Balancing heat and air exchange with night-time temperatures...

ShLUbY

Well-Known Member
It's Michigan winter... and it's cold AF out! When my HPS lights are off for the dark photo period, its gets chilly in the flower room. So I'm looking for a solution to put a heater in there for night time and have some sort of temp controller for my exhaust so it does not get too hot, and so it shuts off at a certain coolness, all while making sure that my heater is not running the entire 12 hours!

I just want to eliminate these temp swings between night and day. Looking for a more stable environment, and warmer nights, because I can tell that metabolism has slowed down during these chilly night temps.

my room is in a Michigan basement (not well contained basement, drafty), 14x6x7, i run passive intake and i have an 8" can max exhaust fan that runs 24/7 currently. my fan controller has stopped working, and either runs 100% or 0% haha. I should probably pick up a new one, but i'm starting to dislike these cheap ones, as they seem to make the motor of my fan hum when i dim it down.

Any and all input is welcome. I'm looking for gear, controllers, methods, whatever. I just want more environmental control this year! Thanks in advance and happy growing.
 
Last edited:

Cold$moke

Well-Known Member
Right now im just using a titan fan controler with thermostat and fan speed built in.

I was needing to run a heater as well cause we were going below 0

But i added insulation to the floor and since my water in my rdwc sits at 72 it acts like a thermal battery

Now my temps havent gone below 63 WITH 0 heat added.

Although my dehumidifier acts as a heater when its running

For the most part though i dont think my exhast fan kicks on much aftef lights out.

Hope it helps bud
 

Chip Green

Well-Known Member
Michigan winter
Michigan basement
Battling the same issues, spent the needed funds for insulation batts, for the new framed walls, the frozen concrete walls had to be covered with plastic sheeting, then foam boards....
The floor is next, as even with a dedicated heat duct, I cant get the room to stay above 62F with the lights off....
To make matters more challenging, I have all DIY LED strip panels, that will do very little as far as generating enough heat to get the numbers I want.....
In my situation, at least for the super COLD months, I'm considering getting some HID going in the future....
Maintaining stable conditions in a N. Michigan basement in Jan/Feb is a major issue....

I don't even want to talk about RH right now.....
 

ShLUbY

Well-Known Member
Battling the same issues, spent the needed funds for insulation batts, for the new framed walls, the frozen concrete walls had to be covered with plastic sheeting, then foam boards....
The floor is next, as even with a dedicated heat duct, I cant get the room to stay above 62F with the lights off....
To make matters more challenging, I have all DIY LED strip panels, that will do very little as far as generating enough heat to get the numbers I want.....
In my situation, at least for the super COLD months, I'm considering getting some HID going in the future....
Maintaining stable conditions in a N. Michigan basement in Jan/Feb is a major issue....

I don't even want to talk about RH right now.....
haha chip, you basically just outlined every thought i have about my environment right now. i mean even with all the insulation... having a room that extracts air constantly it's basically fruitless once you exchange the air when lights are off. and yeah the humidity right now.... FML, so low! plants are definitely working harder!

i'm in the same line of thought though, i'll keep my HID's during the winter, and planning on switching to LEDs for the summer (looking at picking up a HLG 550 and do a test run to see if I want to outfit the entire room with them). I'm hoping that figuring out this stuff over the winter will help me with the summer conditions as well.

seems like the only way to combat the issue is to switched to a sealed room. but that's a whole separate rabbit hole to go down cause you're talking controller with CO2, A/C, humidifier/dehuey.... for now, i'm trying to resolve these issues without going that route as best i can. i know i will never have perfect environment with an air exchange style room...
 

MrStickyScissors

Well-Known Member
I woukdnt like my temps getting below 68 when the lights are off and 78 when they were on. I used my central heat and air and had my exhaust on a timer. Good rhing i live in cali
 

HydroRed

Well-Known Member
It's Michigan winter... and it's cold AF out! When my HPS lights are off for the dark photo period, its gets chilly in the flower room. So I'm looking for a solution to put a heater in there for night time and have some sort of temp controller for my exhaust so it does not get too hot, and so it shuts off at a certain coolness, all while making sure that my heater is not running the entire 12 hours!

I just want to eliminate these temp swings between night and day. Looking for a more stable environment, and warmer nights, because I can tell that metabolism has slowed down during these chilly night temps.

my room is in a Michigan basement (not well contained basement, drafty), 14x6x7, i run passive intake and i have an 8" can max exhaust fan that runs 24/7 currently. my fan controller has stopped working, and either runs 100% or 0% haha. I should probably pick up a new one, but i'm starting to dislike these cheap ones, as they seem to make the motor of my fan hum when i dim it down.

