« Vietnam's Low-tech Food System Takes Advantage of Decay | Main


Feed You can follow this conversation by subscribing to the comment feed for this post.

Nancy E Sutton


Brilliant! Thank you for this exciting history : )

Jan Steinman


Glad you mentioned ondol, the Korean equivalent. When I lived in Korea in the early 1980s, ondol was still widely used, especially in the countryside.

The fuel is cylinders of charcoal with holes through its length. It was put into horizontal flues that run under the floor, then to an elbow in the wall, and up to a chimney.

However, it was considered a public safety menace. Unless the underfloor flues were properly maintained, carbon monoxide would seep into the room.

Once or twice a year, you'd hear of an entire family who died, occasionally killing the odd American GI, too. The threat was to the point that the local base commander forbid living off-site.

I don't know if ondol is still used. When it worked right, it was lovely! Warm floors are so nice!

But when it failed, it failed catastrophically, at least for the unfortunate residents.

I wonder if in your research you uncovered any tales or evidence of the CO poisoning potential of these ancient hypocausts?

kris de decker


@ Jan Steinman

I don't know the answer for sure but it seems to me that CO poisoning was not a major problem with the heat storage hypocaust. It was fired intermittently, and once the fire was extinguished, only hot air could come through the vents for the following hours and days. The Korean ondol is fired more regularly, which increases the chance that people sleep while the fire is burning.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been saved. Comments are moderated and will not appear until approved by the author. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment

Comments are moderated, and will not appear until the author has approved them.

Your Information

(Name is required. Email address will not be displayed with the comment.)

News & Links


Let's build our own internet

Fruit Walls

  • Fruit walls
  • Urban Farming in the 1600s
    From the 16th to the 20th century, urban farmers grew Mediterranean fruits and vegetables as far north as England and the Netherlands, using only renewable energy.

The Chinese Wheelbarrow

  • Chinese wheelbarrow
  • How to downsize a transport network: the Chinese wheelbarrow
    For being such a seemingly ordinary vehicle, the wheelbarrow has a surprisingly exciting history. This is especially true in the East, where it became a universal means of transportation for both passengers and goods, even over long distances.

Wood Gas Vehicles

  • Wood gas cars 2
  • Firewood in the Fuel Tank: Wood Gas Vehicles
    Wood gas cars are a not-so-elegant but surprisingly efficient and ecological alternative to their petrol (gasoline) cousins, whilst their range is comparable to that of electric cars.

Open Modular Hardware

  • Open modular hardware2
  • How to make everything ourselves: open modular hardware
    Consumer products based on an open modular system can foster rapid innovation, without the drawback of wasting energy and materials. The parts of an obsolete generation of products can be used to design the next generation, or something completely different.

Power from the Tap

  • Water motors
  • Power from the Tap: Water Motors
    Just before the arrival of electricity at the end of the 19th century, miniature water turbines were connected to the tap and could power any machine that is now driven by electricity.

Aerial Ropeways

Other Languages

  • Some articles have been translated into French, German, Spanish, Italian and Dutch. Find them here.