Apropos of the ahr thread Gas vs. electric range, someone spoke favorably of ventless gas heaters.
Some time ago, it was complete news to me that "ventless gas" heaters even existed, as I thought it was safety no-no, and also being conditioned to vented Modine blowers -- not cheap, AND you need a stack. But after some reading, I thought I'd died and gone to heaven, regarding my shop heat problem, ie, freezing my ass off.
So I bought TWO, of the "radiant" type, with the ceramic ditty, a small and a large, plumbed gas to the shop, and BAM, from a heat pov, I was in seventh heaven. I need not have bought two, and could have easily gotten by with just the small one! Cheap, too, I think $119 and $79.
But.... BUT..... The air quality was atrocious!! You could FEEL the air in the back of your throat -- and I spent many a youthful winter huddled in a gas-heated kitchen, with no such sensation. A little stuffy, mebbe, but nothing like this. Almost acrid.
Second, the water vapor.... holy shit..... I don't think a dehumidifier coulda kept up with the vapor, and the wall above the unit was just soaked -- not good metal, machinery-wise, OR wall-wise..
They lasted a month, and have been in plastic wrap for years now.
Never could figger out what that smell/sensation was, as they seemed to be burning clean, altho I never did bring down the CO detector. But I'm sure had those sensations been related to CO, I'da blacked out or wound up with a CO migraine.
Too bad, cuz the heat was ossum. In a sense, the poor air quality mighta been a blessing, cuz I proly woulda endured the prodigious water vapor, to the long-term detriment of the shop.
Now, I've added lotsa lighting, proly almost 2 kW worth, so THAT helps in the winter. That, and a long electric baseboard heater (with a 3 way wall switch, you can get high heat and a nice low heat, by switching 120 V to it), the dehumidifer, and the machines themselves keep it OK -- not toasty, like the ventless gas, but OK. A second portable electric heater helps in the super-cold. Also calisthenics.... LOL