Image: Ducts in a row. Photo: Daniel A. Barber. Taken from: After Comfort: A User’s Guide.

Comfort is a construct. Many new commercial and institutional buildings built over the past few decades rely so heavily on fossil-fueled mechanical HVAC systems that they would be uninhabitable without them. Many of the stylistic and programmatic debates in architecture in these same decades similarly relied on HVAC for their explorations and innovations. In other cases, often at the residential scale, buildings have been produced with an expectation of cheap energy, which has meant that adequate insulation, cross ventilation, and other design-based passive thermal measures have not been considered. Our determinedly slow, casual move away from fossil fuels, with limited political or socio-economic support, is already resulting in “green inequity” and novel forms of thermal violence. Over the decades to come, enclaves where upper-class neighborhoods engage with expensive “green tech” such as electric vehicles and heat pumps will coexist alongside poorer areas that cannot afford to make any transition from the carbon-fueled lifestyles they need to get by.

After Comfort: A User’s Guide is a project by e-flux Architecture in collaboration with the University of Technology Sydney, the Technical University of Munich, the University of Liverpool, and Transsolar.

This is a guest post by Mikhesh The Steamer.

It does not have to be just about the winter regarded with apprehension, which did not prove to be as much problematic in Europe at all. In the outlying hills, there is a lack of electricity or gas source. On the other hand, there is usually water and wood nearby. A steam heater can be assembled from things you find in a garbage dump, thrown away in a workshop or in a hobby market.

In a cabin with a fireplace after thirty minutes, the temperature is at best slightly higher, but with steam heating, a T-shirt is enough for that time. You can also spread the steam behind several corners and you don’t have to rely on heat radiation. Wood consumption is equal to a regular fireplace. The difference is in how we deal with its energy.

Steam, that’s what it’s all about.

It is not surprising that many cities used steam for heat distribution in the past. Steam has a much greater heat capacity than water. A supply of 10 liters of water in the tanks is enough for my system to heat a 30m3 brick house from an internal temperature of 5-10°C to 30°C within 3.5 hours. The heat will then pass into the walls and I will last until the morning at 18°C with an outside temperature of 5-10°C. I reach a comfortable temperature within 30 minutes.

I heat these 10 liters of water in pipes which are forming a tank with a total volume of 20 liters. I expect a reserve due to bubbling water and easier regulation. The water itself evaporates according to the intensity of the heating. You will know the appropriate volume after a few tests of your setup and its sound: It manifests itself with a strong bubbling sound.

Disadvantages and risks

The system works with minimal pressure, at a rough guess up to 0.3 atmospheres. I solve the risk of overpressure with a plug loaded with a small weight directly on the tank. I covered this part with a metal cover into which I enter through the small door.

Blowing the plug could be unpleasant. It would flood the room with rapidly cooling steam, which is why I cover it. This has never happened in practical use. The steam must have free passage through the pipe at all times. For this reason, I lead the steam through a rubber hose near the ceiling and gradually slope it downwards so that at no point can the condensing water freeze.

It is not necessary to vent the heating steam system. The penetration of steam through the system and the displacement of air is spontaneous. Only at the end does another exhalation occur – plain water, which I take out of the building through the walls. The captured water can be reused.

Common use

I pour water before starting the fire, never during it, because I might get scalded. The heating does not retain heat and cools down immediately after the fire burns out or the water runs out. In practice, however, the room stays warm for many more hours. Then I repeat the cycle.

Kit sheet

When constructing tanks, you cannot avoid welding. The evaporation containers are sunk into the interior of the fireplace and pass through the plate. They consist of 4 pipes connected in pairs and these are immersed in the combustion space itself, which reduces the internal volume of the fireplace. A tank placed on top of the stove alone would not be efficient enough.

