Professional HVAC System Calculator
Calculate heating, cooling, and ventilation requirements for your building. Get accurate load calculations, system sizing recommendations, and comprehensive cost analysis.
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Calculate heating, cooling, and ventilation requirements for your building. Get accurate load calculations, system sizing recommendations, and comprehensive cost analysis.
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.
SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency. Higher number = more efficient. Minimum legal: 14 SEER. High-efficiency: 18-25 SEER. Each SEER increase saves ~5% on cooling costs. 16 SEER is sweet spot for most climates - good efficiency without premium price.
Professional load calculation (Manual J) is essential. Rules of thumb (like 1 ton per 500 sq ft) are unreliable. Oversized systems: short-cycle, poor dehumidification, higher costs. Undersized: insufficient comfort, overwork. Factor in: square footage, insulation, windows, climate, occupancy. Hire HVAC pro for proper sizing.
Replace if: system is 15+ years old, needs major repair (>$1,000), or has SEER below 10. Repair if: system is <10 years old and minor issue (<$500). Gray area: 10-15 years old - consider efficiency gains (new 18 SEER vs. old 10 SEER = 40% savings) and remaining lifespan.
SEER measures cooling efficiency (air conditioning): 14-25 SEER typical, higher = better. AFUE measures heating efficiency (furnace/boiler): 80-98% typical, higher = better. Modern high-efficiency systems: 18+ SEER, 95%+ AFUE. Each efficiency point saves 3-5% on energy bills. Minimum legal standards: 14 SEER, 80% AFUE in most regions.
Complete HVAC replacement costs: Basic system (14 SEER, 80% AFUE): $3,500-6,000. Mid-efficiency (16 SEER, 92% AFUE): $5,000-8,500. High-efficiency (20+ SEER, 96%+ AFUE): $7,000-12,000. Add for: ductwork modification ($1,500-5,000), zoning ($2,000-5,000/zone), smart thermostat ($200-500). Get 3 quotes from licensed contractors. Consider 10-year financing and utility rebates ($500-2,000).