While a ventless propane heater is a relatively inexpensive means of heating a garage, there are several reasons to avoid them. There are many other types of portable space heaters on the market, most of which are far safer than ventless propane units. Essentially, a ventless propane heater connects to a propane canister for fuel, and draws oxygen from the room to aid in combustion. Consider these 3 reasons to avoid ventless propane heaters:
Lack of Ventilation
By its very nature, a ventless propane heater does not self ventilate. In other words, the harmful carbon monoxide emissions produced through the combustion of gas has nowhere to go. When used in an enclosed space for long enough, this can be deadly. Consequently, the garage door will have to be left open which negates the effects of the heater.
Because of the presence of carbon monoxide emissions, there are potent health risks associated with the use of propane-burning space heaters indoors. Several states have banned them, in fact. These heaters gradually use up all the oxygen in a room, leading to headaches, dizziness and other symptoms.
Growth of Microorganisms
There is also the risk of the growth of microorganisms like bacteria and fungi in a garage owing to the rise in humidity levels. Combined with a lack of ventilation, an enclosed space with a ventless propane heater tends to create an unsafe environment.