The right balance between temps, humidity and CO2?

[lazi]

I don't use air conditioning or added CO2 so the exhaust fan speed is a big climate factor. Too little and the temps are too high and maybe not enough fresh air coming in for new CO2. Too high and the humidity plummets and the plants don't grow as well.

Temperature, humidity and air exchange rate all get talked about separately but I haven't found anything to do with striking a good balance between the 3.

Can anyone give me a min/max range of 1) Temps 2) relative humidity and 3) air exchanges per minute so I can try and get all 3 near enough OK?

Thanks.

[c-ray]

70-90F, 30-70% humidity and roughly 200cfm of airflow per 1000K of hid
sativa types can generally go higher on the temps and humidity
more heat and humidity is tolerable in veg

[The Cannarchist]

Cheap humidity provider.

A 5 gallon bucket and a 150w aquarium heater.

Fill bucket with hot water and put in heater set at 5 degrees higher than ambient room temp.Top up bucket as needed.

I've got 70% humidity and the plants are fine in full bloom.

[gisisi]

Cool trick there, Cannarchist.
What is the volume and ventilation of your space?
Those two factors would help to approximate a scaled version.

Lazi:

Run the fan enough to cool the room to the temp you choose. This will always be more than enough to exchange the air.

Then humidify to desired humidity.

I am afraid that unless you live in a very humid place, you will never get the balance of temp, co2, and humidity you seek using only the fan.

gisisi

[Green Supreme]

If you have LUI going you better get that humiity below 55 or big trouble to come. Peace GS

[lazi]

Thanks for the replies.

Already have a suitable bucket and heater for Cannarchists suggestion so will be giving it a go. Could control the heater with a hygrostat maybe?

Run the fan enough to cool the room to the temp you choose. This will always be more than enough to exchange the air.

That makes me feel better, just temps and humidity to control.

[MajesticWhelk]

Hey I have one humidity question for you guys as well.

Right now my outside temp for where I live is 54F and the humidity is 100%.

Is this going to be a huge problem with an indoor grow in a well-ventilated hut? Will ventilation inside my hut bring my humidity down significantly? Or will the air being brought in at 100% humidity raise my GR humidity dangerously?

[Stone]

Hey I have one humidity question for you guys as well.

Right now my outside temp for where I live is 54F and the humidity is 100%.

Is this going to be a huge problem with an indoor grow in a well-ventilated hut? Will ventilation inside my hut bring my humidity down significantly? Or will the air being brought in at 100% humidity raise my GR humidity dangerously?

Nothing to worry about. With a temp of 54 and 100% humidity outside, your outside dewpoint is 54 as well. Assuming the air in your GR is roughly 75 or so that will produce a relative humidity of about 50% which is perfect. You gotta realize that as you heat air without adding additional moisture the RH has to go down. So, taking outside air at 54 with a 100% RH and bringing it inside and warming it to 75 results in 50% RH.

[MajesticWhelk]

Thank you for clearing that up.

For a little while there I was having horrible visions of bud mold after months of hard work.

In my setup, do you think that it would be worth it to buy a temp/humidity climate controller?

[c-ray]

you should be able to control temps and bring RH into decent levels with just a thermostat