Patio heater

A patio heater (also called a mushroom or umbrella heater) is a radiant heating appliance for generating thermal radiation for outdoor use.

A burner on top of a post, burns liquefied petroleum gas (LPG), propane or butane, and directs the flames against a perforated metal screen. Heat is radiated from the surface of the screen in a circular pattern around the appliance. A reflector atop the burner reflects heat that would be otherwise lost upwards. This is because the reflecting hood is usually silvered which makes it a poor absorber/emitter of heat but excellent at reflecting infra-red radiation back. This reduces the amount of heat lost by conduction as silvered surfaces will not absorb infra-red light. The chimenea is an alternative to the patio heater for home use, which burns wood instead of gas.