Sharing heat from one room to another

[Vadski]

Hi, with winter temps knocking I want to install two exhaust fans to push/pull air from one room to another. Each flower room runs on opposite 12hr cycle so I want to transfer the warm air from the lights on room to the dark room. I have two identical exhaust fans that I hope will create identical pressure force to avoid smell leakage.

Potential benefits
1. Reduced heating cost
2. Free co2

Potential problems
1. Excessive humidity
2. Trouble controlling day/night vpd

My rooms are only fresh air exchanged without ac or co2. I do have dehumidifiers and with this setup I’ll be able to utilize equipment from both rooms as one’ish unit. I’ll still have to find a way to control the two motors on a thermostat available to both rooms.

I’m going to run it jus to see what happens but I’m hoping to hear potential problems I’m not seeing. Main problem is both rooms are on different schedule. Currently room A is on week 6 and room B is on week 3. I will find myself sharing air with a room that needs the humidity to a room that does not.

Any input appreciated, thanks!

 

[Creeperpark]

I would set the photoperiod as close as I could together to make sure the heat is transferred in the normal "day heating" and "night cooling" ranges. Flowering time is cool temps and Veg time temps are warm.

I have 4 fans on a timer 24 hrs a day all running at different times. The timer is set up to move air in and out of the grow. The thing to remember is the water I bring in has to be able to leave grow area. If the growing areas are not exchanged so to speak I will develop mold on my Heating Ducts and other hidden places and never see it or know it. However, one way to know you have mold is by having a runny nose every morning.

Some people are sensitive to molds. For these people, exposure to molds can lead to symptoms such as stuffy nose, wheezing, and red or itchy eyes, or skin. Some people, such as those with allergies to molds or with asthma, may have more intense reactions. Google

 

[Switcher56]

@Vadski
I'm with Creeper on this one... if one grows indoors, you become the environment. It's up to us to ensure our girls are comfortable at every step of the way. I don't have that issue because although I run 2 tents V/F, it is only my bloom that is running. I start vegging at the flush I don't flush (straight H2O (HP Promix)). While I am vegging, I use my bloom room for drying my harvest. By the time I am done with that, after a good cleaning, my girls go into the flower room. That sucker is precisely dialed in. With the reconstruction of our house and heat pumps. I should be able to nail it to a "T". Of course it goes without saying, that once you havre your house dialed in for the proper RH and temp, the rest is up to your tent controllers.

 

[Tynehead Tom]

I use a Lung Room between my veg and flower room. The veg room is powered by HLG LED lighting and needs supplemental heating from October to May. I do have thermostat controlled portable baseboard heater than works very well at controlling temps in that room but in winter months when i flower indoors, I flower with HID lighting. The veg room and flower room both draw air from the lung room which has BOTH humidifier and dehumidifier but very rarely does the dehumidifier come on in my environment. RH outside right now is 15% and -12C to give you an idea of what my lung room intake air is coming in at.
The trick is to balance the humidity so that at lights out when your flower room humidity spikes..... your incoming air from the lung room balances things out quickly.
I have 4 x 50cfm fans, 2 for each room make for an intake and exhaust for each room into the lung room. Exhaust at the top and intakes at the floor. The flower room (250cfm) and the veg room(110cfm) both have exhaust fans to outside as well and they are controlled to kick in on timers for full air exchanges with passive intakes in both rooms.
The set up is hard to describe and there are many backflow preventers in use in the set up as well.
A friend uses grow tents whereas I utilize a 7.5 x 7.5 x 8 room and a 5.5 x 7.5x 8 room
He uses 3 tents set up in a row in his shop and the left one is his veg and clones, the middle one is his lung room with his various appliances for controlling heat/humidity and fresh air intake and the right side one is his flower room. Pretty much set up exactly like I am doing it and he is super happy.
To do it right you need controllers like inkbirds or a couple of the larger all in one environment control boxes.

 

[AmanteSativo]

Me and my friend done the same thing,grow box outdoor in Winter ,in a Little wood house,It work great