Space
Ventless fireplaces can accommodate large and small rooms and outdoor spaces. Various styles are available to suit your room, including perspective or double-sided models. You can get a custom fireplace to fit your space or a fireplace insert to replace an old one.
Material
They are made in many different finishes and designs, and are often lined with stainless steel, cast iron, or other fire-resistant materials. They operate on natural gas or liquid propane. Some even use alcohol gel cartridges, similar to Sterno jars. Most use man-made ceramic fiber logs to create the illusion of a real wood-burning fireplace, lava rock, or pieces of colored fire-resistant glass. Some log sets come with wooden fences, glowing embers, or sand for placement under the logs. Unlike other fireplaces, ventless gas fireplaces do not have doors for any closures because they require ambient room air to fuel the gas flame.
Size
Each space has a maximum thermal tolerance based on its size. Average sizes range from 12 inches to 42 inches, but you can find longer sizes like 72 inches. Heat output varies from 20,000 to 40,000 British Thermal Units (BTU). To calculate the maximum BTU for a room, multiply the length, width, and height of the room to get the cubic feet of the room. Then multiply by 20. For example, if a room is 1,400 cubic feet, it should not emit more than 28,000 BTU. When purchasing a ventless gas log kit, it will list the firebox space requirements and give specifications.
Security features
Well-insulated homes sometimes have low oxygen levels, resulting in slow exchange of indoor and outdoor air. Many ventless gas fireplaces have oxygen detection systems that automatically shut off the unit if the oxygen levels in the room drop below a certain level. Fireplaces may also have built-in carbon monoxide detectors that automatically shut off the fireplace if high levels are detected.
Special option
You can light most ventless gas fireplaces with a switch or by pressing a button on the fireplace or remote. Many are equipped with automatic ignition, eliminating the need for a constant light. Some also have a battery backup mode in case of a power outage. In many cases, you can control the size of the flame and use less gas.
