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Physics-first survival & home science
Cheap home upgrades that actually work, proven by physics.
We take the low-tech tricks that promise to cool, heat, and power your home for almost nothing, and show you the building science that proves whether they hold up. No hype. Just the numbers and where they come from.
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The exact materials from our builds, at Home Depot & Lowe's. Direct affiliate links are coming once those programs approve us — for now these take you straight to the store.
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Deep dives & sources
Winter
Grid down heat · free PDF
Grid Down Warm Room: Cheap Emergency Heat That Keeps You Alive
How a $30 sealed warm room held on your own body heat beats a $3,000 generator when the power dies. Read it, then grab the free printable checklist.
Read →Cooling
DIY AC · thermodynamics
Turn Any Fan Into an AC With 3 Frozen Bottles: The Math They Skip
Three frozen bottles hold about two million joules of cooling. Here's the melt budget the viral clips leave out.
Read →Guide
Heat safety · wet bulb
Why a Humid 95°F Beats a Dry 120°F: The Wet Bulb Guide
The reading that predicts collapse better than any porch thermometer — and the sealed-room playbook that keeps you alive.
Read →Cooling
Attic & ventilation
The $20 Spinning Roof Vent That Cools Your Attic With Zero Electricity
Two old physics tricks dump a baking attic's heat with no motor. Here's what it really does — and what it can't.
Read →Cooling
Geothermal · earth tubes
The $300 Buried Pipe That Cools a Home Without an Air Conditioner
Six feet down the ground sits near 55°F all year. Run your air through it and you get free pre-cooling.
Read →Guide
Summer cooling
7 Cheap Ways to Cool a House Without Running the AC
Ranked by what the building-science data actually shows — radiant barriers, night-flush, evaporative, and more.
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