A recessed heater is a great option for small rooms and entrance areas that don't have heating from the home's heating system. These areas may also include bathrooms, mudrooms, laundry rooms, and sunrooms. Basically, any room that could use a boost in temperature, but without obstructions or flammable material within a safe distance, is a candidate for this type of heater.
Unlike a bathroom fan/light/heater combination, which is mounted in the ceiling, this heater is placed in the wall cavity, closer to the floor. This allows the whole room to be heated as the warm air flows from the floor to the ceiling.
A recessed wall heater is mounted in a metal housing box and is wired directly to the unit wiring. A smaller unit could be added to an existing circuit, but larger units, say, 1,500-watt models, should have their own circuit. The circuit should be a dedicated circuit that allows for a 20-amp connection. This requires a #12 AWG wire that is connected to a 20-amp circuit breaker or fuse. The heater I'm dealing with requires around 6 amps and is located in an entry room off the garage, often referred to as a mud room.
To calculate how much each unit draws, a good rule of thumb is to figure each 250-watt draw will use 1 amp of power. Now, take into account that you may need to place more than one heater in a room to provide heat coverage, and you can see why a dedicated circuit is recommended.
Recessed wall heaters vary in size and are rated from 750 to 1,500-watt heaters. These heaters also have different voltage ratings. Obviously, a small wall heater could be added to an existing 120-volt circuit if the load requirements of that circuit allow it, but a 240-volt model will require a new circuit to run the unit. The efficiency of a 240-volt system is much better than that of a 120-volt model. Again, it depends on the application and the availability of circuit space in your electrical panel.
A line-voltage thermostat is used to control the heater from a remote location like a wall in the room. It's a very simple connection process, connecting the incoming wire from the electrical panel to the line connection of the thermostat and the wire feeding the heater to the load side of the thermostat. ground the thermostat and you're ready to turn up the heat.
Aside from recessed wall heaters, there are some other options for heating rooms that need a little more warmth. You could also install a baseboard heater that serves up heat where cutting in a register vent isn't practical or possible. These baseboard heaters come in different lengths but are usually either 2', 4', or 8' lengths. Add one with a line stat and you'll have heat in the area you want in no time at all.
Another option is a portable electric heater. These come in the old milk house style that have a thermostat mounted right on the unit itself. these units have a built-in safety that shuts the unit off if it tips over. Another model looks like a baseboard heater, only with feet. It also has a thermostat to control the temperature but is much longer for better heating.