1. What is the Mears Domestic Heating Calculator?

Definition: This calculator estimates heat loss through building elements using the Mears method.

Purpose: It helps architects, engineers, and homeowners determine heating requirements for buildings.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat loss (Watts)
• \( U \) — U-value (W/m² K)
• \( A \) — Area of element (m²)
• \( \Delta T \) — Temperature difference (Kelvin)

Explanation: The U-value represents thermal transmittance, multiplied by area and temperature difference to calculate heat loss.

3. Importance of Heat Loss Calculation

Details: Accurate heat loss calculations ensure proper heating system sizing, energy efficiency, and occupant comfort.

4. Using the Calculator

Tips: Enter the U-value (from building materials), surface area, and temperature difference between inside and outside.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical U-value for walls?
A: Modern insulated walls: 0.18-0.30 W/m² K. Older uninsulated walls: 1.5-2.0 W/m² K.

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

Q3: Does this account for air infiltration?
A: No, this calculates fabric heat loss only. Ventilation losses should be calculated separately.

Q4: What about different building elements?
A: Calculate each element (walls, windows, roof, floor) separately and sum the results.

Q5: How does this relate to boiler sizing?
A: Total heat loss for all elements determines minimum boiler output required.