8.
Energy For Heating and Cooling
Archive
of Past Articles for Chapter 8
2010 August 12. Seeking to Cool Air Conditioning Costs. By David LaGesse, National Geographic News. Excerpt: The air-conditioning industry is starting to feel the heat… it's getting tougher to squeeze more efficiency from today's cooling technology, offering little relief anytime soon for consumers fuming from summer electric bills.
…For one, air-conditioning units don't get replaced as often as, say, light bulbs or even refrigerators. It takes longer for more efficient models to spread into homes or businesses. Researchers also struggle to make new cooling technology as cheaply as the refrigeration pioneered by Willis Carrier in the early 1900s.
…AC units built to U.S. national standards, for one, dehumidify the air—a waste of energy in the arid Southwestern states. The U.S. Congress a few years ago authorized new air conditioning (and heating) standards that will divide the country into North, South and Southwest regions.
… [The Western Cooling Efficiency Center at the University of California, Davis] is pursuing several technologies with particular promise in the Southwest. They include radiant cooling that pipes chilled water around a building or systems that use chilly nights to inexpensively produce ice that can help make a building comfortable during the day.
…Some of the most promising advances are in evaporative cooling, which uses water to draw heat from air just as perspiration cools a body. It's already used in "swamp coolers" that tend to be more popular in drier climates.
…An evaporative cooler developed at the National Renewable Energy Laboratory uses drying compounds, or desiccants, to pull moisture from the air.
…A "desiccant-enhanced" prototype at the lab needs less than half, and perhaps 90 percent less, of the energy of a conventional air conditioner. It could be in field trials in three years and on the market soon after, says Eric Kozubal at the renewable energy lab.
2010 Jan 28. White
Roofs May Successfully Cool Cities. NASA Release 10-016. Excerpt:
Painting the roofs of buildings white
has the potential to significantly
cool off cities and mitigate some impacts
of global warming, results of a new
study indicate.
The research, the first computer modeling
study to simulate the impacts of white
roofs on urban areas worldwide, suggests
there may be merit to the idea of turning
roofs white.
...Cities are particularly vulnerable
to climate change because they are
warmer than outlying rural areas.
Asphalt roads, tar roofs and other
artificial surfaces absorb heat from
the sun, creating an urban "heat
island effect" that can raise
temperatures on average by 2-5 degrees
Fahrenheit (about 1-3 degrees Celsius)
or more, compared to rural areas.
White roofs would reflect some of that
heat back into space and cool temperatures,
much as wearing a white shirt on a
sunny day can be cooler than wearing
a dark shirt.
...The model simulations, which provide
scientists with an idealized view of
different types of cities around the
world, indicate that, if every roof
were entirely painted white, the urban
heat island effect could be reduced
by 33 percent.
This would cool the world's cities
by an average of about 0.7 F, with
the cooling influence being particularly
pronounced during the day, especially
in summer.
The authors emphasize that their research
should be viewed as a hypothetical
look at typical city landscapes rather
than the actual rooftops of any one
city.
In the real world, the cooling impact
might be somewhat less because dust
and weathering would cause the white
paint to darken over time and parts
of roofs would remain unpainted because
of openings such as heating and cooling
vents....
2009 July 29. White
Roofs Catch On as Energy Cost Cutters.
By Felicity Barringer,
The NY Times. Excerpt:
...Relying on the centuries-old principle
that white objects absorb less heat
than dark ones, homeowners...are in
the vanguard of a movement embracing “cool
roofs” as one of the most affordable
weapons against climate change.
Studies show that white roofs reduce
air-conditioning costs by 20 percent
or more in hot, sunny weather. Lower
energy consumption also means fewer
of the carbon dioxide emissions that
contribute to global warming.
What is more, a white roof can cost
as little as 15 percent more than its
dark counterpart, depending on the
materials used, while slashing electricity
bills.
Energy Secretary Steven Chu, a Nobel
laureate in physics, has proselytized
for cool roofs at home and abroad....
The scientist Mr. Chu calls his hero,
Art Rosenfeld, a member of the California
Energy Commission who has been campaigning
for cool roofs since the 1980s, argues
that turning all of the world’s
roofs “light” over the
next 20 years could save the equivalent
of 24 billion metric tons in carbon
dioxide emissions.
“That is what the whole world
emitted last year,” Mr. Rosenfeld
said. “So, in a sense, it’s
like turning off the world for a year.”...
2009 May. Don't
Toss Money out the Window. GreenTips - Union of Concerned
Scientists. Windows let the sunshine
in, but in many cases they also let
the heat in (or out, in the winter).
According to the Department of Energy,
heat transfer through windows can
account for 10 to 25 percent of your
heating and air conditioning costs.
