Monday, March 28, 2011

The Tyee – In Snowy Whistler, a House with No Furnace

The Tyee – In Snowy Whistler, a House with No Furnace

In the ground: An insulated foundation
Passivhaus aficionados are obsessed with the reduction of what are called "thermal bridges." A thermal bridge is any hard material that readily conducts heat from the interior of the building to the outdoors (in winter), or vice versa (in summer). Picture the cooling fins on an air-cooled engine, or the concrete balconies that stud near every Vancouver condo tower.
"Thermal bridging is your big enemy when you are building," Dürfeld said. "The first lesson in thermal bridging is going to be in your foundation."
So while nearly every other Canadian building stands atop a concrete foundation in direct contact with the earth, Austria House stands on a concrete foundation poured atop ten inches of expanded polystyrene (EPS) foam. The foam also wraps around the sides of the foundation walls.
"This gives us in thermal mass inside the insulation," Dürfeld explained.
The air inside the house slowly heats (or cools, in summer) that thermal mass. In return, the thermal mass works to maintain a steady air temperature inside the house, rather than continually working to lower the indoor air temperature to that of the surrounding earth.
Standing atop the insulated foundation are 18-inch-thick walls that are more than twice as well insulated (R-50) as a typical British Columbia building. And atop those walls is an even more heavily insulate (R-70) roof.
But it's not just the thickness of the walls that make Canada's first Passivhaus unique. It's the way they are built. Just as veteran skiers dress in many thin layers of clothing rather than one thick parka, so the Austria House is constructed from a series of carefully designed layers.
Layer one: Solid wood mass wall
And in stark contrast to the way Canadians build, nearly every layer in this Austrian-built Passivhaus is made of wood.
As noted yesterday, the Passivhaus standard is less prescriptive than alternative green building systems like LEED or BuiltGreen.
Passivhaus doesn't tell builders how to build. Instead, it sets firm limits on the amount of energy a building is allowed to consume, then lets individual builders decide how to meet those limits.
Sohm Holzbautechnik, the general contractor that prefabricated the Austria House, not only met the standard, but did so by layering wood in ways that few British Columbians have imagined.
"The heaviest wood is on the inside," Dürfeld said during a recent tour.
Indeed, where nearly every Canadian builder installs sheets gypsum drywall, Sohm Holzbautechnik mounted solid walls of spruce two-by-fours. The boards are stood vertically, and lined up one after another, so that only a two-inch side is visible. All of these boards are held together using patented diagonal wooden dowels, which eliminate the need for toxic glues or chemicals of any kind.
"That's not a PassivHaus standard," Dürfeld noted. "That's just the way this company prefers to build."
Like the insulated foundation, this attractive wall of solid spruce provides thermal mass that helps hold the building at a consistent temperature.
"This inside wall, the four inch mass wall, is your structure," Dürfeld said. "The rest is just a blanket."
Layer two: Plywood vapour barrier
Where Canadian builders place large sheets of plastic behind the drywall, the Austrians mount yet another layer of wood.
Austria House’s vapour barrier is built of plywood. Where one sheet of plywood joins the next, the seam is carefully taped.
"They have amazing tapes," Dürfeld said. "We have one tape we're all familiar with, the red stuff. They have different tapes for wood-to-wood, for wood-to-concrete. They have about five or six different tapes, depending on the product they are taping."
And while Canadian vapour barriers are typically punctured every few inches by staples, drywall screws and junction boxes, Passivhaus vapour barriers are sacrosanct. Wiring and plumbing is run inside the barrier (in the sold spruce wall), not through it.
"When we build dimensionally, we tend to penetrate our vapor barrier everywhere. A typical home probably has three to four hundred penetrations in its vapour barrier," Dürfeld said.
Not surprisingly, such buildings are not even close to airtight.
When subjected to a blower door test, which is designed to create a pressure difference of 50 Pascals between the interior and exterior air, a typical Canadian home might measure between four and six air changes per hour. (This is described as 6 AC/H@50Pa). That's not ventilation; that's just leakage.
The R-2000 standard to which BuiltGreen homes aspire is 1.5 air changes per hour at the same pressure. The minimum PassivHaus standard is 0.6 air changes per hour.
Austria House rated only 0.26 air changes per hour.
"This is probably the most critical component," Dürfeld observed. "If you fail air tightness, you're simply not going to get the rest of it right."
More layers, more wood
The Austrian fetish for wood products extends to the outer layers as well.
Beyond the vapour barrier, where Canadian homebuilders install 2x6 studs (a.k.a., thermal bridges) and fibreglass batt insulation, the Austrians install 2x12s and non-toxic insulation such as blown-in cellulose (a wood product) or mineral wool.
"The preference over there is for wood-based insulation," Dürfeld said.
The outside wall, where Canadian builders install yet another layer of plastic (such as Tyvek), the Austrians mount what they call defusion board.
