New Grow room

[Potted]

That’s my only concern with a dehumidifier,the heat it gives off,hope u find a way to vent🤞

[oldjarhead100]

Funny you should mention that when I went down yesterday it was 90 in my room ,so I modified my dehumidifier to vent out the room ,I also was looking at room ac the ones you vent the hot air out of the room by a hose big money though. I was missing a hose clamp for the flex hose so after I got one I redid the duct work so its tighter and straighter

[hycheese]

Did you verify that you are not exhausting your "conditioned" air? Generally, newer dehumidifiers use 2 stacked back to back coils - the humid air flows through the first which is the cold evaporator then continues to flow through the second one which is the hot condenser then back into the room minus the moisture. I don't think you can separate them unless it is an old style using a worm coil.

[oldjarhead100]

as long as it pulls the moist air from the room I dont care if conditioned air goes back

[Potted]

Nice install, do u have a drain hose so u don’t have to empty the reserve manually?

[oldjarhead100]

yes I do have a drain hose that was the problem with the 30 pint one it would not drain by the hose

[oldjarhead100]

well I have more to do with dehumidifier maybe ,I'll know in a few I set up the DH so hose would drain but I think I had it to close to the wall and it didnt get good airflow ,I hope that had something to do with the excessive heat I vented the exhaust from the DH just out into my cellar now I think I'll have to run a vent to the outside , If I cant get temps down the dh just isnt going to do what I need and will go to a AC unit I can vent out of the room .

So I went nuts yesterday and taped up the backs of my receptical boxes and wrapped my exhaust duct fro the light ,wrapped duct from DH with flexible insulation to try and get more heat out of room, after I did all this I was wondering what else I could do (After lights out I stepped in room and checked for light leaks ) I just dont know why these plants wont go into bloom

All the things I did yesterday was to block possible light leaks but I have bloomed plants in the room before with no problems WTF I will have to go down early tomorrow and see when lights do come on at the right time and not early .Don't know what else to do

[Chefbjy]

Man ojh do you have a fancy timer? I have one I can set 7 different times 7 different days with continued runs on some days. And try what Campesino says 13off or even 14 I finished a flowering cycle with 14hrs dark before I put them in the dark.

[PuravidaC]

I read awhile ago that Ed Rosenthal has said if he could change one thing in his grow bible that it would be to go with 13 hours of darkness instead of 12 during flower. Like Campesino and Chefbjy said, give it a try. Don't know about your area by down here in VA we have had a shitload of rain so far this year. That can't be good for your basement ground water issue.

[hycheese]

well I have more to do with dehumidifier maybe ,I'll know in a few I set up the DH so hose would drain but I think I had it to close to the wall and it didnt get good airflow ,I hope that had something to do with the excessive heat I vented the exhaust from the DH just out into my cellar now I think I'll have to run a vent to the outside , If I cant get temps down the dh just isnt going to do what I need and will go to a AC unit I can vent out of the room .

The way you have it set up with the Rube Goldberg vent it does not need to be in the grow room, just dehumidify the basement in general and it may be better for it.

I just looked up a 50-pint dehumidifier and they seem to produce about 500 watts of heat which is equivalent to 1700 BTU's of cooling.

It looks like you are venting the DH from your grow area into your basement which then tempers the air and drawn back in through cracks or door, unfortunately, it sounds like you don't have enough underground cooling to counter effect the heat.

If you aggressively vent to the outdoors then you will create a negative room pressure which may cause even more moisture to be pulled from the underlying ground. If you over pressurize the room from outside then you will force moist air up your wall cavities and could create mold,

You may need to come to grips with that having that much water under your house without proper balancing will be a problem. I just spent over $1000 dollars to balance my house.

Fantech VHR70

[oldjarhead100]

I believe I may have found the problem I went in yesterday around 6 pm lights out at 4 and one led was on I must of hit the timer doing something ffffffffffffffUCK. Its on the back side of the grow .
so I vented the dehumidifier out of the cellar and I made a swamp cooler looking forward to seeing what all my work did if anything .
first 3 pictures are swamp cooler I started with 20 lbs cubes and 1 block of ice I am wondering how long it will last ,4th is of outside vent and the last one is my sons fat cat named him( cheese it )cause he likes them so much it doesn't show though lol

[GreenState]

I thought your cat just had a tiny head! (lol)
Swamp cooler, interesting. I remember when I lived out in Colorado some had what I thought were swamp coolers on some of the commercial buildings, worked by evaporation as I recall.
(Have no AC here and it has been brutal! One more day to go then it's supposed to cool down some ....and rain, we could use it, been dry this summer.

