1. What is an HVAC Estimate Calculator?

Definition: This calculator estimates the required HVAC system power based on room area and the unit's Energy Efficiency Ratio (EER).

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

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — HVAC power requirement (kilowatts)
• \( A_{room} \) — Room area (square meters)
• \( EER \) — Energy Efficiency Ratio (dimensionless)
• 44.6 — Conversion factor (W/m² to BTU/hr)
• 3412 — Conversion factor (BTU/hr to kW)

Explanation: The formula converts room area to cooling load (BTU/hr) then calculates the electrical power needed based on the system's efficiency.

3. Importance of Proper HVAC Sizing

Details: Correct sizing ensures energy efficiency, proper humidity control, and prevents short-cycling or insufficient cooling.

4. Using the Calculator

Tips: Enter the room area in square meters and the EER rating (typically 3.0-5.0 for residential units). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is EER?
A: Energy Efficiency Ratio is the cooling capacity (BTU/hr) divided by power input (W) at standard test conditions.

Q2: What's a typical EER rating?
A: Standard units range 8-12 EER (3.0-4.5 in this formula's units), while high-efficiency units can reach 14+ EER (5.0+).

Q3: Why 44.6 W/m²?
A: This represents a typical cooling load of about 140 BTU/hr per m² (1 BTU/hr ≈ 0.293 W).

Q4: Should I add a safety factor?
A: This calculation provides a base estimate. Consider adding 10-20% for rooms with high heat loads (south-facing, lots of windows, etc.).

Q5: How does this relate to tonnage?
A: 1 ton of cooling = 3.517 kW. Divide the result by 3.517 to get cooling tonnage.