This $300 Tunnel Keeps Any Home 55°F Forever — The Amish System the Cooling Industry Made Illegal

You're standing at the mouth of a tunnel

that runs underneath an Amish farmhouse

in Holmes County, Ohio. No wires,

>> [music]

>> no compressor, no thermostat, and the

air coming out of it is 55°

in the middle of August. This $300

system cools any home to 55° using

nothing but the earth beneath your feet

>> [music]

>> and a fan that draws less power than a

light bulb. The Amish have been building

it for 200 years. The cooling industry

has known about it since 1930, and in

1930, they made sure you would never

find out.

After the last video, many of you asked

the same thing, "What about summer? What

about keeping a home cool?" So, I went

back to Holmes County,

and what I found underneath those farms

is the same physics the Persians used to

store ice through 120° desert summers

2,400 years ago. And yes, this works

even if your

house was built 50 years ago.

>> [clears throat]

>> Here's the number that changes

everything. At 6 ft below the surface,

the ground temperature locks in and

stays constant all year.

Summer, winter, doesn't matter what's

happening above. Oak Ridge National

Laboratory, that's the Department of

Energy's own research facility, measured

it city by city.

In Chicago, the ground sits at 55°

year-round.

In Atlanta, 62. Denver, 58. Phoenix, 67.

Minneapolis, 52.

And in Holmes County, Ohio, right where

those Amish farms sit, the soil

temperature stays between 54°

every single day of every single year.

It never changes.

Now, think about that for a second.

Your air conditioner works by

compressing chemical refrigerant,

forcing it through coils, blowing air

across those coils, and dumping the heat

outside.

It pulls maybe three and a half units of

cooling for every unit of electricity it

consumes. Engineers call that a

coefficient of performance of about 3.5.

An earth tube, a simple buried pipe that

lets air travel through cool ground, was

measured across 47 installations

worldwide with a coefficient of

performance of 28.7.

28 versus three. That gap represents

billions of dollars in equipment,

refrigerant, electricity, and service

contracts every year.

And that's why you've never heard of

this. The physics behind it is so

simple, it almost sounds too good. Soil

is heavy, between 100 and 125 lb per

cubic foot. Moving that mass even 1°

takes enormous energy, 20 [music] to 30

BTUs per cubic foot. When summer heat

bakes the surface, it starts sinking

into the earth, but it moves slowly. Six

to eight weeks to penetrate just 6 ft.

By the time it arrives, the season is

already changed. The earth can't absorb

the heat fast enough to warm up. It

stays cool. It is the largest thermal

battery on the planet,

and it's sitting underneath every home

in America right now doing absolutely

nothing because nobody told you it was

there. The Amish didn't read about this

in a textbook. They figured it out the

way they figure out everything, by

paying attention to what the earth was

already doing and then building around

it. Every farm in Holmes County has a

root cellar dug 10 ft deep. No

insulation, no mechanical cooling. The

soil keeps it between 32° year-round.

That's not tradition. That is applied

physics refined over two centuries. Then

there are the springhouses.

These are small buildings constructed

directly over natural springs, where

groundwater flows at 54°

constant. The water moves under the

floor.

The building stays between 50° all

summer. The Amish in Lancaster County

and Holmes County use them to keep dairy

and produce fresh without a single watt

of electricity. I stood inside one on a

day when it was 91° outside. Inside that

springhouse, I could see my breath. But

the system that matters most for this

video is what the Amish call the breath

of the floor.

Clay pipes buried under the foundations

of their farmhouses. Air enters from

outside, travels underground through

those pipes, and rises through the

floorboards cooled by the earth.

The USDA documented this system in a

manual published in 1903, specifically

noting clay pipe installations in Holmes

County, Ohio. That document is over 120

years old. The system it describes is

still running under Amish homes today.

And here's where it gets interesting.

The Amish who settled Ohio and

Pennsylvania came from Germany and

Switzerland. Those same two countries

now lead the world in modern earth tube

engineering. Germany has 847 monitored

residential earth tube installations

tracked by the Passive House Institute

in Darmstadt since 2005.

Austria requires thermal labyrinth

analysis for any building over 1,000 sq

m.

Switzerland has a 15-year longitudinal

study from ETH Zurich, one of the most

respected engineering schools on the

planet, showing zero degradation in

system performance over the entire

monitoring period. Zero. The knowledge

the Amish carried from Europe 200 years

ago is the same knowledge Europe

rediscovered with modern engineering.

The circle closed, but America never got

the memo because someone made sure it

didn't. In 1902, a man named Willis

Carrier invented mechanical air

conditioning in a printing plant in

Brooklyn. His problem wasn't heat. It

was humidity ruining the paper. The

machine was never designed for human

comfort. [music]

But by the 1920s, Carrier Corporation

launched a campaign called Weather Maker

that repositioned air conditioning as

the symbol of American progress. [music]

Their marketing materials, and I've read

them explicitly, labeled passive cooling

techniques as primitive and unsanitary.

Then in 1930, a Carrier Engineering

Corporation manual included one sentence

that buried 5,000 years of proven

engineering.

It read, "Earth contact cooling is

suitable only for cellars and food

storage." [music]

One line, one corporate manual, and an

entire field of knowledge disappeared

from American construction. It wasn't an

accident. In 1927, the first model

mechanical codes were drafted [music]

with heavy participation from HVAC

industry representatives. Passive

alternatives weren't banned, they simply

didn't exist in the document. The people

writing the rules were the same people

selling compressors. After World War II,

the construction boom standardized

mechanical cooling as the only

acceptable approach.

Passive cooling vanished from

architecture schools. By 1980, fewer

than 3% of American architecture

programs taught any passive cooling

strategy at all. An entire generation of

architects, engineers, contractors, and

building inspectors was trained in a

world where earth tubes didn't exist.

Not because they failed, because they

weren't profitable. The numbers make the

motive obvious.

The Air Conditioning, Heating, and

Refrigeration Institute spent $47.3

million

on political activities in 2022 alone.

The residential cooling market in

America is worth $29 billion a year. The

average lifetime value of a single

residential HVAC customer is over

$15,000.

Every earth tube installed is an air

conditioner that never gets sold, a