1. What is BTU Output for Radiators?

Definition: This calculator estimates the heat output (in BTUs per hour) of radiators based on temperature difference, heat transfer coefficient, and surface area.

Purpose: It helps HVAC professionals and homeowners determine the heating capacity of radiators for proper system sizing.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat output (BTU/h)
• \( \Delta T \) — Temperature difference between radiator surface and room air (°F)
• \( K \) — Heat transfer coefficient (BTU/h·ft²·°F)
• \( A \) — Radiator surface area (ft²)

Explanation: The temperature difference multiplied by the heat transfer coefficient and surface area gives the total heat output.

3. Importance of BTU Calculation

Details: Proper BTU calculation ensures adequate heating capacity, energy efficiency, and comfort in the space being heated.

4. Using the Calculator

Tips: Enter the temperature difference in °F, heat transfer coefficient (default 1.5 BTU/h·ft²·°F), and surface area in ft². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical ΔT for radiators?
A: Most radiators operate with a ΔT between 30-50°F, depending on system design.

Q2: How do I find the K value for my radiator?
A: Check manufacturer specifications or use 1.5 as a default for standard cast iron radiators.

Q3: Does this include heat loss factors?
A: No, this is theoretical output. Actual output may be 5-15% lower due to system inefficiencies.

Q4: How do I measure radiator surface area?
A: Calculate total exposed surface area including fins and multiply by 1.5 for finned radiators.

Q5: What if I have multiple radiators?
A: Calculate each radiator separately and sum the BTU outputs for total system capacity.