1. What is a Radiator BTU Calculator?

Definition: This calculator estimates the heat output (in BTUs) of a radiator based on its size, temperature difference, and heat transfer coefficient.

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The heat output increases with greater temperature difference, larger surface area, and higher heat transfer coefficient.

3. Importance of Radiator Sizing

Details: Proper radiator sizing ensures efficient heating, prevents energy waste, and maintains comfortable room temperatures.

4. Using the Calculator

Tips: Enter the temperature difference (typically 50-70°F), heat transfer coefficient (default 1.5 for standard radiators), and surface area. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical ΔT for residential radiators?
A: Usually between 50-70°F (average water temp of 160-180°F minus room temp of 70°F).

Q2: How do I find the K value for my radiator?
A: Check manufacturer specs or use 1.5 for cast iron, 1.8 for aluminum, 2.0 for copper radiators.

Q3: How do I measure radiator surface area?
A: Calculate total exposed surface area including fins and multiply by 1.5-2.0 for finned radiators.

Q4: What's a good BTU output per room?
A: Typically 20-30 BTU per sq ft in cold climates, 15-20 in moderate climates.

Q5: Does this account for heat loss?
A: No, consider adding 10-20% to account for pipe heat loss and building insulation factors.