Older, single-paned windows are the
biggest energy wasters.
Replacing older windows with energy-efficient
ones can be expensive, but will save
you money in the long run by reducing
your energy use as much as 30 percent.
Energy Star-rated windows are twice
as efficient as typical models sold
just 10 years ago. A variety of factors
determine a window's energy efficiency:
*Solar heat*.... *Heat transfer*....*Glazing*....*Framing*.
...If you can't replace your old
windows now, there are other steps
you can take: *Seal air leaks*....
Affix *Low-E coated film* .... Install
*storm windows*.... Use *insulating
window treatments*.
2009 April 9. Prize
for 'Sun in the box' cooker. By Richard Black,
BBC News. Excerpt: A cheap solar
cooker has won first prize in a contest
for green ideas.
The Kyoto Box is made from cardboard
and can be used for sterilising water
or boiling or baking food.
The Kenyan-based inventor hopes it
can make solar cooking widespread
in the developing world, supplanting
the use of wood which is driving
deforestation.
Other finalists in the $75,000
competition included a device for
streamlining lorries, and a ceiling
tile that cools hot rooms.
Organised by Forum for the Future,
the sustainable development charity
founded by Jonathan Porritt, the
competition aims to support concepts
that have "moved off the drawing
board and demonstrated their feasibility" for
reducing greenhouse gas emissions,
but have not gained corporate backing.
...
It is made from two cardboard boxes,
which use reflective foil and black
paint to maximise absorption of solar
energy.
Covering the cooking pot with a transparent
cover retains heat and water, and
temperatures inside the pot can reach
at least 80C....
...Reducing reliance on firewood
reduces deforestation, but also improves
the health and wellbeing of villagers
who do not have to trek for miles
collecting the increasingly scarce
wood nor spend hours inhaling wood
smoke, a major cause of respiratory
disease....
2008 December 26. Burning
Coal At Home is Making A Comeback. By
Tom Zeller Jr. and Stefan Milkowski.
Excerpt:
SUGARLOAF, Pa. — Kyle
Buck heaved open the door of a makeshift
bin abutting his suburban ranch house.
Staring at a two-ton pile of coal
that was delivered by truck a few
weeks ago, Mr. Buck worried aloud
that it would not be enough to last
the winter...Aptly,
perhaps, for an era of hard times,
coal is making a comeback as a home
heating fuel. Problematic in some
ways and difficult to handle, coal
is nonetheless a cheap, plentiful,
mined-in-America source of heat.
And with the cost of heating oil
and natural gas increasingly prone
to spikes, some homeowners in the
Northeast, pockets of the Midwest
and even Alaska are deciding coal
is worth the trouble...Burning coal
at home was once commonplace, of
course, but the practice had been
declining for decades. Coal consumption
for residential use hit a low of
258,000 tons in 2006 — then
started to rise. It jumped 9 percent
in 2007, according to the Energy
Information Administration, and 10
percent more in the first eight months
of 2008...Coal may never make economic
sense in areas far from where it
is mined. But in places within reasonable
delivery range, the price tends to
be stable, compared with heating
oil or natural gas. Prices for natural
gas more than tripled in recent years
before plunging in the last few months
amid the downturn...
2008 December 26. No
Furnaces but Heat Aplenty in ‘Passive
Houses’. By
Elizabeth Rosenthal. Excerpt:
DARMSTADT, Germany — From the
outside, there is nothing unusual about
the stylish new gray and orange row
houses in the Kranichstein District,
with wreaths on the doors and Christmas
lights twinkling through a freezing
drizzle. But these houses are part
of a revolution in building design:
There are no drafts, no cold tile floors,
no snuggling under blankets until the
furnace kicks in. There is, in fact,
no furnace...The concept of the passive
house, pioneered in this city of 140,000
outside Frankfurt, approaches the challenge
from a different angle. Using ultrathick
insulation and complex doors and windows,
the architect engineers a home encased
in an airtight shell, so that barely
any heat escapes and barely any cold
seeps in. That means a passive house
can be warmed not only by the sun,
but also by the heat from appliances
and even from occupants’ bodies...Decades
ago, attempts at creating sealed solar-heated
homes failed, because of stagnant air
and mold. But new passive houses use
an ingenious central ventilation system.
The warm air going out passes side
by side with clean, cold air coming
in, exchanging heat with 90 percent
efficiency...Inside, a passive
home does have a slightly different
gestalt from conventional houses, just
as an electric car drives differently
from its gas-using cousin. There is
a kind of spaceship-like uniformity
of air and temperature. The air from
outside all goes through HEPA filters
before entering the rooms. The cement
floor of the basement isn’t cold.
The walls and the air are basically
the same temperature...
