Using any non-ventilated combustion system inside an enclosed area is a very bad idea, here’s why… The chemistry involved in the combustion process is the same for any hydrocarbon fuel, it uses oxygen and gives off light/heat, water, carbon dioxide (CO2), and carbon monoxide (CO). It’s the same for natural gas, LPG, coal, gasoline, diesel, etc. CO is created by incomplete combustion, when oxygen is lower than needed for complete combustion. CO molecules attach to your blood hemoglobin and occupy the space that’s usually reserved to carry oxygen. With CO your blood loses the ability to carry oxygen, so you pass out and die. Even if someone finds you passed out from CO poisoning and administers pure oxygen, you still might not recover because it takes hours to get CO out of your system. Even pure oxygen won’t attach to the blood cells so you die of suffocation from the inside.
So in a closed space (no ventilation) using up all the oxygen can kill you. As the oxygen is depleted CO rapidly increases and can kill you. In addition, too much CO2 concentration can kill you because it displaces oxygen (CO2 also is heavier than oxygen so it starts collecting from the floor up). In order of efficiency, LPG non-vented open flame heaters are least efficient and give off the most CO. Non-vented catalytic heaters are more efficient and give off less CO. Vented heaters use outside oxygen and exhaust all byproducts to the outside, and zero CO to the living area.
Here are the facts according to a
Consumer Product Safety Commission study published November 2017. 64 deaths were attributed to heating systems, and an additional 7 deaths involved heating with some additional factor (engines, stoves, etc.). 39 of those deaths involved use of LPG. "12 occurred in a non-fixed location domicile (e.g., camper trailers or boats used as homes) used as a permanent home, or a structure not designed for habitation used as a home (e.g., sea-land shipping container, metal shed). Additionally, an estimated 22 deaths occurred in tents, camper trailers, and other temporary shelters." 78% of deaths, victims were alone at the time. The majority of deaths "...occurred during the 4 cold months of November, December, January, and February." “In the 3 most recent years… (2012–2014), adults 45 years and older comprised about two-thirds (an annual average of 66 percent) of all non-fire, consumer product-related CO deaths, although this age group makes up only about 39 percent of the U.S. population.”
Consider that's 34 deaths using LPG for heating, during the cold months, of people who were alone at the time, in circumstances similar to van dwellers. The highest risk factors are: LPG used for heating, in a domicile not originally designed as housing, during cold weather, alone at the time, in a camper/tent, and over 45yrs… Some might say 34 deaths per a year in comparison to the 325.7 million people in the U.S. is a very small percentage, hence a small risk. Some might even point out that 34 deaths from LPG heaters are significantly less than the 51 (avg.) annual deaths by lightning strikes, but most of us wouldn’t be caught standing in an open field during a lightning storm, so why are we going to stand for a risk of death by CO poisoning. They are both known risks, just one is more understood. Also, consider the CPSC report only speaks to actual deaths from LPG heating, it doesn’t mention all the other people who were sickened but escaped death.
Here’s the point… even the most efficient catalytic heater makes CO and has risk. When they advertise non-vented heater, they are referring to the mechanical structure of the equipment, there is no obvious exhaust vent on the machine. The living area still requires some air exchange. Any combustion heaters inside an enclosed living area requires cross-flow ventilation (cracked windows, open roof vent, etc.). If we understand the chemistry of combustion and accept there is real risk of death (or illness), then that death is preventable. Predictable is preventable.
An interesting side note from that same report; an even bigger risk is portable generators: "Since 2004, portable generators have been associated with an estimated 696 non-fire CO poisoning fatalities, more than any other consumer product under CPSC ’s jurisdiction."
Please be informed and stay safe!
