Heat Recovery Calculator

Heat recovery is a crucial process in HVAC (Heating, Ventilation, and Air Conditioning) systems, enabling the conservation of energy by recovering heat from exhaust air and using it to condition incoming fresh air. This process not only conserves energy but also reduces heating and cooling loads, leading to significant cost savings and environmental benefits.

Historical Background

The concept of heat recovery has been around for decades, evolving with advancements in technology to improve energy efficiency in buildings and industrial processes. It reflects the ongoing effort to optimize the use of energy and reduce carbon footprints.

Calculation Formula

The formula to calculate Heat Recovery is:

\[ HR = 1.08 \times Q \times \Delta T \times \frac{E}{100} \]

where:

• \(HR\) is the Heat Recovery in BTU/h,
• \(Q\) is the airflow rate in CFM,
• \(\Delta T\) is the temperature difference between the air after recovery and before recovery in °F,
• \(E\) is the heat recovery efficiency in percent.

Example Calculation

Given:

• Airflow rate (\(Q\)) = 100 CFM,
• Temperature difference (\(\Delta T\)) = 30°F,
• Heat recovery efficiency (\(E\)) = 50%.

Substitute the values into the formula:

\[ HR = 1.08 \times 100 \times 30 \times \frac{50}{100} = 1620 \text{ BTU/h} \]

Importance and Usage Scenarios

Heat recovery systems are integral in modern HVAC systems, especially in climates with extreme winter or summer temperatures. They are used in residential, commercial, and industrial settings to improve energy efficiency, reduce utility costs, and lower environmental impact.

Common FAQs

1. What does CFM stand for?

   • CFM stands for Cubic Feet per Minute, a measure of airflow rate.

2. Why is the temperature difference important in calculating heat recovery?

   • The temperature difference (\(\Delta T\)) between the incoming and outgoing air streams is crucial because it determines the potential amount of heat that can be recovered.

3. How does heat recovery efficiency affect the calculation?

   • The efficiency percentage (\(E\)) reflects how effectively the heat recovery system can transfer heat from the exhaust air to the incoming air. Higher efficiency means more heat is recovered.

This calculator simplifies the calculation of heat recovery, making it accessible for engineers, HVAC professionals, and students to estimate the efficiency and performance of heat recovery systems.