| When performing home upgrades or buying new | | | | volt variety as discussed above. These 240 volt |
| appliances such as heaters, volts, watts, and BTUs | | | | outlets can also be found in garages, building sites, and |
| should be factors to consider. Some of you may have | | | | other industrial areas, and this is done to provide the |
| noticed that the outlet used to plug in your desk lamp | | | | safer, 120 volt power to outlets that need to supply |
| may not be the same as the outlet behind your | | | | less than 2.4 kilowatts (as opposed to appliances like |
| refrigerator, and without understanding volts, watts, and | | | | clothes dryers, which can pull 4 kilowatts). |
| BTUs, you could be stuck with a heater that doesn't | | | | While a 240 volt garage heater is significantly more |
| produce enough heat to warm your area, or worse | | | | efficient and powerful than a 120 volt space heater, |
| yet, you may find yourself with a heater that won't fit | | | | this may not be necessary for your home. Though |
| in your standard two-pronged outlet. | | | | most space heaters are 120 volts, some wall heaters |
| Voltage | | | | designed for home use are rated at 240 volts and are |
| Voltage is measured as the root mean squared value | | | | just as powerful as garage heaters. |
| between two slots or holes in an electric outlet of the | | | | Watts |
| sort typically mounted in a wall. The purpose of an | | | | A watt is an SI (metric) unit of power equal to one |
| electrical outlet is to provide an area for you to plug in | | | | joule of energy per second. In terms of wattage, |
| various electrical appliances in order to supply them | | | | almost all 120 volt space heaters are rated up to 1500 |
| with power. Most standard power outlets in the United | | | | watts at the maximum setting, and there is a 10/1 ratio |
| States are of the 120 volt variety, which have spots | | | | of watts to square feet heated. Therefore, a 1500 |
| for two plugs, and are rated for 15 amps. Therefore, | | | | watt space heater (120 volts) will be able to heat an |
| for these standard type outlets (used for appliances | | | | area of 150 square feet, and a garage heater rated at |
| such as space heaters), you will be able to use any of | | | | 5,000 watts should be able to comfortably heat an |
| the standard 120 volt heaters. However, it is very | | | | area over 400 square feet. |
| important to keep in mind that these ratings cannot be | | | | Btus |
| exceeded, as the outlet could be damaged or a fire | | | | In terms of Btus, or British Thermal Units, this is also a |
| could be started. In addition, if your outlet is only rated | | | | unit of energy that is used globally in heating and air |
| for 15 amps, you cannot have a 14 amp heater and | | | | conditioning industries, but is not commonly used |
| other appliances running at the same time on the | | | | scientifically. Nonetheless, in North America, the term |
| same circuit, or it will trip the breaker. | | | | Btu describes the energy value of fuels, and is also |
| With that in mind, larger appliances, such as garage | | | | used to describe the power of heating and cooling |
| heaters, are powered through 240 volt plugs, and | | | | systems such as heaters. When used as unit of |
| cannot be powered through standard plugs. If they | | | | power, Btus per hour is the commonly used term, and |
| were fed by a 120 volt supply, they would need more | | | | refers to the amount of heat required to raise the |
| than 20 amps of current running through the wires. In | | | | temperature of one pound of water by one degree |
| other words, the voltage from one hot wire to the | | | | Fahrenheit. To convert watts to Btus and vice versa, |
| other (called line to line voltage) is 240 volts, and the | | | | here are the conversion ratios: |
| voltage from either wire to the neutral center-tap | | | | 1 watt = approximately 3. |
| (called line to neutral voltage) is half that, or of the 120 | | | | |