1. What is a Radiator BTU Calculator?

Definition: This calculator determines the required radiator size in BTUs based on temperature difference, heat transfer coefficient, and surface area.

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The temperature difference between radiator and room is multiplied by the material's heat transfer coefficient and surface area.

3. Importance of Proper Radiator Sizing

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

4. Using the Calculator

Tips: Enter the temperature difference, heat transfer coefficient (default 5.0 for standard radiators), and surface area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is ΔT (temperature difference)?
A: The difference between average radiator temperature and desired room temperature (typically 60-70°F).

Q2: What are typical K values?
A: Standard radiators: 5.0, Cast iron: 2.5-3.5, Aluminum: 6.0-7.0 BTU/h·ft²·°F.

Q3: How do I measure radiator surface area?
A: Calculate total exposed surface area including fins/tubes (manufacturer specs are most accurate).

Q4: Should I add a safety factor?
A: Yes, add 10-20% to account for heat loss through windows/walls in real-world conditions.

Q5: How does this relate to room size?
A: Larger rooms typically need radiators with higher BTU output, but insulation quality is equally important.