CLIPPED NOTES ON ECO-HOUSING CONSTRUCTION. The Gaia House

HAUSDATA CLIPPED NOTES ON ECO-HOUSING CONSTRUCTION. The Gaia House

CLIPPED NOTES ON
ECO-HOUSING CONSTRUCTION

ROOFING:
. . The National Association of Homebuilders Research Center has estimated that somewhere in the neighborhood of 20 billion pounds [10 million tons] of asphalt shingles are thrown into American landfills every year. According to the Metal Roofing Alliance, this is enough so that if a year's worth of tossed out shingles were loaded onto tractor-trailers, and then set bumper-to-bumper, they would stretch from New York to Los Angeles, back to New York, and then on to Chicago! Also, since it takes an estimated 300 years for asphalt shingles to decompose, by the time Year One shingles have disintegrated into the earth, there will have been 6 trillion more pounds of asphalt shingle waste discarded in U.S. landfills.

http://www.roofingcontractor.com/CDA/ArticleInformation/features/BNP__Features__Item/0,3241,85546,00.html

Statistically speaking, it takes approximately 1,173.3 cans, or close to 98 12-packs, to compose one square of a 0.019-inch aluminum shingle system. If you're over 40 years old and are a big soda or beer drinker, there's a good chance that over the course of your lifetime, you've drank an entire roof's worth of cans all by yourself.
. . Aluminum is the lightest roofing -—between 44 and 60 pounds per square, while steel comes in at around 100 to 120 pounds per square, and copper is a little higher yet at about 150 pounds per square. Asphalt shingle roof (280 to 435 pounds per square), wood shake roof (500 pounds per square), slate roof (800 pounds per square) or clay tile roof (as much as a TON per square).
. . Aluminum's low weight, in many cases, allows it to be installed directly over old, heavy roofing without endangering the stability of the structure.

The only results of tests with the new "Hi-R" or highly reflective pigments were completed by FSEC in 2001. It's pretty interesting to note that the dark brown aluminum shake system with Hi-R paint actually experienced a lower attic heat gain than the white aluminum standing seam. It would save a homeowner $128 per year, or 23 percent, when compared with a dark gray asphalt shingle roof. These types of pigments, incorporated into Kynar/Hylar coatings, are just starting to hit the market in force.

http://www.smartroofs.com/metroshingle.html
. . You could use em on walls! A contrasting shade...
. . One guarantee: "MRP's obligation under this warranty shall be, at its option to repair or replace the defective panel(s), provided MRP's liability shall be limited to a total expenditure not too exceed the original cost of the particular defective panel(s) during the first twenty years after installation and declining annually on a prorated basis over the thirty years thereafter."
. . Estimate for 12 sqs: $1800 (even w nails!) 3093 "A" Industry Street • Oceanside, CA 92054 • Toll Free 866-638-7648 • Fax 760-435-1162
. . 31 pcs/Sq.
. . Base Metal Thickness .015" Inches
. . Minimum Pitch 3:12 (12 Degrees)
. . 3.6 lbs. Each panel or 112 lbs. / Sq.
. . Steel Shingles are less than one-third the weight of asphalt.

http://www.metalworksroof.com/question.html
. . MetalWorks Steel Shingles use Valspar's exclusive Fluoropan coating, a two-coat, high-performance Fluoropolymer with exceptional weathering characteristics. Its durability and color retention characteristics are the result of the high molecular weight of its formulation. During its application, the molecules in the paint chemically bond to form a durable, long-lasting finish that resists breakdown by ultraviolet rays and provides the most durable, long-lasting finish available today.
. . A durable layer of zinc. A tough atmospheric layer of zinc carbonate is formed at the surface is microscopically thin and is insoluble. the zinc is sacrificed to protect the steel.
. . Our warranty is transferable; full coverage for the full value of your purchase for the full warranty period. MetalWorks offers a Lifetime, Non-Prorated Limited Warranty covering both materials and labor.

