CFM Cooling Calculator

Natural convection · 76" × 36" sliding door · 1,200 sq ft × 8 ft ceiling · Wood stud / R-19 / ½" drywall · Night cooling · Mountain Time

Location & Forecast

Enter your zip code to load tonight's hourly forecast. Saved locally to your device — enter once.

Cooling Window — Mountain Time

Select the hour you open the door. End time is calculated from duration.

Start Time (MT)

hour door opens

Duration

hours (1–12)

10:00 PM → 6:00 AM MT (8 hrs)

Temperature Inputs

Outside temps auto-fill from forecast. Override manually if needed.

Current Inside Temp

°F

Goal Temp

°F target

Humidity (Inside)

Outside Temp at Start AUTO

°F when door opens

Outside Temp at End AUTO

°F forecasted low

Space Contents — Thermal Mass

Nearly Empty

Bare walls, minimal items, very little furniture or storage

Low thermal mass · 2× air

Lightly Furnished

Some furniture, shelving, light equipment or goods

Moderate-low mass · 4× air

Moderately Loaded

Mixed goods, equipment, shelving — typical occupied space

Moderate mass · 7× air

Heavily Loaded

Dense storage, heavy machinery, concrete floors, packed shelving

High thermal mass · 13× air

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Recommended opening width

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Initial CFM at opening

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Projected temp at end

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Outside temp range

76" H × 36" W

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recommended opening width
slide door from left · height fixed at 76"

— % of max width

Thermal Load Breakdown

Projected Temperature Over Time

Inside air temp

Goal temp

Outside temp (logarithmic drop)