Help Me Make My 400watt Cab Better

Hey All,

I feel I have all the right components to get my cab under 80F, but I can't seem to achieve that without using a wall AC unit.

My setup:
Stealth is paramount. Sound goes hand in hand with that.
47"Wx20"Dx55"H Plus Exhaust Chamber (Overall Height 70")
4" 177CFM Vortex Inline Fan
400W HPS Dimmable Galaxy Ballast - Currently set to 250w because of temp issues.
DIY 2' Duct Muffler
Sun SystemII 6" Air Cooled Hood(Pulling in air from room)
11,000 BTU Wall AC Unit (would like to run as a last resort)Something like 1280W and 12A 120V
Room Temp Avg. 75F-78F (Generally around what the outside temperature is. It will be hot this summer.)
Avg.Cab Temp When Off 75F-77F Usually +/- 1F of room temperature.
Avg. Temps When On
Avg. Bottom Temps 75F-78F
Avg. Middle Temps 78F-84F (Canopy- 12inches from glass)
Avg. Above the Light Temps. 83F.(I guess it's lower because it's not in direct light.)

Currently my cab sits around 84F-85F at the canopy withOUT AC. While the room temp is usually 75F-78F.

When running AC. In a matter of two minutes these temps are down to 66F, the second AC kicks off, temps begin to rise. By 5-8 min mark my AC has to kick back on. Temps never really get above 82F with it on. However, my problem is how often it has to run, in its energy saver mode. It kicks on about every other 5-8mins, averaging 30mins an hour. Running my setup 18/6. So it runs for 9hrs everyday. Costing me about $40-$60/month on top of what the rest of my system is pulling.

Keep in mind that these numbers are my temps while running at 250W.
I tried 400W for about 2hrs and the AC unit had to almost run constantly. Not ideal, that would increase my monthly rate to $70+.

I've purchased some seeds that should be more tolerant to higher temps, but I'd like to not be restricted to these things.

I wasn't running an intake from the room directly to my air cooled hood at first, now it's pulling in air directly from the room the cab is in and exhausts in, through the light, then in my exhaust chamber I have the line splitting off so I can still be exhausting air out of the cab at the same time. There isn't a temperature change really with the light having a direct intake with the split or without the direct intake and no split(my current setup). So I figured I would just run the split exhaust so I can still attach a carbon scrubber and cool the light without having to buy another fan. Really only makes the setup a little louder because it's pulling through 4" hole instead of the 6" hole as before.

I've considered buying a 6" inline fan instead. But that won't happen until next grow because I'd have to upgrade a few other things, plus sound is one of the main things I care about suppressing. I know bigger exhaust diameter equals quieter air flow, but that would involve cutting new holes in an already tired cabinet made from shitty materials. I run the risk of getting a new one. $100 tho, not too bad, just already a lot of money in.

I've considered getting rid of my little exhaust chamber/storage and using the full height of the cabinet. My thinking was the heat would have more height and create a further distance from the canopy. Currently I bring my plants to my light, not lowering my lights to them. So because of this my plants canopy stands at a height in which there is more heat because it has nowhere else to go. I think lowering the lights even in the current setup might help. I had originally planned on installing a pullout shelf so I can access the back of the crowded cabinet. That's why the light is at a fixed height, it would of had a shorter distance to the bottom. Although if I get rid of the exhaust chamber I can still use the shelf and lower the light.

I've been considering the value of running a sealed room and getting my self an Ice Box Chiller maybe DIY it, with a heater core, 5-10gal. res with a Peltier chiller (probe chillers?) instead of one of those expensive ones on the hydro websites. It supposed to be more efficient. It will definitely be quitter than my AC unit. Just don't know if it will be powerful enough, or will I still need to run my 177cfm fan?

Should I insulate my cab? Should I try and just use the AC for the room? My wife would not like that because she hates it being cold. I'm fighting temperatures, noise, landlords, and an already iffy wife, not to mention the setup is less than 5ft from where we sleep. Another I'm not sure about upgrading to a larger fan.

