Question

a)Consider a room in a house that has composite walls with an Rtot=0.7 m2K/W. The total cross sectional area of the walls is 35 m2. During winter, the temperature outside the room is Tout=6∘C. Inside the room, there is an electric heater that emits heat at a rate of 320 W that keeps the room warm. The room is occupied by 3 people that emit heat at a rate 80 W each. What is the temperature inside the room Tin (in ∘C) in winter? Express your answer with 1 decimal place.

b) How much will it cost (in $) to keep the heater ON during the winter season if the heater has an efficiency of 50%? Assume that you keep the heater ON for 8 hours/day. Assume the winter season lasts 50 days. The cost of electricity is $0.12 per kW h. Express your answer with 1 decimal place.

Answer 1