One benefit of a vent-free propane heater is the ease of installation, because neither a vent pipe nor chimney is needed. Some LP heaters do not require electricity, so they are useful in a power outage. They are typically quiet, efficient and simple to use.
In some parts of the United States, propane is one of the least expensive fuels. When LP heaters heat often-used rooms, the devices reduce the overall heating bill.
Ventless propane heaters have some disadvantages. They emit gases into the house instead of sending them outside. Some of these, such as carbon dioxide and water vapor, are non-toxic. However, the heaters also release carbon monoxide and nitrogen dioxide, which are potentially dangerous.