Explanation Determine the amount of electricity used to heat water. Total energy used ( electricity ) = total cost of energy unit cost of energy (I) Determine the net amount of energy transfer to water. Total energy transfer to water = ( Efficiency ) × ( total energy used ) (II) Determine the amount of electricity consumed by the heat pump. Energy usage = Energy transfer to water COP HP (III) Here, the coefficient of performance is COP HP . Determine the energy cost of heat pump. Energy cost = ( Energy usage ) × ( unit cost of energy ) (IV) Determine the money saved per year by the heat pump. Money saved = [ ( Energy cost of electric heater ) − ( Energy cost of heat pump ) ] (V) Determine the simple payback period of heat pump. Simply payback period = additional installation cost money saved (VI) Conclusion: Substitute $350 / year for total cost of energy and $0 .11 / kWh for unit cost of energy in Equation (I). Total energy used ( electricity ) = ( $350 / year ) ( $0 .11 / kWh ) = 3181.8 kWh / year ≅ 3182 kWh / year Substitute 0.95 for efficiency and 3182 kWh / year for total energy used in Equation (II). Total energy transfer to water = ( 0

9th Edition

ISBN: 9781260048766

Author: CENGEL

Publisher: MCG

See similar textbooks

Concept explainers

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a bur…

Videos

Question

Chapter 6.11, Problem 145RP

To determine

The number of year it will take for the heat pump water heater to pay for its cost differential from the energy it saves.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 6.11, Problem 144RP

Chapter 6.11, Problem 147RP

Students have asked these similar questions

A heat engine accepts heat from a source at a rate of 500 kW, and it rejects heat to a sink at a rate of 300 kW. The remainder of the heat is converted to net work output. Determine the thermal efficiency of the engine

A heat engine has a total heat input of 1.3 kJ and a thermal efficiency of 35 percent. How much work will it produce?

Refrigerant as a work fluid to keep an environment at 25 ° C. A heat pump using 134a is used. The heat pump keeps heat entering the evaporator at a temperature of 50 ° C. and 2,718 kW of heat from the geothermal water that comes out of the evaporator at 40 ° C. Cooler fluid enters the evaporator at 15% dryness at 20 ° C and saturated at the same pressure comes out as steam. Since the compressor consumes 1.2 kW of power; a-) Mass flow rate of the refrigerant, b-) The heat provided for heating purposes per unit time, c-) COP value of the heat pump, d-) Find the minimum power required for the compressor in case of providing the same amount of heat.

Chapter 6 Solutions

Thermodynamics: An Engineering Approach

Ch. 6.11 - A mechanic claims to have developed a car engine...Ch. 6.11 - Describe an imaginary process that violates both...Ch. 6.11 - Describe an imaginary process that satisfies the...Ch. 6.11 - Describe an imaginary process that satisfies the...Ch. 6.11 - An experimentalist claims to have raised the...Ch. 6.11 - Consider the process of baking potatoes in a...Ch. 6.11 - Prob. 7P Ch. 6.11 - What are the characteristics of all heat engines?Ch. 6.11 - What is the KelvinPlanck expression of the second...Ch. 6.11 - Is it possible for a heat engine to operate...

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

The number of year it will take for the heat pump water heater to pay for its cost differential from the energy it saves.

Solution Summary: The author calculates the number of years it will take for the heat pump water heater to pay for its cost differential from the energy it saves.

Concept explainers

Videos

The number of year it will take for the heat pump water heater to pay for its cost differential from the energy it saves.

Want to see the full answer?

Chapter 6 Solutions