Calculate heating & cooling requirements
Proper HVAC sizing is critical for comfort and efficiency. Oversized units short-cycle and waste energy. Undersized units run constantly and can't keep up.
Base calculation: Start with room volume (L × W × H), then adjust for insulation, sun exposure, climate, and occupancy.
Cooling (BTU/hr):
• Basic: 20 BTU per sq ft
• Add 600 BTU per person
• Add 10-20% for poor insulation
• Add 10% for sunny rooms
AC Tonnage: 12,000 BTU = 1 ton. Most homes use 2-5 ton units.
Important: This is a simplified estimate. For whole-house systems or commercial applications, get a Manual J load calculation from an HVAC professional.
How to use: Enter room dimensions, select insulation quality, sun exposure, and climate. The calculator provides cooling and heating BTU requirements plus AC tonnage.