Homework: Chapter 2 Homework Save Score: 0 of 1 pt 2 of 3 (0 complete) HW Score: 0%, 0 of 3 pts Problem 2-28 (algorithmic) Question Help Consider a house in Blacksburg, Virginia. The typical annual space heating load for this size of a house is 100 x 10 Btu. That is, with no insulation in the attic, we lose about 100 x 10 Btu per year. With insulation in the attic the amount of heat lost each year will be reduced. The value of energy savings that results from adding insulation and reducing heat loss is dependent on what type of residential heating furnace is installed. Assume that an electrical resistance furnace is installed by the builder, and its efficiency is near 100%. The cost of electricity is $0.15 per kWh. The cost of several insulation alternatives and associated space-heating loads for this house are given in the following table. Which amount of attic insulation is most economical? The life of the insulation is estimated to be 26 years. Amount of Insulation R11 R19 R30 R38 Investment cost ($) 2,200 3,700 5,300 6,500 Annual heating load (Btu/year) 73.8 x 106 69.6 x 106 67.4 X 106 66.3 x 10 Recall that 1 Btu = 0.293 Wh and calculate the cost of electricity per million Btu. Fill in the table below. (Round to the nearest cent.) R11 R19 R30 R38 Investment cost ($) Cost of heat loss per year ($) Cost of heat loss over 26 years ($) Total life cycle costs ($) Enter your answer in the edit fields and then click Check Answer. Check Answer Clear All part remaining Homework: Chapter 2 Homework Save Score: 0 of 1 pt 2 of 3 (0 complete) HW Score: 0%, 0 of 3 pts Problem 2-28 (algorithmic) Question Help Consider a house in Blacksburg, Virginia. The typical annual space heating load for this size of a house is 100 x 10 Btu. That is, with no insulation in the attic, we lose about 100 x 10 Btu per year. With insulation in the attic the amount of heat lost each year will be reduced. The value of energy savings that results from adding insulation and reducing heat loss is dependent on what type of residential heating furnace is installed. Assume that an electrical resistance furnace is installed by the builder, and its efficiency is near 100%. The cost of electricity is $0.15 per kWh. The cost of several insulation alternatives and associated space-heating loads for this house are given in the following table. Which amount of attic insulation is most economical? The life of the insulation is estimated to be 26 years. Amount of Insulation R11 R19 R30 R38 Investment cost ($) 2,200 3,700 5,300 6,500 Annual heating load (Btu/year) 73.8 x 106 69.6 x 106 67.4 X 106 66.3 x 10 Recall that 1 Btu = 0.293 Wh and calculate the cost of electricity per million Btu. Fill in the table below. (Round to the nearest cent.) R11 R19 R30 R38 Investment cost ($) Cost of heat loss per year ($) Cost of heat loss over 26 years ($) Total life cycle costs ($) Enter your answer in the edit fields and then click Check Answer. Check Answer Clear All part remaining
