Verified Mathematical Model & Formulation
Base BTU = Room Area (sq ft) × 20 BTU/sq ft Ceiling Adjustment = Height / 8 ft Total BTU = Base BTU × Ceiling Factor + (Occupants × 600) + Sun Exposure Modifier
Standard ASHRAE cooling guidelines recommend 20 BTU per square foot of living space at standard 8-foot ceiling heights, with additions for solar radiation and body heat.
Configurable Parameters & Standard Units
- Room Length (Feet): (Default: 18 ft)
- Room Width (Feet): (Default: 14 ft)
- Ceiling Height (Feet): (Default: 9 ft)
- Regular Room Occupants: (Default: 2 count)
- Sun Exposure (1=Shaded, 2=Average, 3=Very Sunny): (Default: 2 count)
- Is this a Kitchen? (1=No, 2=Yes): (Default: 1 count)
Standard Worked Example & Practical Verification
Scenario: A 15 ft × 20 ft bedroom (300 sq ft) with 10 ft ceilings, sunny west-facing windows, and 2 occupants.
Practical Takeaway: An undersized unit runs constantly without dehumidifying; an oversized unit short-cycles and leaves the room feeling clammy.
Frequently Asked Questions
How many BTUs are in 1 Ton of air conditioning?
One ton of refrigeration/cooling capacity equals exactly 12,000 BTU/hr (the cooling rate required to freeze or melt one short ton of water ice over 24 hours).
Why is an oversized air conditioner bad?
Oversized units cool the room too fast and shut down before pulling humidity out of the air, resulting in cold, clammy, mold-prone indoor spaces.