Heat Load Calculator
Estimate cooling load and recommended AC tonnage
⚠️ NOT a Manual J Calculation
This is a simplified estimation tool for quick reference only. It does NOT replace proper ACCA Manual J load calculations. DO NOT use this for final equipment sizing — oversizing or undersizing can cause comfort issues, high humidity, short cycling, and premature equipment failure. For new installations or major replacements, always perform a complete Manual J calculation or consult a qualified HVAC engineer.
Room Dimensions
Environmental Factors
Internal Heat Gains
Calculation Results
Load Breakdown
Note: This is a simplified calculation for initial estimation only. For precise sizing, a detailed Manual J calculation or professional load assessment is recommended. Always add 10-20% safety margin for extreme conditions.
Typical Cooling Load Guidelines
| Space Type | W/m² | BTU/h per ft² | BTU/h per 坪 |
|---|---|---|---|
| Residential (well-insulated) | 80-120 | 25-35 | 900-1200 |
| Residential (average) | 120-150 | 35-45 | 1200-1500 |
| Office (standard) | 100-150 | 30-45 | 1000-1500 |
| Retail / Shop | 150-200 | 45-60 | 1500-2000 |
| Restaurant | 250-350 | 75-100 | 2500-3500 |
| Server Room | 500-1000+ | 150-300+ | 5000-10000+ |
Quick Reference
1 RT (Ton) = 12,000 BTU/h = 3.517 kW
1 坪 (Ping) = 3.305 m² = 35.58 ft²
Rule of Thumb
Residential: ~1 RT per 8-10 坪 (25-35 m²)
Commercial: ~1 RT per 6-8 坪 (20-25 m²)