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There are a few different kinds of electric space heaters, convection, radiant , both come with or without a fan. When you want to heat a whole room, a convection heater is your best bet. A convection heater with a fan moves the warm air up and out. You can get a large heater that is movable to heat up a large garage or workroom.
Radiant heaters are made for smaller work areas. Many people get a small radiant space heater for use under a desk at work. Radiant heaters can be an infrared heater that uses quartz tubes, ceramic heaters with ceramic cores or oil filled.
Oil filled heaters are very economical. There is a special thermal oil sealed inside the heater. It is not used up so it never needs to be replaced or refilled. The heating element heats the oil which runs through the radiator coils and heats the air. Oil filled radiators take some time to heat up a room but once the oil gets heated, the heating element can be turned off and the heater will still radiate heat for a long time.
Ceramic heaters heat a ceramic element inside. Sometimes ceramic heaters use fans to push the air out and heat the room quicker. They are lighter than most types of electric heaters, which makes them very portable.
Quartz infrared heaters are a type of radiant heater. Quartz infrared space heaters produce heat similar to the way the sun heats things. Infrared rays actually penetrate the skin and objects to heat them up from the inside. The heaters do not actually heat the air but heat the objects in the path of the rays.
Propane space heaters are great when you do not have a source of electricity. They are mainly used on outdoor camping trips, ice fishing or other activities like that. Propane space heaters make great outdoor patio heaters. Because propane heaters create carbon monoxide as they burn, you need to use them outside or in a well ventilated area.
The best heater you can find is the one that works for you. First determine what you need the heater for, and then find the type that will do that task best. You can find a heater for any budget. It doesn't have to be expensive to work well.