Plenty of recreationists and sportsmen use so-called vent-free gas burning heaters to stay warm in the chilly months. Depending on how and where they are used, there may be better (and more safe) options to consider.
Many high output gas patio heaters need a circulation and an exhaust vent for proper operation. Exhaust vents help expel dangerous gases to the outside of the building or up into the attic. While this is great for safety, it’s not so great for energy efficiency. Vents allow warmed air to escape along with gases, which can certainly lead to poor energy usage.
Thanks to their design, vent-free propane heaters supposedly don’t require a dedicated exhaust or venting system. As you might expect, there are some obvious advantages to this design. First, the overall operating efficiency is increased as you won’t be heating air to only allow it to exhaust into space. Installation and maintenance of the gas heaters is also easier due to the lack of ductwork or venting.
Many ventless heaters require an electric outlet to ignite. However, you can also find models that can operate without electricity (such as the Mr. Heater Buddy Gas Heater). This makes a great fit for ice houses, cabins, tree stands, lodges and other spots where a plug may not be handy.
Sure, vent-free gas heaters sound great. However, there are a few safety concerns that prevent us from completely recommending them for all uses. Surprisingly, some vent-free heaters recommend opening a window in the room being warmed to ensure proper ventilation. Vent-free heaters suddenly seem a little less “vent-free” when you must keep a window ajar when in use.
Truth be told, vent-free heaters will still produce gases that can be dangerous in the right quantities. They are in smaller percentages than your typical propane heater, but even smaller amounts of carbon monoxide can be hazardous, as research has shown. To operate them safely, venting will still be necessary to some degree, which defeats the purpose of a vent-free heater quite a bit!
Happily, modern gas heaters typically utilize an auto-shutoff sensor that measures oxygen levels in the room (similar to common ceramic heaters). While this eases concerns a bit, I would consider taking things a step further. In addition to following all safety recommendations from the manufacturer, you should also install a carbon monoxide alarm near any running propane heater.
When it comes to warming a well-ventilated area (think drafty cabin, partially-enclosed porch, or tree stand) vent-free heaters can be worth a look. Yet, don’t completely take the promise of vent-free heating at face value. There are plenty of safety issues you should take a look at before buying.
