A family uses 300 L of hot water per day. The water is heated from a line temperature of 12° C to 60° C . Calculate the amount of natural gas (Oklahoma) that is required to heat the water in a heater with an efficiencyof 80%.

A heat pump is required for a single-family 2-story, 3-person, 30 ft x 30 ft x 18 ft (L x W x H), energy- efficient residential house in Philadelphia, PA, for a typical winter season. Assuming a comfortable indoor temperature is 70 °F and on a cold winter day the outdoor temperature is 10 °F. Exercise #1: Calculate total heat loss from a house in Philadelphia on a cold winter day. Assume 40% of the wall area is windows with U-value of 0.81 BTU/hr-ft²-°F. The remaining 60% of the walls has a U-value of 0.2 BTU/hr-ft²-°F. The roof has a U value of 0.05 BTU/hr-ft?-°F and the floor U-value is 0.41 BTU/hr-ft²-°F. For simplicity assume that the ground temperature is the same as the air temperature. [However, in your project design calculations you should refine this assumption.] Assume 0.5 air changes per hour (ACH) due to natural ventilation, such as leakage through windows, etc. Neglect any radiative heat loss/grain from the house. Exercise #2: Determine the watts of electricity needed by…

Energy is generated uniformly in a 20cm thick wall the steady state temperature distribution of the wall is indicated on the table below; z (cm) T(C) 0 2 4 6 8 10 12 14 16 18 20 150 177 205 230 250 272 292 310 330 345 360 If thermal conductivity of the wall is 15 W/m.K and the indicated temperatures are in °C, determine the average rate of heat generation in unit volume.

Problem 2: A metal rod 0.4 m long & 0.04 m in diameter has one end at 373 K & another end at 273 K. Calculate the total amount of heat conducted in 1 minute. (Given K = 385 J/ms °C)

4. The right figure shows a simple combustion calorimeter. The sample is ignited electrically. After a few minutes the temperature of the water and calorimeter is constant at AT higher than the starting temperature. Determine the heat of combustion of a sample from the following data: Sample mass Calorimeter mass Water mass 4 g 500 g 5000 g The heat of combustion is defined as = Sample Inlet 0 75 400 Temperature °F 70.0 Cvcalorimeter Cywater Ufinal products of combustion Pressure, psig Elevation, ft Velocity, ft/s AT Stirrer Uinitial fuel+oxygen Au combustion msample 5. A steady-flow water power plant has the following inlet and outlet conditions: Oxygen Outet 0 0 50 70.1 Water Thermometer Heavy steel bomb 0.12 cal/g °C 1.0 cal/g °C 5 °C

A water calorimeter is a device used to measure the specific heat of a substance (see figure below). A 0.134-kg sample has a temperature of 1100 K when it is placed into 1.00 kg of water at a temperature of 280 K. The container is made of steel and has a mass of 0.250 kg. After the sample, the water, and its container reach thermal equilibrium, their common temperature is 293 K. What is the specific heat of the substance? J/kg · K