Air Conditioner BTU Calculator
Calculate the perfect AC size for your room using BTU requirements and cooling capacity
Calculate AC BTU Requirements
Room Dimensions
Standard: 8-9 feet
Room Configuration
Kitchens require additional cooling capacity
Sun exposure affects cooling requirements
Room Occupancy
Each person generates about 600 BTU/hr of heat
Example Calculation
Living Room AC Sizing Example
Room: 15 × 20 feet (300 sq ft)
Ceiling: 9 feet high
Occupancy: 3 people regularly
Exposure: Average sunlight
Calculation Breakdown
Base BTU (300 sq ft): 7,000 BTU/hr
Ceiling adjustment (1 ft above 8 ft): +1,000 BTU/hr
Extra person (1 person above 2): +600 BTU/hr
Sunlight adjustment: No change
Total Required: 8,600 BTU/hr
Recommendation: 9,000 BTU window/wall unit
BTU Size Chart
AC Types by BTU
Window Units
5,000 - 18,000 BTU
Easy installation, affordable
Mini-Split Systems
9,000 - 36,000 BTU
High efficiency, quiet operation
Central AC
18,000+ BTU
Whole house cooling
Portable Units
5,000 - 14,000 BTU
Flexible placement, lower efficiency
Energy Efficiency Tips
Choose ENERGY STAR certified units
Proper insulation reduces cooling load
Regular maintenance improves efficiency
Use programmable thermostats
Seal air leaks and ducts
Understanding BTU and AC Sizing
What is BTU?
British Thermal Unit (BTU) is a unit of heat energy. In air conditioning, BTU/hr measures how much heat an AC unit can remove from a room per hour. One BTU is the energy needed to raise one pound of water's temperature by 1°F.
Why Proper Sizing Matters
- •Undersized: Can't cool the room adequately
- •Oversized: Cools quickly but doesn't dehumidify
- •Right size: Optimal comfort and efficiency
Factors Affecting BTU Requirements
Room Characteristics
- • Area (primary factor)
- • Ceiling height (+1000 BTU/ft above 8ft)
- • Insulation quality
- • Window size and type
Heat Sources
- • People (+600 BTU per person above 2)
- • Kitchen appliances (+4000 BTU)
- • Electronics and lighting
- • Sunlight exposure (±10%)
Important Considerations
- • These calculations provide estimates - consult HVAC professionals for complex installations
- • SEER rating affects energy efficiency and operating costs
- • Local climate conditions may require adjustments
- • Building codes may have specific requirements
- • Consider future needs and room usage changes
AC Selection Guide
Step 1: Calculate BTU
- • Measure room dimensions
- • Consider ceiling height
- • Count regular occupants
- • Assess heat sources
- • Factor in sunlight exposure
Step 2: Choose AC Type
- • Window units for single rooms
- • Mini-splits for efficiency
- • Central AC for whole house
- • Portable for flexibility
- • Consider installation requirements
Step 3: Efficiency Features
- • Check ENERGY STAR rating
- • Compare SEER values
- • Look for smart features
- • Consider programmable timers
- • Evaluate warranty coverage