Water Heater Efficiency Calculator:
Enter the values of mass of water heated, m(kg), specific heat capacity of water, C(J/kg.°C), temperature difference, ΔT(°C) and total energy input, Q(J) to determine the value of Water Heater Efficiency, E.
Water Heater Efficiency Formula:
Water heater efficiency measures how effectively a water heater converts energy input into usable heat for warming water. This metric is crucial in determining the performance and cost-effectiveness of water heating systems. It accounts for the amount of energy transferred to the water compared to the energy supplied to the heater.
The efficiency depends on factors like the specific heat capacity of water, the temperature change (∆T) achieved, and the energy input (Q) provided to the system. A higher efficiency indicates less energy loss, often due to better insulation, advanced heating technology, or reduced heat dissipation.
Efficiency is typically expressed as a percentage, calculated by dividing the energy used to heat the water (output energy) by the total energy supplied to the system.
The calculation helps in selecting energy-efficient water heaters, reducing operational costs, and minimizing environmental impacts. It can also aid in diagnosing performance issues and planning for system upgrades.
Water Heater Efficiency, E in percentage is equal to the product of the mass of water heated, m(kg)in kilograms, the specific heat capacity of water, C(J/kg.°C)in Joules per kilogram per degree Celsius and the temperature difference, ΔT(°C)in degrees Celsius, divided by the total energy input, Q(J) in Joules, all multiplied by 100.
Water Heater Efficiency, E = (m(kg) * C(J/kg.°C) * ΔT(°C) / Q(J)) * 100
E = water heater efficiency in percentage.
m(kg) = mass of water heated in kilograms, kg.
C(J/kg.°C) = specific heat capacity of water in Joules per gram degree Celsius, J/g.°C(4.186J/g.°C).
ΔT(°C) = temperature difference in degree Celsius, °C.
Q(J) = total energy in Joules, J.
Water Heater Efficiency Calculation:
1.A water heater heats 10 kg of water from 25°C to 75°C. The energy input to the heater is 2,100,000 J. Calculate the efficiency of the water heater.
Given: m(kg) = 10kg, ΔT(°C) = 75 – 25 = 50, C(J/kg.°C) = 4.186J/g.°C, Q(J) = 2100000J.
Water Heater Efficiency, E = (m(kg) * C(J/kg.°C) * ΔT(°C) / Q(J)) * 100
E = (10 * 4.186 * 50 / 2100000) * 100
E = (2093000 / 2100000) * 100
E = 0.09966%.
2.A water heater has an efficiency of 85%. It heats 20 kg of water from 30°C to 60°C. Calculate the energy input required.
Given: m(kg) = 20kg, ΔT(°C) = 60 – 30 = 30, C(J/kg.°C) = 4.186J/g.°C, E = 85%.
Water Heater Efficiency, E = (m(kg) * C(J/kg.°C) * ΔT(°C) / Q(J)) * 100
Q(J) = m(kg) * C(J/kg.°C) * ΔT(°C) / E
Q(J) = 20 * 4.186 * 30 / 85
Q(J) =2954823.53J.