1. What is a Heater Wattage Calculator?

Definition: This calculator determines the required wattage for a heater based on room volume, desired temperature increase, and system efficiency.

Purpose: It helps HVAC professionals and homeowners properly size heating systems for optimal performance and energy efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( W \) — Heater wattage (watts)
• \( V \) — Volume of space (m³)
• \( \Delta T \) — Temperature difference (°C)
• \( C \) — Specific heat capacity of air (1200 J/m³·°C)
• \( t \) — Time to achieve temperature (seconds)
• \( E \) — System efficiency (decimal, 0-1)

Explanation: The formula calculates the energy needed to heat a volume of air by a certain temperature in a given time, adjusted for system efficiency.

3. Importance of Proper Heater Sizing

Details: Correct wattage calculation ensures comfortable heating, energy efficiency, and prevents equipment overload or underperformance.

4. Using the Calculator

Tips: Enter room volume, desired temperature increase, heat capacity (default 1200), desired warm-up time, and system efficiency (default 0.9). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the typical SHC_air value?
A: The standard is approximately 1200 J/m³·°C for dry air at sea level and 20°C.

Q2: How do I convert room dimensions to volume?
A: Multiply length × width × height in meters. For feet, convert to meters (1 ft = 0.3048 m) first.

Q3: What efficiency value should I use?
A: Modern electric heaters: 0.95-1.0, gas heaters: 0.8-0.9, heat pumps: 2.0-3.5 (COP).

Q4: How does altitude affect the calculation?
A: At higher altitudes, air density decreases - reduce SHC_air by about 1% per 300m elevation.

Q5: Should I add a safety factor?
A: Yes, consider adding 10-20% to account for heat loss through walls/windows and ventilation.