What I'm hoping to achieve is to be able to run my 400W light actually at 400W and not have to rely on my AC, only have it turn on when it gets to 82F-85F. Or at least cut my use of it in half. Also, Ideally I would like to not spend anymore money, but figure a more efficient way to rearrange my current components. If I have to buy anything new, that's kind of expensive, then I think I will save that for my next grow. I'd also like to cut out the temperature fluctuations, if possible. From 80F down to 66F then right up to 80F, spanning in total about 10mins. So every 10mins the plants are subjected to this while the lights are on. So far it seems to be ok with the up and down, just not sure it's suitable in the long run. Also probably isn't good for the AC unit either. I've order these plug-in thermostats for my fan and the AC unit. In hopes that I can shut the fan of while the AC runs, so that way I'm not sucking the cold air right out. At least extend my AC off period a little longer. I experimented with out them, just by unplugging the exhaust. It helped by 5mins+.

Check out the photos and let me know your thoughts or what you've tried.

This is an old photo, but it shows the dimensions well. Also showing the potential height if I got rid of the exhaust chamber.

View of the exhaust chamber. You can barely see the split in this photo. My AC unit hack in the bottom on the pic.

The split. Not the straightest of bends.

That 4" open duct is where I plan to hook up the carbon scrubber. At the moment it's probably one of the main contributors to my noise. But doesn't make much of a difference in temperature versus being sucked through a single line with a 6" opening at the light.






I haven't committed to a placement on my computer fans. 3 total, on a dimmer. 120mm 90cfm.
Cabs still a work in progress.

Hope I made things clear for you all. More than stoned, which probably can account for the length of this post too.

Thank you all in advanced.

FreshnGreen

What is the temperature of the room that is in?

East Coast said:

What is the temperature of the room that is in?[/QUOT

Click to expand...

Averaging about 75F-78F can get up to 80F.

Does the hood fan, cycle with the grow room temp, OR stay on while the light is on?

The inline fan stays on the whole time the light is on.

Have you considered LED? More to spend now but you'll save on power rather than increase it with air con...

Insulating your grow will help. Can not help but to think, that custom wood is like being a heat sink, from sitting in the main room?

The photo that is showing the split, what does that do? A 90 degree split - not causing a vortex or something stupid like sucking or doing nothing at all?

You are running the lights at night?

Your exhaust vented back into the room isnt going to do much good without the air conditioner on 24/7. Vent it somewhere els or take air from somewhere els.
If you increase the diameter of your cooling ducts you can reduce turbulent noise and increase the volume of hot air exchange.
I would upgrade your cooling fan because when your plants get tall, that is going to be a ton of light and heat up there! Also, upgrading will ensure minimal loss through a carbon filter.
Sorry if i missed it, is this passive ventilated?

Correct on venting into same room as problem. With your setup you NEED to vent heat from light AND from cab. You have ( looks like ) a passive vent in upper corner for venting of fan area but NOT from " cab" area . This enclosed area where fan and ducting are becomes a " pocket " for heated air to accumulate.

I reccomend cutting away top shelf ( leave small ledge for inline fan ) " open up " the cab so any trapped heat can be exhausted. You need to PULL heated air out and either PULL air passively or with A/C hookup as needed. I would put a cylindrical inline ( 6" ) as a top down vent and tube it out window ( maybe from that existing vent ) since that shelf area can be opened and exhausted.

Something like this ...

Scrubbing at exhaust may be needed. Dust shroom or DIY Canister attached to inline from cab .
Maybe a little Mylar at back of cabinet and sides would help maximize reflective characteristics.



Good luck.

Budzbo is correct, i should have mentioned that. The air in the hood will have a less air density (expanded air) then the bottom of the cab. Heated air = less air can fit in a given volume. While your intake and exhaust can be at 200cfm, your exhaust through the hood will not have the same CFM displacement because less air molecules can fit. The hotter your intake temps get, the harder it is to recirculate fresh air.

Now that i think of it, can you pull air from outside? I mean your one step away from a 4" hole by that a/c system. It will save you a ton on electric for that little cab. Another thing, do not block vents any more then the width of the vent! If you have a 4" vent do not put it any closer then 4" to the wall or anything els, as this will cause a major volume loss through the duct.

