

Besides, this is only a thread to help folks understand what is happening with the air flows of an AC unit, and various methods of connection. It is NOT a thread to babysit and walk people through building their units. Especially when people like you are trying to jury-rig stuff, rather than do things proper.
I was trying to help you all I can, and apparently you don't appreciate someone trying to help you. And you do need help with your set-up. And I will be glad to help you get it right...but you can find someone else to help you rig a newbie set-up.

G33k Speak · Aug 16, 2008

See what I mean..... You're still missing the point.

My set ups work fine- I was trying to add some pix and examples for you to use.
But you go rambling off on some random tangent....

I asked about incorporating a thermostatically controlled booster fan- and you're giving me advice about power strips- WTF??? Did you not read or understand the question??

Do you really think I need you to explain CFM to me???

maybe you oughta stop smoking for awhile.

hoosierdaddy · Aug 16, 2008

When you start posting pictures of a motor tag, and asking what CFM that is...then yes someone needs to explain CFM to you, as you have no clue.

Dewd, your whole problem was because you were sucking air from your living space, which is mucho expensive to do. You called it a lung room, yet again no clue...

I dunno where to go with you now. I offered my help, and re-offered it.
One thing is for certain, if you hook up your AC using the methods I've described you will be fine. And you won't be using all of your central air to cool another AC unit.
Get it?

PharmaCan · Aug 16, 2008

hoosierdaddy said:
By you removing all of your posts, it has made a mockery of this thread. Thanks alot, pal.

LOL - I wouldn't worry too much about that. You obviously put a lot of work into making a super-good DIY. Nothing and no one can detract from that!!!

PC

hoosierdaddy · Aug 16, 2008

I really didn't intend to come off as so miffed. Although I do tend to speak my mind without worrying too much about the suck up factor. I'm actually not near as worried about this issue as it apparently appears.

I really never intended for this to be a full blown DIY, but rather some tools so that a man, or lady, can build a nice project from a bona fide DIY that someone has spent time on. I suppose the title is a bit misleading.
Once a person understands what is happening, and how to work with it, the DIY AC unit is old hat.
I do feel that a person needs to be discerning when choosing another's DIY in this area, and having the basics down lets us know what will work and what might work, just as common knowledge.

G33k Speak · Aug 19, 2008

hoosierdaddy said:
When you start posting pictures of a motor tag, and asking what CFM that is...then yes someone needs to explain CFM to you, as you have no clue.

...

That is not what I asked you. :spank:

You strike me as one of those people that understand things, but can't explain them when the question is rephrased.

Thanks anyway.

G33k Speak · Aug 19, 2008

For the sake of civil discussion, let's try a few Q's.

1. Please define 'lung room' for us. Just to make sure we're all on the same page.

2. Other then 'you gonna need a fan'- could you give specific info on calculating fan size for exhausting the AC box?

3. Where is the ambient air for the cooling coil supposed to come from?? You seem to be implying the need for a seperate inlet for 'ambient' air...

ambient ="The surrounding environment coming into contact with the system or component in question."

5000BTU AC.
7 or 8 in exit ducting.

what size duct fan would be required?

AC Boxes Made Easy (to understand and build)

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