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Intake air getting WAY to cold in winter :(

hey!

so the problem is winter obviously, already nighttime temperatures are only 5°C/41°F and expecting up, or should i say down :bigeye: to -51°C/5°F...

the setup is a 4x8 tent in a room which obviously draws in the air via this cold ass window from outside and exhausts though a hole in a door outside of the room.

inside the tent are 2x 600hps.

the lights are too hot to just have them switched on and recirculate in the room with the window closed,
and with the window open or tilted i dont know yet as its the first time in this weather and still then there is the other 12hr window without heat from the lamps...

now i really dont know how to help myself because quite honestly besides way costly heating the intaken air nothing comes to my mind except for maybe running
the two 600s one after the other and doing a 12hr 12hr autoflower setup and recirculate the air in the room to heat it.
(i detailed that idea here: https://www.icmag.com/ic/showthread.php?t=346866 )

please advise, out of ideas and it is getting colder by the day :(
 
M

metsäkana

welcome to my world lol

i yielded 1.5g per watt with night temps 5-20c might got lower just try to keep it as warm as you can with some heater i think in veg it dont even matter or start of flower they dont stretch so much..

put dehumidifier too with the heater latest on after 3-4 weeks of light switch

cold temps make humid.. yeah im thinking connecting the rooms somehow with ''blacked'' fans with temp controller

im still searching good options too

hit -33c on that grow air comes straight from outdoor to grow room
 
M

metsäkana

dehumidifier+heater+termostatfans gets go pretty far but if someone have ideas would be nicee
 

Easy7

Active member
Veteran
This explains the other thread better.

Is the window open? If so, close it.

If it's an old window, plan on switching it out for a newer window. Unless you rent, then consider buying somewhere else.
 
M

metsäkana

my problem is not window the cold air comes in somewhere if its like unheated ''garage'' and pushing air out. cant turn the fans off in flower other wise mold hits, if too cold it hits, if too little fanning it hits :D but i dont know hows hes settup. i dont know if the bouncing hot air from other tent to other or other room to other work that might up the humidity too i have no exprience.. all i know 600w heater is not much vs -33 outdoor air :DD
 
M

metsäkana

also cycle lights on night so they are on coldest time and day off warmest time
 

p0opstlnksal0t

Active member
Circulation air around the canopy should not be the same fan as your atmosphere controlling fans. You need to put your vent/atmosphere control fans on a tstsat. They will flip on when too hot and shut off when too cold. It sounds like you just have open venting with nothing controlling the temp. If this is the case it's time to move that little tent out of the stone age and control that climate better. Intake temp doesn't matter. Your controller will regulate the temp of the tent. You don't need a monster 1000+ cfm fan to do this either. Only 200-300cfm will be needed to regulate the tent temperature with intake temps that low. Once you dial in temp you'll need to see how that cold air is affecting your rh. I imagine with such cold intake temps the rh will be dropping since the dew point is much lower the colder the air temp is. Humidity will want to precipitate out of your tent air as that cold shit get sucked in. That too can be controlled with a humidistat
 
M

metsäkana

yes intake will matter even with 3kw lights hps its not enough to keep the small room heated in -40c even if the the fan is sucking cold in in SLOW speed
if you live in warm climate i think you might not understand

but you cant do nothing to intake.. or buy this
Nayttokuva_2016-3-4_kello_12.10.28.png


i would burn my plants in warm days with so small fan.. thermostat controlled fan is only solution or going there every night to turn it slower when lights go off and morning to speed it up that plants dont burn

it can fluxuate from +0 to -40 :p

also when the fan speed slowdown the lights turn off humidity rise in minutes to +80% you need dehumifier for that time to be on.. lights on it might not be needed.
if you turn it off fully i think humidity rise to 100% with bigplants and they just fall down and mold

if i close my intake it sucks the air from door and the door will froze closen after a few hours =)
 
M

metsäkana

its fine line balancing on too cold, too little air, too humid.. but you can make it good if you watch a little, silica and bacteria and kelp meals i think help with cold temps and molds not sure if chitin does

i have not done much closed rooms circulating same air with dehumidifiers but also the dehumidifier water line freeze when it gets out of the room xD i guess in closed room you need to use co2
 

St. Phatty

Active member
please advise, out of ideas and it is getting colder by the day :(

join forces with the guy who's grow room is over-heating ?

