When choosing permanent over-head radiant gas patio heaters, I generally encourage a phone conversation, because there are too many variables to cover in a short description or blog post. Call 888-927-6456 (888-warm-glo).
Infrared Dynamics SunPak is the original. (Models S25 and S34) Any and all others are imitations. The SunPak can be mounted in unsheltered areas. The S25 has the lowest combustible mounting clearances of any gas patio heater I know of. It is reasonably quiet. It is reasonably reliable. It requires external 24 volt wiring. Black or stainless steel finish optional. Natural gas or propane optional. Excellent customer service and support. Made in California.
Twin Eagles TEGH48 is also a good product. It has the advantage of a low and high setting. It must be somewhat sheltered. It requires significant combustible mounting clearance above and behind. It is reasonably quiet. It is reasonably reliable. It requires no external wiring, but batteries must be periodically replaced. It has a remote control for operation. Stainless-Steel finish only. Natural gas or propane optional. Excellent customer service and support. Made in California.
DCS by Fisher and Paykel's DRH48N (also called Del Rey) is very hot. In my opinion the lowest part of the DRH48N should always be mounted above 9 feet high. It can be mounted in unsheltered areas. It requires the most clearance from combustibles of all similar heaters. The powerful burner is a bit louder than the SunPak and Twin Eagles. It requires external 24 volt wiring. Stainless-Steel finish only. Natural gas only. Made in Mexico.