BTU per Hour Calculator

BTU per Hour Formula:

\[ Q = A \times \text{BTU/ft}^2 \times F \]

BTU per Hour (Q): BTU/h

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1. What is a BTU per Hour Calculator?

Definition: This calculator estimates the BTU (British Thermal Unit) per hour required for heating or cooling based on area, BTU per square foot, and a factor.

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

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q = A \times \text{BTU/ft}^2 \times F \]

Where:

\( Q \) — BTU per hour (BTU/h)
\( A \) — Area in square feet (ft²)
\( \text{BTU/ft}^2 \) — BTU per square foot per hour (BTU/h·ft²)
\( F \) — Adjustment factor

Explanation: The area is multiplied by the BTU requirement per square foot and then adjusted by the factor for specific conditions.

3. Importance of BTU Calculation

Details: Proper BTU calculation ensures efficient HVAC system sizing, energy efficiency, and comfortable indoor temperatures.

4. Using the Calculator

Tips: Enter the area in square feet, BTU per square foot (default 20 BTU/h·ft²), and 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 this varies by climate.

Q2: When would I change the factor?
A: Adjust the factor for room height (1.1 for high ceilings), insulation (0.8 for well-insulated), or sun exposure (1.2 for south-facing rooms).

Q3: How do I find the area?
A: Measure length × width of the space in feet. For irregular rooms, divide into rectangles.

Q4: Does this include windows and doors?
A: The factor should account for these. Add 0.1 to factor for each large window or exterior door.

Q5: How precise should my calculation be?
A: Round up to the nearest 5,000 BTU for practical HVAC unit selection.