Passive Solar Technique: Let Nature Heat Your Home
Homeowners are increasingly worried about their dependence on fossil fuels. They’re also more and more intrigued by the information about solar energy. Why? Because it saves money, benefits the planet, and makes for a comfortable house that requires little in the name of back-up fuel.
James Kachadorian, civil engineer and founder of Green Mountain Homes, has all the information a homeowner needs in order to implement a passive solar house. Read on!
The following is an excerpt from The Passive Solar House: The Complete Guide to Heating and Cooling Your Home by James Kachadorian. It has been adapted for the web.
During the summer of 1973, the U.S. economy was booming. We were all whizzing down the highway at 70 miles per hour, the legal speed limit. Gasoline was about 39 cents per gallon, and the posted price of Gulf crude oil was $2.59 per barrel. That year, my wife Lea and I had purchased a lovely old Vermont farmhouse, heated by a coal-stoking boiler that had been converted to oil. The base of this monster boiler was about three feet by six feet, and when it fired, it literally shook the house. We tapped our domestic hot water directly off the boiler, so we had to run the unit all four seasons: Every time we needed hot water, the boiler in the basement fired up. We were burning about 2,500 gallons of fuel oil each year, and in the coldest winter months, it was not unusual to get an oil delivery every two weeks.
Since we had no other way to heat our home, we were entirely dependent on the oil-gobbling monster, and on our biweekly oil deliveries to survive the Vermont winter. Our only alternative source of heat was an open fireplace. Though aesthetically pleasing, the fi replace actually took more heat out of the house than it gave off.
At that time, I was the vice president and general manager of a prefabricated post-and-beam home operation. Like others, I shared the industry opinion that the heating contractor’s job was to install the heating system that the homeowner wanted. As designers and home producers, we were not responsible for that part of new home construction. Home building plans were typically insensitive to the position of the sun. Our prefabricated home packages were labeled simply “front, back, right side, left side,” not “south, east, west, north.” We offered little or no advice on siting, except that we needed enough room to get a tractor-trailer to the job site.
To give you an idea how little energy effi ciency was considered in 1973 in house design (an area of home construction that has since received enormous attention), our homes had single glazed windows and patio doors; R-13 wall and R-20 roof insulation were considered more than adequate. (“R” is the thermal resistance of any housing component; a high R-value means a higher insulating value. Today’s homes typically have much higher R-values.) Homeowners in the 1970s rarely asked about the R-values of their home components, and our sales discussions were less about energy efficiency than about how the house would look and whether it would have vaulted ceilings.
The point is, we were not yet approaching the task of design and construction in an integrated, comprehensive way. We had not yet recognized that all aspects of a design must be coordinated, and that every member of the design team, including the future resident, needs to be thinking about how the home will be heated from the first moment they step onto the site.
THE OIL CRISIS
In 1973, an international crisis forever changed the way Americans thought about home heating costs. After Israel took Jerusalem in the “Six Day War,” Arab oil-producing nations became increasingly frustrated with the United States’ policy toward Israel. In the fall of 1973, these oil-producing nations began to utilize oil pricing and production as a means to influence international policy. In October 1973, the Organization of Petroleum Exporting Countries (OPEC) met and unilaterally raised oil prices 70 percent. The impact of this price hike on U.S. homeowners who heated with oil was spectacular. Fuel oil prices soared.
Then the oil embargo hit. In November 1973, all Arab oil-producing states stopped shipping oil to the United States. By December 1973, the official OPEC member-price was $11.65 per barrel—a whopping 450 percent increase from the $2.59-per-barrel price of the previous summer. Iran reported receiving bids as high as $17.00 per barrel, which translated to $27.00 per barrel in New York City.
In addition to giant price increases, oil supplies became uncertain and the United States, which depended on foreign oil for fully half its consumption, was facing the real possibility of fuel rationing for the first time since World War II.
Richard Nixon was president, and his Secretary of State, Henry Kissinger, spent most of that winter in what was termed “shuttle diplomacy,” racing from country to country attempting to bring a resolution to the crisis. He didn’t succeed until March 18, 1974, when the embargo against the United States was lifted. It had lasted five months.
As the international oil crisis was played out over those five months, every oil delivery to our home was marked by a price increase, invariably without notice. Worse, our supplier could not assure delivery. My wife and I had two small children, an energy dinosaur of a house, and no other way to keep warm but to burn huge amounts of oil. We couldn’t even “escape” to a warmer climate, because there were long lines at the gasoline pumps. We had never felt so dependent on others as we did that winter. It was plain scary!
We have done a little better recently, as today only one-fourth of U.S. oil comes from OPEC. Most imports come from more stable Western sources, and are so diversifi ed that a full-scale war in the Persian Gulf in 1991 caused
no gas lines at home. However, we are still over 50 percent dependent on foreign oil sources.
All the concerns about energy seem to have reached a boiling point in September and October 2005. Back-to-back hurricanes in the Gulf region of the United States crippled our refining and fuel distribution capabilities, and oil and propane gas soared to new record highs.
THERE HAD TO BE A BETTER WAY
I have a background in engineering, and the energy crisis of 1973–1974 provided an incentive for me to investigate solar heating. It was obvious to me that as a country, we had forgotten the basics of good energy management. I just knew that there must be a better way to design and build houses that would capture the sun’s heat and work in harmony with nature. I also have a background in business, and I realized that the energy crisis had opened up a market ready for new ideas about how to heat homes. The energy crisis had shaken us all into action.
The years immediately following the 1970s energy crisis saw a remarkable emergence of new ideas about solar energy. Solar conferences were held, and the public was treated to frequent articles that described new solar home designs in popular magazines. The results of this collective effort were largely positive. Many new ideas were tested. Some succeeded, and others failed, but building specifications focused on energy efficiency developed during that time have now become standard practice. For example, double-pane high-performance glass is now used almost universally in windows and patio doors. Standard wall insulation is now R-20. That was previously the roof standard; standard roof insulation is now R-32. The science of vapor barriers took huge leaps forward, and highly effective vapor barriers are now standard. Exterior house wraps, such as Typar and Tyvek, are applied on most new construction to tighten up air leaks. Appliances are now more energy efficient. Heating systems have undergone major improvements. These days, it is even common for “smart houses” to monitor lighting and to turn lamps and heating equipment on and off according to need. In sum, we are now building better energy-efficient houses, in large part due to the wake-up call we got in the winter of 1973–1974.