Thursday, December 24, 2009

PROLOGUE

My research into superinsulation led me to PHIUS, the Passive House Institute United States, located in Urbana IL. This is the North American branch of the PassivHaus Institute located in Germany. They are known for developing standards and procedures for the design of buildings using passive house principles. If one wishes to get into the technology and engineering of passive house design, I would recommend contacting them. For local contact I would suggest their certified Canadian consultant located in Nova Scotia.

What I have found is a general lack of actual details and drawings that incorpoarate passive house design. The designs and details that I will be sharing on this blog are derived from many of the principles that PassivHaus and PHIUS have developed. I will not, however, try to demonstrate how my designs and details are in complete compliance with all passivHaus standards. While it is important to acknowledge the science behind passive design, residential housing has developed through commonly held and known practices. The Canadian R2000 program has developed many of the building practices and techniques that will be required for future superinsulated homes.

The designs and details I will share are based upon traditional or vernacular housing types that are common to the maritimes. These traditional housing types were developed in response to the environment and culture of this region. House designs I intend to include are:

Maison Grande-Digue House
Home design built for veterans returning from WWII.

Maison Cocagne House
Traditional house type that features a central dormer.

Maison St. Thomas House
Hillside home or cabin designed for the coast of Nova Scotia.

Maison Scoudouc House
Small single person or couples homes.

Traditional wood frame construction is used as the trade or way of building is common and known by local trades. Materials were also selected on the basis of local manufacturers and availability. While all the materials may not meet the most stringent passivHaus requirements, they will offer dramatic improvements over current building practices. The details will include the names of these products.

The construction drawings and details that have linked in my blog and those I will be including in my future blogs can be downloaded and printed for your use. These details only reflect one approach to building a superinsulated building. There are no doubt others that have been used and may well be better than the ones I have provided. I would love to see and share drawings and details with others.

Finally, I am including a link to Greener than green, a testimonial about a passive house builder and his home located in Oregon. It says more than I can write in this blog. You can find our more about Ted Nickell by typing his name into your search engine.

Monday, December 7, 2009

SUMMARY

SUPERINSULATED HOUSES

Following is an article that could be interesting in our discussions of superinsulated houses:

"Super-insulated building is a method of energy-efficient construction that can be adapted to any structure, commercial or residential, in any climate.

A super-insulated (SI) home can save 75% of the annual energy costs for heating and cooling compared to a standard home, and is also more comfortable and healthy for the occupants. SI houses can be of any design—Colonial, Victorian, Contemporary, Ranch, etc..—and often look identical to a conventional home, especially from the exterior.

The design and construction of a conventional house will vary according to the area of the country, and the climate, in which it is built. The same is true for a SI house. A super-insulated house built in Florida, where there is a "cooling climate" requiring cooling most of the year, will be very different in construction from an SI house built in the northeast, which has a "heating climate". This article will focus on residential construction in the northeast.

Flexibility is a key trait of SI homes. They can be built on any building lot, facing any direction. If a building lot has an unobstructed southern exposure, it is recommended that the house be oriented to take advantage of the solar gain, but this is not required.


Elements of Superinsulated Houses

All superinsulated houses share three important elements:

1) They are constructed to be air tight.

2) Compared to conventional houses, they have a higher level of insulation, hence the name "superinsulated".

3) They have a ventilation system to control air quality.

All three of these elements are planned into the SI house during the design stage.

Although SI homes resemble conventional ones in appearance, there are numerous, subtle differences. SI houses are constructed using conventional building materials for the most part, but these are assembled somewhat differently, using more care and attention to detail during certain stages of construction. For example, very important air tightening procedures are commonly performed integral with the framing of the house. In fact, all construction on a SI house, from the beginning to the end, is performed with the simultaneous installation of preplanned air tightening, insulation, and ventilation systems in mind. This requires careful education, communication, coordination, and supervision of subcontractors.

