1. What is a Supply House BTU Calculator?

Definition: This calculator estimates the heating or cooling capacity needed (in BTU/h) based on area, BTU per square foot, and adjustment factors.

Purpose: It helps HVAC professionals and homeowners determine the appropriate heating or cooling capacity for a space.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total BTU/h required
• \( A \) — Area in square feet
• \( \text{BTU/ft}^2 \) — BTU per square foot requirement
• \( F \) — Adjustment factor for special conditions

Explanation: The area is multiplied by the base BTU requirement per square foot, then adjusted by any special factors.

3. Importance of BTU Calculation

Details: Proper BTU estimation ensures efficient HVAC system sizing, energy efficiency, and comfort in the space.

4. Using the Calculator

Tips: Enter the area in square feet, BTU per square foot (default 20 BTU/h·ft²), and adjustment factor (default 1.0). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical BTU/ft² value?
A: For heating, 20-30 BTU/ft² is common. For cooling, 15-20 BTU/ft² is typical, but varies by climate.

Q2: When would I change the factor?
A: Adjust for high ceilings (1.1-1.3), poor insulation (1.2-1.5), or sun exposure (0.8-1.2).

Q3: How do I measure the area?
A: Multiply length by width of the space. For irregular spaces, divide into rectangles.

Q4: Does this include ventilation needs?
A: No, this is for heating/cooling only. Ventilation requires separate calculation.

Q5: How accurate is this calculation?
A: It provides a rough estimate. For precise sizing, consult HVAC Manual J calculations.