Advice on dialing in temps and humidity in tent .

Imcamping86

Well-Known Member
oscillating fans and intake fans help plenty with that. exchanging air (letting you tent air out) helps as well adding some fresh air
right now I currently have a little 6 inch fan sitting next to the open flap aimed at the plants . I have the other flap open with a fan hooked to my dehumidifier slot on my controller and my temps currently at 82f and 62 rh . I can lower whatever if need be . I just figured that is a good setting to have now . I’m not using exhaust ventilation system but every once and a while I will turn it on and let it run for 5 minutes . I have another black oscillating fan but I’m not currently using it as I fear it may be too strong for the less than a month old plants and seedlings .... I’m open to advice .
 

Tht_Blk_Guy27

Well-Known Member
Dude outside humidit is irrelevant when its 20 degrees outside and 70 inside.
mehhh outside temp would matter if you indoors and using a tent. the moment i moved my tent out of the corner away from my A/C unit (its 20 degrees here, so it runs at 75) it changed my in tent variables, humidity the most as i no longer had temp surges
 

Imcamping86

Well-Known Member
mehhh outside temp would matter if you indoors and using a tent. the moment i moved my tent out of the corner away from my A/C unit (its 20 degrees here, so it runs at 75) it changed my in tent variables, humidity the most as i no longer had temp surges
I’m not worried about controlllong temp or humidity with the vent system off. I’m worried about if I’m getting enough fresh air in there . That little fan by flap is enough ?
 

Tht_Blk_Guy27

Well-Known Member
I’m not worried about controlllong temp or humidity with the vent system off. I’m worried about if I’m getting enough fresh air in there . That little fan by flap is enough ?
id recommend running two smaller fans if they're small. i have a lot going on rn in my 4x2x6 and next payday I'm investing in a AC Infinity inline fan to help out my little fan that currently is struggling to make a difference lol
 

Imcamping86

Well-Known Member
I looked at that fan but settled for the 4 inch vivo with carbon air . But regret not getting it . Might get it like you said as a back up . And I’ll get another little fan to throw in there . Thanks for the input
 

JoeBlow5823

Well-Known Member
I’m not worried about controlllong temp or humidity with the vent system off. I’m worried about if I’m getting enough fresh air in there . That little fan by flap is enough ?
Probably not. You should have a dedicated in-line fan running 24/7 that pulls air in through he flaps and out somewhere else.
 

Driver733

Well-Known Member
This is my latest setup.

I installed a used Rinnai direct vent propane gas heater I bought on craigslist for $200, it has a digital thermostat with clock and programmable if needed. I had to pay for professional installation (not diy on gas, thank you very much) so that was an added cost but living in Vermont heat is not an option. I was temporarily using an electric space heater but they terrify me, but I might use an electric oil-filled register heater if I had no other choice.

I am using the heater to heat the room, and then the tent draws heated air in by the passive intake of the inline fans. I have an evaporative humidifier in the tent running only with the lights on, this keeps the humidity around 55% in the tent during the winter. The air here is dry and without the humidifier I would be around 30% or less in the winter.

This is my first winter, so after a bit of experimentation with ventilation, I found that I need two inline fans on my 4x4 tent to control the heat and maintain humidity without losing too much of both out the window. I pull fresh air passively into the room from the rest of the house, never from directly outside due to condensation in the winter.

What I found works best is I have a 6" AC Infinity fan with carbon filter exhausting air from the tent into the room, I keep this on a low #2 setting running continuously with lights on. This fan will shut off if the tent gets too cold but so far that is not an issue. This fan keeps the air moving and refreshing in the tent (I also have 3 small hurricane fans inside the tent blowing air around). I have a second AC Infinity 4" fan without carbon filter that exhausts the tent and vents directly outside, this fan is set to kick on at #8 when the heat gets up to 80 degrees F or humidity over 60%.

Since the 4" fan vents outside, this keeps the room from getting too hot, also keeps the humidity in check without losing too much, while forcing fresh air into the room and tent (by exhausting out the window). This way, I am able to use the heat from the lights on in the tent to keep the room warm without running the propane heater, exhaust excess heat out of the building, exhaust excess humidity, keep fresh air passive intake and maintain continuous recirculating air without getting the tent too cold or too hot.

When the lights go out, I keep the 6" fan on #4 exhausting into the room, and the 4" fan is set to exhaust outside when the humidity in the tent gets above 60%, this keeps the room and tent from getting too humid without a constant exhaust losing heat by exhausting outside. I set the propane heater to 72 degrees F with the lights off, and it keeps the tent at about 70 degrees F. I also keep a de-humidifier in the room set to 45%, this prevents the room from getting too humid from the 6" fan which can also be a real problem in very cold weather due to condensation.

It might seem elaborate but so far it is working perfectly.
 

Imcamping86

Well-Known Member
This is my latest setup.

