DIY powered respirator

A powered "positive pressure" respirator that uses a Volkswagen air filter? Why not?

Jake at Steampunk Labs developed an allergy to pine sawdust. He says, "At first I didn't realize what my trouble was. It started with a mild headache that just wouldn't go away. After about four days I grew concerned enough to go to the doctor."

For painting I've always used a Pro-Air Supplied Air Respirator that deliveres fresh air to me via it's 50 foot hose.

However, walking around the wood shop dragging a 50 foot hose gets old real quick. Step by step with pics here.

via hackaday

The harder knock

There are many craft builders that may have heard their inner voice saying, "I'd like to build a front door." Steve woke up saying to himself, "I'd like to build a concrete front door."

A designer/builder living in Mexico, he says "Concrete is a plastic medium and has incredible potential for creating fluid, sculptural forms. I will admit that some of the dullest structures around are made of concrete but dullness isn't a limitation inherent in the material."

Flying Concrete experiments with and delivers affordable and efficient structures, including low income housing and housing that's fun.

Arches and vaults can have various shapes and sizes, but the line of thrust for a uniform dead load always follows the shape of an inverted catenary curve.

Define: catenary - the curve assumed by a section that is perfectly flexible but not capable of being stretched.

A green hot shower

The design features of a conventional shower minimize thermal comfort, maximize energy use and water consumption while exacerbating moisture problems. Most of these negative effects are caused by evaporation. As small droplets of water fall from the showerhead, the high surface area and velocity of the particles of hot water experience conditions, which maximize evaporative cooling of the droplets.

Water saving showerheads that produce exceptionally small water particles can actually further increase evaporation. Water Particles can be cooled by as much as 30ºF as they fall from the showerhead to the ground.

There is a simple solution to this myriad of related problems; preventing airflow to and from the showing area is the key, in other words sealing the shower stall. Additional benefits can be obtained by the incorporation of insulated low thermal mass walls that heat up rapidly.

The result is a shower stall where air currents are minimized, humidity is increased and the air is warmer. All these effects will increase thermal comfort and reduce energy and water consumption. Sun Frost Energy Efficient Shower

Bacteria heating water. Yes.

Composting Greenhouse with Straw Bale Foundation

Compost heats the water
Two PVC 3/4 inch water lines ran underground from the house to the greenhouse. The cold water supply originated at the washer hookup cold line. Hot water returned from the greenhouse in an insulated line after circulating in the hot compost and entered the house plumbing at the washer hot water hookup.

more frugal stuff here

New color for commercial exteriors

A colorful cube. One half above ground.

The new building for the Netherlands Institute For Sound And Vision consists of five levels under ground and five levels above ground. In the underground, the national archives of Dutch radio and television recordings are stacked around a deep canyon. Above ground, a staged volume contains the media museum. The third element is the office building of the institute. The three volumes together enclose a large public atrium. The facade of the building is a screen of coloured relief glass that depicts famous images of Dutch television, a composition by graphic designer Jaap Drupsteen.

NYT has an article in its Arts section:
Heaven, Hell and Purgatory, Encased in Glass

Head injuries caused by nail guns

The brain blog Mind Hacks reports on nail gun injuries.

You might think brain injuries from nail guns would be rare, but there are a startling number of case studies in the medical literature.

A recent review of suicide attempts by nail gun noted it was unusual, but this new case series suggests that many of this type of brain injury are caused in this way.

In fact, out of the 12 cases, three quarters were attempting to kill themselves.

Mostly, the cases concern a single nail, but one case was particularly extreme:

The other case involved a staggering 24 nails of 5cm length and represents the largest number of intra-cranial nails in a surviving patient.

This beats the previous record of 12 nails, held by a man reported in a case study from a neurosurgery team in Portland, Oregon.

The picture is the X-ray of Isidro Mejia, who survived a nail gun accident in 2004, where he was unfortunate enough to have four nails embedded in his skull and two in his neck.

Low tech and low cost

4 of every 5 solar hot water systems sold in the world in 2005 were in China.

At least 30 million Chinese households have a solar thermal system. [link]

Straw house stronger than wood

Strawjet is developing low cost energy efficient, housing free from environmental toxins, answering the need to find better uses for agricultural by-products such as straw left over after the harvest of grains.

Previous technologies from straw bale construction to the recent development of compressed straw-board and straw panels have all begun with crushed, chopped straw.

The fundamental advance embodied in the Strawjet technology - which won the 2006 Inventors' Hall of Fame Award - is the use of the whole undamaged plant stem.

The compressive strength of straw when loaded parallel with the stem is impressive. The Strawjet system seeks to use that strength by bundling the plant stems into "cables" about 2 inches in diameter. (see: how it works)

"Ten years of research and head scratching led to the building of the first prototype of a harvester that could bind straw into a cable, the first stage on the way to a useful product."

A StrawCore structure is substantially stronger than a typical wood framed structure because of the nature of composite construction.

With composite systems, loads are distributed across the entire panel rather than the point loading that occurs with stud framing. Due to the extreme low cost of this type of construction, it’s entirely feasible to add additional layers to obtain desired structural strength and/or thermal insulation. [StrawJet]

Inventors' Hall of Fame winner

In the winter, ...there is no logical reason to use a drop of fuel, or a watt of energy, to heat or cool any home or building attached to the Earth.

Just below the surface, within reach of the average basement, is an infinite reservoir of heat that never drops below 50° F.




And in the summer, ...there is no logical reason to use a drop of fuel, or a watt of energy, to heat or cool any home or building attached to the Earth.

Just below the surface, within reach of the average basement, is an infinite reservoir of heat that never drops below 50° F.



