Solar Radiation Cooling Load for Glass Calculator

Solar Radiation Cooling Load Formula:

\[ Q_{cl} = SHGF \times A_g \times SC \times CLFG \]

Maximum Solar Heat Gain Factor:

W/m²

Area of Glass:

m²

Shading Coefficient:

Cooling Load Factor for Glass:

Solar Radiation Cooling Load (W):

1. What is Solar Radiation Cooling Load for Glass?

Definition: This is the heat gain entering through glass due to solar radiation that contributes to the cooling load of a space.

Purpose: It helps HVAC professionals and architects determine the cooling requirements for spaces with glass windows or facades.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q_{cl} = SHGF \times A_g \times SC \times CLFG \]

Where:

\( Q_{cl} \) — Solar radiation cooling load (Watts)
\( SHGF \) — Maximum solar heat gain factor (W/m²)
\( A_g \) — Area of glass (m²)
\( SC \) — Shading coefficient (0-1)
\( CLFG \) — Cooling load factor for glass (0-1)

Explanation: The formula calculates the solar heat gain through glass, adjusted for shading and cooling load factors.

3. Importance of Calculation

Details: Accurate calculation ensures proper HVAC system sizing, energy efficiency, and thermal comfort in buildings with significant glass areas.

4. Using the Calculator

Tips: Enter SHGF (typically 200-1000 W/m²), glass area in m², shading coefficient (default 0.75 ±5%), and cooling load factor (default 0.83 ±5%). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical SHGF value?
A: Varies by location and orientation - 200-300 W/m² for north-facing, 800-1000 W/m² for south-facing in summer.

Q2: How is shading coefficient determined?
A: It's provided by glass manufacturers, with lower values (0.3-0.5) for high-performance glass.

Q3: What affects the cooling load factor?
A: Room characteristics like mass, color, and furnishings that absorb and re-radiate heat.

Q4: Why the ±5% tolerance on SC and CLFG?
A: These factors can vary slightly based on installation and environmental conditions.

Q5: How to reduce solar cooling load?
A: Use low-SHGF glass, external shading, or reflective coatings.