Quote Originally Posted by oldmac

First thing to buy, since you grow where you live and sleep, is a Carbon Monoxide Detector.
This isn't true when using tanked CO2, at least from a reputable source.
Lab and Technical Gases - Airgas.com

a CO detector should be purchased when burning propane as a faulty burner or a lack of sufficient can create CO

The biggest issue about running CO2 where you live/sleep is if valve, regulator, monitor, or timer fail for whatever reason you can be suffocated in your sleep. I think this is generally considered enough reason to not run CO2 in your living area.

But on topic: Sleeping in your grow room may not increase CO2, but exercising definitely does. I've seen an increase in 700PPM on my monitor when me and one other are working hard