INSULATION
http://www.nahn.com/mtsiproj.htm
. . Montana Superinsulation Project: Space Heat Savings - The demo houses used an average of 66 percent less space heating than control houses built to current practice (HUD Minimum property standards) by BPA in Montana. Total annual average electrical savings were projected at 10,900 kilowatt hours (kWh). At national average electricity prices, these savings would have a value of about $817 annually. Total space heating costs annually were only $311 in climates with more than 8,000 heating degree days.
. . Hot Water Savings - On average, the houses used about 36 percent less electricity for hot water than did the control houses built by BPA. A total savings of about 1,900 kWh (about $140 at national electricity prices) annually
. . $25-35 per square foot, depending on land and finish costs. They cost no more to build than conventionally constructed homes without these conservation features. This means that the payback for adding the conservation features in this case was immediate. no space heat was required.

Superinsulation Designs:
. . http://www.nahn.com/hplan.htm
. . http://www.nahn.com/mtsiproj.htm
. . http://www.orderhomeplans.com/main.asp?action=listplans&hspos=B4UNET&hsgv=1&sessionid={5BFC91A3-F351-4A2A-83EE-5EA39596B399}

http://www.nahn.com/hplan.htm
. . "A Low-Cost, Three Bedroom, Two-Bath Superinsulated House for Cold Climates: (House Plans), Version 2.1, copyright 1984, Superinsulation Designs/Corbett-Hansen and Associates. Featuring:
. . R-40 double-wall construction
. . R-60 attic insulation
. . Sealed combustion water and space heating devices
. . Heat Recovery Ventilation System
. . High performance windows and doors

Ned Nisson wrote The Superinsulated Home Book.

http://www.orderhomeplans.com/main.asp?action=listplans&hspos=B4UNET&hsgv=1&sessionid={5BFC91A3-F351-4A2A-83EE-5EA39596B399}

1.) Install insulation on the outside of the building rather than the inside. 2.) Use spray polyurethane foam as the insulation rather then other materials on the market like rigid foam boards. Brick ties are attached to the exterior sheathing, the exterior insulation is applied and the brick veneer is added, leaving an air space between the brick veneer and the insulation for drainage.
. . Insulating the outside of a building has many advantages:
. . Applying insulation from the outside avoids the problem of thermal bridging.

http://www.foam-tech.com/case_studies/exterior_wall.htm <

. . Because the insulation is on the outside and there is no cold surface on the backside of the exterior sheathing, condensation inside the wall cavities is avoided. While rigid foam board can serve as the air barrier if it is properly cut, fit, and the joints and penetrations sealed, it cannot serve as the vapor retarder.
. . Spray foam forms a continuous thermal barrier around the building envelope. There are no seams to seal, which makes it less labor intensive. Foam creates a tight seal around the brick ties, thus maintaining the integrity of the thermal envelope. Polyurethane foam not only serves as the insulation, but can also be the air barrier and vapor barrier, if applied at the correct thickness.
. . There are many benefits to the inside-out method. Even with the added expense of purchasing lumber for the exterior frame, the final expense can be less then purchasing stressed-skin panels, a crane and a crew of foam technicians to seal the joints as the panels are installed.
. . Initially, the building is wrapped with rigid foam sheets to provide a thermal break. Then a 2 x 4 stud wall is built on the outside of the rigid foam. Spray-applied foam is then applied in the bays of this wall.
. . The roof can also be framed and insulated using this technique. Sheathing is placed on top of the roof timbers. Plastic or tarpaper is applied on top of the sheathing. 2 x 4 or 2 x 6 rafters are then placed on top of this assembly. Foam is then applied between the rafters and another and another layer of plywood sheathing completes the roof assembly. Roofing material like shingles or standing seam can then be added.
. . http://www.foam-tech.com/theory/theory.htm

Rigid fiber board is a mineral-wool insulation made from basalt and slag.

