1. What is an Electric Unit Heater Sizing Calculator?

Definition: This calculator determines the required size of an electric unit heater based on the building's heat loss and system efficiency.

Purpose: It helps HVAC professionals and property owners select properly sized electric heaters for optimal performance and energy efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( S \) — Heater size (kW)
• \( H \) — Heat loss (kW)
• \( E \) — System efficiency (dimensionless, 0-1)

Explanation: The heat loss is divided by the system efficiency to determine the required heater capacity.

3. Importance of Proper Heater Sizing

Details: Correct sizing ensures adequate heating, energy efficiency, and prevents equipment from overworking or short cycling.

4. Using the Calculator

Tips: Enter the calculated heat loss in kW and system efficiency (default 0.95). Efficiency must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine heat loss?
A: Heat loss calculations consider building size, insulation, windows, and climate. Professional heat loss calculations are recommended.

Q2: What's a typical efficiency for electric heaters?
A: Most electric heaters have near 100% efficiency (0.95-1.0) since all electricity is converted to heat.

Q3: Should I round up the calculated size?
A: Yes, it's common practice to round up to the next available heater size for a safety margin.

Q4: Does this account for multiple heaters?
A: No, this calculates total required capacity. Divide the result by the number of heaters needed for individual sizing.

Q5: What about voltage and amperage requirements?
A: This calculator determines kW size only. Electrical requirements should be calculated separately based on voltage.