Who wants to help me design and cool two 4k rooms with passive air?

[spaceboy]

Hi everyone,

I just purchased a 4k flip flop setup called a purgro and Im trying to figure out how I'm gonna cool this thing. Im not able to seal these room atm so Im wondering what I would need in order to cool these with just passive air. It would be a lot easier to buy a few extra fans rather than two ACs.


The rooms are both 13 x 8 x 7 and both have a lung room attatched to them and this is where the air would have to be exhausted out of house as niether room has a window.

So just to recap 2 rooms 4k each 13 x 7 x 8. And they both will have to exaust into lung room which has one small window. How many fans/cfm would I need in each room and also what setup would u all recommend with the lights. Plant count is 48. Thanks for any knowledge u guys can drop on me here

 

[Skunkxx]

good luck
I am running 3K in a room about that size and my small fan and small a/c works good.Outside temp does chnge how I run it ,,
Peace Out
Good Luck
Skunkxx

 

[spaceboy]

Thanks skunk. How many btu is the ac that you are using?

 

[flat9]

I'm sure DHF will chime in on this one and tell you that you likely want another 1k (50 watts per square foot), and air exchange at least twice per minute.

My guess is you're looking for at least 1500 cfm inline fans for each room, and most likely more if your duct-work has to take some twists or turns in order to exhaust.

I have two 8 x 4.5 x 6.5 rooms and both use 550 cfm fans w/ 1800 watts and things stay stable around 80 degrees, which is pretty much ideal for cannabis cultivation anyway (see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550641/, and also read about VPD to get humidity in the right region); I'm able to run 2400 watts which I'd prefer, but it requires an active intake fan to come on once in a while, and very rarely this will trip the circuit breaker (don't have a lot of amps to play with), so for the time being I'm just using 1800 to my chagrin.

Now I cannot say whether things scale linearly -- i.e., just because I'm able to do passive doesn't mean if we multiply the numbers by a constant to get to your numbers that you will be able to do passive. But yeah, maybe start w/ around 1500 cfm to 2000 cfm and see what happens when you've got all the bare bulbs running. Keep in mind that the plants themselves will reduce the airflow a bit, so make sure those temps are easily controlled during your test run.

 

[flat9]

Also keep in mind what the temps are for the passive air intake and how they may change over time...

 

[DabOnDabs]

Depending on your climate, You may find it almost impossible to run 4k with passive air only. You may be able to get away with it at night, but I'm assuming this is a flip flop and there will be one room on during the day.

Even if you are somewhere thats cold as fuck, you're gonna need a ton of air exchange to keep the temperature down...This means humidity will likely drop to <30% and you'll have VPD issues.

SO;

You either need fans + foggers, or A/C's, Dehueys, and CO2.

I've tried to do shit on the cheap myself, but when it comes down to it, I wish i would have skipped on the extra ballasts/lights, and invested the money into one smaller room w/ all the bells and whistles.

BUT; there's always room for an upgrade.

edit; And flat9 hit the nail on the head. Any dialing you do is gonna need to be adjusted EACH and EVERY time outside temperature/humidity fluctuate outside of a given range. Its a bitch, but doable; Also, keep in mind we're finishing off winter grows right now...Spring and summer are just around the corner, and when it comes to an 8-12 week flower cycle, you can bet your ass by the time you have shit set up and pumping, its gonna be hotter than a dog dick sandwich outside....Passive + 4k watts + Summer = gang of issues

 

[DHF]

Depending on your climate, You may find it almost impossible to run 4k with passive air only. You may be able to get away with it at night, but I'm assuming this is a flip flop and there will be one room on during the day.

Even if you are somewhere thats cold as fuck, you're gonna need a ton of air exchange to keep the temperature down...This means humidity will likely drop to <30% and you'll have VPD issues.

SO;

You either need fans + foggers, or A/C's, Dehueys, and CO2.

I've tried to do shit on the cheap myself, but when it comes down to it, I wish i would have skipped on the extra ballasts/lights, and invested the money into one smaller room w/ all the bells and whistles.

BUT; there's always room for an upgrade.

edit; And flat9 hit the nail on the head. Any dialing you do is gonna need to be adjusted EACH and EVERY time outside temperature/humidity fluctuate outside of a given range. Its a bitch, but doable; Also, keep in mind we're finishing off winter grows right now...Spring and summer are just around the corner, and when it comes to an 8-12 week flower cycle, you can bet your ass by the time you have shit set up and pumping, its gonna be hotter than a dog dick sandwich outside....Passive + 4k watts + Summer = gang of issues

Active intakes with air exchange twice per minute is yo friend guaranteed....

