Correct me if I'm wrong - after "scanning" both articles.
The first one is about unvented heaters. No break-down into catalytic and blue flame. Blue flame ones produce more CO/CO2 per BTU than catalytic do (might not be in any of these articles, I read another study on this subject before and quoted it here few times). What constitutes an adequate air flow, and most important - WHEN your rig have it and when doesn't - is not clear.
Another article compares "burner" radiant heaters and "heater-cooker" radiant heaters, neither one includes catalytic types. Conditions included specified air flow, I don't know how to translate this into, say, square inches of open vents/windows in absence of drafts (but there are always drafts), or forced fan flow.
As much as I'm trying to support manufacturing other than Chinese, I don't have anything good to say about
ventedcatheater.com. Couldn't even get one when tried few years ago. Small business. For several months he was busy with warranty repairs, and then didn't return my emails. Ordered Olympian cat heater on Amazon for half the price of that vented heater and use it with windows and vents slightly open (screen door is often open until I go to bed). Also keep a very thick and heavy duvet and often use it in the night, and then shut the heater down. Saves propane and all the other worries. End of story.
Edit - PS: it might also be of interest to traveling people that in-cabin CO concentration on a highway often exceeds those ANSI norms.