[Chefbjy]

Glad you figured it out...maybe you'll get some pistils now. 😉

[oldjarhead100]

boy is this frustrating the vent works great not so much for the cooler ,Ice was gone overnight but temp didn't go below 80 humidity is just below 60 , I disconnected the cooler to see if rh goes down ,did some super cropping,
Campesino I'm a little concerned now too lol all I can do it keep laying them down as far as time I figure if we drop seeds on the 11th then 4 weeks its middle of September that would give them 10 weeks to finish up worse case I let them veg for a couple of extra weeks and a couple of days to hook up watering system/Drain system ,I have enough trays to start setting them up early so if I get it all ready before hand it shouldn't be to bad (Like I haven't heard that before lol)
I have 2 other rooms I can use to veg in and a seed starting platform as well so space isn't a concern . I have some Alienvstoofless seeds on the way and I'm going to drop four of them right off but they are autos so it wont affect the challenge
The heat wave is over so maybe that will help ,the urge to buy a dam ac unit is pretty strong ,I just keep thinking that maybe the ac will do both reduce RH and temps .I just need to wait until I see if everything settles down

[hycheese]

10 years ago I experimented with an ice chiller, I could not get it to work very well as it needed too much ice to be effective. I calculated that it needed 20lbs of ice per hour to remove 1000 watts of generated heat = 480 pounds of ice per day.

[oldjarhead100]

yes I do remember flip day if there are no more problems I should make it with about 20 minutes to spare lol

[oldjarhead100]

well for being over the heat wasn't as bad only 76 but the humidity was so thick it was like walking into a wall

My assessment of the situation is this, the dehumidifier wont work if you duct out the hot air next step trying it out in main cellar to lower the whole room like hycheese suggested then its the ac

I am trying to keep the cost down February electric 780 3 rooms with seedling area so 2 8 bulb t5s 1 4 bulb t5 and 6 300 watt leds in veg rooms then in bloom 1000 watt hps and 6 100 watt light bars, with just the bloom room running my electric was 273 not good but not so bad either

I think if I ran both the dh and ac it would be significantly more ,

My Alien vs toofless should be here soon so I will be starting the seeds so the seedling area will be on 24/7 for a couple of weeks then outside they go, dam wouldn't it be a laugh if the seeds I dont have yet go into bloom before the tuts

This fixed income thing is for the birds not alot of extras lol

[Sheesh]

Hey OJH, Take a look at the DH manual or online and see where the dehumidified air (and heat) come out. My 30 pint unit is similar looking to yours and the DH air comes out the top vents. There is no way around it, IME - the warm air is the air that has lower humidity. I did exactly what hycheese said and left my dh in the basement to lower all the humidity before it is sucked into my tent. For portable AC, I have used two and the second one is way better than the first. My first was a single hose 8000 btu LG portable AC. Worked pretty good but single hose AC units cause negative pressure which sucks in hot air from every crack and crevice in the space. This year I bought a 14,000 btu Whytner dual hose portable AC. No more negative pressure with the two hoses and the unit is a beast. It cost $450 but gives me total temp control even over the last week with the heat wave. If you're going to try a portable, go straight to the Whynter if you can. It will help keep humidity down some but you'll probably still need the DH when the humidity is high. Those plants are monsters and they must be dumping tons of water back into the room by transpiration. How many sq feet total are you trying to condition?

[hycheese]

How big is the rest of your basement? are you actively bringing in and exhausting air from the outside? CFM? I spent 40 years in industrial automation working with enthalpy problems using 100-ton chillers but seems the smaller the space the harder it is to control (kinda like a fish pond). anyways, gots go to my part-time job.


Okay I'm back home, I came up with a list of questions on my 3-hour drive that may have an effect on your total room environment. Because you are essentially in a hole in the ground these may have a greater impact than an upstairs room.


Outside of the 100sqft grow room is the rest of the basement dirt floor?

Do you have a sump pump and does it run? how much?

Do you have an active cistern?

Do you have gutters and downspouts? A 1000sqft roof will dump approximately 600 gallons of water per inch of rain down your basement walls.

Do you have 18" thick flagstone walls? have drain tiles?

What are the average outside daytime and nighttime temperatures and humidity levels?

