1. What is a Room Heat Loss Calculator?

Definition: This calculator estimates the heat loss of a room to determine the appropriate radiator size needed to maintain comfortable temperatures.

Purpose: It helps homeowners and heating professionals properly size radiators for efficient heating system design.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat loss (Watts)
• \( U \) — U-value of room surfaces (W/m²K)
• \( A \) — Total surface area of room (m²)
• \( \Delta T \) — Temperature difference between inside and outside (°C)

Explanation: The calculator first determines the total surface area of the room, then calculates how much heat is lost through these surfaces based on insulation quality (U-value) and temperature difference.

3. Importance of Heat Loss Calculation

Details: Accurate heat loss calculation ensures properly sized radiators that maintain comfortable temperatures without wasting energy.

4. Using the Calculator

Tips: Enter room dimensions in meters, U-value (default 2.5 W/m²K for average insulation), and temperature difference (default 21°C for 21°C inside and 0°C outside). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical U-value?
A: Modern insulated walls: 0.3 W/m²K, Older walls: 1.5-2.5 W/m²K, Single-glazed windows: 5.0 W/m²K.

Q2: How do I determine temperature difference?
A: Subtract the lowest expected outside temperature from your desired room temperature.

Q3: Does this include ventilation heat loss?
A: No, this calculates fabric heat loss only. Add 10-20% for ventilation losses.

Q4: How does this relate to radiator size?
A: Choose a radiator with an output (W) equal to or slightly higher than the calculated heat loss.

Q5: Should I add any safety margin?
A: It's recommended to add 10-15% to the calculated value to account for unusually cold weather.