I have 8 of these and i have been using 2 24/7 since febuary. http://www.amazon.com/Electronics-PFC1212DE-120x120x38mm-Cooling-252-85/dp/B004Z29YOM you will need 65 watts per fan. And sorry, but they are much louder then the seller list them, sounds like i live in a damn 747. Buy some 5/6" ducts and mount the fans in the grow box and have them come on with the light's. When the lights go out, you can get away with just 100cfm.


Btw, take your ferts out of the light lol

Uzzi said:

Have you considered LED? More to spend now but you'll save on power rather than increase it with air con...

Click to expand...

I considered LED awhile but decided to just go with an HPS. I think money was the deciding factor and I wasn't sure about the results, but that was a couple years ago when I bought my light.

East Coast said:

Insulating your grow will help. Can not help but to think, that custom wood is like being a heat sink, from sitting in the main room?

The photo that is showing the split, what does that do? A 90 degree split - not causing a vortex or something stupid like sucking or doing nothing at all?

You are running the lights at night?

Click to expand...

I think next grow I will buy some insulation board and then but the panda film over it. The split allows me to still pull air through my light which has a direct intake from outside the cab, while still pulling air out of the cab, albeit at a weaker rate. I don't believe it's causing a vortex or anything like that. I put my hand under it and I feel it still pulling pretty well. Also when my cab is all velcro'd down I get a good amount of negative pressure. It is definitely helping, I'm just not sure it's at its full potential. I don't run my setup at night because it's in my bedroom and my wife wouldn't like that. I think I would be fine temperature-wise if I was able to run it at night, but oh well, just glad to be growing.

SPLFreak808 said:

Your exhaust vented back into the room isnt going to do much good without the air conditioner on 24/7. Vent it somewhere els or take air from somewhere els.
If you increase the diameter of your cooling ducts you can reduce turbulent noise and increase the volume of hot air exchange.
I would upgrade your cooling fan because when your plants get tall, that is going to be a ton of light and heat up there! Also, upgrading will ensure minimal loss through a carbon filter.
Sorry if i missed it, is this passive ventilated?

Click to expand...

I wish I could exhaust and/or pull in air from some other location. The best I can do in regards to pulling in air from the outside, (which my cab is right next to the window) is having a hole cut in the side of the cab and opening the window to suck in air.(which is basically how I'm already pulling in air to my cooled hood) I can't put anything on my window, at least nothing that looks like ventilation. If I could figure that out, maybe I could pull it off. No exaggeration, the recycling bins for the whole complex are 6" to the right of my window. Unfortunately the driveway and side of the adjacent apartment complex are right outside my window. Kind of hate where I live, but the market sucks. And my wife wouldn't be cool with me running a length of ducting out our bedroom into the living room. Which is about the only other option.
I know I can get a used 6" inline fan somewhere in my area, I'll probably go with that and hope to box it in like my 4" for sound.
By passive ventilated you mean? I have passive intakes, other than when the AC kicks on. (x2)8"x8" darkroom louvres. The cab gets air pulled out of it through the split, a 4" opening in the top right corner. The fan is pulling air to cool the hood and exhaust air out of the cab. Then it's all getting pushed out the top through a duct muffler. Had to push out the top because I can't have wind blowing on my vertical blinds constantly, and I used to have it blowing out the back, but that made a lot of noise because it was hitting the wall behind it.

Budzbuddha said:

Correct on venting into same room as problem. With your setup you NEED to vent heat from light AND from cab. You have ( looks like ) a passive vent in upper corner for venting of fan area but NOT from " cab" area . This enclosed area where fan and ducting are becomes a " pocket " for heated air to accumulate.

I reccomend cutting away top shelf ( leave small ledge for inline fan ) " open up " the cab so any trapped heat can be exhausted. You need to PULL heated air out and either PULL air passively or with A/C hookup as needed. I would put a cylindrical inline ( 6" ) as a top down vent and tube it out window ( maybe from that existing vent ) since that shelf area can be opened and exhausted.

Click to expand...

