1. What is a Radiator BTU Calculator?

Definition: This calculator estimates the heat output (in BTUs) of existing radiators based on temperature difference, radiator factor, and surface area.

Purpose: It helps HVAC professionals and homeowners determine the heating capacity of existing radiators for system evaluation or upgrades.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat output (BTU/h)
• \( \Delta T \) — Temperature difference between radiator and room (°F)
• \( K \) — Radiator factor (BTU/h·ft²·°F)
• \( A \) — Radiator surface area (ft²)

Explanation: The temperature difference multiplied by the radiator factor and surface area gives the heat output in BTUs per hour.

3. Importance of Radiator BTU Calculation

Details: Proper heat output estimation ensures adequate room heating, system efficiency, and helps when replacing or upgrading heating systems.

4. Using the Calculator

Tips: Enter the temperature difference, radiator factor (default 1.5 BTU/h·ft²·°F), and surface area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I measure temperature difference?
A: Subtract room temperature from average radiator surface temperature.

Q2: What's a typical radiator factor (K)?
A: Cast iron radiators typically have K=1.0-1.5, while modern panel radiators may have K=1.5-2.0.

Q3: How do I measure radiator surface area?
A: Calculate total exposed surface area including fins and multiply by number of sections for sectional radiators.

Q4: Does this work for baseboard heaters?
A: Yes, but use appropriate K values (typically higher than traditional radiators).

Q5: How accurate is this calculation?
A: It provides a good estimate but actual output may vary based on water temperature, flow rate, and radiator condition.