Electrical Loads

July 31, 2003

You can usually find the wattage of most appliances stamped on the bottom or back of the appliance, or on its "nameplate." The wattage listed is the maximum power drawn by the appliance. Since many appliances have a range of settings (for example, the volume on a radio), the actual amount of power consumed depends on the setting used at any one time.

Here are some examples of the range of nameplate wattages for various household appliances:

Aquarium = 50-1210 Watts
Clock radio = 10
Coffee maker = 900-1200
Clothes washer = 350-500
Clothes dryer = 1800-5000
Dishwasher = 1200-2400 (using the drying feature greatly increases energy consumption)
Dehumidifier = 785
Electric blanket- Single/Double = 60 / 100
Fans
   Ceiling = 65-175
   Window = 55-250
   Furnace = 750
   Whole house = 240-750
Hair dryer = 1200-1875
Heater (portable) = 750-1500
Clothes Iron = 1000-1800
Microwave oven = 750-1100
Personal Computer
   CPU - awake / asleep = 120 / 30 or less
   Monitor - awake / asleep = 150 / 30 or less
   Laptop = 50
Radio (stereo) = 400
Refrigerator (frost-free, 16 cubic feet) = 725
Televisions (color)
   19" = 110
   27" = 113
   36" = 133
   53"-61" Projection = 170
   Flat Screen = 120
Toaster = 800-1400
Toaster Oven = 1225
VCR/DVD = 17-21 /20-25
Vacuum cleaner = 1000-1440
Water heater (40 gallon) = 4500-5500
Water pump (deep well) = 250-1100
Water bed (w/ heater, no cover) = 120-380

Refrigerators, although turned "on" all the time, actually cycle on and off at a rate that depends on a number of factors. These factors include how well it is insulated, room temperature, freezer temperature, how often the door is opened, if the coils are clean, if it is defrosted regularly, and the condition of the door seals. To get an approximate figure for the number of hours that a refrigerator actually operates at its maximum wattage, divide the total time the refrigerator is plugged in by three.

Determining your total electrical load for both battery and charging configuration can be time consuming.  The link below is a work sheet which can help you identify load requirements.

Thanks to the folks at Cruising Concepts for letting me steal the template.