"It looks like fiberboard. It's denser than a donna conna. But it can pass vapour," Dürfeld said. "Again, it's a wood-based product."
In Northern Europe, a (wood slat) rainscreen is attached to the diffusion board, and (typically wooden) siding is mounted on the outside.
The Whistler house, however, is clad with distinctive black cementations siding similar to Hardiplank. This, too, was provided by one of the building's sponsors.
Windows that shut tight
Windows are a notable exception to the Passivhaus standard's performance-bases approach. This is because there is virtually no possibility of meeting the Passivhaus air tightness requirements with the relatively poor quality windows sold in North America.
"The windows are absolutely key," Dürfeld said. "That can be the biggest heat loss in your house."
In Europe, the Passivhaus standard specifies windows tested and registered by the Passivhaus Institute or affiliates. These windows are typically constructed from three panes of coated glass separated by two gas-filled chambers, each of which is more than a half-inch thick. Also, the window frames are exceptionally airtight, typically incorporating two ore more rubberized gaskets. The frames are also quite thin.
"The frame is your enemy, because the frame is less efficient. There's more thermal conductivity through the wood than through the glass and the air," Dürfeld said.
The doors are similarly constructed. And all are sealed to the vapour barrier with more specialized tapes.
"To my knowledge there are no North American made wooden doors or windows that will meet the Passivhaus standards," Dürfeld said. "This could be a business opportunity for the right company."
Buildings that breathe easy
One of the most common misconceptions about Passihaus and other airtight buildings is that they are stuffy. The truth is that because they are actively ventilated, they tend to harbour significantly higher indoor air quality than comparable buildings.
The name Passivhaus was selected to describe the intention that such buildings eschew "active" heating (such as a boiler or conventional forced-air furnace) or air conditioning systems. But nearly every Passivhaus building does include an active ventilation system called a heat recovery ventilator, or HRV.
An HRV is a device that draws cold air from the outside through one side of a series of baffles that act as a low-pressure heat exchanger. Indoor air passes through the other side of those baffles as it is expelled from the building. Thus the indoor "heat" is "recovered," as fresh air entering the building is warmed.
Heat recovery ventilators typically operate quietly and blow air much more gently than a forced-air furnace. The airflow is barely perceptible, but by running continually. In Austria House, the air is completely exchanged every 90 minutes.
"It's constant. You can never shut this thing off," Dürfeld explained.
The final 10 per cent
Superinsulation and extreme air-tightness are the core of the Passivhaus approach, and provide most of the energy savings. Dürfeld estimated that Austria House uses about 10 per cent of the energy of a comparable building.
"During construction, we were able to heat the house with one of those little 1,500-watt ceramic heaters," he said. "One day I remember, it was about seven below outside. Just really, really cold. But all your interior surfaces, floors ceilings windows walls, were all within about a degree and a half of each other."
Austria House generates much of what little heating energy it requires from a low-tech ground-source system.
Dürfeld and his crew buried three long ABS plastic hoses beneath a 20-meter-long yard in front of the building. Dürfeld described them is "giant slinkys," and said they were placed about two meters deep then covered with gravel.
The fluid that runs through these hoses is cooler than air in summer, and warmer than air in winter. It runs through a compressor, thereby creating about four kilowatts of energy. That's enough to heat the building's hot water and --- at times --- further raise the temperature of incoming air flowing through the HRV.
Lost Lake Passivhaus
Austria House worked for its builders. As seen on Austrian TV, the 2010 Winter Games looked at times like an infomercial for the Austria Passive House Group. When the games were through, they gave the house to the municipality of Whistler for use as a cross-country ski base.
The building has since been renamed Lost Lake Passivhaus.
Lost Lake Passivhaus --- nee Austria House --- is working for Whistler, too.
"We always had the vision of trying to leverage some sort of a country house in this location to help support our cross-country operation," said the city's Roger Weetman.
"It worked out fabulously," he continued. "From a sustainability perspective, it was a perfect marriage, right? It was exactly in line with what Whistler is trying to do."
And the project worked well for Dürfeld.
"This is the most interesting thing I've done in all the years I've been here," he said. "It's like taking a car from 30 miles per gallon to 100 miles per gallon."
Dürfeld's company is headed in "a whole new direction" in the wake of the Austria House project. (More about that tomorrow.)
"We're going to reinvent the envelope we live in," he said. "And then we can recreate how we build."
What remains to be seen is whether the lessons embodied in Austria House will be learned by the British Columbia wood products industry --- or, like the Saskatchewan Conservation House, politely forgotten.
Previous: Step Inside the Real Home of the Future: Passivhaus
Next: Affordable Housing that Slashes Carbon Emissions  [Tyee]

