Q1- the heating system shown in figure below consists of four radiators (R1, R2, R3, R4), a water heater, and one water pump. Each radiator requires flow rate of 200 kg/h. All pipes have inner diameter of 12 mm, and outer diameter of 15 mm. a) Calculate total pressure drop in the system (pressure loss in R1 is 2 kPa, and in water heater it is negligible). Estimate the electrical power required for pump (W), considering 75% pump efficiency. For this part you need explain your approach step by step clearly in one or two paragraphs first (typewritten please) Hint: for calculating the total pressure drop in the system, you need to find the critical path first which is defined as the path in which the pressure drop is maximum. b) Calculate the total heat loss from hot water pipes assuming average temperature of 80 C for hot water. If all pipes be covered with a 5 mm thick isolation layer (conductivity-0.03 W/m K), how many percent reduction in heat loss would be achieved? c) If cold-water leaving radiators is in thermal equilibrium with air, estimate the total heat required in water heater. (Average value given for temperature of hot water could be used) d) Natural gas price is 25 cents/m, considering 75% efficiency of water heater, calculate the annual cost of natural gas. e) In designing HVAC systems for building, the following formula is used for estimating the total capacity of water heater: Btu = 500 + Flowrate (GPM) * AT (F) Assuming the density of water is constant and 1000 kg/m, calculate the amount of heat needs to be generated in the water heater (in watts) and report the difference with your results in part c. T-3-300 K h-23 W/mK hot water Supply cold water Return Pump Heater R1 R3 (1 m/ Figure 1: Heating system 1 3m