1. What is a Heat Load Calculator?

Definition: This calculator estimates the heat energy required to maintain a space at a desired temperature, accounting for heat transfer through surfaces and other losses.

Purpose: It helps HVAC professionals, engineers, and architects determine heating requirements for buildings and systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total heat load (Watts)
• \( U \) — U-value (Thermal transmittance in W/m²K)
• \( A \) — Surface area (m²)
• \( \Delta T \) — Temperature difference (Kelvin)
• \( L \) — Other heat losses (Watts)

Explanation: The formula calculates conductive heat transfer through building elements and adds additional heat losses.

3. Importance of Heat Load Calculation

Details: Accurate heat load calculations ensure proper HVAC system sizing, energy efficiency, and occupant comfort while preventing over- or under-sizing of equipment.

4. Using the Calculator

Tips: Enter the U-value of the building element, surface area, temperature difference between inside and outside, and any additional heat losses. All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: What is U-value?
A: U-value measures how well a building element conducts heat. Lower values indicate better insulation.

Q2: How do I determine ΔT?
A: Subtract the outside design temperature from the desired indoor temperature (both in Kelvin or Celsius, as ΔT is the same in both scales).

Q3: What are "other losses"?
A: These include infiltration losses, ventilation requirements, and heat loss from equipment. For precise calculations, these should be calculated separately.

Q4: Typical U-values for common materials?
A: Single glazing ~5.7, Double glazing ~2.8, Brick wall ~2.1, Well-insulated wall ~0.35 W/m²K.

Q5: Should I add a safety factor?
A: Professional calculations often include 10-20% safety margin to account for uncertainties.