The Conservatory Radiator Size Calculator helps you determine the appropriate radiator size needed to maintain a comfortable temperature in a conservatory. It calculates the total heat requirement based on factors such as heat loss through walls, windows, and the roof, as well as ventilation losses. By selecting the correct radiator size, users can ensure efficient heating and energy savings.
Formula of Conservatory Radiator Size Calculator
Step 1: Determine the Heat Loss from the Conservatory
Heat loss through the conservatory’s structure is calculated as:
Heat Loss (Q) = U × A × ΔT
Where:
- Q is the heat loss in watts (W).
- U is the U-value of the materials (W/m²·K).
- A is the total surface area (m²) of walls, windows, and the roof.
- ΔT is the temperature difference between the inside and outside (°C or K).
Step 2: Adjust for Ventilation Heat Loss
If significant air exchange occurs, include ventilation heat loss:
Additional Heat Loss = Volume × Air Change Rate × ΔT × 0.33
Where:
- Volume is the conservatory’s volume in cubic meters (length × width × height).
- Air Change Rate is the rate of air exchange per hour (commonly 0.5 to 1.0).
- 0.33 is a constant for the specific heat capacity of air.
Step 3: Total Heat Requirement
Add conduction and ventilation losses to find the total heat required:
Total Heat Requirement (Q_total) = Heat Loss + Ventilation Heat Loss
Step 4: Select the Radiator
Radiators are rated based on their heat output (in watts). Choose a radiator with an output equal to or slightly greater than QtotalQ_{\text{total}}Qtotal:
Radiator Output (W) = Q_total
Step 5: Adjust for Efficiency Factors
Increase the radiator output by 10–15% if placed under windows or in areas with obstructed airflow:
Required Radiator Output = Radiator Output × Adjustment Factor
General Table of Heat Loss and Radiator Outputs
Surface Type | U-Value (W/m²·K) | Area (m²) | ΔT (°C) | Heat Loss (W) |
---|---|---|---|---|
Single-glazed glass | 5.8 | 10 | 20 | 1,160 |
Double-glazed glass | 2.8 | 10 | 20 | 560 |
Insulated roof | 0.25 | 15 | 20 | 75 |
Brick wall | 1.5 | 12 | 20 | 360 |
Example of Conservatory Radiator Size Calculator
Scenario
A conservatory has the following specifications:
- Double-glazed windows: 15 m²
- Brick walls: 10 m²
- Insulated roof: 20 m²
- Indoor temperature: 22°C
- Outdoor temperature: 5°C
- Volume: 60 m³
- Air Change Rate: 0.5 per hour
Solution
Step 1: Calculate heat loss for each section:
- Windows: Q = 2.8 × 15 × (22 – 5) = 714 W
- Walls: Q = 1.5 × 10 × (22 – 5) = 255 W
- Roof: Q = 0.25 × 20 × (22 – 5) = 85 W
Total conduction heat loss: 714 + 255 + 85 = 1,054 W
Step 2: Calculate ventilation heat loss:
Additional Heat Loss = 60 × 0.5 × (22 – 5) × 0.33 = 168.3 W
Step 3: Total heat requirement:
Q_total = 1,054 + 168.3 = 1,222.3 W
Step 4: Select the radiator:
Choose a radiator with a heat output of at least 1,222.3 W.
Step 5: Adjust for efficiency factors:
If the radiator is under a window, increase the output by 10%:
Required Radiator Output = 1,222.3 × 1.1 ≈ 1,344.53 W
Result
A radiator with an output of at least 1,350 W is recommended.
Most Common FAQs
It estimates the appropriate radiator size to maintain desired temperatures in a conservatory by accounting for heat loss and ventilation factors.
Placement under windows or in areas with obstructed airflow reduces efficiency, requiring a 10–15% increase in radiator output.
Yes, the principles apply to any room where heat loss and ventilation need to be calculated for radiator sizing.