Icynene, a spray-on, liquid foam insulation

. . Some manufacturers, such as Owens Corning and Johns Manville, have introduced formaldehyde-free fiberglass insulation products. Miraflex, an Owens Corning product, contains two types of glass fiber that expand and contract at different temperatures. This causes the fibers to curl and twist, which helps them bind together without chemicals. Miraflex is soft and nonirritating to skin. Moreover, the fibers have greater tensile strength than those in standard fiberglass insulation. Johns Manville has replaced the formaldehyde binding agent in all of its products with a nontoxic acrylic resin. Another advance in fiberglass insulation is the greater use of recycled glass. Fiberglass manufacturers typically use 30 percent to 40 percent recycled glass in their products.
. . Manufacturers now also produce high- and medium-density fiberglass batts. In these more tightly packed batts, smaller air spaces between the fibers reduce air circulation, increasing resistance to heat flow, known as the R-value. A higher R-value means better energy efficiency. Standard medium-density fiberglass blankets for 2x4-inch walls, for example, have a nominal rating of R-11, while the comparable high-density blankets are rated at R-15. They cost about 20 percent more.
. . Fiberglass also settles, resulting in a decline in R-value over time. Like other forms of insulation, its R-value drops dramatically when it becomes moist.

Some manufacturers add a moisture-activated acrylic binder that causes the cellulose particles to adhere better, which reduces settling.
. . Cellulose insulation is generally less expensive (up to 25 percent) than fiberglass batts, and provides more insulation per inch (R-3.2 per inch) than low-density fiberglass (R-2.2 per inch).
. . Cellulose insulation does have some disadvantages. Dry-blown cellulose may settle and sag, creating air spaces. It also can absorb moisture, decreasing its R-value over time. If it remains damp for prolonged periods, cellulose can mold and rot. With its use of acrylic binders, wet-blown cellulose is supposed to solve the problems of settling and sagging. Cellulose is less expensive, but installation costs may be higher than those for fiberglass batt.

Mineral wool insulation is similar to fiberglass, except the fibers in mineral wool come from stone or from iron-ore blast furnace waste. Although mineral wool is much heavier and costs more than fiberglass and cellulose, it does offer some substantial benefits. Mineral wool is moisture-resistant and maintains its insulative properties when wet. It also is a good acoustic insulator and is more resistant to heat than fiberglass. Mineral wool insulation is noncombustible

There are three types of rigid foam insulation: (1) expanded polystyrene (EPS); (2) extruded polystyrene (XPS) and (3) polyisocyanurate, also called polyiso. Although most rigid insulation is made from various polymers (foam plastics), builders also can purchase rigid insulation made from basalt rock and slag (the same materials used to make some mineral wool insulation products) from Roxul (www.roxul.com).

1: Expanded polystyrene (EPS), also known as beadboard. EPS can be molded into large sheets with R-values ranging from about 3.8 to 4.4 per inch, depending on the density of the material. However, air spaces in EPS can accumulate and retain water. Because water is a good conductor of heat, some form of moisture barrier may be required to prevent this problem, especially when EPS is used around foundations. To make the product more durable, waterproof, and thus suitable for in-ground use, EPS is now being manufactured with thin-foil and plastic facings.

Also known as blueboard, extruded polystyrene (XPS) is a closed-cell insulation board made from polystyrene and a hydrochlorofluorocarbon (HCFC) expansion agent. HCFCs are much less damaging to the ozone layer than their chlorofluorocarbon (CFC) predecessors, but this new generation of blowing agents still releases chlorine atoms when exposed to sunlight.
. . XPS is more expensive than EPS, but it has a slightly higher R-value, about R-5 per inch. XPS also tends to be more consistent in density, has a higher compressive strength than EPS and is much more resistant to moisture.

Manufactured using HCFC-141b, polyisocyanurate is the least environmentally friendly foam-board insulation. Although less damaging to the ozone layer than CFCs, HCFC-141b is the worst of the new generation blowing agents. Several companies now offer HCFC-free polyiso, in anticipation of HCFC's eventual phase-out.
. . Polyiso offers superior insulation properties - the highest of the rigid foam insulation materials - with an average R-value between R-6.5 and R-8 per inch. Its various facings, such as plastic or aluminum, further increase its resistance to heat.
. . Like other forms of insulation, polyiso suffers from thermal drift, a gradual deterioration of R-value over time. Out of the mold, polyiso foam boards are rated about R-9 per inch, but within two years the R-value declines to its stable insulation value, about R-7 per inch. (Foil facing adds about R-2 to the insulation.)