I think I'm confused or I didn't make it explain my setup very well. Sorry. I have my fan on a split that's separately pulling air from the cab and then it's also pulling air through the air cooled hood from outside the cab. I don't however, as you said, have ventilation for the heat that builds up in the exhaust chamber(the top portion), I can cut some passive holes in the back and let the air flow out on its own or throw one of my CPU fans in there. If i'm understanding you correctly.

Budzbuddha said:

Something like this ...

Scrubbing at exhaust may be needed. Dust shroom or DIY Canister attached to inline from cab .
Maybe a little Mylar at back of cabinet and sides would help maximize reflective characteristics.

View attachment 3398679

Good luck.

Click to expand...

You don't think I'll be able to scrub before my fan? I thought maybe I could attach it where the split is exhausting air. Or if I put it before the light I thought about running a 90* ducting off the front of the light towards the back of the cabs interior, there's some space there for a small scrubber.

According to your diagram I would be pushing air out from the fan that down the line meets up with a Y connector joining a passive ducting line coming from the cab? Would the force of the air being blown out cause a slight(or bigger) pull when it blows by the opening and out to the different pressure outside? Since I can't attach to my window, the best I could do is place the exhaust at the open window behind the vertical blinds which would then just be blowing constantly smacking around, plus I don't want to run the risk of venting out into the area where everyone who lives in my complex has to drive pass. I don't think it works. I do wonder if there is a way I can somehow use the whole cut in the wall for the AC Unit. If I pull it out you can see that it's not in it's protective cover, which would draw attention, but maybe there's something I can do with it. I however don't really have a clue.

Also is scrubbing at exhaust still as effective interns of odor control?

SPLFreak808 said:

Budzbo is correct, i should have mentioned that. The air in the hood will have a less air density (expanded air) then the bottom of the cab. Heated air = less air can fit in a given volume. While your intake and exhaust can be at 200cfm, your exhaust through the hood will not have the same CFM displacement because less air molecules can fit. The hotter your intake temps get, the harder it is to recirculate fresh air.

Click to expand...

This makes sense. Basically, I just need cooler air to be pulled through the hood. When it's cool outside, I open the window all the way and crack my blinds and have the 6" intake that goes to the hood pulling in air from the outside, it's about 12" away from direct widow contact, the AC unit prevent me from pushing it closer to the window. I could, maybe, if it's stealth enough, put a length of ducting from the cab just up to the window and then still exhaust into the room?

SPLFreak808 said:

Now that i think of it, can you pull air from outside? I mean your one step away from a 4" hole by that a/c system. It will save you a ton on electric for that little cab. Another thing, do not block vents any more then the width of the vent! If you have a 4" vent do not put it any closer then 4" to the wall or anything els, as this will cause a major volume loss through the duct.

I have 8 of these and i have been using 2 24/7 since febuary. http://www.amazon.com/Electronics-PFC1212DE-120x120x38mm-Cooling-252-85/dp/B004Z29YOM you will need 65 watts per fan. And sorry, but they are much louder then the seller list them, sounds like i live in a damn 747. Buy some 5/6" ducts and mount the fans in the grow box and have them come on with the light's. When the lights go out, you can get away with just 100cfm.


Btw, take your ferts out of the light lol

Click to expand...

It's the damn reducer that's making the 4" ducting kind of smash agaist the wall of the cab just off the light. I've been thinking, if I upgrade to the 6" fan(almost inevitable) I can run all 6" ducting and avoid losing all that length off the light to the reducer. I couldn't find a shorter reducer. I actually had to modify the one coming off the exhaust onto the duct muffler because I need the space. I need a 6"-4" collar reducer, if something like that exists.

Instead of buying new CPU fans, those are must higher CFM than mine, but I have 3 90CFM 120mm fans. Think I could use them in that situation. I'm having a hard time imaging the setup you're referring to with the 5/6" ducts, do the fans go inside the ducting and then the ducting get fitted into a top of the cab? Thanks on the fertilizer bit.



Thank you all for you time and input so far. Much appreciated.

Would the dust shroom be in addition to a carbon scrubber or can it control odor on it's own?