Bromic Heating Tungsten Smart-Heat 38,500 BTU Propane Gas Freestanding Portable Patio Heater. Freestanding Patio Heaters. Bromic Heating leads the market in supplying your outdoor patio with radiant heaters that demonstrate outstanding performance and unbeatable quality. Unlike the elements on dome or mushroom style portable patio heaters, the 38,500 BTU infrared directional standing Tungsten heating element does not suffer from vertical heat loss. Most heaters heat the air around them. As that hot air rises, the heater ends up heating the air above them instead of the people and space around them. The radiant heater element on the Bromic Tungsten Freestanding Portable Heater heats directionally to warm 200 square feet, up to twice the area of other portable dome, mushroom or tower style propane heaters. The heat radiates evenly so the warmth is directed toward people and deep into open areas. A single push of a button starts the heater, and a control knob allows you to increase or decrease the heat output as needed.