Stelrad Heat Loss Calculator

Heat Loss Formula:

\[ Q = U \times A \times \Delta T + \text{Ventilation} \]

U Value:

W/m² K

Area:

m²

Temperature Difference (ΔT):

Ventilation Loss:

Heat Loss (Q):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is a Stelrad Heat Loss Calculator?

Definition: This calculator estimates the heat loss (Q) through building elements using the U-value, surface area, temperature difference, and ventilation losses.

Purpose: It helps heating engineers and installers determine the appropriate Stelrad radiator size needed for a space.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q = U \times A \times \Delta T + \text{Ventilation} \]

Where:

\( Q \) — Heat loss (Watts)
\( U \) — U-value (W/m² K)
\( A \) — Area of the element (m²)
\( \Delta T \) — Temperature difference (Kelvin)
\( \text{Ventilation} \) — Additional ventilation losses (Watts)

Explanation: The formula calculates conductive heat loss through building elements and adds any additional ventilation losses.

3. Importance of Heat Loss Calculation

Details: Accurate heat loss calculations ensure proper radiator sizing, energy efficiency, and comfortable room temperatures.

4. Using the Calculator

Tips: Enter the U-value of the building element, its surface area, the temperature difference between inside and outside, and any additional ventilation losses.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical U-value for walls?
A: Modern insulated walls might have U-values around 0.3 W/m²K, while older uninsulated walls could be 1.5 W/m²K or higher.

Q2: How do I determine ΔT (temperature difference)?
A: Subtract the outside design temperature from your desired room temperature (e.g., 21°C inside - -3°C outside = 24K ΔT).

Q3: What are typical ventilation losses?
A: This depends on air changes per hour, but a typical value might be 10-20% of the fabric heat loss.

Q4: How does this relate to radiator sizing?
A: The calculated heat loss (Q) indicates the minimum radiator output required to maintain the desired temperature.

Q5: Should I add a safety factor?
A: It's common practice to add 10-15% to the calculated heat loss to account for uncertainties.