1. What is a Heat Loss Calculator?

Definition: This calculator estimates the rate of heat transfer through a building element or surface using the basic heat loss equation.

Purpose: It helps engineers, architects, and energy assessors determine heat flow for building design and energy efficiency calculations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat loss rate (Watts)
• \( U \) — U-value (W/m²·K)
• \( A \) — Surface area (m²)
• \( \Delta T \) — Temperature difference across the surface (Kelvin)

Explanation: The U-value represents thermal transmittance, area is the surface size, and ΔT is the temperature gradient driving heat flow.

3. Importance of Heat Loss Calculation

Details: Accurate heat loss calculations are essential for proper HVAC system sizing, energy efficiency assessments, and building code compliance.

4. Using the Calculator

Tips: Enter the U-value (thermal transmittance) in W/m²·K, surface area in m², and temperature difference in Kelvin. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical U-value for walls?
A: Modern insulated walls typically have U-values between 0.1-0.3 W/m²·K, while older walls may be 1.0-2.0 W/m²·K.

Q2: How do I convert °C to Kelvin for ΔT?
A: The temperature difference is the same in °C and Kelvin (1K difference = 1°C difference).

Q3: Does this account for air infiltration?
A: No, this calculates conductive heat loss only. Additional calculations are needed for air leakage.

Q4: How accurate is this calculation?
A: It provides a basic estimate. For precise results, consider thermal bridges and other complex factors.

Q5: Can I use this for windows?
A: Yes, but use the specific U-value for the window (typically higher than walls).