We need:

*A fireplace with a cooking plate that will be adjusted for:
*Thick-walled non-galvanized pipes with a wall of 4 mm and a diameter of 40-50 mm for the tank itself in the fireplace. We plunge these through the stovetop and connect them at the top. Their shape therefore resembles a “C”. From there, we lead the couple further to…
*Ordinary water pipes with G thread. An oakum impregnated with vaseline is wound on the screw-threads. Never use a rubber gasket. The steam continues to..
*Brass taps for regulating the given distribution branch. Previously, these taps were used for gas in Central Europe. From here we take the couple out to…
*Thick-walled rubber hoses of the required length. Hoses from compressors for the distribution of compressed air have proven themselves. Subsequently, the steam passes into..
*Old radiator. We are already draining the water from it outside the building.

Tips:

*All elements must be resistant to 100°C.
*Try to assemble the device in a smaller version in the workshop. You will learn to regulate it and check if it makes sense for you.

I successfully conduct steam up to ten meters away. But it depends on your enthusiasm for experiments. I built my system myself from scraps from work and landfills. Even yours can be unique, where the steam will warm you, also with a great feeling of using discarded items and well-done work.

Plan:

Steam heating (10m)

1. The wall
2. Possible retention of condensed water
3. Pipe weldment with a diameter of 100mm
4. An old tin heating element
5. Tilting (drainage of condensed water)
6. Water
7. Partition without a hole
8. Partition with a hole
9. Water heater insulation
10. Silicone funnel cap
11. Weight
12. Valves resistant to 100°C
13. Hose resistant to 100°C
14. Different forms of enlargement of the transmission area
15. The body of the steam generator placed on the stove instead of the hot plate.

Images

1. Overall view:

2. another example of a heating element:

3. Evaporation tank inside the fireplace:

4. Opening to fill:

5. Fulfillment:

6. Operational water supply:

7. Heating distribution throughout the building:

8. An old heating element is enough:

9. Demonstration of transition of rubber hoses:

10: Securing the hole, the steam does not escape, but no explosion can occur:

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.

Thermal comfort

The hip scarf can significantly improve thermal comfort for two reasons. First, it insulates the body’s core, a condition to be comfortable in winter. If the core temperature falls, your body reduces the blood flow to the extremities by vasoconstriction. In extreme cases, this can save your life (at the expense of some fingers or toes), but in daily life, it results in cold hands and feet. The hip warmer keeps your core warm, which increases blood circulation and distributes warmth throughout the body.

Second, the hip warmer covers a part of your body that is otherwise easily exposed to the cold because of movements and body postures. Some modern clothes cover the body from neck to ankles (long dresses, ski suits, baby clothes), but most clothing nowadays consists of an upper part (shirt, sweater, blouse) and an underpart (pants, skirt). Consequently, bending over or stretching out can leave the hips, the belly, and the lower back exposed to the cold. Even if this happens only briefly, the warm air between skin and clothes will escape to the surroundings. The hip scarf prevents this.

Some activities make the hip warmer extra handy. For example, it works great for cyclists to prevent naked lower backs, and it insulates the belly of breastfeeding moms.

Hip Scarves. Image by Marie Verdeil.

The advantages of “fragmented” clothing

Hip warmers are related to both arm and leg warmers (or wrist and ankle warmers), which are also examples of “fragmented” clothing — garments that seem to be “incomplete.” I invented the term because I could not find a collective name for these pieces of clothing. The leaflet in the box of my hip scarf also shows knee and elbow warmers for sale.

It may seem odd to wear incomplete pieces of clothing. Why wear elbow, arm, and belly warmers when you can wear an extra layer of “normal” clothes, such as a thick sweater? However, these clothes offer an advantage: they can be put on and taken off quickly without stripping down. Whether or not we feel comfortable depends on many factors, and these are prone to change. The environment (temperature, air movement, humidity), our metabolism (the level of physical activity), and the objects that we are exposed to and in contact with (cold floor, hot cup of tea).

