Heating Green is here to explain the difference between watts, volts, and amps.
All electric appliances have 3 specifications: wattage, amperage, and voltage. To understand how electricity work think of it as if it were water flowing through a garden hose.
- Amperage is the flow rate of the water through the hose. For example, let’s say you have two hoses next to each other, each with a flow rate of 3 gallons per minute. They have the same amperage.
- Voltage is pressure. From example 1, imagine those 3 gallons of water flowing out of hose #1 with no nozzle. The water might pour up to a few feet out from the hose as it gushes out. Imagine that you put your thumb over hose #2 and apply double the pressure. You can create a stream of water that shoots across the lawn. Doubling the pressure on hose #2 is equivalent to doubling the voltage. However, the water no longer gushes out of the hose, it’s in a concentrated stream. With hose #2, the flow rate (amperage) is decreased to half of its original flow rate, it’s a narrower but more intense stream of water.
- Wattage is output (power). The equation for wattage is voltage times amperage (Watts=Volts*Amps). In our example, hose #1 with 3 gallons of water flowing out has the same wattage as hose #2 with double the pressure and half the flow rate (1.5 gallons). 1*3 =3 and 2*1.5=3
When it comes to infrared heaters, what is the most efficient combination to use?
The measuring stick which defines cost to run an infrared heater is wattage (power). You pay your electricity bill by the amount of kilowatts (1 kilowatt is 1,000 watts) that you use per hour. Remember the equation watts = volts*amps. If you have a 1,500W heater at 120V, it is using 12.5amps (1,500/120=12.5). Alternatively, if you have a 1,500W heater at 240V, it is using 6.25amps (1,500/240=6.25). The only difference is the amperage. Since the wattage (output) is the same, there is no difference in cost to run the 1,500W 120V version vs the 1,500W 240V version.
The only advantage to using higher voltage is that the amperage is lower, and this is what your electrical panel is restricted by (most panels are 200amps). By reducing the amount of amperage, you can also fit more heaters on each circuit. This results in reducing the amount of wiring required for an electrician to install the heaters, and generally means a lower installation cost! For this reason, with hardwiring any system we generally recommend using the highest voltage available at your home or business. You can read more here on our blog post on selecting the right voltage to determine what is best for your scenario.
A cautionary note: Heaters are voltage specific i.e. they are made to run at a certain voltage. For example, if you connect 240V into a heater which is made to run at 120V, you are applying twice the voltage (pressure) that it is designed to run at. While you are actually getting twice the output (3,000W), it is overloading the heater and it will have a propensity to fail prematurely, if it runs at all. Conversely, if you connect 120V into a heater which is made to run at 240V, you are getting half of the output (750W), when you could have gotten 1,500W by ordering a 120V heater. There is no difference in cost for different voltage heaters, so it is always best to match apples-to-apples and order the correct voltage heater for your application.
If you are concerned about the getting the right heating solution for your available power please don’t hesitate to work with one of our heating and power experts.
Written by: Jeff Abel, VP of Sales, Heating Green