1. What is HVAC Load Calculation?

HVAC load calculation determines the heating and cooling capacity needed for a space. The basic rule of thumb is that 1 square foot requires about 25 BTU/h for cooling in moderate climates.

2. How Does the Calculator Work?

The calculator uses the basic HVAC load formula:

Where:

• \( BTU/h \) — British Thermal Units per hour (cooling capacity)
• \( Area \) — Area of the space in square feet
• \( 25 \) — BTU per square foot factor for moderate climates

Explanation: This simple calculation provides a rough estimate of cooling needs for residential spaces in moderate climates.

3. Importance of Proper HVAC Sizing

Details: Proper HVAC sizing is crucial for energy efficiency, comfort, and equipment longevity. Oversized units short-cycle, while undersized units can't maintain temperature.

4. Using the Calculator

Tips: Enter the area in square feet. For more accurate calculations, consider factors like insulation, windows, climate, and occupancy.

5. Frequently Asked Questions (FAQ)

Q1: Is 25 BTU/sq ft always accurate?
A: No, this is a rule of thumb. Actual needs vary by climate (20-40 BTU/sq ft), insulation, windows, and other factors.

Q2: What if my space has high ceilings?
A: For ceilings over 8 feet, multiply the area by the height factor (e.g., 10 ft ceilings = area × 1.25).

Q3: How does this differ for heating?
A: Heating typically requires fewer BTUs (20-35 BTU/sq ft) depending on climate and insulation.

Q4: When should I use a Manual J calculation?
A: For precise sizing, especially in extreme climates or unusual buildings, use ACCA Manual J calculations.

Q5: What about room additions?
A: For additions, calculate the new space separately and add to existing system capacity if possible.