1. What is HVAC Load Calculation?

HVAC load calculation determines the heating/cooling capacity needed for a space, measured in BTU/h (British Thermal Units per hour). Proper sizing is crucial for efficiency, comfort, and equipment longevity.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( Area \) — Floor area in square feet
• \( Height \) — Ceiling height in feet
• \( \Delta T \) — Temperature difference between inside and outside (°F)
• \( U \) — U-value (insulation factor)
• \( Occupants \) — Number of people in the space
• \( Equipment \) — Heat-producing equipment count

Explanation: The calculation considers building envelope heat transfer, occupant heat gain, and equipment heat output.

3. Importance of Accurate Load Calculation

Details: Proper load calculation prevents oversizing (which reduces efficiency and increases costs) and undersizing (which leads to inadequate comfort).

4. Using the Calculator

Tips: Measure room dimensions accurately. For ΔT, use design temperature difference (typically 20°F for cooling). U-values range from 0.02 (well-insulated) to 0.5 (poor insulation).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical BTU/h requirement per square foot?
A: Roughly 20 BTU/h per sq ft for cooling, but varies by climate, insulation, and other factors.

Q2: Why include occupants in the calculation?
A: Each person generates about 400 BTU/h of heat (more when active).

Q3: What U-value should I use?
A: 0.05 for well-insulated walls, 0.25 for average, 0.5 for poor insulation.

Q4: Should I add a safety factor?
A: Professional calculations often add 10-20%, but this calculator provides raw results.

Q5: How does this differ from Manual J calculations?
A: Manual J is more comprehensive, considering windows, orientation, and more factors.