The night-day cycle is more than ample to raise that temperature into the comfort zone, with a simple shift in Time. The use of daytime heat at night, and nighttime cool by day, is made possible by Thermal Inertia, and the engineered Lag-in-Time is a property of the thickness and Specific Heat of the solid wood walls.

Michael Sykes' "Enertia" building system traps solar energy to produce homes that heat and cool themselves.

The system contains spaces between the walls that are connected to a sunspace that stores solar and geothermal energy.

That 'sunspace' contains cellulose, lignin and resin seeded with mineral crystals that release thermal energy over time to heat a home. During warmer months, the process is reversed and the structure instead absorbs heat from home appliances and people in the home.

An air flow and access channel, or Envelope, runs around the building, just inside the walls - creating a miniature biosphere. Here solar heated air circulates, pumping and boosting geothermal energy from beneath the house, storing it in the massive wood walls. Thermal inertia causes the house to "float" between the cycles of night and day, and even between the seasons.

"When I first became aware of the greenhouse effect, I was surprised to learn that the building and heating of homes was the biggest user of fossil fuels," Sykes said in a statement.

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Although Sykes' Enertia system uses new and advanced designs and a method of storing heat in 'mineral salts' embedded in the construction material itself, the use of natural air movement has long been known to be a positive approach to energy conservation.

I designed a home for South Lake Tahoe using the convection envelope method in 1977. The plan angled the house on the lot in order to orient the longest part of the design toward the sun for full exposure. Heat-absorbing metal roof panels were elevated above the roof cladding to create a vast air duct - an air furnace. The rear, colder wall of the home was a hollow, two foot air duct to create a wall-size space for downward return air during winter. The flowing air from the rear wall fell over a crawlspace filled with tons of clean boulders to hold heat in their thermal mass. A system of automatic temperature sensitive greenhouse-style slats controlled air movement near the roofline and at the floor. In the hottest of summer, the heated air would vent upward and outward at the ridge, pulling colder ground air into the home from underneath the bottom flooring.

The house was built, but without these solarized innovations. It was too difficult to get a permit from the town and to convince the owners and their contractors to follow through with this unusual approach to reducing power bills.

Also posted at One Stop Thought Shop

Green builder's search engine

A Google for green building products

You can think of Green Building Studio as a mashup between Autodesk and Google.

The Santa Rosa, Calif.-based company makes a computer automated design application for architects and builders that evaluates a building's energy efficiency. And after it does that, it pops up product recommendations for insulation, lighting and other products to increase efficiency. It makes money from the software as well as generating leads for product suppliers.

Ladder accident warning

There's a 50 percent increase in the number of ladder-related injuries.

With a high hospital admission rate, and the predominance of injuries in non-occupational settings, increased efforts are needed to prevent ladder accidents in and around the home.

Dr. Gary Smith at The Ohio State University College of Medicine says, "Ladders should be treated with the same respect and caution as any potentially dangerous tool, such as a power saw." [story]

Replacing glass

What is nonstick, nonporous, stretches 300%, strong, light weight and so slick that dirt, snow, and rain simply slide off?

A new recyclable plastic building material from Dupont, ETFE.

BusinessWeek reports that DuPont didn't really care about pushing ETFE to architects at all. That fell to Stefan Lehnert, a German mechanical engineering and business administration student and avid sailor, who stumbled across the material in his search for new sail technologies. Having discounted it as inappropriate for his sailing needs, he nonetheless saw building-material potential in its transparency and its self-cleaning and structural properties.

In 1982, he founded Vector Foiltec—a design and manufacturing company specializing in the use of ETFE—in Bremen, Germany, and began shopping the material around to architectural firms. Since then, ETFE has become increasingly popular, especially in Europe.

A large glass panel might measure 10 ft. by 5 ft.
A strip of ETFE could be 180 feet long and 12 feet wide.

Using local materials

Production of concrete, that staple of modern building, alone accounts for up to 10% of man-made greenhouse gas, but two and one-half acres of hemp are enough to build a house.

Tom Woolley, a professor of architecture at Queen's University Belfast, has shown that land should be converted to produce hemp stalk to build houses. He is arguing convincingly that sustainable rotation crops like hemp are the cost-effective future of building. In many cases, building costs can be 30-50% cheaper than existing dwellings.

Environmentally-friendly architecture is becoming big business in the developed world. But 80% of the world's population, the developing world, has access to less than 20% of the world's construction materials.

There are workable traditions we have forgotten, as well as innovations that we can explore.

R. L. Hails Sr. says,
"I am an engineer, who designed my house, in humid Maryland USA, utilizing a unique flat roof, and roof spray system. On hot days, my roof is repeatedly wetted, and dries; it never gets hot. I estimate it is a 6 - 10 ton unit (zero at night), which costs circa ten cents per day. Roughly half of a house's heat load is due to the roof; most folks pay for air conditoning to fight it. My electric bill is roughly a third of similar homes. My cost penalty is heavy trusses to support winter snows, and slightly more water usage, roughly another washing machine load. The design paid for itself in one summer, thirteen years ago."

R. T. Marshall says,
"Straw, after threshing, baled in wire and laid in brick courses on a bale-wide concrete foundation, with rebar every 16" through the bales. The bales are covered in wire netting and lime on the exterior and gypsum wallboard on conventional studs interior. The hay must be sealed off at windows and doors, and a wide overhang roof is best. Typical temperature under an R38 insulated roof is 54-58 degrees while outside temps swing from 34 to 80. The straw can be chemically fireproofed and is structurally sound to 24' structures. In earthquake zones, flying buttresses are inexpensive."

Mike says,
"I deliver building materials all day long. I'd like to think that one day I'll be delivering sustainable technology.

And Peter says,
"Try and get a mortgage on a house built of hemp!"