1. What is a BTU to Radiator Size Calculator?

Definition: This calculator determines the heat output (in BTUs) of a radiator based on temperature difference, heat transfer coefficient, and surface area.

Purpose: It helps HVAC professionals and homeowners properly size radiators for heating systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The heat output increases with greater temperature difference, better heat transfer materials, and larger radiator surface area.

3. Importance of Proper Radiator Sizing

Details: Correct radiator sizing ensures efficient heating, prevents energy waste, and maintains comfortable room temperatures.

4. Using the Calculator

Tips: Enter the temperature difference (typically 50-70°F), heat transfer coefficient (default 5.0 for cast iron), and radiator surface area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical ΔT value?
A: Usually 50-70°F, representing the difference between radiator surface temperature (180-200°F) and room temperature (68°F).

Q2: How do I find the K value for my radiator?
A: Consult manufacturer specs - cast iron radiators are typically 5.0, while modern panel radiators may be higher.

Q3: What if I know the required BTU output?
A: Rearrange the formula to solve for A (area) when you know the required Q (BTU output).

Q4: Does this account for room insulation?
A: No, this calculates radiator output only. Heat loss calculations should consider insulation separately.

Q5: How accurate is this calculation?
A: It provides a good estimate, but real-world performance may vary based on installation, airflow, and other factors.