Polyurethane products also relied on a blowing agent known as CFC-11, a potent ozone-destroying chemical. And many found that the foam offered incomplete protection, as it failed to fill cavities evenly, resulting in uninsulated regions in walls.

Today, manufacturers use carbon dioxide gas as the blowing agent. One of the leading polyurethane insulation products is Icynene. It is applied by a trained installer and is sprayed in a paint-thin layer into open wall cavities.

Icynene adheres readily to all surfaces it contacts and quickly expands to approximately 100 times its original volume, filling cavities. Excess can be trimmed off with a handsaw. Although Icynene is typically sprayed into open cavities before wallboard or paneling is applied, it can be applied in closed wall cavities. A carefully measured amount is poured into the cavity through a small opening in the wall. The product expands from the bottom up, filling the voids.
. . Icynene provides about R-3.6 per inch. Because it forms an airtight seal and also is resistant to water vapor, Icynene eliminates the need for vapor barriers in standard stick-frame construction. Further adding to its benefits, Icynene does not settle, sag or shrink. Unlike most other insulation materials, Icynene's R-value does not decline over time. Additionally, its production uses no CFCs or HCFCs, the foam does not outgas harmful chemicals and it offers no nutritive value to termites.

Introduced in the late 1970s, Air Krete, a cementitious foam product containing magnesium oxide, is one of the few insulation products that chemically sensitive individuals seem to tolerate. Like other spray-in foam insulation materials, Air Krete is stable and does not shrink or settle after being applied. It supplies about R-3.9 per inch, but must be applied by people trained in its application.

Insulation Type Average R-Value per inch of thickness
. . Fiberglass blanket or batts 3.2
. . High-density fiberglass blanket or batts 3.8
. . Loose-fill fiberglass 2.5
. . Loose-fill rock wool 2.8
. . Loose-fill cellulose 3.5
. . Perlite or vermiculite 2.7
. . Expanded polystyrene board 3.8
. . Extruded polystyrene board 4.8
. . Polyisocyanurate board, unfaced 5.9
. . Polyisocyanurate board, foil-faced 7.0
. . Spray polyurethane foam 5.9

The foam blocks used in the "lego-type" concrete-forms construction are 2.5". You can tear them off the inside and install them on the outside --perhaps stopping infiltration thru them by spraying between them with foam from a handheld can. Easiest if the wall is bermed! That totals 5" --R17, plus a small amount from the berm.

Building Envelope Theory Topics
. . Insulation Basics
. . Moisture Barriers
. . Air Barriers
. . Vapor Retarders
. . Fire Barriers
. . Thermal Bridges & Breaks
. . Roof Ventilation Basics
. . Causes of Ice Dams
. . Vented vs. Unvented Roofs
. . R-value Drift
. . Noise Reducing Barriers
. . Sustainability & Embodied Energy
. . Theory vs. Practice

The test results from the U.S. Department of Energy verify that Fiberglas R-values are compromised when a 25° Fahrenheit temperature difference exists between the inside (70°) and the outside (45°). When the test conditions reached an outside temperature of -18°, the R-values of the fiberglass insulation (both blown-in and batts) decreased to less than 50% of the manufacturer’s stated R-value.
. . Cellulose R-values, on the other hand, went up. The R-value of Cellulose began to rise when a 25° Fahrenheit temperature difference existed between the inside (70°) and the outside (45°). When the test conditions reached the outside temperature of -18°, the R-values of the Cellulose continued to rise above the manufacturer’s stated installed R-value. It was determined that cellulose improves in R-value any time a temperature difference of 25° or more exists.

It is now well established and accepted by most architects and builders that controlling air infiltration is the best and most cost-effective means of reducing wasteful heat loss and providing a comfortable indoor environment.

