Gassing animals with CO2 cartridges, supercharged greenhouse atmospheres and even employees succumbing in brewing chambers are not even remotely in the same class as CO2 levels in a residence.

I am not a code expert, but I don't see where IRC2012 requires that every room has fresh air in. It makes sense for sleeping rooms, but is this the same sort of thing as saying that every room needs a heat source? Maybe you could point us to the code or developing code that will require this.

Posted By Gary Olsen on 30 Oct 2012 09:22 AM

CO2 is extremely dangerous. As an exterminator, it was the easiest and quickest way to exterminate a raccoon, or skunk. A CO2 cartridge, a trash can with a lid, and 2 minutes was all it took. I have heard of pot growers who use CO2 in their growhouses. Some have died due to lack of careful use of the CO2.

CO2 as found in compressed tanks is not the same concentration levels as found from people breathing. An air tight home is not a submarine filled with people that is submerged under the ocean for months or years.

Carbon dioxide content in fresh air varies between 0.036% (360 ppm) and 0.039% (390 ppm), depending on the location. Concentrations up to 1% (10,000 ppm) will make some people feel drowsy. Concentrations of 7% to 10% (70,000 ppm - 100,000 ppm) may cause suffocation within a few minutes to an hour.

For a home to reach levels of 10,000 ppm or let alone 70,000 ppm would take a long time and a lot of people. It couldn't be done on accident, it would have to be intentional.

So I call BUNK on the whole air tight home and CO2 poisoning. IMHO, it's basically a mentality based on fear mongering. It's like this contractor I know. He is so old school that he believes the leakier the home, the better. When I mention air tight homes and ERV/HRV, he completely finds building an air tight home to be ridiculous. He is set in his ways and he views change with hate. He also thinks that over-insulating a home is a waste of money and thinks R-19 fiberglass batts is the most insulation one would ever need.

Posted By ICFHybrid on 31 Oct 2012 08:20 PM
I am not a code expert, but I don't see where IRC2012 requires that every room has fresh air in. It makes sense for sleeping rooms, but is this the same sort of thing as saying that every room needs a heat source? Maybe you could point us to the code or developing code that will require this.

The 2012 IRC does not require multiple ERV/HRV for a residential home. Unless one was building air tight rooms within the home, the air circulates throughout an entire home. When someone burns popcorn the smell goes throughout the home, into every room.

Good points ICFHybrid and Lbear.
I am responding from my S/O's computer. Mine is in repair, out soon. So I cannot easily give the link or code numbers that refer to my reply. The code did NOT specify an HRV for every room. That was my brain thinking that small HRV's would take less ductwork, smaller wattage fans, and would be easier to clean. Plus if HRV's are activated by body sensors, the air is kept clean in occupied rooms.

Sorry about the focus on CO2. I recall a National Geographic film showing a small pit in the ground that allowed a bowl of CO2 to collect somewhere in Africa that killed many animals, from small to big. I also used CO2 cartridges in my pest control business to exterminate raccoons. While my experiences are the worst case scenarios and do not relate to air quality in a home, CO2 is one of the pollutants they test for. There are several. I will dig out the detail when I get my computer back.

Ken Kearn wrote in his book about Masonry Stoves about old homes. Written in the 60's, he discussed the history of burning wood for heat. He mentions that old homes leak air like a strainer which kept the air fresh when the stove was used. He emphasized that heavily insulated homes get stale air because they dont have enough fresh air for burning wood.

I also wonder what is coming our way regarding air quality. Human population, wars, traffic, hurricanes, earth quakes, global warming, etc. make it difficult to pick the best way to make a new habitat. I can't change any of those, so I don't worry about it as much as it may seem from my reply. I can just make some decisions to minimize my risk, to some degree. Hopefully.

So most of you do not think air quality is of much significance?

Proper ventilation in any building structure is a necessity .ASHRAE 62.2 goes into great details what is required to meet minimum ventilation and exhaust requirements.Any rate less than ASHRAE 62.2 is subjecting the occupants to an unsafe health risk.

Posted By Gary Olsen on 03 Nov 2012 10:52 AM

So most of you do not think air quality is of much significance?

Quite the opposite. When it comes to tight homes, the ERV/HRV is what controls the air quantity and quality. The incoming air can be filtered through HEPA filtration. The amount and cleanliness are all controlled.

With a leaky home the air coming in is not controlled and it can be polluted and it will not be filtered. The amounts can be high at times and then low, it's never regulated and unfiltered.