There are many different methods for building a SI house including: double wall, strapped wall, stress skin panel, air-tight drywall approach, 2x6 with foam inside, 2x6 with foam outside, strawbale, and others. Builders generally select the method they feel most comfortable with depending on their experience and the skill level of their crew and/or subcontractors.

Although SI construction may seem complicated, any skilled, veteran, professional builder with a commitment to quality and close attention to detail can successfully build a SI house. Contractors who build quality conventional houses already have 90% of the skills they need to master SI construction.

Any existing house can be retrofitted to be superinsulated; many have been done and many more will be. This being said, it is easier and more cost effective to build a SI house from the ground up. Many of the components and systems (notably the air sealing and insulation systems) are integrated within the exterior walls of the SI house, and usually require extensive and costly renovation to retrofit.

The ventilation system is a critical component of a SI house. It purges stale air and indoor air pollutants. It introduces the correct amount of fresh air for proper air quality into the house and distributes it evenly throughout the living space. The importance of a properly designed and installed ventilation system for a SI house cannot be overemphasized.

Stale air is typically exhausted from the kitchen and the bathrooms, since these areas have a high concentration of moisture. Moisture is a primary indoor air pollutant, and frequently needs to be removed. Other pollutants, such as carbon dioxide, cooking odors, and smoke, also need to be purged, but moisture remains a key "indicator" pollutant. When water is seen to condense on cold surfaces such as window panes, the relative humidity is too high in the house and the rate of ventilation (measured in whole house air changes per hour or ACH) must be increased. As a rule of thumb, for proper air quality, most SI houses require 1/3 ACH, or 10-20 CFM (cubic feet per minute) per person when occupied.

Ventilation systems fall into two types: heat recovery and non heat recovery. The Heat Recovery Ventilator or HRV is the most common of the recovery machines. A HRV is a machine which takes warm, stale air out of the house and brings cold fresh air in. The HRV runs both air flows through a heat exchanger, using the heat from the outgoing stale air to preheat the incoming fresh air. Ducts then carry the fresh air throughout the house. There are a number of manufacturers and several different types of HRVs.

A new type of HRV becoming popular is the ERV or Energy Recovery Ventilator, which recovers moisture as well as heat. The ERV is helpful to control the indoor relative humidity; a level of roughly 35% is recommended.

The most common of the non-heat recovery ventilation systems are the Exhaust Only systems. With these systems, only the exhaust air is fan forced and runs in ducts. An exhaust only ventilation system can be as simple as running kitchen and bath fans continuously when the house is occupied. A high-tech hole in the wall (with a diffuser to mix the incoming air and prevent drafts) is provided for each room of the living areas to let in a continuous trickle of fresh air.

Safety is an important attribute of the SI house. SI homes always use sealed combustion heating units when fossil fuel furnaces, boilers, or domestic hot water tanks are specified. Sealed combustion heating equipment does not use any inside house air for its operation. It takes its combustion air directly from outside of the house, and it blows its exhaust gases directly back outside. Since there is no contact between combustion gases and house air in a sealed combustion heating unit, backdrafting of flue gases (carbon monoxide) is impossible.

Any fireplace or wood stove in a SI house must have a duct to supply outside combustion air as well. In addition, dedicated make-up air should be provided for any large or powerful exhaust fan such as a kitchen rangehood. This can be accomplished by simply cracking a window in the kitchen when the rangehood is operating.

SI builders take precautions against radon, a naturally occurring radioactive soil gas, and a suspected cancer agent. If radon is present in the soil or the ground water at a site, it can enter the home through the basement. Provisions for a radon mitigation system are built into each SI house. After testing the finished home, if radon gas should pose a problem, the mitigation system can be quickly and easily hooked up.


