1. What is BTU Calculation?

The BTU (British Thermal Unit) calculation estimates the heating and cooling capacity needed for a space. For heat pumps, proper sizing is crucial for efficiency and comfort.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( Area_i \) — Square footage of each room
• \( Factor_i \) — BTU per square foot factor (20-40)

Explanation: The calculator sums the BTU requirements for each room based on its size and insulation characteristics.

3. Importance of Proper Sizing

Details: An undersized heat pump will struggle to maintain temperature, while an oversized one will short-cycle, reducing efficiency and lifespan.

4. Using the Calculator

Tips:

• Measure each room's square footage accurately
• Choose appropriate BTU factors based on insulation and sun exposure
• Add 10-20% to the total for safety margin in extreme climates

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between BTU factors?
A: 20-25 for well-insulated rooms, 30 for standard, 35-40 for poorly insulated or sunny rooms.

Q2: Should I include hallways and bathrooms?
A: Yes, include all conditioned spaces, though bathrooms may need higher factors due to ventilation.

Q3: How does ceiling height affect BTU needs?
A: For ceilings over 8 feet, multiply the area by (height/8) before applying the factor.

Q4: What about windows and exterior walls?
A: Rooms with many windows or exterior walls may need higher BTU factors (35-40).

Q5: Is this calculator sufficient for final sizing?
A: This provides a good estimate, but professional Manual J calculation is recommended for final sizing.