New Grow room

[GreenhouseEffect]

That makes sense, I was kinda thinking that might be the case.
I have noticed with the mulch that it becomes more important to keep my soil fertility up, and just using the worm casting tea becomes less effective.

[oldjarhead100]

I use straw in veggie garden ,this is just a temporary problem I will find a solution with everyone's help it should be easy lol

[GreenhouseEffect]

I don't know if it's even at all practical with how your grow is set up, but I think one of the biggest things that has helped me with humidity and temperature management in my greenhouse this summer, has been covering my soil.
In my case I use straw. I end up using way less water, which means less contributing to humidity. I alternate which section I water, so most of it on any given day is dry and moisture sucking, instead of wet, and moisture giving.
The cooler root zone helps at least the plant to cope with the heat better, and it does seem to bring the temperature down slightly.
Not sure how that would work with an indoor grow, would probably slow down growth with less Nutes being given, but figured it might be useful for the whole temperature and Humidity Battle.

[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.

[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

[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]

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

[Smokesteve]

Old DH with knob

[hycheese]

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

[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.

[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]

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?

[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?

[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

[oldjarhead100]

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