Efficiently warms a room up to 160 square feet.
= 1440 watts total (4913 BTU/Hr). A 12' x 12' room with an 8' ceiling would require a 1500 watt fan forced heater. The best place for installing a baseboard heater is on an outside wall under a window.
The first technique is to simply figure the square footage of the space you want to heat. In warmer climates, multiply this number by 10 - 15. In more moderate climates, multiply by 20 - 30. And in cold climates multiply the square foot number by 30 - 40.
But in general, since central heating powered by natural gas is cheaper than heat from electricity, heating a large space will cost less with an HVAC system that runs on gas.
the amount of electricity consumed by an electric heater depends on the type of heater, how often it is used, and for how long. Space heaters usually consume between 400 and 1500 watts of electricity, and the majority use around 800-1000 watts.
To understand how many watts are needed, it is important to know how well your room is insulated. The more insulation, the less wattage is needed to effectively heat the space. But with that said, you are going to need somewhere between 5-10 watts per square foot.
A heater that is too large for the space will not heat the space more quickly. A heater that is too large for the room will continue to heat for an extended period of time beyond the temperature set point, wasting energy. We call this a temperature swing.
In this case, if you have a room that measures 10 feet in length and 10 feet in width, the calculation would be straightforward. So, the equation would look like this: 10 feet (length) x 10 feet (width) = 100 square feet. This means that a 10x10 room is 100 square feet.
Calculating the number of BTUs needed to heat an area
For example, a 300 square foot room typically requires 7,000 BTUs to maintain a comfortable temperature, while a 1,000 square foot room requires 18,000 BTUs.
A unit of power density. In a data center this is a bulk term that refers to the total load in a particular space divided by the total area of that space.
A 400W heater produces the same heat as a 400W light, because light is a form of heat. Light which falls on a surface and is absorbed will heat that surface. A 30% efficient light should dissipate 30% of its heat (120W worth) in the form of light.
Generally speaking, Halogen heaters are one of the most inexpensive types of electric heater. They average around 1200W in terms of power output and because they provide instant-heat at close quarters, you shouldn't need to leave them on for long periods of time.
Oil heaters. They cost around half the amount to run than fan heaters do. Other benefits include better heat retention, safer use, and less dried-out air. When planning on investing in a new heater, whether it's oil or fan, make sure your room has a good level of insulation so it can retain heat better.
A good rule of thumb to determine how many watts you need to heat your space is to remember, 10 watts per square foot. 500 watts is great for up to 50 square feet, spaces like a desktop, cubicle, or bathroom.
An electric space heater rated at 1,500 watts will put out the same amount of heat regardless what you pay for it. You would be better off to take the money you would spend on a space heater and put it toward weatherization improvements to your home, such as adding insulation and caulking.
Calculating Your Garage Heater Size
Watts are easy enough to follow as they can be quantified by 10 watts per square foot of space.
A 400-watt heater uses 400 watts of electricity when it's running. If you leave it on for one hour, it will consume 0.4 kilowatt-hours (kWh) of electricity, because 1,000 watts equals 1 kilowatt. So, if you keep it on for a whole day, that would be about 9.6 kWh.
The average home refrigerator uses between 350-780 watts. Some refrigerators are more energy efficient than others, so you'll want to check the label on yours or look it up online to see how much power it consumes.
The Energy Department estimates that the cost to heat an entire home with electric space heaters cost 43% more than a gas furnace. Using a space heater in your bedroom only while you sleep is a practical way to use a space heater and won't make much of a dent in your electricity bill.