View Full Version : Leaving windows open at night for fresh air.

01-30-2012, 08:13 PM
It gets too hot during the summer to leave my windows open during the day, so if I just left them open at night would that be enough to recirculate co2 into the room? Would a 4'x4' garden use up the co2 in the room during the day?

Also, what's the point of using a tent?

01-31-2012, 10:26 AM
A 4'x4' garden could use up the co2 from fresh air in less than an hour. If your only source of CO2 is from fresh air, you generally want the air in the room to be exchanged about every 3 min. ie) if your room measures 8'x8'x8' you have 512 cubic feet of space. Divide that by 3 and you need a fan capable of at least 170 cfm. If you add a carbon filter for odor control, be sure to check the filtered cfm is still within range.

Are you using grow lights during the daytime? If possible, it may be easier for you to control temps running the lights at night. You may also save a little on your electricity bill.

A tent basically makes controlling your environment much easier. With a tent, there is no work involved in controlling the light cycle and you can have multiple light cycles in the same room - so you save space, its more cost effective to add additional co2 (like from a co2 tank), and easier to manage pests and diseases. The floor of the tent also helps control spills and the walls of tent usually offer some reflectivity so less light is wasted. You also don't need to worry about doing any real construction like hanging lights from the ceiling of your room or cutting holes in walls for ducting.

01-31-2012, 03:39 PM
Thanks Boze, that helped. So, I will probably use a tent so that I don't have to worry about disturbing the light cycles. If I have a tent with a fan exchanging the air from the room into the tent every 3 minutes, would it be getting enough co2 if I left the door of the room open to the living room? Or will I have to exchange the air from outside or use a tank?

02-02-2012, 03:12 PM
Using a tank or a CO2 product to increase levels beyond what is normally found naturally in the atmosphere will yield the best results. But going that route requires to you arrange your ventilation system a little differently so you dont also exhaust the CO2 you are trying to create. For my area (Los Angeles) CO2 levels are around 300ppm, sometimes higher if you live near the freeways. When enriching with CO2, you generally shoot to raise levels to about 1500 ppm. The nice thing about tents is you can use products like Excellofizz or the GreenPad to generate CO2 in small spaces. If youre not sure about investing in a tank or generator setup, those products are a good trial.

You can have air exchanged from the room or outdoors. If you choose to intake from outside, you're could be subject to heat problems during warmer weather (assuming you can run A/C indoors) and possibly intaking pests/molds without a proper intake filter.

01-31-2013, 01:12 AM
Thanks for threads and reply to related query which grower faced. It’s helpful to me because I thought to have an indoor gardening.

04-13-2014, 11:24 PM
Good thought.

04-13-2014, 11:25 PM
Great one.