Advantages of Superinsulated Homes

SI homes have many important advantages:

* They conserve energy without impacting the occupants’ lifestyle.
* They are more comfortable, with no drafts, cold spots, or temperature stratification.
* They are healthier because air quality is not left to chance but is controlled and can be monitored.
* There is commonly a higher relative humidity in a SI house. People who are bothered by dry house air in the winter will be more comfortable.
* They are safer because backdrafting of combustion appliances is impossible.
* They are quieter to outside noise because of thicker walls and better windows.
* They save money, frequently 75% of heating and cooling costs.
* They are more durable because of the quality of the materials used, the care in construction, and because of applied building science principles.
* They are environmentally friendly, helping to build a sustainable future.


What does all this cost?

Superinsulated construction typically costs about 5-7% extra compared with conventional construction. Most of this cost is associated with better windows and doors, high-efficiency HVAC equipment, more insulation, and air sealing. A premium is almost always paid for quality, whether the product is an automobile, a consumer product, or your home.

Superinsulated building is now a force in the marketplace. SI building practices are included in Canadian building codes and are standard practice in many parts of Europe. Changes to the Model Energy Code have been implemented by the US Department of Energy and US Department of Housing and Urban Development in this country. Monetary incentives, such as Energy Rated Mortgages which increase the borrowing power of buyers of energy-efficient homes, are in place at banks right now. Programs like the Energy Star Homes Program, sponsored by the Environmental Protection Agency and the Department of Energy, encourage builders to build SI homes and provide a rating system to evaluate energy performance.

Consumers interested healthy indoor environments, decreased energy costs, environmental friendly lifestyles, and quality in their homes can insure that superinsulated building becomes standard practice in the US."

**This article, Superinsulated Houses, appeared in the Fall 2001 issue of NESEA’s magazine, the Northeast Sun. It was written by Jim Vann, owner of Ra Solar Company, and a builder of superinsulated, suntempered, environmentally friendly homes. He chairs NESEA’s Quality Building Council.

nesea@nesea.org
Northeast Sustainable Energy Association
50 Miles Street
Greenfield, MA 01301
413-774-6051
Copyright © 2001 by NESEA. All rights reserved.

BIBLIOGRAPHY






I would recomend the following list of books to begin a journey into the subject of super insulation and home design. You may be able to find most of the books at your local library. Some are not in print, but available on Amazon.





THE SUPERINSULATED HOME BOOK
J.D. Ned Nisson & Gautam Dutt
John Wiley & Sons, 1985
(Available thru Amazon.com)

SUPER INSULATED RETROFIT BOOK
Brian Marshall & Robert Argue
Firefly Books Ltd., 1981

THE STRAW BALE HOUSE
Athena Swentzell Steen, Bill Steen & David Bainbridge
Chelsea Green Publishing Company, 1994

A PATTERN LANGUAGE
Christopher Alexander, Sara Ishikawa & Murray Silverstein
Oxford University Press, 1977

BUILDER’S GUIDE TO COLD CLIMATES
Joseph Lstiburek, P.Eng.
The Taunton Press, 2000

CANADIAN SOLAR HOME DESIGN MANUAL
S. Henderson, D. Roscoe & J. Ward
Solar Nova Scotia, 2009
(Available at www.solarns.ca)

PASSIVE HOUSE PLANNING PACKAGE
Dr. Wolfgang Feist
Passive House institute, 2007
(Available at www.passivehouse.us)

Hope you enjoy these books. I will be drawing from them as I make my future postings.

Richard

Wednesday, December 2, 2009

BEGINNINGS

This is the beginning of what I hope will be a resource for those interested in the idea of superinsulated home design. The idea of superinsulation began in response to the 1970 oil embargoes. With rising fossil fuel costs the concept is once again receiving public interest. Working with the Cocagne Sustainable Development Group, we have been developing designs for superinsulated homes based upon traditional home designs and using concepts developed by the PassivHaus Institure of Germany. This is a model of our first design - The Cocagne House. In the future, we plan to share the details that we have been developed for building a superinsulated house in our region.