I installed a used Rinnai direct vent propane gas heater I bought on craigslist for $200, it has a digital thermostat with clock and programmable if needed. I had to pay for professional installation (not diy on gas, thank you very much) so that was an added cost but living in Vermont heat is not an option. I was temporarily using an electric space heater but they terrify me, but I might use an electric oil-filled register heater if I had no other choice.

I am using the heater to heat the room, and then the tent draws heated air in by the passive intake of the inline fans. I have an evaporative humidifier in the tent running only with the lights on, this keeps the humidity around 55% in the tent during the winter. The air here is dry and without the humidifier I would be around 30% or less in the winter.

This is my first winter, so after a bit of experimentation with ventilation, I found that I need two inline fans on my 4x4 tent to control the heat and maintain humidity without losing too much of both out the window. I pull fresh air passively into the room from the rest of the house, never from directly outside due to condensation in the winter.

What I found works best is I have a 6" AC Infinity fan with carbon filter exhausting air from the tent into the room, I keep this on a low #2 setting running continuously with lights on. This fan will shut off if the tent gets too cold but so far that is not an issue. This fan keeps the air moving and refreshing in the tent (I also have 3 small hurricane fans inside the tent blowing air around). I have a second AC Infinity 4" fan without carbon filter that exhausts the tent and vents directly outside, this fan is set to kick on at #8 when the heat gets up to 80 degrees F or humidity over 60%.

Since the 4" fan vents outside, this keeps the room from getting too hot, also keeps the humidity in check without losing too much, while forcing fresh air into the room and tent (by exhausting out the window). This way, I am able to use the heat from the lights on in the tent to keep the room warm without running the propane heater, exhaust excess heat out of the building, exhaust excess humidity, keep fresh air passive intake and maintain continuous recirculating air without getting the tent too cold or too hot.

When the lights go out, I keep the 6" fan on #4 exhausting into the room, and the 4" fan is set to exhaust outside when the humidity in the tent gets above 60%, this keeps the room and tent from getting too humid without a constant exhaust losing heat by exhausting outside. I set the propane heater to 72 degrees F with the lights off, and it keeps the tent at about 70 degrees F. I also keep a de-humidifier in the room set to 45%, this prevents the room from getting too humid from the 6" fan which can also be a real problem in very cold weather due to condensation.

It might seem elaborate but so far it is working perfectly.
Holy crap man , you got hella fans lol so far I have been using a small 6 inch fan to pull air in from outside to blow over the canopy . That’s pretty much all I have been using . The vent system I haven’t been using my ventilation system yet because it doesn’t smell yet and it just sucks all the heat out and all the humidity. So i just don’t use it yet . Gonna get another fan soon or two lol
 

Driver733

Well-Known Member
Holy crap man , you got hella fans lol so far I have been using a small 6 inch fan to pull air in from outside to blow over the canopy . That’s pretty much all I have been using . The vent system I haven’t been using my ventilation system yet because it doesn’t smell yet and it just sucks all the heat out and all the humidity. So i just don’t use it yet . Gonna get another fan soon or two lol
Thanks! I know it seems complicated, but the reason I did this is for the same reasons you started this post.

You need to keep the air in the tent constantly exchanged - we both have a 4x4x80" tent which = 107.62 cubic feet (CF). Ideally, you want the air in the tent exchanged every 3 minutes minimum, every minute even better.

So for that, you need a fan pulling between 107.62/3 = 35.57 Cubic Feet per Minute (CFM) and 107.62 CFM.

The 6" inline fan is 392 CFM, 392*0.80 (carbon filter reduction)/10 speeds = 31.36x3=94.08 CFM, so running the fan on #3 will exchange the air in the tent almost once every minute.

The 4" inline fan is 196 CFM, that runs intermittently as needed to exhaust the excess heat and humidity out of tent. Your 4" fan should move the same volume of air but reduced due to the carbon filter.

This way, you only need auxiliary heat when the lights are off, and the tent gets maximum air exchange.

Oh, I almost forgot, 65% humidity is plenty, especially in winter in a basement. The last thing you want is powdery mildew, so if anything, 65% may be too high. I never go above 60% in winter and that is only in veg, in flower 40-50%.
 

Imcamping86

Well-Known Member
Thanks! I know it seems complicated, but the reason I did this is for the same reasons you started this post.

You need to keep the air in the tent constantly exchanged - we both have a 4x4x80" tent which = 107.62 cubic feet (CF). Ideally, you want the air in the tent exchanged every 3 minutes minimum, every minute even better.

So for that, you need a fan pulling between 107.62/3 = 35.57 Cubic Feet per Minute (CFM) and 107.62 CFM.

The 6" inline fan is 392 CFM, 392*0.80 (carbon filter reduction)/10 speeds = 31.36x3=94.08 CFM, so running the fan on #3 will exchange the air in the tent almost once every minute.

