With temperatures dipping below freezing across the United States, older furnaces can have trouble keeping homes comfortably warm. To add heat, people use unventilated or portable gas heaters, often called "space" heaters, kerosene heaters or salamander heaters. But are they safe? If used with common sense and following the manufacturer's instructions, the answer is yes.
Most people worry about carbon monoxide (CO) from unventilated gas heaters. There is a low risk of CO poisoning in newer indoor gas space heaters that have a built-in oxygen depletion sensor (CO is the result of incomplete combustion caused by lack of oxygen). Older space heaters or outdoor heaters do not have oxygen depletion sensors. When used in enclosed spaces, CO can reach dangerous levels.
No matter what kind of gas heater you have, it makes sense to keep a carbon monoxide alarm nearby. CO alarms are inexpensive, and readily available in home improvement stores. For added safety, follow the heater manufacturer's instructions carefully, and avoid using unventilated heaters when you are sleeping.
However all gas space heaters produce large concentrations of carbon dioxide (CO2). While not normally harmful, too much CO2 in an enclosed space results in sleepiness, headaches, and contributes to what we often call “cabin fever.”
To monitor indoor CO2 levels, many people use our TIM10 Desktop Meter. If CO2 levels are high (above 5,000ppm) it is time to open a window or go outside for some fresh air.