1. What is HVAC Load Calculation?

HVAC load calculation determines the heating and cooling capacity needed for a space. The basic rule-of-thumb method multiplies the area by a factor that accounts for climate, insulation, and other variables.

2. How Does the Calculator Work?

The calculator uses the basic HVAC load equation:

Where:

• \( Area \) — Floor area in square feet
• \( Factor \) — BTU per square foot (typically 20-30 for cooling)

Explanation: This provides a rough estimate of the cooling capacity needed. More precise calculations consider insulation, windows, orientation, and climate.

3. Importance of Proper HVAC Sizing

Details: Correct sizing improves efficiency, comfort, and equipment lifespan. Oversized units short-cycle, while undersized units run constantly.

4. Using the Calculator

Tips: Enter area in square feet. The default factor of 20 BTU/sq ft works for moderately insulated homes in temperate climates. Adjust higher for poor insulation or hot climates.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical factor for residential cooling?
A: 20-30 BTU/sq ft, with 20 for well-insulated homes and 30 for older/poorly insulated homes.

Q2: How many square feet will a 140k BTU unit cool?
A: Approximately 4,600-7,000 sq ft (using factors of 20-30 BTU/sq ft).

Q3: What's the conversion from BTU/h to tons?
A: 1 ton = 12,000 BTU/h, so divide BTU/h by 12,000 to get tons.

Q4: When should I use Manual J calculations?
A: For precise sizing, especially for new construction or major renovations.

Q5: Does this work for heating calculations?
A: Heating factors are typically lower (10-20 BTU/sq ft) as heating loads are often less than cooling loads.