The most preferred type of permanent patio heaters are wall or ceiling mounted gas infrared heaters. The state-of-the-art SunPak outdoor heaters are installed up and out of the way, and light with a flick of a switch. The infrared burner tiles glow orange ten minutes after igniting the heater, projecting efficient warmth. SunPak heaters are American made by Infrared Dynamics. Beware that some overhead gas heaters are designed for warehouse use, and will not endure an outdoor installation. The outdoor-rated SunPak heaters are slick looking at 8” x 8” x 48”. One will heat an area approximately 8’ to 12’ square, depending on the model, orientation of the heater, and ambient conditions. A flammable ceiling must be at least 9’ high to even consider using an overhead gas patio heater under it. A 10½’ (or higher) ceiling will give you maximum versatility of model and ability to tilt the heater. Currently the only overhead gas heater with a low setting is the Twin Eagles, which is also American made. Infrared Dynamics is working on a dual heat SunPak patio heater. I anticipate that it will be on the market in 2012. The disadvantage of permanent gas overhead patio heaters is the purchase price. Overhead natural gas patio heaters are convenient and inexpensive to operate.