You need an apartment for rent and as shown in the figure, you can see that the 3rd floors of each of the 2, 3 and 4 blocks of the buildings, whose front faces are adjacent, are for rent. You also learn that Block 2 is heated by a coal boiler operating at 75% efficiency, Block 3 is heated by a natural gas boiler operating at 92% efficiency and Block 4 is heated by a heat pump with a COP (coefficient Of Performance) of 4.5. We know that the heating process takes place uninterruptedly for 150 days, during these 150 days, the interior of the apartment remains constant at 22 °C. average outside temperature T = 0 °C and average of wind speed u* = 5 m/s Find the total heating cost for all three blocks. The average heat transfer coefficient in apartment is h inside = 10 W/m2K thermal resistance of the wall Rwall = 1 m2K/W Assume that heat is lost only from the front and back of the blocks. In addition, the electricity unit price of 0.71 $/kWh, natural gas unit price of 0.14 $/kWh, unit price of coal is 0.1 $/kWh. NOTE: In the solution, if you will make an acceptance that is not given in the question, state this clearly. Wind Uco = 5 m/s Too = 0 °C 3rd Floor H=4m(meters)

You need an apartment for rent and as shown in the figure, you can see that the 3rd floors of each of the 2, 3 and 4 blocks of the buildings, whose front faces are adjacent, are for rent. You also learn that Block 2 is heated by a coal boiler operating at 75% efficiency, Block 3 is heated by a natural gas boiler operating at 92% efficiency and Block 4 is heated by a heat pump with a COP (coefficient Of Performance) of 4.5. We know that the heating process takes place uninterruptedly for 150 days, during these 150 days, the interior of the apartment remains constant at 22 °C. average outside temperature T = 0 °C and average of wind speed u* = 5 m/s Find the total heating cost for all three blocks. The average heat transfer coefficient in apartment is h inside = 10 W/m2K thermal resistance of the wall Rwall = 1 m2K/W Assume that heat is lost only from the front and back of the blocks. In addition, the electricity unit price of 0.71 $/kWh, natural gas unit price of 0.14 $/kWh, unit price of coal is 0.1 $/kWh. NOTE: In the solution, if you will make an acceptance that is not given in the question, state this clearly. Wind Uco = 5 m/s Too = 0 °C 3rd Floor H=4m(meters)

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter2: Matter And Energy

Section: Chapter Questions

Problem 27RQ: How many Btu/h would be produced in a 12-kW electricheater?

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