A typical electric water heater has an efficiency of 95 percent and costs $350 a year to operate at a unit cost of electricity of $0.11/kWh. A typical heat pump-powered water heater has a COP of 3.3 but costs about $800 more to install. Determine how many years it will take for the heat pump water heater to pay for its cost differential from the energy it saves.

Q: thermal machine operates between 2 tanks at 800ºC and 20ºC; half of the power produced by this…

A:

Q: An inventor claims to have devised a refrigeration cycle operating between hot and cold reservoirs…

A: Given data as per question  Temperature of hot reservoirs = 308 K   Temperature of cold reservoirs =…

Q: A heat engine is operating on a Carnot cycle and has a thermal efficiency of 47 percent. The waste…

A: Given: The thermal efficiency of the Carnot cycle is η=0.47 The rate at which heat is rejected to…

Q: A completely reversible heat engine operates with a source at 1500 R and a sink at 500 R. At what…

A: Write the formula for thermal efficiency of a reversible heat engine in terms of source and sink…

Q: 3. A Carnot engine is coupled to a Carnot refrigerator so that all the work produced by the engine…

A: Given:Qr=35 KJ/sTL=0 CTH=25 CTH=150 C

Q: A refrigeration system uses a water-cooled condenser for rejecting the waste heat. The system…

A: Given data: The absorbed heat, QA = 21,000 Btu/h. The estimated coefficient of performance, COP =…

Q: An air-conditioning system operating on the reversed Carnot cycle is required to transfer heat from…

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Q: orbing heat from the cold outdoors at 5 degrees celsius and supplying heat to a house at 22 degrees…

A: Given:TL=5°C =268 KTH=22°C =295 KQH=18000 KJ/h =180003600 KWP=2.5 KW

Q: Assuming neither the heat input nor work required by the pump do not change, what is the new thermal…

A: Given data: qin=2823.2 kJ/kgqout=1985.0 kJ/kgwpump,in=4.05 kJ/kg Need to determine the thermal…

Q: A heat engine is operating on a Carnot cycle and has a thermal efficiency of 75%. The waste heat…

A: Need to determine the power output of the motor and the temperature of the source.

Q: In a power plant, water (density = 1000 kg, is pumped from 80 kPa to 3 MPa. The pump has an…

A: Given data; The density of water is ρ = 1000 kg/m3. The initial pressure is P1 = 80 kPa. The final…

Q: . Dr. Eismann placed a refrigerator in his office. Since then he didn’t touch the refrigerator. The…

A: Draw the temperature-entropy diagram i.e. the T-s diagram for the cycle showing the ideal…

Q: A Carnot heat engine receives heat from a reservoir at 900°C at a rate of 800 kJ/min and rejects the…

A: Given: The temperature of the reservoir is T1=900°C. The temperature of the refrigerated space is…

Q: Between 300K and 600K is the operating temperature of a pair of heat pumps connected in series. The…

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Q: Consider a Carnot heat-engine cycle executed in a steady-flow system using steam as the working…

A: Given data:

Q: You are an engineer in an electric-generation station. You know that the flames in the boiler reach…

A: Given Boiler temperature = 1200 K Cooling water temperature = 300 K To find Maximum efficiency of…

Q: A power plant having a Carnot efficiency produces 1000MW of electrical power from turbines that take…

A:

Q: The schematic below shows a heat pump that operates using R-134a as the working fluid, which flows…

A: Given:Refrigerant=R134aMass flow rate of refrigerant, m˙ref=450 kg/hr=4503600kg/s=0.125 kg/sHeat…

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 burner, heats up because of the flame underneath it.