Article lies it does have a furnace. A geothermal system.

How much does this building cost above traditional Canadian stick build. My gues is close to double. Solid 2x4 wall, good for our forest industry but using over 12 times the amount of wood. Obviously only a house for the rich and foolish.


There is one window manufacture that claims to meet the requirements for Passivhaus, Serious Windows make an R-11 window made with fiberglass.



Green needs to be affordable to be widely adopted

While stories like this are really great for letting people know what the ultimate possibilities are, the cost of building a house like this is out of reach for most families, so they are likely to simply discount the entire thing as being "too expensive" or "greenwash". Same reason so many people don't buy super energy efficient windows or heating systems. Either that or building codes are so restrictive that really efficient and cost effective buildings are not allowed (like
It is very possible to build a highly energy efficient home for the mass market. It's also possible to encourage people to build and renovate green through the use of incentives. Look at how many people took advantage of the homeowner grant or the energy efficient grant. Changing building and tax codes to make green building and renovating cheaper than traditional renovations would do a lot more to solve climate change than setting a standard too high for most people to achieve in the current market.
What a lot of green cheerleaders miss is the fact that we have a lot of existing housing stock that's not going away right now. We're not going to tear down all the 50's neighbourhoods to build passive houses. What can be done is to change taxes, codes and practices to ensure that it's cheaper to renovate this housing stock and make it as efficient as possible than to keep building new McBurbs with crappy construction. Where new construction is put in, THAT should be held to a higher standard.
Some things I'd like to see:
1) Permanent and significant tax breaks on all energy efficient upgrades and new builds
2) Energy efficient windows and heating etc. required in all new construction
3) Public education, tax breaks and support for solar, wind and geothermal power
4) All new construction required to incorporate solar power, water conservation, geothermal heating and cooling or heat pumps where practical
5) Less emphasis on building cookie cutter developments that look exactly alike and perform like crap and more on building or renovating to a higher standard.
There's tons more, but those are what I can think of right now.

Plain Nuts: Walnuts Are Tops For Your Diet Overall

Plain Nuts: Walnuts Are Tops For Your Diet Overall

For all the claims that are made on behalf of almonds, the humble walnut might be the nut that's most nutritious.
So say researchers who presented their findings last week at the National Meeting & Exposition of the American Chemical Society. Joe Vinson, a professor of chemistry at the University of Scranton, found that walnuts have twice as much antioxidants as any of the other popular nuts. The study also included the nutritional value of almonds, pecans, peanuts pistachios, hazelnuts, Brazil nuts, cashews and macadamias.
And unlike many other nuts, walnuts are rarely roasted, which Vinson says diminishes much of the nutritional value.

So you never met a nut you didn't like. You love your cashews and pistachios, your Brazilians and pecans. Did you know however, that walnuts are the best source of antioxidants and bad chemical element defenders made by nature on the planet? It's true according to a new study presented at the American Chemical Society's National Convention this week.

