Electrical Power Systems Technology

Heating Systems 317

U

W = ——

3.4

= 0.3584

= ———

3.4

= 0.1054 watts heat loss

Solution (with insulation):

R = a + b + c + d + e + f

= 0.80 + 0.75 + 0.04 + 0.85 + 0.35 + 11.0

= 13.79

1

U = —

R

1

U = ———

13.79

= 0.0725 Btu per ft^2 per hour per °F

U

W = ——

3.4

= 0.0725

= ———

3.4

= 0.0213 watts heat loss

You can see from the results of this problem that the adding of in-

sulation into the walls of a building has a great effect upon heat loss. The

insulation has a much greater effect in controlling heat loss than do the

construction materials used for the building.

Electric Heating and Cooling Systems

Several types of electric heating systems are used today. Some com-

mon types are baseboard heaters, wall- or ceiling-mounted heaters, and