1. What is a Radiant Floor Heat BTU Calculator?

Definition: This calculator estimates the heating load (in BTUs per hour) required for radiant floor heating systems based on floor area, heat output per square foot, and a heating factor.

Purpose: It helps HVAC professionals and homeowners properly size radiant floor heating systems for optimal comfort and efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heating load (BTU/h)
• \( A \) — Floor area (square feet)
• \( \text{BTU/ft}^2 \) — Heat output per square foot (BTU/h·ft²)
• \( F_f \) — Heating factor (dimensionless)

Explanation: The floor area is multiplied by the required heat output per square foot, then adjusted by a heating factor that accounts for heat loss and system efficiency.

3. Importance of Proper BTU Calculation

Details: Accurate BTU calculation ensures comfortable heating, energy efficiency, and prevents system over/under-sizing which can lead to higher costs or inadequate heating.

4. Using the Calculator

Tips: Enter the floor area in square feet, BTU per square foot (default 25 BTU/h·ft²), and heating factor (default 1.2). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical BTU/ft² value?
A: Most residential systems use 20-30 BTU/h·ft², with 25 being common for well-insulated homes.

Q2: What does the heating factor represent?
A: It accounts for heat loss through floors, system efficiency, and temperature differential. Higher values (1.2-1.5) are used for colder climates or poor insulation.

Q3: How do I measure floor area?
A: Calculate length × width for each room, then sum all areas to be heated by the system.

Q4: Does this include domestic hot water needs?
A: No, this calculates only space heating requirements. Additional capacity is needed for domestic hot water.

Q5: Should I add a safety margin?
A: Yes, consider adding 10-15% to the calculated value for design safety margin.