Professional HVAC System Calculator
Calculate heating, cooling, and ventilation requirements for your building. Get accurate load calculations, system sizing recommendations, and comprehensive cost analysis.
Loading calculator...
trustpilot.message
🔥 NEW: Radiator Pro — 5-Step Professional Radiator Sizing with 3D Visualisation & Premium Access
❄️ NEW: AC Sizing Calculator — Free BTU/h & Tons Estimator for Summer 2026
🎉 New: Thermopy 2.0 Beta is Live! - Completely Redesigned Platform
📊 NEW: Premium PDF Reports in 13 Languages - Professional Analysis with 3 Tiers (Basic/Pro/Business)
🌍 Now Available in 13 Languages
⚡ Faster Calculators & More Accurate Results
Calculate heating, cooling, and ventilation requirements for your building. Get accurate load calculations, system sizing recommendations, and comprehensive cost analysis.
trustpilot.message
Enter building size, insulation quality, window area, and climate zone. Calculator determines heating/cooling capacity needed in BTU/hr or tons. Proper sizing crucial - oversized systems waste energy, undersized can't maintain comfort.
Inspect existing ducts for leaks, damage, or poor insulation. Leaky ducts waste 20-40% of conditioned air. Consider professional duct sealing ($300-1,000) before new system install for maximum efficiency.
Choose system SEER (cooling) and AFUE (heating) ratings. Minimum: 14 SEER / 80% AFUE. High-efficiency: 18+ SEER / 95%+ AFUE. Higher efficiency = higher cost but lower operating bills. Calculate payback based on energy savings.
Decide if zoning makes sense (multi-story, varying occupancy, large buildings). Zoning adds $1,500-3,500 per zone but can save 20-40% on energy. Best ROI for buildings with uneven heating/cooling loads.
Calculator shows equipment cost, installation, estimated annual operating cost, and potential savings vs. old system. Include maintenance costs ($150-400/year). Get professional Manual J load calculation before purchasing.
Pro Tip: Use Ctrl+Enter to calculate quickly, or Ctrl+R to reset the form.