@Coach_Ron, this is CO2 accumulation in the room where my TACX bike is set up. I’d originally planned to have my TACX in our gym which has a 300 CFM exhaust system to keep CO2 levels (and odors) low. If I’d known it’d be in this room in our loft I’d have installed an exhaust fan in there (which I may do yet). When I can I’ll open the window in there which results in natural exhausting, lower CO2 and better performance but when it’s raining, snowing or really cold out then that’s not a good option.
420 PPM is actually pretty good as a base indoor ambient level. Fewer than 1% of homes in the U.S. will have anything much lower than 440 with many above 800-1200. Our outside level is around 390 PPM and we have a quite extensive ventilation system that ventilates 10 minutes / hr as well as anytime CO2 levels are above 550. We have just about twice the ventilation recommended by ASHRAE and I’d say we barely have enough.
Normal sampling is done w/ a uRAD A3 which is one of the most accurate available for the $. We also have 4 IQ Air monitors, an AWAIR v2 (v1 were terribly inaccurate, v2 much better) a Foobot (the most inaccurate available) and a couple of others in addition to the 7 sensors for the ventilation system. I have a Gaslab 505 that’s used when greater accuracy is needed.
Performance degradation is largely fewer watts produced. Occasional headaches but only over about 1800 PPM. When I get time I’m hoping to do a lot more CO2 analysis including heart rate, Blood Ox, Lactic acid (if we can get a working K’watch or something), etc.