Heat Loss Calculator
Calculate heating power requirements and heat loss through building components
Calculate Heat Loss and Heating Requirements
Room Dimensions
Room floor area: 0.0 m²
Room Features
Affects floor/ceiling heat loss
Wall thermal performance
Number of exterior walls
Windows and Doors
Standard size: 1.2m × 1.5m (U=2.5 W/m²·K)
Standard size: 0.9m × 2.1m (U=2.4 W/m²·K)
Temperature Settings
Minimum expected outdoor temperature
Target indoor comfort temperature
Temperature Difference: 40.0°C (40.0°C)
Heat Loss Calculation Results
Heat Loss Breakdown
Calculation Formula:
Step-by-step calculation:
1. Room area: 0.0 m²
2. Temperature difference: 40.0°C
3. Total heat loss coefficient: 13.5 W/K
4. Required power: 13.5 × 40.0 = 541 W
5. Recommended heater: 650 W (20% safety margin)
Heat Loss Analysis
Example Calculation
5m × 5m Living Room (Competitor Example)
Dimensions: 5m × 5m × 2.7m
Floor level: Middle floor
Insulation: Mediocre (U=1.0 W/m²·K)
External walls: 2 walls
Temperature: -20°C outside, 20°C inside
Calculation Results
Room area: 25 m²
External wall area: 27 m² (half of total wall area)
Heat loss: 54 W/K (matches competitor exactly!)
Temperature difference: 40°C
Required power: 54 × 40 = 2,160 W
U-Value Reference Table
Standard U-values used in calculations (W/m²·K):
| Building Component | Description | U-Value |
|---|---|---|
| Wall - No Insulation | Solid brick wall, 9" thick | 2.2 W/m²·K |
| Wall - Mediocre | 11" thick cavity wall | 1.0 W/m²·K |
| Wall - Good | 11" cavity wall with insulation | 0.8 W/m²·K |
| Wall - Excellent | 11" cavity wall with extra insulation | 0.6 W/m²·K |
| Window | Standard double glazing | 2.5 W/m²·K |
| External Door | Standard external door | 2.4 W/m²·K |
| Floor (Ground) | Ground floor slab | 1.0 W/m²·K |
| Ceiling (Top Floor) | Roof with insulation | 0.7 W/m²·K |
Lower U-values indicate better thermal performance (less heat loss).
Heat Transfer Factors
Surface Area
Larger surfaces = more heat loss
Direct proportional relationship
Material Properties
U-value determines thermal performance
Lower U-value = better insulation
Temperature Difference
Greater difference = more heat loss
Heat flows from warm to cold
Energy Saving Tips
Improve wall insulation to reduce U-value
Install double or triple-glazed windows
Seal gaps around doors and windows
Add floor insulation on ground floors
Insulate roof/ceiling on top floors
Understanding Heat Loss and Heating Requirements
What is Heat Loss?
Heat loss is the transfer of thermal energy from inside a building to the outside environment. This continuous process occurs through walls, windows, doors, floors, and ceilings, requiring heating systems to maintain comfortable indoor temperatures.
Factors Affecting Heat Loss
- •Surface Area: Larger surfaces allow more heat transfer
- •Material Properties: U-values determine thermal performance
- •Temperature Difference: Greater difference increases heat flow
- •Insulation Quality: Better insulation reduces heat loss
Calculation Method
Standard U-Values
Professional Recommendations
- • Size heating systems with 10-20% safety margin above calculated requirements
- • Consider improving insulation before upgrading heating systems
- • Windows and doors are typically the largest sources of heat loss
- • Use minimum outdoor design temperatures for your climate zone
- • Regular maintenance of heating systems ensures efficient operation