Fragmented clothes allow for adjusting clothing insulation quickly. Putting on or taking off the hip warmer takes no more than 5 seconds: you can step into it and pull it up. That allows for micro-management of the body’s thermal balance. It may be a bit harder when you have wide hips because you need to pull the hip scarf over your head.

In contrast, a layer of thermal underwear can land you in serious trouble when the thermal environment changes. I am speaking out of experience here. My wool thermal underclothing keeps me comfortable in surprisingly low air temperatures. However, when I need to enter a heated indoor space in winter, it becomes a curse rather than a blessing. My body will overheat quickly, and there’s only one way to solve it: strip down to the underpants.

On the move

Fragmented clothes are handy while being on the move. A small package can make a big difference. For example, when I cycle to the city, I usually leave in the afternoon when the sun shines. I would quickly overheat with winter clothes. However, I come back after sunset, when it is much colder. In between, I may be in a heated shop but just as well on a frosty bar terrace.

Carrying a hip warmer and a pair of arm warmers, I now need to take fewer clothes. By insulating those body parts most exposed to the cold — on the bike the wind blows right into my jacket sleeves — I need less insulation overall. I don’t have leg or ankle warmers (yet), but they would protect another part of the body exposed to cold on a bicycle.

How to wear a hip scarf

You can wear a hip scarf in different ways. You can tuck it into your shirt and pants or skirt so that it remains largely invisible to the outside world, or you can show it off, wearing it above anything else except for your jacket. The second method is the most practical because you can remove the hip warmer quickly. However, these are not the 1980s, so you need a certain level of indifference for fashion. Intermediate solutions are also possible. I sometimes wear the hip scarf under my shirt but over my pants, which looks like I have an extra shirt underneath.

Until recently, the Japanese regarded the “belly warmer” — or “Haramaki” — as out-of-date underwear worn by old men. Traditionally, it was considered a functional piece of clothing, usually hidden under clothes and considered slightly embarrassing. However, in recent years it has become a fashionable item largely thanks to Japanese game designer Itoi Shigesato, who launched a Nintendo-themed collection. His creations invite you to show off. There is talk of a revival of the Haramaki. Indeed they are now also sold under that name in other countries.

Image: Ultra Warm Merino Haramaki, Nukunuku.

Haramaki from Japanese brand Hobonichi.

Haramaki and leg warmers from Japanese brand Hobonichi.

Dr. Gibaud’s Thermal Brace is still for sale and now available in several colors.

Pain relief & sports

Dr. Gibaud, the company that made my hip warmers, keeps selling the same product. However, it doesn’t promote it as a fashion article. Dr. Gibaud now promotes hip warmers as a pain relief method. For example, keeping your lower back warm can prevent or relieve the symptoms of lower back pain. A belly warmer can also relieve bladder, kidney, rheumatic and menstrual pains. Nowadays, people often use heat pads to relieve those pains, but hip warmers (and hot water bottles) can do similar things for much less money and waste.

Fragmented clothes are also handy during sports and other physical activities. They keep you warm during and after exercise, which decreases the chance of damage to muscles and ligaments. Leg warmers originated as athletic wear for keeping dancers warm. They only became a fashion hype in the early 1980s through movies like Flashdance and Fame. Finally, hip scarves should not be confused with corsets (which make you look thinner) or support braces (which correct a posture).

Thanks to Adriana Parra.

Related articles: 

• Insulation: first the body, then the home.
• The revenge of the hot water bottle.
• Heating people, not spaces: restoring the old way of warming

“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.”

The scoping review is freely accessible online: Neumeier, Malte, et al. “State of the art of windthermal turbines: A systematic scoping review of direct wind-to-heat conversion technologies.” Journal of Energy Resources Technology 144.4 (2022). From the abstract:

Windthermal turbines convert wind directly into thermal energy. Albeit it is an uncharted field of research, the overall system efficiency and costs of fully developed windthermal turbines are promising; since they can contribute to a sustainable energy transition. We identify the current state of the art of windthermal conversion principles, technology maturity, applications, substitutes, advantages, and disadvantages.

