Where should I mount my electric shop heater?
• For workshop heaters you can use a hardwired or portable electric heater. Make sure you look and the heaters mounting system before your buy it.
Some model don’t come with wall or ceiling brackets, this is a bracket or bent metal bar the is screwed ceiling beam or wall.  Most people mount them over they shop table and not blowing directly on to them. Some people find the blowing from the fan on your head to face is unappealing. As long heater is pointing down at an angle in your general area you should be comfortable.      
• Don’t mount it to high and not point the fan point downward, the only thing with will do is heat the ceiling. Heat rises quickly from the fan, about 10 to 15 feet then back up to the ceiling.
What to look for before buying an electric shop heater.
• Unlike gas heater electric shop heaters don’t work during power outages.
• Like all fan force heaters garage heaters do make some fan noise.
• Before buy an electric shop heater be sure to read the user manual for proper clearances from walls, ceilings, and combustible items in your garage. Sheetrock and wood paneling walls are classified as a combustible wall. 
• Before purchasing or installing a new electric heater make sure your electric panel can handle the extra power load. Many homes only have a 100 amp service and adding a 10,000 watt electric heater with a 42.1 amp power load could trip the main circuit breaker every time you turn the heater on.
• Some shop heaters come with two heat settings High and Low. This is a nice feature because it isn’t January every time you want to put the heater on. Sometimes half the heat is all you need in the spring and fall.  
Electric shop heaters permanently wired VS portable electric heaters.
• Most portable models max out at 5,000w to 7,500 watts. Unit heaters can go up to 10,000 watts on a 240 volt power supply.
• A standard Portable garage heater needs a 30 amp on top of the heavy gauge wire you just had to buy. If you’re not going to move the heater form room to room just hardwire it to the wall and you’re done.
• Sometimes a portable heater is a great garage heater option so you don’t have to heat the whole room just your work space. If you have multiple 240v outlets around the room you can carry the heater around the room.
 
Is an electric shop heater efficient?
• Yes – Electric heat is 100% efficient, in fact all other shop heaters are compared to electric heat. Indirect gas and oil heaters need a flue vented to the outside. Anytime you need a flue energy is lost & vented outside. Electric heaters are simply devices 240 volts goes through the electrical safety devices to the heating element. The element heats up and the fan cools the element down. A thermostat wall or unit mounted measures the return air temperature. It the air I cooler than the desired setting the electric keeps flowing, when room air is at or above the desired temperature the power supply to the heater is disconnected. No wasted energy, all the heat is pushed into the room and nothing is vented outside.

 
What size shop electric heater shop should you get?
 
Most shop heaters are 3,000, 4,000 & 5,000 watts. On average the best-selling shop heaters are 4,000 watts with a mounting bracket and built-in thermostat.
 
Electric heating is any process in which electrical energy is converted to heat. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an electrical appliance that converts electrical energy into heat. The heating element inside every electric heater is simply an electrical resistor, and works on the principle of Joule heating: an electric current through a resistor converts electrical energy into heat energy.