Dabs and Flat gotchas covered , but 50 watts per sq ft and 70% RH till end of stretch will make bitches explode.....I can see I`m not needed cuz my boys got this , but holler back if we can help......

Retired old fart that mostly fishes these days , but I check on Vert-ville every couple days or so......

Good luck SB....

Peace....DHF...........

 

[DabOnDabs]

Haha you've preached and preached... The choir is in full effect

 

[flat9]

Sorry to hijack the thread but while we are on the topic of flip rooms, does anyone know of a cheap flip box for 8 lights? For the prices I saw, it was actually about the same price to just buy 4 new 600 Watt hps systems... Which is preferable in that you'd let the ballast chill out for 12 hrs a day... I think it was about 5 Benjamins for the 600 Watt systems and 4 Benjis for the flip box (sans fixtures and bulbs), in which case I'd just take the bulbs and ballasts.

 

[DHF]

Sorry to hijack the thread but while we are on the topic of flip rooms, does anyone know of a cheap flip box for 8 lights? For the prices I saw, it was actually about the same price to just buy 4 new 600 Watt hps systems... Which is preferable in that you'd let the ballast chill out for 12 hrs a day... I think it was about 5 Benjamins for the 600 Watt systems and 4 Benjis for the flip box (sans fixtures and bulbs), in which case I'd just take the bulbs and ballasts.

I always used twice the ballasts and bulbs too Flat , just cause I was away from said setups for a week at a time , and it was redundant insurance for my old ass to have EACH ballast on it`s OWN timer couple minutes apart so power surges weren`t as noticeable down here in Hell....

The very reason I began flip rooms every 12 hrs was so amperage draw would be as close to consistent as possible 24 hrs a day for the powerbill and LEO , and trust me...

Contactors wear out and flip boxes fail.....bet on it.....When ?......Only God knows , but livin and growin onsite helps a lot as far as makin sure shit works and is maintained on the reg.....

Flip boxes are fine for what they do , especially for larger commercial setups , just always remember that EACH bell and whistle added to your situation is 1 more thing yas gotta stay on top of....and lastly....

There are MANY electronic ballasts that won`t "flip" per se and end up damaging the bulbs AND ballasts , so do your homework before ploppim down buncha cash guys.....anyways....

Sorry for the hijack as well , but thought it pertinent to respond....

Peace....DHF..........

 

[frankenstein2]

I'm cooling a room with 4k worth of hps and 900 watts of t5's right now. I have 4 of the 500 something cfm fans jamming all the time. Before I say how I have it set-up, know that this is far from ideal, but it works. I have a fan bring air to my lights from outside the house. Then each set of two lights has it's own exhaust with a fan pulling air thru them and out of the room thru filters. That takes up 3 of my fans. The last fan pulls air directly from outside and dumps it in the room. Doing it like this allows me to use co2, and temps in the room never get above 85. This is strictly my winter set-up. In late spring and summer the fan that dumps cold air in the room is reversed to suck hot air out of the room from a 12,500 btu standing ac unit. It works for me, and I have ALOT of bends and curves in the ductwork just to let ya know.

 

[Mister_D]

Dabs pretty much nailed why I don't bother with intake/exhaust rooms any more. My suggestion is to buy an a/c good for 4K + equipment (18-24K btu, depending on your outside climate and insulation), 4 bulb/sockets (instead of 8, use the extra money for the other equipment I listed), some form of co2 enrichment (tank, or burner), and a dehumidifier. Run just the 4k for a harvest then buy more lights and equipment when you have money for proper upgrades.

 

[DabOnDabs]

I always used twice the ballasts and bulbs too Flat , just cause I was away from said setups for a week at a time , and it was redundant insurance for my old ass to have EACH ballast on it`s OWN timer couple minutes apart so power surges weren`t as noticeable down here in Hell....

The very reason I began flip rooms every 12 hrs was so amperage draw would be as close to consistent as possible 24 hrs a day for the powerbill and LEO , and trust me...

Contactors wear out and flip boxes fail.....bet on it.....When ?......Only God knows , but livin and growin onsite helps a lot as far as makin sure shit works and is maintained on the reg.....

Flip boxes are fine for what they do , especially for larger commercial setups , just always remember that EACH bell and whistle added to your situation is 1 more thing yas gotta stay on top of....and lastly....

There are MANY electronic ballasts that won`t "flip" per se and end up damaging the bulbs AND ballasts , so do your homework before ploppim down buncha cash guys.....anyways....

Sorry for the hijack as well , but thought it pertinent to respond....

Peace....DHF..........

Even with the ballast that have the hot start prevention, and delay/sequential starting; Its only a matter of turning them off before you flip the load... You can get away with any ballast, any model etc, as long as you have a good cycle timer handling the time.

