Sizing a dehumidifier

[ruwtz]

Brand new grow facility, flower room measures 10 x 12 x 10ft high. Running sealed w/ four 750DE Gavitas + CO2 + 2-ton AC. Everything fitted except dehumi as I wanted to size it based on running room tests.

Outside RH % runs in the 50's (temps high 80's F), inside humidity currently at 65% steady with AC running to keep temps between 73-75F. No plants are in this room as yet. AC is pulling some condensate but humidity doesn't drop noticeably.

See what you make of my calcs here, based on the assumption that plants will transpire 99% of what they are fed:

Flower room will max out at 16 plants drinking 1 gallon per plant every other day, so 16 gallons to remove. 8 pints to a gallon = 128 pints. AC may handle 20% of this (25 pints), leaving 102 pints or 51 pints per day.

So, am I shopping for a 50 pint dehumidifier here or am I way off with something here?! I'm inclined to size up by one more for best efficiency, just depends on price at this point as budget is blown.

Also, since warm air holds more moisture and heat rises I plan to rig it as high as I can without tearing the wall down with the weight of 50 pints. Anyone else running sealed doing a similar thing???

 

[Carolina Dream'n]

Quest105 Dual Dehumidifier. Most efficient on the market watt for pint.

 

[ruwtz]

Quest105 Dual Dehumidifier. Most efficient on the market watt for pint.

Whoa that looks awesome... wall mounted, excellent capacity and top notch efficiency. Sucks I can't afford it right now, will file this under future upgrade though. Thanks!

 

[Carolina Dream'n]

Yea they are not cheap.

I honestly feel like they pull more than 105 pints a day. I've had one run a 12'x18' grow with a 9'x12' canopy space for about 2 weeks when the other in the room quit working.

 

[ruwtz]

Do you pump the condensate out or just collect every day?

I bet thats just about the purest water going too.

 

[Carolina Dream'n]

Do you pump the condensate out or just collect every day?

I bet thats just about the purest water going too.

It's got a condensate line. No pump, less to break. Mine goes straight into my Rez.

 

[ruwtz]

I know not to trust manufacturer ratings as they're not exactly speccing to what we use this gear for. I read they rate capacity with 80F / 60%rh conditions.

Maybe i'm still too small going with a 70pint? I expect the AC will help during the day but not for night time spikes, and I especially don't want this to be a problem for late flower ripe.

What do you sealed folks reckon?

 

[ruwtz]

My feeding calcs above may be way off so feel free to pull me up if you think so...

 

[ruwtz]

Another crucial thing is hygrometer accuracy. I have multiple digital devices all around the room and the sway between them all is pretty dramatic, like +/-10%. Is humidity really that hard to measure, or do I just have bad units?? I will probably calibrate everything with salt before anything goes into flower, but still.

I expect most dehumidifiers have built in sensors, but does anyone run theirs on a humidistat controller at the wall at the same time?

 

[ruwtz]

K rambling over now, lol.

 

[ruwtz]

Anyone for anything?

 

[since1991]

Yea they are not cheap.

I honestly feel like they pull more than 105 pints a day. I've had one run a 12'x18' grow with a 9'x12' canopy space for about 2 weeks when the other in the room quit working.

Or Sante fe Classic...the one i use anyways. Quest wasnt around or i hadnt heard of Quest when i picked up a Classic from Sante fe. Now that Quest is established i would go with them. Same thing really....you want a commercial dehuey to do the job you need it to do. Dont cheap out on 50 and 70 pint grandma basement dehueys from Home Depot....trust me. Same with air conditioners. Been there...done that. Trying to save initial cash by buying junk never works. Those cheap appliances cannot handle the job first off....and you will be paying more to operate them anyways.

 

[ruwtz]

Or Sante fe Classic...the one i use anyways. Quest wasnt around or i hadnt heard of Quest when i picked up a Classic from Sante fe. Now that Quest is established i would go with them. Same thing really....you want a commercial dehuey to do the job you need it to do. Dont cheap out on 50 and 70 pint grandma basement dehueys from Home Depot....trust me. Same with air conditioners. Been there...done that. Trying to save initial cash by buying junk never works. Those cheap appliances cannot handle the job first off....and you will be paying more to operate them anyways.

Truth / Good advice and I would take it except I literally have no budget left for a decent system at this stage. Nada. Will have to drop on something ok and upgrade at a later date.

 

[since1991]

If yer gonna fork over the bucks for high end commercial double ended hps lamps designed for serious indoor/greenhouse gardening....go with Quest/Sante fe dehueys and Mitsubishi (or any other HIGH seer rating and quality - careful - there is junk out there) mini split air conditioners.

 

[since1991]

Truth / Good advice and I would take it except I literally have no budget left for a decent system at this stage. Nada. Will have to drop on something ok and upgrade at a later date.

After the first banger.....grab them commercial grade appliances. ...and never look back. Trust me. I been where your at rite now. Good luck

 

[ruwtz]

If yer gonna fork over the bucks for high end commercial double ended hps lamps designed for serious indoor/greenhouse gardening....go with Quest/Sante fe dehueys and Mitsubishi (or any other HIGH seer rating and quality - careful - there is junk out there) mini split air conditioners.

We'll get there for sure!

 

[The Hippy]

Yup why loose it all to humidity. It's pretty important to take care of it or it can screw your crop completely. Then you loose everything.
I just bought a quest 205...big boy for big work.
As said above if you've got the Gavita's you need a commercial grade unit. The home units seem to last a year or two...then they fark up.
Not too mention overkill can be a good thing sometimes.

 

[ruwtz]

OK so i'm set for a commercial unit, I've ran the numbers on efficiency and running costs and they prove themselves all the way. Not that I didn't believe you guys or anything, I just like to prove it on paper too.

Quest and Santa Fe appear to be the same manufacturer with different badges, but only Quest will warranty for grow ops. They clearly add that into the price though and as much as I want it I really can't stretch to the Quest 105 right now.

Anyone running with the Santa Fe Advance 2? Decent price here and free shipping: http://www.sylvane.com/santa-fe-advance-dehumidifier.html

309CFM, 90 pint, 640w = 6 pints/watt. At $1,4k I reckon I can stretch.

 

[Carolina Dream'n]

I paid 1600 for my quest 105. Shop around before settling with the less efficient SantaFe

 

[ruwtz]

I paid 1600 for my quest 105. Shop around before settling with the less efficient SantaFe

Thats a good deal. Any tips on where? Or case of "Google is your friend?"