If you are trying to heat something bigger like a garage or a shop, you want to avoid using a radiant heater. Instead, using a convection-style heater that has an infrared quartz heating device inside of it.   The way this works is that cool air is pulled from the room you are heating into the heating device. As the air cycles through the device, the infrared quartz heating coil inside of it warms that air instantaneously. The now warmed air then gets blown gently back into the room to circulate and warm the entire room. Infrared quartz is incredibly efficient at heating the air that is cycled through these devices. They use the least amount of electricity possible to do their job. On top of their efficiency, they don't need time to warm up. Once you turn on a heater and set the thermostat, the infrared quartz heating coil should start working immediately. After turning one of these heating devices on in your shop or garage, you should feel the warmed air pouring out of the blowers almost immediately. While it may take a couple of minutes for the air to circulate and heat the room, the space directly next to the heater will feel the warmed air right after the device is turned on.   Many infrared heating devices use an adjustable thermostat. An adjustable thermostat lets you set the temperature to whatever your preference is. Whenever the temperature drops below this number, the heating coil will work a little bit harder to put out more heat and bring the temperature back up. Whenever the temperature is right or above the setting, then the adjustable heating coil will work less or stop completely until the temperature drops back down. This is very similar to the way a central heating and air conditioning system works.