 

[DabOnDabs]

Dabs pretty much nailed why I don't bother with intake/exhaust rooms any more. My suggestion is to buy an a/c good for 4K + equipment (18-24K btu, depending on your outside climate and insulation), 4 bulb/sockets (instead of 8, use the extra money for the other equipment I listed), some form of co2 enrichment (tank, or burner), and a dehumidifier. Run just the 4k for a harvest then buy more lights and equipment when you have money for proper upgrades.

I just wanna throw it out there;;; I used a 15k btu window banger for two summer grows in CO, bare bulb, 4kw. IT can be done on the semi cheap...

It probably costs more to run that son of a bitch than a mini split would have in the first place tho

 

[DHF]

Even with the ballast that have the hot start prevention, and delay/sequential starting; Its only a matter of turning them off before you flip the load... You can get away with any ballast, any model etc, as long as you have a good cycle timer handling the time.

As I said above , if yas live onsite , flipboxes are fine but contactors burn out.....at some point in the game.....and we`re only talkin bout a 4 light setup from the get , so really.....a flip box ?....and yeah....

I understand all about how to cut the ballasts off and then cut em back on again with cycle timers Dabster , but they`re still not meant to be run that way and it will shorten ballast AND bulb life guaranteed.....

But WTF.....If you`re rockin 60 lights on 30 ballasts , then Hell yeah yas can afford ta swap out bulbs EVERY run and ballasts every 4th run like some of my left coast bro`s roll with , but again....

We`re talkin bout a lil `ol 4K setup , and the OP wants ta cool it with passive intakes that ain`t gonna happen , so that`s the only reason I came here was to reiterate air exchange twice per minute with "active" intakes SINCE there`s already a Lung room in place to facilitate said cooling.....but....

Dbro`s right as well with sealed and CO2 supplements , but I gotta step up and say since the lungroom`s already there , roll with it and put oversize a/c , foggers , and dehuey in lungroom and pump in and suck out perfect environment 24/7....and....

My fliprooms always had aux a/c and dehueys in each grow area for insurance , like a/c for deep summer if lungroom couldn`t keep up , and dehuey`s for the lights off rooms in late flower to offset conditioned air in and out the rooms.....anyways....

My 2 cents from all them yrs....

Peace....DHF........

 

[Skunkxx]

Alot of good info here. I think my A/C is 3500 BTus.i had it on my boat for sometime.
Its one of the samest window units I could find.
Good Luck
Peace Out
Skunkxx

 

[flat9]

I always used twice the ballasts and bulbs too Flat , just cause I was away from said setups for a week at a time , and it was redundant insurance for my old ass to have EACH ballast on it`s OWN timer couple minutes apart so power surges weren`t as noticeable down here in Hell....

The very reason I began flip rooms every 12 hrs was so amperage draw would be as close to consistent as possible 24 hrs a day for the powerbill and LEO , and trust me...

Contactors wear out and flip boxes fail.....bet on it.....When ?......Only God knows , but livin and growin onsite helps a lot as far as makin sure shit works and is maintained on the reg.....

Flip boxes are fine for what they do , especially for larger commercial setups , just always remember that EACH bell and whistle added to your situation is 1 more thing yas gotta stay on top of....and lastly....

There are MANY electronic ballasts that won`t "flip" per se and end up damaging the bulbs AND ballasts , so do your homework before ploppim down buncha cash guys.....anyways....

Sorry for the hijack as well , but thought it pertinent to respond....

Peace....DHF..........

Cheers. For the record, I think w/ digital ballasts you have to use a timer to flip them off 5 minutes before the flip, and then flip them back on 5 minutes after the flip, such that their detection circuitry doesn't think something has run amok when the flip occurs. As far as I understand it, this is actually a useful feature of the ballasts in that if a bulb dies, it isn't trying to supply power to an open circuit.

At any rate, I'm not gonna use them because it was actually cheaper for me to just get new bulbs, fixtures, and ballasts, which surprised me. Seems like it's just a bunch of relays, no?

Finally, I'm doing exactly what you're doing -- just setting it up w/ timers. Though I'm running 600s, and I'm using two to each Hydrofarm digital timer, which are all synchronized (when I program their time). Try to get a good sixty seconds between firing up another 1200 watts.

Now that I've totally hijacked the thread, back to the original poster. Is this the device you got?

http://www.purgro.com/ballast.html

Maybe you can just purchase another 1K ballast and a single light flipbox (or alternatively two 1K ballasts) and go from there to get up to 48 watts/sq-ft. Actually that thing you purchased kind of scares me -- seems like your light cycle is fucked if there's a failure of any sort!