It sounds like you are venting the grow room directly outside? are you also bringing in the same amount of fresh makeup air back in?

[Smokesteve]

I have found with my room that running the dehumidifier on a timer approximately 1 hour on 1 off and it maintains 40-50 rh. I also keep a good size fan pointed at the DH running constantly. I still need an exhaust but it's not terribly hot like when I ran the DH constantly.

[hycheese]

Do you have an older knob dial unit or one with them newfangled electronics controls?

[Smokesteve]

Old DH with knob

[hycheese]

Okay, I'm back home, I came up with a list of questions on my 3-hour drive that may have an effect on your total room environment. You are essentially in a hole in the ground and these may have a greater impact on you than a ground level room.


Besides the 100sqft grow room is the rest of the basement dirt floor? how big is the common area of the basement?

Do you have a sump pump and does it run? how much?

Do you have an active cistern?

Do you have gutters and downspouts? A 1000sqft roof will dump approximately 600 gallons of water per inch of rain down your basement walls.

Do you have 18" thick flagstone walls? have drain tiles?

What are the average outside daytime and nighttime temperatures and humidity levels?

It sounds like you are venting the grow room directly outside? are you also bringing in the same amount of fresh makeup air back in?


Here are some of the things I would check or experiment with;
First get a couple of feet of clear tubing and some food dye and make a water manometer, once you form the U-shape and mounted to the wall push one end into your grow room and tightly seal, leave the other end open to the common basement. With all fans off and no type of air movement mark the water column (they should be of equal hight). Turn on the exhaust fan and measure the column again, if it went up 2" then you would have a negative 4"wc in the room. I would put an adjustable heat register in the bottom grow wall and open it until the water level is equal, optionally I would either slow down and/or install a bypass damper on your exhaust system to redirect some/most of it back into the common area of the basement.

Your 100sqft grow room is about 800cuft, as an example, a 50 cfm fan will suck it clear out in 16 minutes. Do you need that much?
I would exhaust the grow room with a smaller vent fan into the common area of the basement and let that 400 tons of cold basement wall be a heatsink then if that won't keep-up then vent the common area to the outside, same with the fresh air intake.

The reason being is that a larger area is less prone to micro changes in the system, also if you aggressively power vent the small room to the outside then any changes you make to the inside environment be it humidity or otherwise will be negated and will only be throwing good electric money out the window.

Moving the dehumidifier into the common area may also be the better choice, let the small grow room exhaust fan create a slight negative pressure allowing the cooler drier common air to be drawn back through the heat register near the floor. Using strategic bypass dampers and blend doors should also cut back on the need for heat in the winter too.

Now admittedly I am not an expert with these systems as a whole as my expertise was PLC programming and instrumentation but got to see the entire workings while troubleshooting many of the cause and effect scenarios I outlined above - it seems everybody blames the programmer until it can be proved otherwise, sure am glad I retired to a 15 hour a week parts delivery driver. only 100 weeks left until full retirement.

[oldjarhead100]

hycheese thats what i'm concerned about Lets do a little background I built the room last summer I have had some decent grows in it but I never had a issue with rh until I started fertigating every day ,now that I've increased the water volume in the room my humidity was staying around 80% ,so I debated about an dehumidifier or an Ac I just didn't want to run both .

Now that I have rh and temp issues I got the dh ,RH came down but heat went up so I tried to vent the dh into the rest of the back cellar that raised the temp in the cellar to 84 while the room was 82 so I vented outside still didn't do it .we were in a heat wave right now the temps are in mid 70s and rh is 46 in the room I am going to continue to try and fix the problem in case we get another heat wave

Thanks everyone for all the help I will continue to work on this so be ready for more questions lol

[oldjarhead100]

I decided that I'm going to take a few clones of the tuts and keep a mother plant for one more try at this plants, but the ones in the bloom room need to go into bloom if they dont soon I think I'll cut the scrog net up and move all of them out side where they can finish when they are ready , I dont plan on that though I think the threat will make them go into bloom finally

[oldjarhead100]

Thought I was seeing white pistils yesterday but I've thought that before lol, I broke down and bought a room ac for the bloom room its way oversized so should keep it cool easily and dehumidified

I'm going to bring the dehumidifier back hopefully they take it I cut the box up to use in garden lol

heading out to water again this morning and open up some light for the ones that need it

[hycheese]

Undersized AC's do the best for dehumidifying, oversized ones will make temp setpoint too soon and shutoff. I still think you will need both.