Joe Vinson, Ph.D. explains:

"Walnuts rank above peanuts, almonds, pecans, pistachios and other nuts. A handful of walnuts contain almost twice as much antioxidants as an equivalent amount of any other commonly consumed nut. But unfortunately, people don't eat a lot of them. This study suggests that consumers should eat more walnuts as part of a healthy diet."

Nuts in general contain plenty of high-quality protein that can substitute for meats for example. They contain a multitude of vitamins and minerals, dietary fibers and are dairy and gluten free. Regular consumption of small amounts (a few nuts a day) of walnuts or peanut butter with decreases risk of heart disease, certain kinds of cancer, gallstones, Type 2 diabetes, and other health problems.

Vinson continues:

"There's another advantage in choosing walnuts as a source of antioxidants. The heat from roasting nuts generally reduces the quality of the antioxidants. People usually eat walnuts raw or unroasted, and get the full effectiveness of those antioxidants."

Walnuts roasting on an open fire next holiday season?

Despite all the previous research, scientists until now had not compared both the amount and quality of antioxidants found in different nuts, Vinson said. He filled that knowledge gap by analyzing antioxidants in nine different types of nuts: walnuts, almonds, peanuts, pistachios, hazelnuts, Brazil nuts, cashews, macadamias, and pecans. Walnuts had the highest levels of antioxidants.

In 2003, the FDA recognized the benefits of nuts and their role in heart disease prevention by approving a health claim for 7 kinds of nuts (almonds, hazelnuts, peanuts, pecans, some pine nuts, pistachios and walnuts). These seven nuts were approved as they are the only kinds that contain less than 4 grams of saturated fats per 50 grams.

Nuts in general are high in calories, so moderation is the key. The best approach is to reap the health benefits of eating walnuts but not add excessive calories to your daily intake. Therefore, instead of just adding walnuts to your current diet, eat them in replacement of foods that are high in saturated fats (such as cheese and meat) and limit your intake of these tasty treats to the recommended 1.5 oz per day. That is about 20 walnut halves.

Nuts account for barely 8% of the daily antioxidants in the average person's diet. The form of vitamin E found in walnuts is somewhat unusual, and particularly beneficial. Instead of having most of its vitamin E present in the alpha-tocopherol form, walnuts provide an unusually high level of vitamin E in the form of gamma-tocopherol. Particularly in studies on the cardiovascular health of men, this gamma-tocopherol form of vitamin E has been found to provide significant protection from heart problems.

Ancient Soil Replenishment Technique Helps In Battle Against Global Warming

Ancient Soil Replenishment Technique Helps In Battle Against Global Warming

ScienceDaily (Aug. 9, 2010) — Scientists demonstrate that biochar, a type charcoal applied to soils in order to capture and store carbon, can reduce emissions of nitrous oxide, a potent greenhouse gas, and inorganic nitrogen runoff from agriculture settings. The finding will help develop strategies and technologies to reduce soil nitrous oxide emissions and reduce agriculture's influence on climate change.

    A research team led by Bhupinder Pal Singh from Industry and Investment New South Wales and Balwant Singh from the University of Sydney, tested the effects of four types of biochar on nitrous oxide emission and nitrogen leaching from two different soil varieties. Their results are reported in the July-August 2010 Journal of Environmental Quality, published by the American Society of Agronomy, the Crop Science Society of America, and the Soil Science Society of America.
    The study revealed for the first time that interactions between biochar and soil that occur over time are important when assessing the influence of biochar on nitrogen losses from soil. The scientists subjected soils samples to three wetting-drying cycles, to simulate a range of soil moistures during the five-month study period, and measured nitrous oxide emissions and nitrogen runoff.
    Initially, biochar application produced inconsistent effects. Several early samples produced greater nitrous oxide emissions and nitrate leaching than the control samples.
    However, during the third wetting-drying cycle, four months after biochar application, all biochars reduced nitrous oxide emissions by up to 73%, and reduced ammonium leaching by up to 94%. The researchers suggest that reductions in nitrous oxide emissions and nitrogen leaching over time were due to "ageing" of the biochars in soil.
    "The impacts of biochars on nitrous oxide emissions from soil are of interest because even small reductions in nitrous oxide emissions can considerably enhance the greenhouse mitigation value of biochar, which is already proven to be a highly stable carbon pool in the soil environment," according to senior author Bhupinder Pal Singh. "This research highlights that impacts of biochar on nitrogen transformations in soil may change over time and hence stresses the need for long-term studies to assess biochar's potential to reduce nitrogen losses from soil."
    In addition to the three wet-dry cycles, the soil samples also received glucose and nutrient applications to supply of carbon and inorganic nutrients for optimal microbial activity. The research team tested biochar from two different sources, wood waste and poultry litter. Biochar is made when organic material is burned at high temperatures in the absence of oxygen.
    Research is on-going at Industry and Investment NSW to investigate the causes of the reductions in nitrous oxide emissions by biochars, especially under field conditions, and to determine optimal rate and timing of biochar and fertiliser applications to agricultural soils to maximize the greenhouse mitigation value of biochar.
    This study was funded by the New South Wales Department of Environment, Climate Change and Water, and the biochars were supplied by Pacific Pyrolysis (previously known as Best Energies, Australia).

