The REAL Cost of Air Conditioning
Mary Anne White
University Research Professor of Chemistry and Physics
Dalhousie University
Halifax, Nova Scotia, Canada
Institute for
Research in Materials
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Our world….. scaled to fuel consumption
maps from www.worldmapper.org
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Wasted Energy
The U.S. economy wastes 55% of the energy it consumes.
The Atlantic, May 2008
30%
coolant
5%
friction
25% mobility
and
accessories
40%
exhaust
70% of the combustion
energy of gasoline goes out
the tailpipe as waste heat!
F. Stabler, DARPA/ONR Progress Review and
DOE High Efficiency Thermoelectric
Workshop, San Diego, March 2002.
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Energy and Sustainability
Scientists are working hard to make more energyefficient devices and products, but the easiest way to
reduce energy consumption is to use less of it!
One of the biggest wastes is air conditioning!
• 75% of US homes have at least one air conditioner
• heating and cooling accounts for 150 million tons of
CO2 in the US annually
• air conditioning and refrigeration accounts for 15% of
global electricity consumption
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Wasted Energy – AIR CONDITIONING
• North American residential/commercial buildings account
for 40% of energy consumption.
• AC accounts for 40% of energy costs of running household
in North America (compared with 5% for lights).
• It costs more energy to cool by 1 oC than to heat by 1 oC!
• “Seasonal temperature inversion” (rooms colder in summer
than winter) is wasteful!
• Japan introduced Cool Biz policy in 2005: offices kept at
28 oC from June to September; in 2007, CO2 emissions
reduced by 2 million tons
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Too low a temperature reduces worker productivity….
Keystroke analysis of office workers:
Mean Correct
Keystrokes per
Minute
19 employees
over 4 weeks in
real workplace
Study by Professor Alan Hedge, Cornell University, 2008
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Bottom line:
Stay cool and heat up the planet.
OR
Turn up the temperature on your air conditioner and:
• reduce energy consumption
• reduce CO2 production
• directly reduce production of heat
• increase worker productivity
• decrease home/workplace operational costs.
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In warm weather…
Be cool…. turn UP the temperature!
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