October 22, 2013
Proper Home Winterizing Could Save Billions In Energy Costs
redOrbit Staff & Wire Reports - Your Universe Online
If every homeowner in the US took steps to winterize their homes during the coldest months of the year, the country as a whole could save up to $33 billion annually in energy costs, researchers from the Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered.Berkeley Lab scientist Jennifer Logue and her colleagues set out to determine how much energy is wasted from houses that are leaky or drafty. Furthermore, they wanted to determine the optimal standards of air tightness – the level at which the homeowner could maximize his or her energy savings while also minimizing the cost of achieving those savings.
“Currently people who weatherize can get their homes about 20 to 30 percent tighter. But they’re not sealing all the cracks. There’s still quite a bit left on the table, and those extra leaks and cracks could potentially save a lot of energy,” Logue, who served as lead author of a paper recently published online in the journal Energy and Buildings, said in a statement.
According to the researchers, the 113 million homes that make up the US residential sector consume approximately 23 percent of the country’s source energy each year. Source energy, they explain, refers to the power that is consumed by structures for electricity and heating, as well as the raw energy needed to produce and transmit it. Nearly all of that energy is used to heat or cool residential buildings, they added.
“The largest potential savings are in the hottest and coldest climates,” the researchers report. “As new air enters homes through leaks and cracks, it has to be cooled or heated. Although the trend has been towards building tighter houses, Logue says the science is still not settled on the best ways to minimize leaks.”
She and her co-authors established five levels of “tightening” – average, advanced, the International Energy Conservation Code (IECC) standard, the R2000 standard (which is tighter than IECC standards and is common in Canada), and the “passive house” standard (the tightest and most difficult to achieve).
They found that upgrading all homes to advanced level would reduce energy demand by 2.6 quads. The residential housing sector used 22 quads of source energy each year, and this reduction would result in about $22 billion in energy savings. Furthermore, achieving the IECC standard would yield savings of 3.83 quads in annual source energy, resulting in as much as $33 billion in savings, the researchers said.
“The study found that the IECC standard offered most of the benefit that the tighter standards would yield. Moreover this standard is likely more achievable than the tighter standards,” the researchers said, adding that they found that “raising the U.S. housing stock to the IECC standard would reduce airflow in homes by a median value of 50 percent.”
“As we move forward and look to build better housing stock, we want to know what standards we should enforce,” added Logue. “It looks like the IECC standard gets us the majority of the benefit of air sealing. More research is needed to determine the costs of implementing each of these standards in new homes to see which are cost-effective. As we get better at air sealing, we can move towards tighter envelopes in buildings.”