To scope relevant literature, we follow the Joanna Briggs Institutes selection and screening process resulting in 61 relevant publications from which we identified three main conversion types, namely, compression-, friction-, and induction-based windthermal devices. These devices can directly supply thermal energy for space heating or industrial processes, work as a component of wind-powered thermal energy systems, short windthermal energy system (WTES), or can substitute any conventional or renewable heat device.

Although heat is the lowest form of energy, windthermal applications could provide cheap renewable energy that can be stored easily enhancing security of supply. However, these technologies are currently on laboratory scale, and we suggest scaling up the existing prototypes to engineering scale. Finally, due to a missing general terminology, we propose to establish one of the terms windthermal energy, ventothermal energy, or anemothermal energy to distinguish these specific wind energy conversion technologies.

The cost assessment, which was quoted in the Low-tech Magazine article, is also online: Cao, Karl-Kiên, et al. “Expanding the horizons of power-to-heat: Cost assessment for new space heating concepts with Wind Powered Thermal Energy Systems.” Energy 164 (2018): 925-936.

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.

The Gloria

Remarkably, the gloria is alive and kicking. Several villages, especially in the wider region around Burgos, still have houses with subterranean fireplaces of which some are in working order.

In January, my friend Pedro took me to his uncle’s house in Hontangas, a tiny village at some 100 km from Burgos. The uncle, now in his late sixties, fires the gloria once every morning during the “nine months of winter”.

A gloria heats one or at most two different rooms, usually kitchen and/or living room. The firebox is located outside the house, often in a courtyard but sometimes on the street. The wall above it is black from soot. The chimney is on the other side of the heated room.

The warm exhaust gases from the combustion heat are led through one or more ducts  that run under the floor of the heated room(s), and then rise through the chimney. The floor and the walls slowly radiate this heat into the room. In summer, a natural air current in the gloria cools the room(s).

The expression “estar en la gloria” (to be inside the gloria), meaning that someone feels happy and comfortable, refers to this medieval heating system.

The obvious downside of the gloria is that you have to get outside in the cold to “turn on” the heating, first thing in the morning. This takes about 20 minutes. Vine cuttings are added first, followed by some firewood.

When the fire is burning well, the firebox is covered with a some metal plates to slow the combustion rate and keep the heat inside. One firing suffices for a day of warmth.

The gloria is related not only to the hypocaust but also to the Korean ondol and the American “crimean oven“.

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.

“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.”

“Today the term stove refers to a certain kind of container for fire; the stove warms the room. In earlier times stove meant the heated room itself… The dwelling was a container for the fire that burned on the open floor. A hole in the roof let the smoke out. The door admitted air for combustion, just as the adjustable air inlet does today on the door of an iron stove… The beehive houses of Scotland’s Western Isles, and the central-hearth houses of Ireland, normally had two doors. Whichever door lay on the side away from the wind was used to adjust the draft. American Indians did much the same with their tipis, lifting the skins on one side as a draft adjustment for the fire that lay on the open floor.”

“Sometimes, as in Scandinavia, there was a louver in the roof, a kind of trapdoor that could be closed and opened with a pole. During the early and smoky stages of the fire the louver was opened. It was closed to keep the heat in after the fire had burned down to charcoal and offered little smoke. In the manors and larger buildings of England, louvers became quite elaborate architectural features. Instead of simple trapdoors, they took the form of cupolas. These blocked the rain but let out the smoke in winter and the heat in summer.”

“The atmosphere in the central-hearth building depended on various factors, including the design of the building, weather, the quality of fuel and its moisture content, and the skill of the firetender. By present-day standards, conditions must have left a good deal to be desired… Still there were real advantages to the chimneyless house. The fire on the floor offers all its heat to the room; it is 100 percent efficient. The chimneyed fireplace offers a meager 10 percent efficiency as a rule, channeling 90 percent of the heat outdoors.”

