Enter an address to pull sqft, year built, and era-based insulation defaults (FDOR, free) — or fill the form manually.
The house
Insulation & air
Windows
Advanced — tech numbers (auto-filled from above)
Design temperatures
Envelope areas (peach = auto; edit to pin)
Window sqft by side
Floor / foundation
System
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Start with an address
Type the home's address on the left and we'll pull its size, age, and construction details automatically — or fill in the square footage yourself. The heat load appears here.
Property data
Results
TOTAL COOLING
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BTUh
TOTAL HEATING
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BTUh
Recommended size—
Capacity @ SHR—
Cooling airflow—
Heating airflow—
Sensible cooling—
Latent cooling—
Supply vents (6″ est.)—
Sqft per ton—
Per-floor systems (auto zone split)
Duct design (estimate)
Equal-friction sizing — supply runs & trunk at 0.10″/100 ft (trunk ≤900 FPM),
returns at 0.08″/100 ft (≤700 FPM), filter grilles at ≤300 FPM face. Flex must be pulled taut —
compressed flex chokes airflow. Planning estimate; final design per ACCA Manual D with room-by-room loads.
Suggested duct layout
Radial "spider" layout — distribution boxes centered over their run clusters,
registers around the outside rooms, return pulled from the center. Box sizes are duct-board
outside dimensions (width×length×height). Sketch is to scale from the home's footprint; actual
register spots follow the real room layout.
Heat load through the day
Cooling — hottest summer dayHeating — coldest winter day