Page 62 - Green Builder Magazine Spring 2018 Awards Issue
P. 62
ENERGY S0LUTIONS
Sustainable Power From This Day Forward
Taking the Fast Track
to Efficient HVAC
Why wait for the future? Heat pumps are ready to employ now.
BY PAUL HAWKEN
Gwyn Pris, professor emeritus at the
Note: This article is taken from Drawdown: The London School of Economics and Political
Most Comprehensive Plan Ever Proposed to Science, suggests that addiction to air
Reverse Global Warming, which describes the 100 conditioning (AC) is “the most pervasive and
most substantive solutions to climate change, as least noticed epidemic” in the United States—
well as their financial histories, the carbon impacts where the amount of electricity used to keep
they provide, the relative cost and savings and buildings cool is equal to what the whole of CREDIT: TERRENCE MCCARTHY
Africa uses—for everything.
each solution’s path to adoption.
It is easy to understand how this happened:
ENJAMIN FRANKLIN may be Fossil fuels were plentiful and cheap, no one
the only diplomat to have studied worried about greenhouse gas emissions or “In the United States, the
the science of refrigeration. That global warming, and cool air was a welcome
was in Cambridge, England, relief at home and at work. Critics argue AC is amount of electricity used
Bin 1758, when he was trying to one road civilization should never have taken
reduce tensions between King George and and must now exit. Perhaps, but an exit is to keep buildings cool is
the world—many of them living in the hotter equal to what the whole of
the American colony but found time for the not likely. A top aspiration of people around
lab as well. He and English chemist John
Hadley were intrigued by a Scottish scientist’s climates of Asia and Africa—is the comfort Africa uses—for everything.”
discovery, made a decade earlier, showing of air conditioning.
how the evaporation of volatile liquids Demographics alone dictate that the as usual generates spiraling emissions
manifested a secondary eect: cooling. The world is set for a massive increase in from heating and cooling; and maximum
basic principle is that higher-energy (hotter) AC demand in this century. One study e¤ciency could cut energy use by 30 percent
molecules evaporate rst, leaving the lower- predicts as much as 33-fold by 2100. China’s to 40 percent.
energy (cooler) ones behind. experience foreshadows: In the decade-plus
In Cambridge, the researchers’ equipment between 1995 and 2007, the percentage of Better Energy Efficiency
consisted of a beaker of ether, a mercury bulb air-conditioned homes in Chinese cities the Easy Way
thermometer and a bellows. After wetting increased from 7 percent to 95 percent. The means to increase efficiency are at
the thermometer in the ether, they worked China will soon surpass the United States hand and not necessarily high tech. For
the bellows hard to evaporate the liquid as the leading consumer of AC. example, smart thermostats that correlate
as rapidly as possible. The thermometer Air conditioning grabs most of the the temperature setting inside the building
recorded the temperature, which dropped headlines when the subject is conservation with the temperature outside and with
to seven degrees Fahrenheit in one trial, and efficiency, but heating is just as actual human occupancy make good
and the accumulation of ice solidied the susceptible to inefficiency and just as sense, but are often missing. Fan speeds
experiment. prime for improvement. The building are surprisingly important and are often
Franklin wrote a friend, “One may see the sector worldwide uses approximately 32 set incorrectly. Heat exchangers to recover
possibility of freezing a man to death on a percent of all energy generated; more than heat or cold from air ventilated outside
warm summer’s day.” An exaggeration, but one-third of that is for heating and cooling. are vital. Retrofitting existing structures
the famous polymath was, yet again, on Various bodies have analyzed the potential with these low-tech interventions is more
the right track. Could he have foreseen the for increased e¤ciency and projected the expensive, but in any new building they
consequences of his insight? results. All agree on two points: Business should be mandatory. They save money,
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