While older houses will have 3" to 4" of ceiling insulation (about R-9 to R-12), a new energy-efficient house will have 13" to 21" of insulation (R-30 to R-49}.
. . These higher levels of ceiling insulation lead to a few adjustments in how the ceiling is put together.
. . In a vaulted or cathedral ceiling, the framing members have to be large enough to hold the insulation and allow an air space for ventilation. A minimum 1" air space or "clearance" is required. Since this could involve a very large framing member, it's often done by using a scissor truss or using high-density batts.
. . In a situation where there is an attic space, it's usually easy to get enough insulation in place. The one problem spot is the outer edge where the rafter or truss sits on the outside wall. In a typical case there would not be room to install 12" to 15" of insulation in this location. One solution is to use an oversized truss or "raised heel truss." In an oversized truss, the top and bottom chords come together beyond the exterior wall and typically have a steeper roof pitch. This allows enough room for both the insulation and ventilation.

One technique used to ensure good air leakage control is to test the house as it's being built. By using a device called a fan door, the house can be pressurized or depressurized. You can then inspect the house with a smoke stick that will point out unwanted air leaks. These leaks can then be sealed up before they are lost behind the dry wall.

R-11 in standard construction, walls in superinsulated houses generally achieve insulating values of R-25 to R-40.
. . ceilings in superinsulated homes usually range from R-35 to R-50.

Insulation gaps that occur in standard construction are addressed by careful design, such as the raised heel truss.
. . Framing can also be avoided entirely with Structural Insulating Panels (SIPs), the latest technology for achieving highly insulating walls and ceilings. The prefabricated panels sandwich a foam core between two sheets of plywood and are manufactured to precise design specifications.

Cellulose: settled density is about 2.20 lb. for cubic foot; performance is about 3.80 R per inch. Comes in 28 lb. bags.

Expanded Volcanic Stone
. . - loose fill; no facing; primary use for ceilings, walls and floors; not designed for exposed application, does not act as vapor barrier, settled density is about 8.00 lb. for cubic foot; performance is about 2.70 R per inch. Non combustible. Comes in 4 cu foot bags and weighs around 28 lb.. Very dusty during application.

Cementitious Foam - foamed in place; no facing; primary use for ceilings, walls and floors; does not act as vapor barrier, high permeability for moisture; settled density is about 2.07 lb. for cubic foot; performance is about 3.90 R per inch. Non-combustible. Mixed at job site and applied at the same time by specialized contractor.

Under ordinary conditions, extruded styrene mainly outgases the blowing agent. Most of this is gone within a few months of manufacture. Thermoplastics generally begin changing in the greater than 140xF range. This foam is closed-cell, and it looses its blowing agent much more slowly than the polyisocyanurates, which have permeable cell-wall membranes. They do loose their blowing agent in 6 - 12 months.
. . This process occurs progressively more slowly as air replaces the blowing agent, thereby lowering its insulation value. Polystyrenes are not known to loose as much R-value, though they don't claim as high an R-value to start with. The end result is that both types, polystyrene and polyisocyanurate, end up with similar R-values over time. The polystyrene is also less water absorbent.

The higher density material will cost you more, but it has the same R-value per inch. The higher density is intended for use in deck insulation situations where there are compressive loads on it.

Polyisocyanurate: In my opinion, the compounds which are outgassed by styrene products ar less offensive (and less harmful) than polyisocyanurates. mid (methyl isocyanurate) which is the catalyst is a close relative relative of mic (methyl isocyanate) of Bhopal fame and although less unstable is still very toxic and easily absorbed through the skin. It is not safe to handle poly isocyanurates until totally *cross-linked*. (?)
. . PLEASE do not mess with foamed in place poly-iso insulation products. These chemicals should never be taken out of a carefully controlled manufacturing environment and in my opinion are not safe in any environment.

