Forgotten Clothing: Hip Scarves

Hip Scarves. Image by Marie Verdeil.

Last year my partner stumbled upon a fascinating piece of clothing in a second-hand shop in Donostia, Basque Country. It looks like a miniskirt but is a (unisex) piece of underwear that increases thermal comfort in winter.

The clothing piece comes by different names: hip warmer, hip hugger, hip scarf, waist scarf, back warmer, belly warmer, tummy band, core warmer, warming belt, thermal brace — the list goes on. It is known as a “Haramaki” or “belly wrap” in Japan.

My hip warmers come in different sizes and are made from 69% wool, 22% cotton, and 9% elastodiene. Judging by the packaging design, they date from the 1970s or early 1980s. [Read more…]

November 6, 2022 by kris de decker Filed Under: Clothes, Heating appliances, Random

State of the Art of Windthermal Turbines

As Low-tech Magazine wrote in 2019, given the right conditions, a mechanical windmill with an oversized brake system is a cheap, effective, and sustainable heating system. Earlier this year, Malte Neumeier from the German Aerospace Center informed us that he and his team are investigating the technical and economical challenges of the technology.

“We started our research, with a birds eye techno-economic analysis and a scoping review. The results were promising, so we decided to build our own prototype. To refine our analysis, we are now searching for people, who already have experience with this technology. Maybe we could discuss some lessons learned. Do you have contact to any person experienced in wind-thermal energy applications? I would really appreciate this.” [Read more…]

May 16, 2022 by kris de decker Filed Under: Heating appliances, Wind Power, Windmills

Medieval Heating System Lives on in Spain

The Meseta Central is a vast plateau in the heart of Spain with long, cold winters and short, scorching summers. The locals say that there’s “nine months of winter” and “three months of hell”. The region has little trees, so heating (and cooling) has always been a challenge.

In the early middle ages, the Castillians developed a subterranean heating system that’s a descendent of the Roman hypocaust: the “gloria”. Due to its slow rate of combustion, the gloria allowed people to use smaller fuels such as hay and twigs instead of firewood. [Read more…]

February 8, 2017 by kris de decker Filed Under: Heating appliances, Random

Don’t Heat your Room with Tea Candles

hoax te candle heater

Friends and readers keep sending me links to a “low-tech” heating system in which tea candles heat a combination of ceramic flower pots. It seems you all need a course in thermodynamics, so let’s start with some basics:

1. First law of thermodynamics: you can’t create energy out of nothing, (and you can’t destroy it). This means that placing two ceramic pots on top of four candles does not increase heat production. You get the same amount of heat if you burn four candles without the pots.

2. Now imagine heating your room with four tea candles.

3. Get more tea candles. One tea candle can produce around 30 watts of heat, which means that you need at least 20 to 30 tea candles to heat a very small room (and replace them every 3 to 4 hours).

4. You have now built a small fireplace using tea candles. However, it isn’t running on wood but on petroleum — the stuff paraffin is usually made of. And above all,  you have built a fireplace without a chimney. Chimneyless fireplaces are very efficient, but they’re not so healthy and that’s exactly why the chimney was invented. Connecting your tea candle fireplace to a chimney will solve the indoor air pollution issue, but unfortunately 85-90% of the heat will then escape through the chimney. So you need more candles.

5. Forget tea candles, get some thermal underwear.

November 19, 2014 by kris de decker Filed Under: Heating appliances, Random

Chimneyless Houses

central hearth

“Early shelters were built of availale materials. Hides spread over poles or the bones and tusks of mammoths formed a type widely used. Stone and clay were common early building materials. Usually there was only a single room, with the fire located at the center of the living area. In many parts of the world this pattern changed little from the earlies times right up to the present. Smoke escaped from such dwellings as it could, through the low door or a smoke hole in the roof… The Scots developed a special word, snighe, for rain that worked its way through the roof sods and dripped down black with soot upon the people below.” [Read more…]

October 22, 2014 by kris de decker Filed Under: Fire, Heating appliances, Random

Crimean Ovens

“Starting in 1861, the wintertime Union field tent hospitals of the U.S. Civil War often used subterranean heating systems known as Crimean Ovens. The system under discussion was basically a firebox, or oven, on the outside of the tent, with a shallow, brick-lined, sheet-metal-covered trough running down the center of the tent’s interior, and ending in a chimney on the opposite exterior side of the tent. The tents were placed on ground with slight inclines, allowing the hot air to naturally rise and escape out the flue.”

crimean oven

“Dr. Charles Tripler, Surgeon and Medical Director of the Army of the Potomac, writes in a letter of November 1861 the following description of “a modification of the Crimean Oven”, devised and put into operation by Surgeon McRuer, the surgeon of General Sedgewick’s Eighth Brigade:

A trench 1 foot wide and 20 inches deep to be dug through the center and length of each tent, to be continued for 3 or 4 feet farther, terminating at one end in a covered oven fire-place and at the other in a chimney. By this arrangement the fire-place and chimney are both on the outside of the tent; the fire-place is made about 2 feet wide and arching; its area gradually lessening until it terminates in a throat at the commencement of the straight trench. This part is covered with brick or stone, laid in mortar or cement; the long trench to be covered with sheet-iron in the same manner. The opposite end to the fire-place terminates in a chimney 6 or 8 feet high; the front of the fire-place to be fitted with a tight movable sheet-iron cover, in which an opening is to be made, with a sliding cover to act as a blower.

crimean oven 2By this contrivance a perfect draught may be obtained, and use more cold air admitted within the furnace than just sufficient to consume the wood and generate the amount of heat required, which not only radiates from the exposed surface of the iron plates, but is conducted throughout the ground floor of the tent so as to keep it both warm and dry, making a board floor entirely unnecessary, thereby avoiding the dampness and filth, which unavoidably accumulates in such places.

All noise, smoke, and dust, attendant upon building the fires within the tent are avoided; there are no currents of cold air, and the heat is so equally diffused, that no difference can be perceived between the temperature of each end or side of the tent.”

Read more: 1 / 2 / 3.

March 4, 2014 by kris de decker Filed Under: Heating appliances, History, Random, War