Any and all input is welcome. I'm looking for gear, controllers, methods, whatever. I just want more environmental control this year! Thanks in advance and happy growing.
run a small $16 1500W heater with a built in thermostat. Set it to roughly 68*F and put it on a timer so it only runs when lights are off. Then have the room exhaust set to 78-80*F. This way the exhaust is never sucking out the heat while the heater is on. If your room is well insulated the heater may only come on a cpl times briefly over a 12 hr period.
 

somedude584

Well-Known Member

HydroRed

Well-Known Member
Plug your exhaust fan into one of these^^^, set it and be done. Its been very reliable for me. My room doesnt go below 68*F lights off and above 80*F lights on. I use passive intakes as well in this frigid MI weather.
 

somedude584

Well-Known Member
Plug your exhaust fan into one of these^^^, set it and be done. Its been very reliable for me. My room doesnt go below 68*F lights off and above 80*F lights on. I use passive intakes as well in this frigid MI weather.
Only problem I have is the wicked low humidity from the air exchange during lights on... but what can you do? At least it's my flower room.
 

HydroRed

Well-Known Member
Ya, I've had to incorporate a dehu for lights off and humidifier for lights on as well. Each only running when needed during lights on/off.
 

Chip Green

Well-Known Member
1500W heater
I've considered this, but that defeats my whole purpose of running the LEDs.... LOL
For my application, in this particular location, during these months, LED may not be the most suitable lighting source.
The area I have issues in, is a supplemental room, the real work is done at another location. This one is in the experimental, "see if I can manage conditions" phase before any plants go into it....

EDIT: I guess if the heater was only running intermittently it might be worthwhile.....
 

HydroRed

Well-Known Member
I've considered this, but that defeats my whole purpose of running the LEDs.... LOL
For my application, in this particular location, during these months, LED may not be the most suitable lighting source.
The area I have issues in, is a supplemental room, the real work is done at another location. This one is in the experimental, "see if I can manage conditions" phase before any plants go into it....
I get it. Thats why I cant do led grows in winter. I use hps in winter since I've already paid for the heat of the lights, and then for warmer months I cap off my inlet and exhaust and run a closed room with cob LED and AC etc. Switching between the two allows me to run my room in the winter without a heater and still allows me to run my room in the hot summer months too without going broke on HVAC. My room is very well insulated from top to bottom. I havent had a heater in my room since I finished it off with insulation/panda film and 3" gorilla tape on all seams.
 

somedude584

Well-Known Member
I get it. Thats why I cant do led grows in winter. I use hps in winter since I've already paid for the heat of the lights, and then for warmer months I cap off my inlet and exhaust and run a closed room with cob LED and AC etc. Switching between the two allows me to run my room in the winter without a heater and still allows me to run my room in the hot summer months too without going broke on HVAC. My room is very well insulated from top to bottom. I havent had a heater in my room since I finished it off with insulation/panda film and 3" gorilla tape on all seams.
I use my heat from my bulbs to heat my house lol, works nice from 1am-1pm, but gets chilly after that!
 

ShLUbY

Well-Known Member
@HydroRed

so during the lights on period, your exhaust fan only kicks on when the temp gets to your set parameter? or is it on during the entire lights on cycle? Just wondering if you have periods of no air exchange during lights on time. Curious about this because I don't know how quickly 8-12 plants would deplete CO2 levels in my room. its just under 600 cubic feet i think...
 

ShLUbY

Well-Known Member
and FWIW, i run glassless hood right now, so the bulbs would definitely heat the room up, but my ceiling and one framed wall is not insulated, so i'm sure i'm losing heat pretty quickly.
 

Cold$moke

Well-Known Member
Im in alaska there is no replacment for rigid foam board insulation :)

Was below 8 the other week and my room didnt go under 63. But its super insulated and air sealed

Also using hps. But i might switch to led after i do a build and check out the strips
 

Cold$moke

Well-Known Member
and FWIW, i run glassless hood right now, so the bulbs would definitely heat the room up, but my ceiling and one framed wall is not insulated, so i'm sure i'm losing heat pretty quickly.
Absolutley need to insulate everything or you pay for it in the form of heaters

I havent used a heter since i insulated my floor and its only gone down to 63 :)
 

HydroRed

Well-Known Member
@HydroRed

so during the lights on period, your exhaust fan only kicks on when the temp gets to your set parameter? or is it on during the entire lights on cycle? Just wondering if you have periods of no air exchange during lights on time. Curious about this because I don't know how quickly 8-12 plants would deplete CO2 levels in my room. its just under 600 cubic feet i think...
Correct. I have my temp set to 77*F and the exhaust fan plugged into the thermostat controlled outlet linked above in post #7. The intervals of cycles are often, but quick. Like 50-60 seconds every 6-7 minutes in sub 10*F weather. The warmer it is outside, the longer the fan runs between cycles.


Absolutley need to insulate everything or you pay for it in the form of heaters

I havent used a heater since i insulated my floor and its only gone down to 63 :)
Same here. After finishing my room properly, I havent had to use a heater since last year. By the time its getting chilly in the room (67-68*F), the lights are coming on again.
 

whitebb2727

Well-Known Member
Why not treat it like a passive green house? If the grow area has a good seal you can turn the exhaust off or turn it as low as you can. Put some jugs or small barrels of water in the grow room. They will draw heat when the lights are on and release it at night.

Water, stones or anything of the sort will store heat and release at night.
 
Top