“The central hearth also saved woodcutting at a time when woodcutting tools were poor. Long sticks could be fed gradually into the fire. And there was room for more people close to the warmth. Many continued to use the open hearth, including some of the colleges of Oxford, long after the chimney became known.”

Quoted from “The Book of Masonry Stoves: Rediscovering an Old Way of Warming“, David Lyle, 1984.

The illustrations are from “The English fireplace: a history of the development of the chimney, chimney-piece and firegrate with their accessories, from the earliest of times to the beginning of the XIXth century“, 1912. It talks about smoke louvers (or smoke turrets) on pages 5-9.

Related: Well-tended fires outperform modern cooking stoves.

“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.

By 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.

Research by the Dutch research institute TNO (Dutch Organization for Applied Scientific Research) shows that contact heating through the wrists is the most efficient way to warm the body — one can turn down the heater 1 to 4 degrees C°. If the undersides of the wrists are warm, the whole body will be warm. By working at a computer, for example, using the mouse, or writing, the wrists are placed on the work top.

The heating elements are integrated into the table top. This is possible, because Bloooms exclusively works with bamboo, which is eminently suitable to apply heating. It’s a stable material, that conserves its shape and properties when heated. A sensor triggers the heating the moment someone sits down at the desk, and turns it off when no one is sitting at the desk. The heating can be individually adjusted, and is therefore excellently suited to be used in spaces where there are several people at work.”

Bloooms heated desk. The company is working on a new version of their heated desk, which can be controlled by a laptop and will be ready in a few months. Related: Several readers have sent us a link to a prototype of a thermoelectric bracelet. It monitors air and skin temperature, and sends tailored pulses of hot or cold waveforms to the wrist to help maintain thermal comfort. Heat the individual, not the building.

Related articles:

• Heat Your Clothes, Not Your House
• Insulation: First the Body, then the House
• The Solar Envelope: How to Heat and Cool Cities Without Fossil Fuels
• Sunbathing in the Living Room: Tiled Stoves
• More heating technology & heating strategies

A rocket stove is not quite as efficient and clean-burning as a masonry heater, but it is much more DIY-friendly to build. The idea is that the configuration allows excess oxygen to increase the burn temperature of the fire. Hotter temperature means you want to store the heat energy into a high thermal mass material. Lots of great links at I fucking love rocket stoves.

“The town I live in is located near the Alberta-BC border, about 100 miles north of the US Canada border. Winters here are long and cold, but many days are crystal clear and sunny.”

“Our tool shed has a south-facing wall which was ideal to mount a solar thermal direct-air collector panel. The collector panel exterior dimensions are 48” high x 49.5” wide. Total budget: $200.00 Result: 16 sq ft harvest up to 6 kWh/day.”

Build a Solar-Thermal Direct-Air Heater (PDF). Introduction (and another project) here.

“I had a lot of motivators here, but the primary motivator was the greenwashing being done around fluorescent light bulbs. My power company sent me literature telling me that I should replace all of my incandescent light bulbs with fluorescent light bulbs to save energy and money. Based on my lighting usage, the most I could possibly save is $5 per year. Yet, with changing my heating habits, I think I have proven that I can save $500 per year.”

Read more: Micro heaters cut 87% off my electric heat bill. Via Treehugger. Previously: Insulation: first the body, then the home.

Dutch inventor Kees van der Geer sends us this paper and wants to know what we think of it. Comments are open.

“Heating with a sun collector costs nothing and contaminates nothing. In this article I propose a solar heating system consisting of a large solar collector, suitable for the heating of a house and a heat store, capable to bridge a week of cloudy weather. Both are made from simple materials.”

“Maybe a practical solution to make a heat store is to buy a inflatable swimming pool of 17m3 and construct an insulating box around it. ”

Large area solar heating system (pdf), Kees van der Geer, 2011. (Artículo en Español).

Picture gallery. Previously: Sunbathing in the living room: oven stoves and heat walls.