Even though vent-free gas heaters capitalize on the clean-burning properties of natural gas or propane to provide room heat, controversy surrounds the issue of how clean they actually are. Several conditions limit their use, and California prohibits them for residential heating altogether, although you can use one to heat an outbuilding or even a shed. Controversial or not, vent-free room heaters are easy to set up, requiring nothing more than a secure location and a supply of gas.


Whereas a standard gas heater draws air from the space or from outside to burn its gas and exhausts the combustion gases outside, a vent-free heater recycles space atmosphere. The elegant design of the heater lowers the production of combustion gases to a minimum, and proponents of vent-free heat claim 99-percent efficacy. Compared to traditional heaters, vent-free heaters have a compact design, and because they don’t need vents, they could fit into small spaces. All they need for operation is an ongoing flow of gas, usually supplied via a hose in a remote tank.

Sizing Your Heater

To determine whether the heater you intend to set up is the right size, then you want to form a ratio of the room’s volume to the quantity of heat produced by all appliances in it, such as the proposed heater. If the ratio exceeds that determined by the National Fuel Gas Code to constitute a “confined” space, then you need to either use a smaller heater or find a way to admit additional air into the space. Failure to do either could contaminate the space with unacceptable levels of carbon dioxide and carbon monoxide. You should consist of rooms which adjoin the space you are heating on your calculation, even if they don’t have doors.

Installing the Heater

When you’ve determined your heater is secure to get the space in which you are installing it, the actual installation procedure isn’t difficult. If the heater has legs, then you can simply place it in a corner of their room or against a wall. A heater without legs just hangs on screws set into wall liners, like a picture. You might have to make a hole in the wall to get the gas hose as it’s illegal to store gas containers indoors. The heater includes a typical screw-on link, but you might have to purchase a particular fitting to create the connection.


Among the key products of the combustion process of a vent-free heater is water vapor. A 40,000 BTU heater puts out a gallon of water each 2 1/2 hours, which may raise the humidity from the space to uncomfortable levels and make moisture-related problems. Moreover, the heater also lowers air quality by placing out nitrogen dioxidethat unites with the water to form nitric acid. Furthermore, if the heater is not cleaned frequently, it may emit black carbon deposits which end up layer everything in the room. A dirty heater may also make an unpleasant odor.

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