1. What is a Heat Loss Calculator?

Definition: This calculator estimates the heat loss in a building based on U-value, surface area, temperature difference, and ventilation losses.

Purpose: It helps architects, engineers, and homeowners determine how much heat escapes from a building to properly size heating systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total heat loss (Watts)
• \( U \) — U-value of the building element (W/m²K)
• \( A \) — Surface area of the element (m²)
• \( \Delta T \) — Temperature difference between inside and outside (Kelvin)
• \( \text{ventilation} \) — Additional heat loss through ventilation (Watts)

Explanation: The formula calculates conductive heat loss through building elements plus any additional ventilation losses.

3. Importance of Heat Loss Calculation

Details: Accurate heat loss calculations ensure proper heating system sizing, energy efficiency, and occupant comfort while avoiding overspending on oversized equipment.

4. Using the Calculator

Tips: Enter the U-value (thermal transmittance), surface area, temperature difference, and any ventilation losses. 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/m²K, while older uninsulated walls may be 1.5-2.0 W/m²K.

Q2: How do I calculate temperature difference (ΔT)?
A: Subtract the outside temperature from the desired inside temperature (both in °C or K - the difference is the same).

Q3: What includes ventilation losses?
A: Heat lost through air changes, infiltration, or mechanical ventilation systems.

Q4: Should I calculate for each building element separately?
A: For accurate results, calculate heat loss for each element (walls, windows, roof, floor) and sum them all.

Q5: Does this account for thermal bridging?
A: No, for precise calculations you should account for thermal bridges separately or use specialized software.