2008 August 26. Serving
Architects, Consultants in Everything
Green Become Mainstays. By LISA CHAMBERLAIN, The
New York Times. Excerpt: On a recent
Friday, when the rest of the staff
of the architecture firm Beyer Blinder
Belle was out of the office enjoying
a beautiful August day, about 25
people sat in a windowless room learning
about the Leadership in Energy and
Environmental Design (LEED) certification
process.
Conducting the seminar was Lauren
Yarmuth of YRG Sustainable Consultants,
one of a growing cadre of consultants
who specialize in helping developers,
architects and sometimes tenants
gain an official stamp of approval
from the United States Green Building
Council through its LEED certification
program — the undisputed calling
card of environmental bragging rights.
...“Going green used to be
part of just a handful of organizations’ mission
statements, but now it’s become
part of everyone’s agenda,” said
Ashley Katz, communications director
for the Green Building Council. “That
has, of course, increased the need
for sustainability consultants.”
Many of the consultants are, like
Ms. Yarmuth, trained as architects
and work directly with the Green
Building Council to develop and refine
the guidelines they help clients
follow. At the end of 2006, the Green
Building Council’s membership
included 679 consultants. By July
31 this year, there were 1,590.
...Despite a seemingly straightforward
point system and scorecard, getting
LEED certification is not always
easy. Even large firms with employees
with titles like “environmental
strategist” hire consultants
to walk them through the process.
A year ago in May, CB Richard Ellis
developed a corporate policy to be
carbon neutral by 2010, according
to Sally R. Wilson, global director
of environmental strategy for the
real estate investment and management
firm....
...Ms. Wilson brought in Holley Henderson,
a principal of H2 Ecodesign, based
in Atlanta, to manage the process
and make sure the architect was designing
to LEED standards.
“Certified wood is a hot topic
right now” with the Green Building
Council, Ms. Henderson said by way
of example. “The requirement
is, 50 percent of wood has to be
sustainably harvested. But keep in
mind, if you use wheat or sunflower
board or some other alternative,
those are grasses, not wood. The
way the credit reads, 50 percent
is a lot, so the more you reduce
your wood, the easier it is to get
this credit. People who just look
at the scorecard and checklist wouldn’t
understand these nuances.”
...According to Thomas W. Hicks,
vice president for international
programs at the council, there are
LEED projects under way in 75 countries. “There
is tremendous demand to bring LEED
in and localize it to their conditions,” Mr.
Hicks said.
2008 July. Energy
efficiency in the built environment. By Leon R. Glicksman,
Physics Today. Excerpt:
...buildings are the largest energy
consumer in the US, which is a surprise
to many people. The combined residential
and commercial building sectors consume
close to 40% of the total primary
US energy... The combined residential
and commercial building sector also
uses 70% of US electricity...
Given the enormous energy consumption
by the building sector, a viable
part of a CO2 control strategy should
include increased energy efficiency
for that sector...
Achieving substantial levels of energy
efficiency requires a combination
of technologies. If there is something
approaching a silver bullet, it is
integrated design—architects,
developers, engineers, and energy
consultants working together from
conceptual design to finished construction...
Space heating constitutes the largest
energy use in residential buildings.
Active or passive solar-energy systems
can meet a majority of the heating
needs in most climates. Such systems
require windows or solar thermal
collectors—which collect the
Sun's energy for heating purposes—oriented
to receive a maximum of solar irradiation
in the winter...
For commercial buildings, lighting
represents the largest primary energy
consumption. Higher-efficiency lighting
has seen continued progress through
compact fluorescent bulbs, higher-efficiency
commercial fluorescent tubes and
ballasts, and solid-state LEDs. Effective
use of daylight combined with dimmers
and occupancy sensors that eliminate
unneeded artificial light can reduce
energy use for lighting by more than
50%...
Energy for cooling both commercial
and residential buildings is becoming
a larger portion of the energy demand
as the US population in southern
regions continues to increase...
Shading and spectrally selective
glazing can reduce solar heating
of building interiors. Highly reflecting
roofs, so-called cool roofs, can
also reduce heat transfer to interiors;
that approach is especially useful
for single-story buildings with flat
roofs. And novel integration of heat
pumps and air conditioners in the
buildings can meet the remaining
cooling loads while yielding an overall
energy savings...
Natural ventilation can reduce the
seasonal energy requirements for
cooling commercial buildings by 50%
or more in many US and European climates...
2007 November 6. Massachusetts
Looks at Using Biofuel in Home
Heating Oil. By KATIE ZEZIMA.
Excerpt:
BOSTON, Nov. 5 - Gov. Deval L.
Patrick and legislative leaders
proposed a bill on Monday to require
all home heating oil and diesel
fuel to contain at least 5 percent
biofuel by 2013.
