ventilation/exhaust/air circulation questions

Hi all!

So I am setting up the second bedroom and ensuite bathroom, and I would really appreciate some help designing the ventilation.

The room will be several trays in a perpetual grow scenario, with a smaller light (400 or 600 watt) above each section rather than a single huge light.

My climate is quite cool in the winter, and quite warm in the summer.

I know that during the winter, the lights will keep things warm so I will not have to run a heater or anything. So that takes care of the temperature during cold season. But what about fresh air? I can have fans blowing, but eventually the CO2 in the room will be depleted and there will be a buildup of oxygen, right? So how do I solve this without having to open up a window and blow my temperatures away? Is there some way to vent into another part of the house? I would really like to do this without having to use CO2 tanks (this is my first serious grow).

Also, during the summer, I will have the opposite problem. It will be too hot outside to open up the window, how do I keep my room from getting too low CO2 to Oxygen ratio?

Thanks!

Here's a drawing of the room if it helps.

You might want to consider LED's or T5's rather than HID lights, especially for the veg stage. If you have the door open, you'll be getting ambient air which will have CO2 and will naturally exchange.

There is no veg, as soon as the clones root they will go into flowering.

I can't leave the door open, which is why I have a fresh air concern.

I have been thinking that if there was some way I could vent the air from the bedroom out to another room in the house (preferably as far away as possible) somehow, and then rig the door so it allows air to pass through but not light, then it would create a slight vacuum in the room and pull in air through the door. Would that work?

Beats me. It all depends on your creativity and the variables. Think out of the box and you can find a solution. Do or do not, there is no try.

it should work, vent the air out to anothr room or w/e and then just put a 90 d angled pvc or duct part and possibly have a pc fan for it blowing in too, its all up to you though. But as long as your xhaust fan and your intake size provide (-) pressure then your good to go.