humidity in cold winter climate needs to be below 40%?

[kronicking]

Hi, I am looking to start growing and I have purchased tents cmh lights day/night fan controller etc. I am wondering what you guys do in winter if you live in a cold climate where the humidity inside is supposed to be below 40%. During winter outside usually stays around 0F or -10F according to this website and a couple others https://www.hvac.com/faq/recommended-humidity-level-home/ the humidity in your home during those temps is supposed to be no higher than 25% for -10F and 30% for 0f. I was wondering what suggestions you guys have? Is it okay to grow at those humidity levels because I have been reading about 40-60%. I don't know if it makes any difference but I have autoflowers.

[gbauto]

Hi, kronicking
I try to run my grows using a VPD chart to determine what my RH should be.
This link may give you some info. https://pulsegrow.com/blog/vpd?utm_s...cts#chart-calc
I find that the room/tent environment is really dependent on how much plant matter you have in there.
Most typical grows using HID lighting run temps in the upper 70's and RH depends on what growth stage the plants are in.
An inexpensive IR temp gun is a valuable tool for setting proper leaf/room temps

[dilvish]

the tent should contain the humidity. tents are designed to contain the grow environment. if it is warm enough in the tent, the water in the soil will evaporate and create humidity so the "house" humidity can be lower (or higher as the case may be). If it is a concern get a RH meter. They are relatively cheap and also have a temp gauge on them if you buy a digital one.

[dbdDemon]

I live in a cold climate too, Maine USA, I keep my basement at 50 rh in the winter time 45 in the summer. I don’t dare go to much lower to keep my room at a higher rh. I am still having issues of too low of a rh in my clone/mother section of the room. My flower section seems to be doing well tho

[kronicking]

Hey, thanks for the info I was just checking out the vpd calculator and was wondering I tried to get my vpd to 1 on the calculator and the only way I get close is if I lower my temperatures in the grow room to 62.6F which gives me 1.4 kpa (air). I was thinking about getting some heating mats for the pots (keeping soil warm) but I was wondering if growing at a temperature of 62.6F to get the vpd closer to 1 would be better than keeping my tent at around 70F. The temperature surrounding my tent fluctuates from 59F-62.6F so I am worried about keeping the tent too hot because I read that I should never let the temperature drop 15F at once because it will stunt growth and I really dont want a small autoflower.I guess I could also just try and buy a small humidifier and just use fans to try and keep the humidity in the tent as long as possible and try to get my exhaust air to spread out quick but I am worried that the humidity will slowly build up somewhere in the house. Guess I could just take a shot and see what happens.