1. What is a BTU Radiator Heat Output Calculator?

Definition: This calculator estimates the heat output of a radiator in BTUs per hour based on temperature difference, heat transfer coefficient, and surface area.

Purpose: It helps HVAC professionals and homeowners determine radiator performance for heating system design and evaluation.

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)
• \( K \) — Heat transfer coefficient (BTU/h·ft²·°F)
• \( A \) — Radiator surface area (ft²)

Explanation: The temperature difference drives heat transfer, multiplied by the radiator's efficiency (K) and its size (A).

3. Importance of Heat Output Calculation

Details: Proper heat output estimation ensures adequate room heating, energy efficiency, and correct radiator sizing.

4. Using the Calculator

Tips: Enter the temperature difference, heat transfer coefficient (default 5.0 BTU/h·ft²·°F for standard radiators), and surface area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical ΔT for radiators?
A: Usually 20-40°F difference between radiator surface and room temperature.

Q2: How do I find the K value for my radiator?
A: Check manufacturer specifications or use 5.0 as default for standard cast iron radiators.

Q3: What affects the heat transfer coefficient?
A: Material (cast iron, steel, aluminum), design (finned, flat), and water flow rate.

Q4: How do I measure radiator surface area?
A: Calculate total exposed surface area including fins and multiply by a factor (typically 1.5-2.5) to account for enhanced surface.

Q5: Does this include convection effects?
A: The K value inherently includes both radiation and convection heat transfer.