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Heat Loss Formula:
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Heat loss calculation determines the amount of thermal energy transferred through building elements. It's essential for proper heating system design, energy efficiency assessments, and building regulation compliance in the UK.
The calculator uses the fundamental heat loss formula:
Where:
Explanation: The formula calculates the rate of heat transfer through a building element based on its thermal properties, size, and the temperature difference between inside and outside.
Details: Accurate heat loss calculations are crucial for sizing heating systems correctly, ensuring energy efficiency, meeting building regulations, and reducing carbon emissions in UK properties.
Tips: Enter U-value in W/m²K, area in square meters, and temperature difference in Kelvin. All values must be positive numbers. Typical UK U-values range from 0.1-2.0 W/m²K depending on construction.
Q1: What is a typical U-value for UK homes?
A: Modern UK building regulations require walls around 0.18 W/m²K, roofs 0.13 W/m²K, and floors 0.15 W/m²K. Older properties may have much higher values.
Q2: How is temperature difference determined?
A: ΔT is the difference between desired indoor temperature (typically 21°C) and design external temperature (varies by UK location, typically -1°C to -4°C).
Q3: Why use Kelvin instead of Celsius?
A: Kelvin is used because it represents absolute temperature, but numerically 1K = 1°C difference, so the values are interchangeable for temperature differences.
Q4: What are typical heat loss values for UK houses?
A: A well-insulated modern UK home might have total heat loss of 2-4 kW, while older properties can exceed 10-15 kW.
Q5: How does this relate to heating system sizing?
A: Total building heat loss determines the minimum boiler/heating system capacity required to maintain comfortable temperatures during coldest conditions.