Massachusetts would be the first
state to require that home heating
oil contain renewable fuels, a significant
issue in a state where 36 percent
of homes use home heating oil, according
to Census figures. That compares
with the 8 percent national average.
Maine leads the nation, with 87 percent
of its homes using heating oil, according
to the Census.
The bill would require that all home
heating oil and diesel fuel contain
2 percent renewable fuel alternatives
by 2010 and increase to 5 percent
by 2013.
...Brooke Coleman of the Northeast
Biofuels Collaborative said the savings
would be modest.
"The biodiesel mandate will
only have a small positive effect
on fuel prices," Mr. Coleman
said. "On the biodiesel side,
the short-term price impact is going
to be small. But the overarching
goal here is to provide a foothold
for biodiesel providers in the state,
which will stabilize oil and diesel
prices."...
2007 October. GREENTIPS
- A Tip to Warm Your Hearth. Excerpt:
With fall in the air, it's time to
ensure your home is properly insulated.
Insulation prevents heat from leaking
out of your home in winter and into
your home in summer, making it more
comfortable year-round and reducing
your energy consumption, global warming
pollution, and heating and air conditioning
costs.
The many options on the market today
include fiberglass rolls, spray foam,
rigid foam, and loose-fill cellulose
made from old newspapers. To determine
the best fit for your needs, consider
these factors:
R-value. This number represents an
insulation's ability to resist heat;
the higher the R-value, the more
effective the insulation....
Target spaces. Attics and cathedral
ceilings are great places to start
to get the most bang for your insulation
bucks. Next in line should be walls,
floors, crawl spaces, and basements.
Raw materials. Insulation made from
non-petroleum resources, with a high
recycled content, requires less energy
to process, reduces waste, and uses
fewer natural resources. ....
Installation. Foam insulation has
traditionally been sprayed onto walls
using chlorofluorocarbons (CFCs)
or hydrochlorofluorocarbons (HCFCs)-chlorine-based
chemicals that deplete the ozone
layer. But it is now possible to
apply foam insulation using chlorine-free
agents such as hydrofluorocarbons
(HFCs), carbon dioxide (CO2), and
even water....
Disposal. In addition to choosing
insulation with a high recycled content,
consider whether it can be recycled
at the end of its useful life....
2007 July 11. Hot
off the grid/Solar ovens utilize
nature's rays for energy-efficient,
everyday cooking -- even in foggy
San Francisco, Tara Duggan,
SF Chronicle Staff Writer, Excerpt:
... 'I have to have one of those
sun ovens,' says Sharon South, who
recently moved from San Jose to Tuolumne
County. "Because
in the summer, who wants to turn
the oven on?" This
spring, South started using her
solar oven about three times a
week and plans to buy a second
one so she and her husband can
cook more dishes at once when they
have guests. Solar cookers like
the Sun Oven can maintain temperatures
of 350 degrees or higher and start
around $230. Less-insulated and
simpler versions such as one called
the CooKit cost about $32 and cook
food in the low to mid 200 degrees
-- hot enough to boil water, which
is all you need for most cooking.
...The Sun Oven ... consists of
a well-insulated box with a glass
lid and four reflective panels
that direct sunlight into the box.
... Solar cooking typically takes
two to three times as long as conventional
cooking. But once you get used
to the relaxed rhythm, it can be
easy and convenient, kind of like
using a Crock-Pot. ... We found
it perfect for low-and-slow cooking,
such as a whole-grain rice pilaf....
Over 2 billion people, a third of the world's population, rely
on wood-fueled fires to cook food. Of these people, around 500
million frequently encounter fuel shortages yet live in ideal
climates for solar cooking, says Kevin Porter of Solar Cookers
International (SCI) in Sacramento. Many women, especially refugees,
trek miles to obtain cooking fuel, and the reliance on wood for
fuel has led to deforestation in many areas. SCI and other organizations
help impoverished communities gain access to solar ovens to cook
food, pasteurize water and sterilize medical equipment. Since
1995, SCI has taught 30,000 families in eastern and southern
Africa how to use solar ovens and has helped establish solar
businesses in refugee communities. [Article also has:] Where
to find solar ovens [and recipes:]
Baby Beet Salad with Feta, Walnuts & Arugula
Buttermilk Cornbread
Peach & Blackberry Cobbler
Rice Pilaf
Wheatless Apricot Cake
Shrimp & Lemon Skewers
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Solar
Cookers International (SCI) -
Establishes programs in countries
around the world to teach people
to make and use solar ovens and cookers.
Reduces deforestation and saves time
for cultures that normally would
gather wood for cooking fires. Reduces
carbon dioxide (greenhouse gas) emission
in cultures that normally use natural
gas or electricity for cooking. See
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