For Energy Consumption, No Place Like Home
According to a survey commissioned by the Johns Manville company (a leading manufacturer of an extensive line of energy-efficient building products, such as insulation materials) most Americans think that the transportation sector (cars, trucks, buses, etc) is the number one user of energy in the country.
Americans are incorrect in their thinking.
The family car is not the number one energy hog, it’s the family home. (Since most homes are energized by fossil fuels, American homes are also responsible for the most greenhouse gas emissions.)
Johns Manville’s Energy Awareness Month Survey of 1,032 Americans, conducted by Opinion Research Corporation, revealed that 35 percent thought that road transportation was the single largest consumer of energy in the US. Only 12 percent of respondents said that residential buildings ranked first as the single largest energy consumer.
Further the largest number of respondents, 44 percent, also said that road transportation ranked as the largest contributor of greenhouse gas emissions; only 4 percent said it was residential buildings and 6 percent said commercial buildings.
The reality check comes from the May, 2007 report from the McKinsey Global Institute titled “Curbing Global Energy Demand Growth: The Energy Productivity Opportunity” which showed that the US residential sector ranks as the single largest energy consumer in the world, and homes worldwide account for 25 percent of total energy use.
On the greenhouse gas front the U.S. Energy Information Administration supports the McKinsey claim. The EIA says that residential and commercial buildings are responsible for almost half, 48 percent, of greenhouse gas emissions in the US.
Why are US homes the number one energy consumers? According to the Harvard University School of Public Health, 46 million, or 65 percent of U.S. homes, are currently under-insulated. The US Department of Energy estimates that 40 percent of all air leaks in the average home are in the attic. (Johns Manville of course, and correctly so, would like to help in that regard by encouraging people to stuff more insulation up there.)
Kateri Callahan, president of the Alliance to Save Energy had this to say about homes, “Many homeowners don’t realize that a typical house releases almost twice as much carbon dioxide annually as a typical car. But when you consider the energy needed for heating, cooling, lighting and appliances, it becomes apparent that today’s homes can be real ‘energy guzzlers.’ The good news is that there are ample opportunities for homeowners to assess their homes’ energy use. Energy-efficiency upgrades not only reduce energy consumption and greenhouse gas emissions, but also lower home energy bills.”
Kateri is absolutely correct, of course. There’s a whole cornucopia of techologies readily available to cut energy consumption and thus greenhouse gas emissions from homes. Further, the building and building systems industries continue to add new ideas, new concepts, new products to the already bursting horn of plenty.
For example Johnson Controls recently completed the design and installation of a unique heat pump-based HVAC system and controls for the new headquarters (a refurbished bank branch) of Integrated Design Associates (IDeAs), the IDeAs Z2 Design Facility in San Jose, California. The efficient heat-pump system circulates either warm or cool water through the concrete floor slab to create radiant heating or cooling, depending on the season. Note the key phrase “warm or cool water through the concrete floor slab to create radiant heating or cooling.” Typlically heat pumps are known as moving warm or cool AIR through ductwork in a building to heat or air condition it. Radiant heating is considered the most comfortable and most efficient way to heat a building, home or commercial. (Radiant cooling is something new to me.)
There are also solar panels on the roof to run all systems and equipment in the building. Skylights and high-efficiency windows working in conjunction with energy-efficient lighting that include sensors that will switch off most of the facility’s lighting to decrease energy consumption.
The building is one of the first net-zero energy, zero carbon emission commercial office buildings in the US.
In Europe, where energy efficiency has been the mantra for decades, there’s already a standard for ultra-low energy homes - the passivhaus building standard developed in Germany.
There are over 5000 homes built in Germany, Austria and Switzerland that do not need central heating despite a cool temperate climate, according to CEPHEUS,
To meet the passivhaus standard, triple-glazed windows need to be optimized for south-facing and contribute close to 40 percent of space heating demand. The building envelope, as well as window frames, must be superinsulated and air tight.
Aside from solar thermal heating from windows the buildings must use heat recovery systems and latent heat recovery from hot exhaust air as well as subsoil heat exchangers for fresh air preheating. To keep air from gettin stale inside there’s directed air flow throughout the homes with exhaust air extracted from damp rooms.
Heat for domestic water comes from renewable sources, perhaps stylish and readily available pellet water heaters. And, high efficiency, low energy consumption,electric appliances complete the package by slashing power consumption by 50 percent.
CEPHEUS (Cost Efficient Passive Houses as European Union Standards) is a project involving the construction and scientific evaluation of about 250 housing units built to Passive House standards in five European countries