    Thursday, March 10, 2011

    Simple summer comfort

    In even the hottest climates it is possible to stay comfortable without depending on A/C and the electrical grid.
    Heavy mass walls and night time ventilation can recharge the walls with "coolth" for the next day.
    Heat build-up from fridge or incoming sun can be vented out passively by having a ceiling hatch to let warm air escape, this works best if you can allow cooler air to enter from the basement, thus creating a stack effect to drive the airflow.
    I open a window on the shady side in the basement and let the air rise into the living space, to push the hottest air at ceiling level into the attic space, where it joins the airflow from the eaves, and pushes the hottest air out through a cupola at the highest point.
    The cupola has a wind vane that only allows air to escape on the downwind side, where there is a lower air pressure.
    Another method uses evaporation to induce cooling, but this does not work in moist conditions.
    In Iraq in the old days people retired to the basement during the hot afternoon, but first they would spray the wall, let it evaporate thus cooling the air. This principle works well in hot weather when you wear a wet teeshirt under a ceiling fan!
    I know, i lived in India in an apartment with lots of rebar in the ceiling that wicked the heat from the outside walls all around me, and even during a coool night outside, i would swelter inside.
    And then the power goes off, you start to look for a place to sleep outside!
    now i know why many roofs in hot places are flat, this makes a good sleeping place, and watertank, shower too!


    During hot summer days the power usage peaks due to all the A/C usage.
    In BC, Canada that means that we import dirty power from Alberta coalfired powerplants.
    This means that if we reduce our A/C usage we immediately reduce greenhouse gas emissions.
    So here are some strategies that are practical, cost effective and on top of that, provide peace of mind, with assured comfort, regardless of brownouts, blackouts, price rises!

    To keep cool in summer, the first priority is to exclude direct sunlight, into the windows, and not with indoor blinds, because the heat is then already trapped inside, where the greenhouse effect will keep the heat in!
    Instead, the blind has to be outside the glass, such as the traditional outhinging wooden shutter with horizontal blinds, excluding sun but bringing in breeze and soft light.
    In hot climates it makes sense to have overhanging rooflines to shade openings, and a wraparound porch can provide shady sitting areas, that take full advantage of prevailing breeze. Don't forget to allow opposing openings on all sides to encourage the breeze throughout!
    Traditional homesteads often were built under a big shade tree on the southwest corner, to keep the heat out..
    If your house feels hot and stuffy at night, check if your floors feel warm, if so, then chances are your ceiling is radiating down, pumping heat into your livingspace. Then make sure that heat does not build up under the roof. Proper ventilation slots are needed under the eaves, all around, and outlets at the rooftop, taking care to have a low pressure downwind outlet, away from prevailing breezes, and an outlet at every peak... Turbine type exhausts are not very effective, a straight up and out pipe is better, a solar chimney with rotating wind deflector is more effective yet.
    If your water comes from a deep well, or otherwise is cool enough, it can provide direct cooling in metal radiators on the ceiling to provide cool radiant exchange where ever desired, such as above the bed , and reduce humidity by condensation, which can be piped away to a drain.