1. What is a Radiator BTU Calculator?

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

Purpose: It helps homeowners and heating engineers determine the appropriate radiator size for UK heating systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat output (Watts or BTU/h)
• \( \Delta T \) — Temperature difference between radiator and room (°C)
• \( K \) — Heat transfer coefficient (W/m²·K)
• \( A \) — Radiator surface area (m²)

Explanation: The temperature difference multiplied by the radiator's heat transfer characteristics and size determines its heat output.

3. Importance of Radiator Sizing

Details: Proper radiator sizing ensures efficient heating, energy savings, and comfortable room temperatures in UK homes.

4. Using the Calculator

Tips: Enter the temperature difference (typically 50-60°C for UK systems), heat transfer coefficient (default 11 W/m²·K for standard radiators), and surface area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical ΔT for UK central heating?
A: Most UK systems use ΔT 50°C (flow 75°C, return 65°C, room 20°C), but modern systems may use lower temperatures.

Q2: How do I find my radiator's surface area?
A: Measure height × width × number of panels, or check manufacturer specifications.

Q3: What K value should I use?
A: Standard steel panel radiators are ~11 W/m²·K, while aluminum may be higher (~12-13 W/m²·K).

Q4: Why calculate in both Watts and BTU?
A: Watts are standard in the UK, but BTU is still commonly used in radiator specifications.

Q5: Should I add extra capacity?
A: Consider adding 10-15% for rooms with large windows or poor insulation.