does your grow tent need outside air

Its winter time so I have to keep all my wimdows closed or it gets too cold (not to mention I get sick at night because my grow is in my bedroom). I have good ventilation in my grow tent with intake/oscillating ans/exhaust but no outside fresh air. Is this ok?

There's still outside air, it's virtually impossible to make a house air-tight.

Too many plants will technically lower the co2 levels below outside, but unless your heating with electric, the co2 from the furnace and water heater probably makes the co2 levels higher. My basement will have 800-1000ppm of co2 in the summer just from the hot water heater (outside is about 600, and slowly increases as fossil fuels are burned)

Wouldn't all of the c02 produced by those appliances be pumped out side, i know by looking at my water heater that there would be some c02 escaping into the house because the ducting is not completely sealed that connects to the water heater but still the way the duct is shaped directly above the flange with an inch or so gap would lead me to believe that most of the heat and co2 are escaping the house via the roof, as far as the furnace goes i really do not think there would be any co2 escaping from it that is a lot of gas being burned up when it kicks on so i would think that the combustion chamber would be sealed and vented to the roof.

I am not an hvac specialist or a plumber though this is just my personal opinion, as far as the question of enough c02 being in your house goes i would say it would be fine unless you have a huge grow with huge plants, as the previous dude said you cant make a house air tight and every time you open the door you are getting some fresh air.

I have a sealed tent, they get enough fresh air just from the amount of times I open up to check on them a day lol.

Just sleep in the tent. This way you get to take in all of the fresh Oxygen from your babies, and your plants take in all of the Co2 that is being produced by you breathing. That will make you happy and healthy.

As far as air exchange with the air in the room you will be fine