The inlet air has to be fresh, not from the outside.

It could be drawn from inside the living area of the house.

I always thought companies like Google and Apple would be wise to let the heat from their server farms perform a function like household heating.

Maybe you could find somebody who is CONVINCED they want to get into Bitcoin Mining - and have them set up 5kW of server in your inlet air room.
 

Douglas.Curtis

Autistic Diplomat in Training
Lux-100 (Thermostat controlled outlet) I've used one of these, down to -50F/-40C. Run your ducting from the window, around the upper part of the ceiling of the room, point the outlet into the middle of the ceiling of the room. This gives the air a minute to warm up in the grow room environment. Not much, but it does help. Mount your fan near the outlet exit, mount the thermostat at canopy level. You'll have to use an extension cord to reach the fan. (Do they make Lux-100's for your type of power/outlet??)

You'll need fans moving air around the room 24/7, whether the intake fan is on or not. Mold, yeah?

I grow in very low humidity, so my intake ducting did not condense water. Should you get a lot of condensation, insulate the ducting. ;)
 

p0opstlnksal0t

Active member
you said in the first post
the lights are too hot to just have them switched on and recirculate in the room with the window closed

so are they hot enough to heat the room up or not?

Also i dont think you are understanding what needs to happen here. it doesnt matter what the intake temp is. you should be able to easily have sufficient equipment to keep the temps steady. it doesnt sound like you are utilizing any kind of atmospheric controls. you just turn the fans on, crack a window and hope it all stays stable. well it wont... firstly you should have that window sealed up and the container insulated to hell. secondly, your intake and exhaust should be controlled on a thermostat. you should have intake and exhaust continually running 24/7 or when lights are on. Intake and exhuast should only happen when the atmos in the room is out of balance and an exhaust/intake purge is needed to control the temp. If you dont plan on sealing it all up and running a mini split then you have to control the temps with a thermostat and exhaust/venting. if your container cannot sustain temps warm enough then introduce a heater on its own thermostat. you dont just plug a heater in without proper controller devices and hope shit stabilizes. your carbon scrubber is your exhaust outlet technically it should be set to circulate within the room 24/7 on an inline fan this fan discharge should have a "Y" or splitter. you get a hvac ducting damper thats Normally open and another damper that normally closed and they get installed on the 2 ends of your "Y". you plug them into a tstat. when the tstat kicks on the dampers both energize and air goes from circulating inside to exhuasting outside. when the room cools enough the tstat kicks off and the dampers flip back to their Normal parameters and air recirculates in the room again. you drill a fresh air intake hole somewhere in the shell of the building when the tstat kicks the exhaust phase on the fresh air will be drawn into the room. this fresh air intake should have a manual damper on it as well. this way you can fine tune the intake air intake rate since it will be so cold and when it dumps into the grow room have an ELL or something diffuse the intake air into the top of the grow/ceiling so its not blasting directly on your plants

HVACdamper1.png


adc_1_1_1.jpg


yes intake will matter even with 3kw lights hps its not enough to keep the small room heated in -40c even if the the fan is sucking cold in in SLOW speed
if you live in warm climate i think you might not understand

but you cant do nothing to intake.. or buy this View Image

i would burn my plants in warm days with so small fan.. thermostat controlled fan is only solution or going there every night to turn it slower when lights go off and morning to speed it up that plants dont burn

it can fluxuate from +0 to -40 :p

also when the fan speed slowdown the lights turn off humidity rise in minutes to +80% you need dehumifier for that time to be on.. lights on it might not be needed.
if you turn it off fully i think humidity rise to 100% with bigplants and they just fall down and mold

if i close my intake it sucks the air from door and the door will froze closen after a few hours =)
 

Phaeton

Speed of Dark
Veteran
My first window air blend box was rather simple. An empty appliance box (microwave) that matched the 21" x 40" window.
A side was cut off and placed over the open window hole. Another side had a square cut out for a box fan to fit snugly.

Three fan settings for actual airflow control and I would pivot an edge away from the window to mix in room air, depending on outside temperature.
Also there was a sliding cardboard cover on the outlet so the room could run at a slight positive pressure. That way the filtered (furnace filter on suck side of fan) window air would push dust, bugs, and cat hair out of the room.

Cats and bud rooms, not a good combo, it was them as much as the temperature control that led to obsessive control over air circulation.
 
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