The 4" inline fan is 196 CFM, that runs intermittently as needed to exhaust the excess heat and humidity out of tent. Your 4" fan should move the same volume of air but reduced due to the carbon filter.

This way, you only need auxiliary heat when the lights are off, and the tent gets maximum air exchange.

Oh, I almost forgot, 65% humidity is plenty, especially in winter in a basement. The last thing you want is powdery mildew, so if anything, 65% may be too high. I never go above 60% in winter and that is only in veg, in flower 40-50%.
Hold on , the 6 inch fan I speak of is a desk top fan not inline . The 4 inch fan I have IS inline with carbon cleaner . Should I put the fan in a vent port to push fresh air in ? Or You’re saying I need a second inline fan system ? And I just dialed humidity back to 55 percent . Sorry for the newb talk . New to indoor
 

Imcamping86

Well-Known Member
Thanks! I know it seems complicated, but the reason I did this is for the same reasons you started this post.

You need to keep the air in the tent constantly exchanged - we both have a 4x4x80" tent which = 107.62 cubic feet (CF). Ideally, you want the air in the tent exchanged every 3 minutes minimum, every minute even better.

So for that, you need a fan pulling between 107.62/3 = 35.57 Cubic Feet per Minute (CFM) and 107.62 CFM.

The 6" inline fan is 392 CFM, 392*0.80 (carbon filter reduction)/10 speeds = 31.36x3=94.08 CFM, so running the fan on #3 will exchange the air in the tent almost once every minute.

The 4" inline fan is 196 CFM, that runs intermittently as needed to exhaust the excess heat and humidity out of tent. Your 4" fan should move the same volume of air but reduced due to the carbon filter.

This way, you only need auxiliary heat when the lights are off, and the tent gets maximum air exchange.

Oh, I almost forgot, 65% humidity is plenty, especially in winter in a basement. The last thing you want is powdery mildew, so if anything, 65% may be too high. I never go above 60% in winter and that is only in veg, in flower 40-50%.
Also my tent doesn’t get very warm without the space heater I have on and set to 80 in the tent . . I only have the one Mars hydro ts 1000 on currently with the other 3 off . My tent doesn’t get passed like 73 lol
 

Driver733

Well-Known Member
Hold on , the 6 inch fan I speak of is a desk top fan not inline . The 4 inch fan I have IS inline with carbon cleaner . Should I put the fan in a vent port to push fresh air in ? Or You’re saying I need a second inline fan system ? And I just dialed humidity back to 55 percent . Sorry for the newb talk . New to indoor
Not sure if you're asking about the 6" desktop fan or the 4" inline fan, but you don't need either fan to push fresh air into the tent.

The 4" inline fan setup to exhaust air out of the tent is sufficient to passively pull fresh air into the tent, that is your negative pressure.

However, you need to allow for air to be passively pulled into the tent without the flaps open during flower while the lights are off, unless the room is 100% dark the flaps will let light into the tent. I use 4" and 6" ducting in the unused port holes in the tent, make them long enough and the light cannot get up the duct into the tent.

I am using two inline fans, one 4" and one 6", because I have them. In the summer, I use the 6" to exhaust the tent out the window, and the 4" fan is an intake fan bringing fresh air from directly outside into the tent. I run the lights on over night during the summer to take advantage of lower night temps outside, I use that air to cool the tent. The AC Infinity controllers allow each fan to run independently and keep the perfect temperature.

The problem with inline fans is none of the inline fans on the market allow the user to set a constant low speed and then a much higher speed that only kicks on if the temp or humidity goes over a certain maximum. But even if they did work that way, I would still need two fans - one to recirculate air from the tent into the room, and the second fan to exhaust air from the tent out the window. One fan cannot do both, but one fan needs to be running 24/7 to maintain air exchange in the tent. To do this in the winter and not lose all your heat, that fan has to exhaust into the room. Therefore, a second fan to exhaust only excess heat out the window.

In the winter, I don't want fresh air directly from outside, it's too cold and there would be ridiculous condensation. The house I live in is a renovated 100 year old farmhouse so it's still pretty leaky, and I get plenty of fresh air drawn into the room from the rest of the house.
 

Beehive

Well-Known Member
I've been messing with using two inkbird humidity controllers. Using two humidifiers.

One meter is plug in with full time power. The other is plugged into the light timer.

Lights on, 63% with a 5% difference to the negative. Daytime humidity levels. Primary humidifier.

The second meter is set 57% with a 5% difference. When the lights go off. This is the meter that controls night humidity %. Secondary humidifier.

......


Problems are extremely low outside humidity. When it falls below 40%. Both humidifiers are running. Above 40% and the two meters work like planned.

Since I used my spare Inkbird. I get to buy a third. The third will be used on the drying tent. Which is why I had two inkbirds.
 
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