Automation and how best to manage peeks and/or averages of the climate Q.?

[Bluey]

Is there material available on this? Do we need to manage brief peaks of humidity high/low. Do we set for averages?

I have humidity set for off/on at 55%RH of a day and it typically swings 50 to 61 but only briefly....are these swings a problem with flower if she peaks above 55 whilst set at 50 of a day re mould?

When set at 55 it maintains an average of 55 over an hour with readings every minute. It's pretty good at that. Currently AC
cycling off and on for 10 to 15 minutes each.

Temp is maintained with under 4⁰F variance.

i have a 12gal/day dehumidifier and an ultrasonic mister...im running both of them off their own sensors calibrated, seems to do just as well as the automation, probably better as no sensor lag on the dehumidifier.

[90Gizmo]

I've read that it's best to keep the dehumidifier and AC outside the tent and in the room. I interpret that as making a "dry air bank" the size of the room ready to shuffle the room's dryer/colder air into the tent by turning on fans. The duct fan won't have the concern of minimum on-off times that the compressors do so I think a so I think it will be possible to nail the target settings in the grow tent with very little over or undershoot. Hopefully someone will say that +/- 5% RH okay but I think you can narrow that range.

[90Gizmo]

Do you have a room exhaust? Can you turn it on or up to control humidity overshoot?

[Bluey]

I have the gear but I dodged at installing the exhaust and exhaust penetration to keep it discreet...an AC hanging out through the window looked more natural. I decided to go with the mostly sealed room approach. I do have a room below I can control the climate in and use that...it's a much better idea as I can keep that room closer to 21 and put my nute tank in there..currently the tanks in the room and a few degrees higher than ideal but not causing problems yet.

[90Gizmo]

I think you'll need a lot lot of flow to use the air-handler idea for a whole room. I was thinking of a good window fan (which would look like a good window fan from the outside with some sort of one-way air flap jury-rigged on the inside for when it's turned off. And sufficient air intake somewhere else. Your scale is above and beyond what I've been thinking of here which is a second grow tent acting as an air-handler for a smaller grow tent with the vegetation inside.

[3Berries]

Maybe gut a window AC unit and use it to hide an exhaust?

[Bluey]

I'll see how this grow goes....bud rot is my main concern, if I avoid that this grow I should be fine with top yields of quality weed...but if not I'll definitely go the climate chamber route.
Some great ideas there...I like the way you think 3Berries

[Bluey]

Done some testing on the setup utilising the individual units thermostat & hydrometers...getting slightly improved results of a day and even tighter of a night with the lower temps...
I think I can manage this room like this satisfactory but have yet to test night late flower which I'll be aiming for low 40's%Rh.
Keeping temps down atm for conservative VPD and going easy on the photons...low to mid 400's still slowly increasing.
I will get closer to 950 on the lights late flower butcan overall conservative approach, even on the nutes....last harvest only used about 50% flower nutes...and still close to nute burn but list control of the climate..so no measure I guess

[3Berries]

I don't try and maintain low humidly with lights out. I aim for under 80%. I do keep air moving in the tent with lights off. And there usually is some slow flow through bringing in fresh air. Without mechanical dehumidifiers it's near impossible to hit something like 40% here.

One time I found bud rot after the pick on one cola. It's been a few years. I do have a filter on the intake air for the flower tent but don't take any other precautions for mold other than keeping it clean.

High plant populations in close quarters probably aggravates the situation. I usually only do a couple plants at a time.

[SoOrbudgal]

Hurry and get the grow on Bluey we want to see something LOL

[Bluey]

Patience Grasshopper SoOrbudgal
3Berries last grow I too had 80%RH for 2 weeks straight, in mid flower, and I lost every large cola to bud rot. It was a rude shock, and terribly disappointing. This grow I have a dehumidifier and extra airflow. I can get low 40s of a night and high 40s of a day....I won't let that happen again now I can avoid it. 80% of that crop went into the bin. I have a filter on the AC & dehumidifier but I won't rely on them plus I want to bring out the terpines which I haven't done before as I've always grown outdoors with these.
These seed strains can best be described by me as Old School bush...qualities many people in there 40s and older appreciate...not striving for high THC. Current daytime climate data below

I have 4 of 7 remaining from seed....still letting the other 3 grow a little more to be 100% they are male then I'll pull them and rearrange the pot and lighting layout and flip to flower..last crop I only got 2 of 7 to flower, user error mostly and males, so 4 will be a big bonus for me. I need lots more glass jars.

[3Berries]

My 80% is only when the lights are out just for the record. Lights on it's regulated to the VPD 1.10 range or so usually upper 60%s

A lot depends on the local environment too I suppose as far as fungus and mold spores in the air.

[Bluey]

VPD currently averaging 1.1, swings 1 to 1.2 every half hour or so, 57% RH 80⁰F

[Bluey]

Ambient is all over the place...temps as high as 95⁰F and low as 71⁰F of a day, does get to 115⁰F on hot days in hot years. Nights lows of 50⁰F to 70⁰F. Humidity is normally 30% to 80%RH.

I live in wet temperate rainforest that does experience long hot and dry periods.

Their could be unclassified mushrooms on my property and 100s of other moulds and whatnot...paradise for all them here.

I realised last outdoor grow that the climate was not condusive to growing outdoors..I got 8 out of 8 males and many growers around have had black mould on some of their buds...nasty stuff.