1. What is a BTU Calculator?

Definition: This calculator estimates the heating load required for a space based on temperature difference, heat transfer coefficient, and surface area.

Purpose: It helps determine the appropriate radiator or heating system size for UK buildings and homes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heating load (Watts or BTU/h)
• \( \Delta T \) — Temperature difference between inside and outside (°C)
• \( K \) — Heat transfer coefficient (W/m²·K)
• \( A \) — Surface area of the space (m²)

Explanation: The formula calculates the heat energy required to maintain the desired indoor temperature.

3. Importance of BTU Calculation

Details: Proper heating load calculation ensures energy efficiency, comfort, and correct sizing of heating systems.

4. Using the Calculator

Tips: Enter the temperature difference, heat transfer coefficient (default 0.33 W/m²·K for typical UK walls), and surface area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical ΔT value for UK homes?
A: For winter heating, a ΔT of 21°C is common (indoor 21°C, outdoor 0°C).

Q2: How do I find the K value for my walls?
A: Check building specifications or use standard values: 0.33 for insulated walls, 1.5 for single glazing.

Q3: Why show both Watts and BTU/h?
A: Watts are standard in the UK, but BTU/h is still commonly used for radiators.

Q4: Does this include heat loss through windows?
A: No, calculate windows separately and add to the total heating load.

Q5: Should I add a safety margin?
A: Yes, add 10-20% to account for unusually cold weather and heat losses.