SUB-SLAB INSULATION: long-term testing at the Foundation Test Facility (FTF) has shown that the savings are maximized for a uniform wall R-value not exceeding R-8 in the Minneapolis region (for example, increasing the R-value to 14 produces no significant increase in energy savings). Savings can be realized from sub-slab insulation that can serve also to decrease moisture infiltration.
. . Sub-Slab Insulation: 4-7"
. . The wing insulation (horizontally, in a ring around the foundation) is sloped away from the thickened edge at a nominal slope of 1 in 12. However, this is not critical, and smaller (but not larger) slopes are satisfactory. The intention is to prevent pooling of surface water above the wing insulation.

Beaver Plastics produces a 2" expanded polystyrene (EPS) foam insulation board, named INSULWORKS, for use below concrete slabs with radiant hydronic heating systems. We have noted market resistance to the use of insulation below concrete slabs because the existing research suggests that little or no insulation is required in this location for energy savings.
. . Also, in many cases, slabs are placed over wet soils (i.e., highly conductive) or even over high water tables (very high capacity heat sinks).
. . Soil Description
Conductivity (W/mK) Heat Capacity (MJ/m3 K)
Dry Sandy Loam 0.70 . . . 1.50
Moist Clay . . 1.50 . . . 1.65
Wet Sand . . . 2.30 . . . 1.8

The heat flow below grade requires approximately 3 to 5 years to stabilize from a uniform temperature start.
. . Savings: 28.2 kWh/yr 2" rigid R-10 sub-slab insulation and 6 mil poly vapor-barrier.
. . In cold climates, builders place horizontal ground insulation around the foundation and extra insulation at the corners, which tend to have higher heat loss.
. . It extends 16". If it extends more than 24" from the slab, you must protect it with pavement, cementitious board, etc.

GEOTHERMAL HEAT PUMPS

Michael Holigan: For a new 2,500 square foot home, you might expect to pay around $16,000 for a fully installed geothermal heat pump. That's about three times the cost of installing a traditional heating and air conditioning system. But there are some good reasons to make that initial investment. The cost of a traditional system for this size home will cost around $2,500 a year to operate while a geothermal heat pump should only cost around $900 a year. That's saving you about $1,600 on utility bills a year. Your geothermal system can also be designed to provide you with about 70% of the hot water you use in your home for free.
. . Federal law prohibits the sale of heat pumps with a HSPF rating less than 6.85 and a SEER rating less than 10.
. . ENERGY STAR labeled heat pumps have a minimum HSPF of 7 and a SEER of 12. ENERGY STAR labeled heat pumps may include upgrades such as: two speed compressors, high-efficiency motors, variable speed fans and improved heat exchangers. Additionally, some heat pumps are installed with desuperheaters to capture waste heat for hot water heating. ENERGY STAR labeled air source systems use 10 percent to 30 percent less energy than standard heat pumps while water and ground source systems can use up to 75 percent less energy.
. . The system needs about 240 feet of tubing in the ground for every ton of air-conditioning if you place it in the ground vertically. If you put it underground horizontally, you'll need about 35% more tubing.

Make sure you get a caulking package that includes sealing all wiring holes and anywhere there's a seam between materials. Then, on the outside, a breathable housewrap should go on before siding, stucco or brick.
. . The wall insulation should have a minimum R-value of R-15 to 19 --R-value being the measure of resistance to transfer of heat and cool. But if you ask your builder for 2x6 exterior wall studs instead of the conventional 2x4s, the R-value will be even higher.

The U.S. Department of Energy (in conjunction with the Environmental Protection Agency) mandated an increase in the installation of geothermal heat pumps from approximately 40-thousand to 400-thousand annually by the year 2000. It was a part of President Clinton's program to help reduce the greenhouse effect. [don't know how that went, or if the program was distroyed later...]

Many residential systems also incorporate a small auxiliary heat exchanger called a desuperheater to heat the domestic water supply, providing 60% of the normal household hot-water load. In the summer, the hot water is a byproduct of air conditioning and in winter, hot water is made at one-third the cost of operating an electric hot water tank.

http://www.motherearthnews.com/185/energy185_geothermal.html

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