I didn't think I'd be back visiting this thread this quick, but the older I get the faster the world spins around me. We've encountered yet another issue, and it's a doozy.
Being an HVAC guy, I thought I pretty much had an edge when it came to conditioning an environment, as I have conditioned hundreds and hundreds of unique dwellings, however 128 females 2 weeks into flower releases far more water into the air than this country boy ever imagined, and I've grown my share indoors, just NEVER to this degree.
So what's a country boy supposed to do? More research and a little math. Follow along.
Two weeks into flower and the girls are sucking up over 40 gallons of water and nutes every 24 hours. This means 97% of that 40 gallons is ending up in the air and causing more humidity than we can deal with, and I still haven't kicked the lights up. We need more dehumidification, and those home units simply don't cut the mustard.
Our Ideal commercial unit extracts about 70 pints a day. the two home unit we have, maybe realistically 35 pints a piece, meaning we are extracting 150 pints a day or less, yet the plants are transpiring more than that.
We need more dehumidification, and they aren't cheap. I went digging around and found a listing for a large commercial dehumidifier, with one caviot. Well, maybe two. First up, it comes on but didn't dehumidify. 2nd, it's used for drying out wet environements, no so much grow rooms and it has two settings. Off and on. However, it was dirt cheap (about 3600 bucks new). A road trip and 200 bucks and we owned it.
Now, on first look one would think this unit would pull out a good 200 pints a day, right? Yes and no. It will remove 200 pints a day, under a 90 deg ambient and 90% rh, something NO grow room will ever see. Kind of misleading and they ALL do it. Almost anyway. When we wind it down to more realistic figures, this unit will extract right at 135 pint every 24 hours with an 80 deg ambient and 60% rh, much more real-world for us.
After opening her up and performing a little diagnostic work, I found an integrated relay on the control board that powers the compressor and wasn't working. The board cost as much as I paid for the unit, so I developed a work around and fired her up.
This added an easy 135 pints of removal to the equation, and on the cheap! I'll add humidity control using one of these digital humidistat. It's based on the same platform as the temp control I used for the Happy Chiller, and it was only 25 bucks.
That's the good news.
Now for the bad.
It still isn't enough to get me to my comfort zone between 40% and 50% rh, and it's only going to get worse when I crank the lights up. We now have the ability to remove around 270-280 pints per 24 hrs. That should do it.
But it didn't. I need to be able to remove close to 400 pints a day. Talk about hindsight. There are two ways to figure your needs in the grow room. Here they are for your amusement:
1st. Figure how much water your feeding every 24 hrs. Bingo! There's your answer, because most of that water, (97% of it) ends up back in the air in the form of humidity that needs removed.
2nd. Figure each light to 10-12 pints a day times however many lights you have. Either way you calculate it, the answer is pretty close. We are in a bit of a pickle.
I spent the last few nights researching a fix, and there isn't an easy or cheap one available. The best I've came up with, and the unit I'd invest in would be a Quest, hands down. Quest not only represents their products removal ability using a real world grow room formula, but they also break it down into how many pints of removal per KW hour. They ARE the most energy efficient units that I am aware of, and they aren't cheap.
Our room, for a final fix needs two Quest 225 units, something I NEVER would have imagined a 40x22 room could ever require, but the numbers don't lie. Talk about hindsight.
Our plan is to try and scrape up enough moola for one Quest 225. This, with what we have already should get us through this grow, then we need to purchase another one for a final fix. One on the north end and one on the south end, both ceiling mounted.
When the stars align for a solution, I'll chime in. Until then, the show must go on, and our mother/veg room has over 150 clones ready for Stage ll veg, and those tables, while basically built aren't painted and don't have the hydroponic plumbing ran, so while Happy Santa was busy spreading the girls legs in the flower room (that sounds kinda bad, huh?) I got to painting.
We increased to size of all the returns on the hydroponic tables to 2 inches. The 1.5" we ran in the flower room is really too small to carry a 30 foot row of plants. Lessons learned. Even though these tables are only carrying 12 plants each in 5 gallon buckets and 2 inch is kind of overkill, it will make transfers from Stage ll veg to flower pretty seamless.