Heat Recovery Calculator:
Enter the values of flow rate, Q(ft3/min), temperature difference, ΔT(°C) and efficiency factor, E to determine the value of Heat Recovery, HR(kW).
Heat Recovery Formula:
Heat recovery refers to the process of capturing and reusing the heat that would otherwise be wasted from industrial, commercial, or residential processes. This recovered heat can be used to reduce energy consumption by heating water, air, or other substances in the system, improving overall energy efficiency. Heat recovery systems are commonly employed in industries such as HVAC (heating, ventilation, and air conditioning), power generation, and manufacturing, where large amounts of heat are produced as a by-product.
The goal is to reduce the demand for external energy sources, thereby saving energy and reducing greenhouse gas emissions. Heat recovery technologies include heat exchangers, thermal wheels, and heat pumps, each designed to recover heat from various processes. A key aspect of effective heat recovery is the temperature differential, as the greater the temperature difference (ΔT), the more heat can be recovered.
The heat recovery rate depends on the efficiency of the system and the heat transfer medium used. Heat recovery is essential for energy management, lowering operational costs, and promoting sustainability by reducing reliance on fossil fuels.
Heat Recovery, HR(kW) in kiloWatts is calculated by multiplying 1.08 by the flow rate, Q(ft3/min) in cubic feet per minute, the temperature difference, ΔT(°C) in degree Celsius and the efficiency factor, E in percentage and then dividing by 100.
Heat Recovery, HR(kW) = 1.08 * Q(ft3/min) * ΔT(°C) * E / 100
HR(kW) = heat recovery in kiloWatts, kW.
Q(ft3/min) = flow rate in cubic feet per minute, ft3/min.
ΔT(°C) = temperature difference in degree Celsius, °C.
E = efficiency factor.
Heat Recovery Calculation:
1.A heat recovery system operates with a flow rate of 1000 CFM, a temperature difference of 25°C and an efficiency factor of 80%. What is the heat recovery rate (HR)?
Given: Q(ft3/min) = 1000ft3/min, ΔT(°C) = 25°C, E =80%.
Heat Recovery, HR(kW) = 1.08 * Q(ft3/min) * ΔT(°C) * E / 100
HR(kW) = 1.08 * 1000 * 25 * 0.8 / 100
HR(kW) = 21600 / 100
HR(kW) = 216kW.
2.A heat recovery system has a temperature difference of 15°C and an efficiency factor of 90%. If the heat recovery rate (HR) is 540 kW and the flow rate (Q) is unknown, calculate the flow rate.
Given: HR(kW) = 540kW, ΔT(°C) = 15°C, E = 90%.
Heat Recovery, HR(kW) = 1.08 * Q(ft3/min) * ΔT(°C) * E / 100
Q(ft3/min) = HR(kW) * 100 / 1.08 * ΔT(°C) * E
Q(ft3/min) = 540 * 100 / 1.08 * 15 * 0.9
Q(ft3/min) = 54000 / 14.58
Q(ft3/min) = 3704.7ft3/min.