A Specimen Light Allowance

Below is a typical table of lights for a large farm house, the barns and barn-yard. It is given merely as a guide, to be varied for each individual case:

Watts
Kitchen, 2 lights @60 watts 120
Dining room, 1 light, tungsten 100
Living room, table lamp with 3 tungstens @40 120
Living room, 2 wall fixtures, 4 lamps @60 watts 240
Parlor, same as living room 360
Pantry, 1 hanging lamp 60
Cellar, one portable lamp 60
Woodshed, 1 hanging lamp 60
2 bedrooms, 2 lights each @ 60 240
2 bed rooms, 1 light each @60 120
Bathroom, 1 "turn-down" light, @60 60
Hall, downstairs, 2 lights @60 120
Hall, upstairs, 1 light 60
Attic, 1 light 60
Porch, 1 light 60
Barn and barn-yard:
Barn-yard entrance, 1 tungsten 100
Watering trough, 1 tungsten 100
Front gate, 1 tungsten 100
Horse barn, 4 lights @60 240
Cow barn, 4 lights @60 240
Pig house, 1 light 60
Hay barn, 2 lights, @60 120
———
Total for farmstead2,800

This provides for 44 lights, an extremely liberal allowance. How many of these lights will be burning at any one time? Probably not one-half of them; yet the ideal plant is that which permits all fixtures to be in service at one time on the rare occasions when necessary. Thus, for lighting only, 2,800 watts maximum service would require a 4 kilowatt generator, and 10 water horsepower, on the liberal rating of two to one. A 3 kilowatt generator would take care of these lights, with a 30 per cent overload (which is not excessive) for maximum service. The above liberal allowance of lights may be cut in two, or four—or even eight—and still throw a kerosene lamp in shadow. It all depends on the number of lights one wants burning at one time; and the power of the water wheel.

If the 36 carbon lights in the above table were replaced by 25 watt tungsten lights, the saving in power would be 35 watts each, or 1,260 watts, nearly two electrical horsepower; while the added first cost would be 14 cents a light, or $5.04. A generator of 2 kilowatt capacity would take care of all these lights then, with 460 watts to spare.

Heating

Electric heating and cooking is in its infancy, due to the prohibitive cost of commercial current in our cities. Here the farmer has the advantage again, with his cheap current.

For heating the house, it is calculated that 2 watts is required for each cubic foot of air space in a room, during ordinary winter weather. Thus, a room 10 × 12, and 8 feet high, would contain 960 cubic feet, and would require 1,820 watts energy to heat it in cold weather. Five such rooms would require 9.1 kilowatts; and 10 such rooms, or their equivalent, would require 18.2 kilowatts.

Electric heating devices are divided into two classes: (1) those which can be used on lamp circuits, and do not draw more than 660 watts each; and (2) those which draw more than 660, therefore require special wiring. The capacity of these devices is approximately as follows: