Struggling with heat/low humidity air flow issue

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FentonsBalls

Member
I am growing in a hot attic it measures around 4mx2.5mx2.5m (lxwxh)

I am running 6x630w cmh lights

Passive intakes

8inch isomax fan

Temps getting up to 36 degrees

Humidity is like 10 degrees


I am wondering do I buy a 10 inch high power isomax 2430cmh will this solve my problem? (I would also put in two misters on a controller)

Any help is very appreciated

Thanks
 
coreywebster

coreywebster

Well-Known Member
I used to have an 8" Isomax , good fan but I wouldn't buy one again, not really quiet for the money.
Get a hurricane or gecko box fan, 12" and get an intake.

You really need to shift a lot of air to run that much in a hot attic.

I know folks run two 600hps in attics in uk and need massive airflow to do the job.

Where you venting the heat to?
 
coreywebster

coreywebster

Well-Known Member
FentonsBalls said:
Effectively yes, it is very well sealed though
Click to expand...
Still a massive impedance on the fan though, going to be restricting the airflow and making the fan work hard.

Personally I like to tap into a disused chimney. If not that then a series of roof vents.

Problem is you really need about 4000m3ph fan assuming a summers day is 25 degrees c and that would probably blow your roof off.
 
Renfro

Renfro

Well-Known Member
If you put one of these massive swamp coolers in one end of the attic and have a open gable vent on the other you might get your temps and humidity numbers to a workable area. But if the humidity spikes outdoors (rain) then your swamp cooler won't cool as well but humidity will get way to high for flower.

swamper.PNG

Really though you are fighting such extremes that you will run into problems and end up hauling all the gear back down from the attic lol.
 
Renfro

Renfro

Well-Known Member
UK? Don't you have higher ambient RH%? Swamp coolers really only help if the ambient air is dry. They cool the air by adding cool water content.
 
F

FentonsBalls

Member
Hmmm I believe airflow may solve the issue alone, I mean ambient intake temps outside the room don't go above 24degrees it's just getting someone with a better know how of airflow to help balance these.

Most recent grow pulled off just over a gpw with 600hps in euro reflectors
 
coreywebster

coreywebster

Well-Known Member
FentonsBalls said:
UK pal
Click to expand...
Yeah I thought so from the Isomax fan.

If you have the luxury of owning the house and have disused chimney that's not falling to bits then that would be my first choice.

Don't know if its possible to air cool 630 cmh, but if its workable then that going to help.

After that an evaporative cooler can help with both humidity and some of the heat.

Cant understand why its 10% rh though. In UK.


Ive set up a lot of attic grows, but on the slightly smaller scale and always had the option of many roof vents or chimneys.
 
coreywebster

coreywebster

Well-Known Member
End of the day airflow would be enough with ambient of 24c , but its such a lot of airflow and such a restrictive method of extraction you currently have.

It will take 4200m3ph extraction to stay 5 degrees f above ambient with that wattage.

Maybe find a happy medium taking out a couple of lights in summer and still increasing extraction.
 
Renfro

Renfro

Well-Known Member
The swamp cooler is a massive blower and can be run with the pump on or off. So it could really bring in a LOT of fresh air and if you want it will also humidify the air. You will want an "open window" to maximize flow (passive exhaust 2.5x the intake area).
 
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