Ancient Korean Ondal Smoke Heated Floor

Korean smoke heated Ondal floor explained in detail, ancient and current uses as well as how to use one for a greenhouse.

[dell]

I spent all of 1969 in a mountainous area of Korea in a very rural area and can tell you this heating system works very well.

[curtra]

Storing excess heat or even cold in your floor or wall has always seemed like such a good idea to me. It blows my mind that it's not standard practice.

[철크노트]

Thank you for your interest. First of all, the name of this heating system is "Ondol", not "Ondal". It means a warm stone. In modern Korea, more advanced hot water underfloor heating is used. If you apply this with Ondol, you can use the warmth more efficiently. The type of boiler can be used depending on the conditions, such as wood boiler, oil boiler, gas boiler, electric boiler, solar heat and sun light, etc.

[marittasidoroff]

My grand father had 3 greenhouses heated this way here in Finland. It was a common way back in the 1950s. Greenhouses where 30m long built in a slope to get the heat to rise and circulate. Smoke channels where of red tiles not to crack by the heat. Carbon monoxide was a real problem. Main source of heat was though raised compost beds and this method was used only as additional heating method during early spring and the coldest nights. In 1960s steel pipes became affordable so hot water central heating replaced this heating method.

[technosaurus]

One of the primitive technology channels did a video where they used clay tiles + clay to cover a trench that crossed the floor with the fire and chimney on opposite sides of the hut. Pretty cool for long term winter camping.

[federicocamilo]

We have been using a similar system in Spain since Roman It's called "La Gloria" underfloor heating.. In the Castilian countryside you will find lot's of these kinds of Buildings.

[who]

I spent a little over a Year in Korea, Weonju. Even though I didnt have the floor heating system, I hardly ever turned my central heat system on.
I was living on the 3rd floor of a building, the room below, keep there room very warm, and the one above me the same.

The floor was always warm to the touch, around high 80 degrees, and the ceiling was warm from the occupants above.
I really enjoyed that time in that country, but I did spend a couple nights in a traditional korean house, which the floor kept me plenty warm....

[WhatDadIsUpTo]

Although I heat my greenhouse with waste heat from my house heater, in Winter, I grow onions, garlic, cabbage and loose-leaf lettuce, crop choice being more the determining factor than mechanical heating.

I live in North Texas and right now, we are having an ice storm, but all the plants inside my greenhouse are just sailing through it.

[camperspecial]

Ive thought of this for years, modeled after the Roman bath houses- but with no water. Thanks for sharing

[brucef]

Brilliant. I thought I had heard of all the Permaculture ideas for heating, from Kachelofen to Kang to Rocket Mass Heaters to Long Houses but this one is new to me and makes total sense.. Congratulations for finding it.

[bellakaldera]

I did a tour of duty in the ROK and have stayed in Ondol heated homes. This was in the '70s and the Air Force brass told us not to sleep over in an ondol heated house because if there was a crack in the floor, CO can intrude and asphyxiate you. I remember the women sweeping up pine needles that would be compressed and heated into cylindrical Ondal briquets, each about the size of a 14"x 6" cylinder perforated with longitudinal holes, just the right size to put in a terra cotta tube (the stove) that when ignited vented the smoke under the floor, warming it comfortably. It gets very very cold in the ROK, they didn't call it "Frozen Chosen" for nothing.

[goatman]

Ondal is actually the charcoal brick used in the stoves. It can be used in cooking stoves, inside heating (was most common) and for radiant heat, though all the buildings I saw when I was there in the 80's had a ondal stove in the kitchen used for cooking and floor heat together. The kitchen was dug down about 2 feet, and each room (normally total of 4) had a slightly raised floor for the smoke to slowly rise underneath. Third room raised a bit higher, and 4tj room at ground height with the moke exiting to the outside.

[Theoatob]

Im no especially knowledable in this world but plants growing in soil heated from below has caused problems with soil drying out from below while roots try to grow down low. This is was my experience with underfloor heating, raisng the plants off the ground certainly helped the plants.

[noodle]

Many years ago I lived in my Grandma's house in North east china, which has similar weather like Korea. They had a mass clay based bed that occupied more than half is the house. The bed was toasty after cooking dinner, and the heat last the whole night. That system is much more effective than fireplace. The only draw back is if someone wet the bed, it could collapse:)

[gogadanature]

난 한국인 입니다. its Ondol . Decades ago Korean use it not only heating house but cook and boil water nowdays its tranformed modern style . Thanks

[seantewillis]

I just discovered your channel today. It is my new favorite channel.

[littlepotato]

Personally, I'll be going for a rocket mass heater. Similar idea except it uses a modified rocket stove for the fire, then runs the exhaust through some mass, and of course out of the house. I think my favorite mass that I've seen is a cob bench. It's really efficient on the amount of firewood that you need to use to get enough heat.

Although, I do walk around barefoot a lot. A warm floor sounds very nice.

[samscrumpet]

Are you reading my mind? I've been looking for Ondol information in English lately and it is difficult to find. Thank you so much!

[blisterbill]

I was in the US army stationed in Korea in the 1980’s. I still remember the smell of ondal during the winter.
I remember there were occasional deaths from carbon monoxide, mainly because the entire floor had to be completely sealed from the fumes below the floor. Some of the older houses in the village were built right after the war so they were already leaky. The available materials were pretty basic back then.
Ondal in the 80’s was a compressed cylinder of charcoal about the size of a coffee can. It had several holes from top to bottom so they could be stacked and still burn from bottom to top with flow of gasses. Most of the stoves would take two of the charcoal cylinders. I think they would last about 5 or six hours.

[ximono]

I have seen a greenhouse (in Korea I think) with a rocket heater and a bench. I liked that idea, as the bench can be used as a heat mat for seedlings in early spring, and as a nice bench to sit on in summer. Or just to place pots on.