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LEGISLATION
DOE Officials Say They Plan to Market R5 Volume Purchase
Program Aggressively
Department of Energy (DOE) officials plan to market the R5 Volume Purchase
program aggressively, and offered additional details on the program during
a recent webinar titled “Cost-Effective Triple Pane (R-5) and Low-e Storm
Windows— Available Now.”
The speakers highlighted DOE’s effort to bring affordable triple-pane
and low-E storm windows to the marketplace at a competitive price (see
related story in June 2010 DWM, page 34).
Speakers included Marc LaFrance, DOE’s technology manager for Building
Envelope and Windows Research and Development, who talked about the purpose
of the program.
“All of these policies are so triple-pane windows become more cost-effective,”
said LaFrance. “What is cost-effective? Most windows in program have a
U- factor of .22 or lower (depending on whether they are fixed or operable)
and the price would have to be lower than $4 per square foot.”
On the manufacturing side, LaFrance pointed out that the DOE has been
working with manufacturers on production issues, “to help them develop
high-volume factories.”
LaFrance also commented on the R-value versus U-value debate, which has
come up again in the industry in recent weeks (see related article on
opposite page).
www.windowsvolumepurchase.org
offers online information on the R5 program.
“All windows have to be based on a whole window U-factor,”
said LaFrance. “We use the term R5 to give people a general perspective
of window performance. It also gives people perspective of how windows
relate to other building components with R values.”
He also cautioned manufacturers from offering misleading information when
it comes to R-values.
“We know that there are some companies [that] report center-of-glass performance,
such as an R-value of 15, and this very misleading. This program requires
whole window performance,” said LaFrance.
Nils Petermann, project manager, Efficient Windows Collaborative, also
pointed out to attendees that R5 windows will make the biggest impact
“when there is a substantial heating season.”
Graham Parker, senior staff engineer, Pacific Northwest National Laboratory,
addressed webinar attendees to stress that awards were not made to manufacturers
based on price.
“You could offer whatever you were comfortable with,” he said. “Prices
may not be increased during the program, but, of course, then can be decreased
[if a manufacturer chooses to do so].”
He also pointed out that prices are not listed by vendor. Additionally,
Terry Mapes, engineer for Pacific Northwest National Laboratory, said
that 95 percent of the products offered by manufacturers are vinyl-based
and that the products had to be offered minimally in a white. Some manufacturers
may offer additional colors and this may or may not require an extra cost,
as that is up to the manufacturer. Many of the speakers stressed that
buyers will have to do research.
“It’s not set up like Amazon or buy.com,” said Mapes. The site offers
list prices, but does not include shipping, taxes, etc. However, the site
is set up so that buyers can choose based on shipping regions to help
narrow down the search.
Phase Two of the program, which will be looked at next year, may incorporate
different window types, possibly including a solar heat gain coefficient
requirement, and may even expand into the commercial market, said Mapes.
But for now, the DOE needs to work to get the word concerning Phase One
out. Jason Bogovich, manager of DOE contractor Energetics Inc., said he
welcomes input from the industry on how to do that.
He reported that stakeholders and partners will work to get the message
out to possible buyers and that includes three regional workshops that
are in the works, though locations have not yet been set.
“We will be very aggressive in getting out on the street and marketing
the program,” Bogovich added.
Many attendees had questions about price, but Parker reiterated that the
“prices are quite wide-ranging” and clarified that there are “no subsidies
to vendors.”
“We know manufacturers have been working for several years on this to
lower manufacturing costs,” said Parker. “We are simply using market forces
to bring high-performance products to market at lower prices.”
“The whole point is to offer these at an affordable price,” added LaFrance.
“Obviously this program doesn’t address all window types. It’s to get
to mainstream and to offer at an affordable price,” said LaFrance.
Industry Discusses U-Factor Versus R-Value
for Window Performance
Historically, the term U-factor, the rate of heat transfer of a material,
has been used to explain window performance. However, questions have arisen
recently as to whether the term R-value, which measures the thermal resistance
of a material, could be used as an alternative.
It is critically important that product
performance is communicated
consistently to all interested parties.
–Jim Benney, NFRC
Dr. Brandon Tinianov, P.E., LEED AP, chief technology officer with Serious
Windows, has written a paper titled “The Use of R-Value Versus U-Value
to Describe Window Performance,” and states “if the use of U-value is
established, why would one have a desire to use R-value as an equivalent
alternative?”
Tinianov explains that first, “U-values [U-factor] are small, usually
less than one, with diminishingly smaller values as performance improves.
In contrast, R-values are presented in a number range of highest comfort
for a consumer-between 1 and 10 (possibly 20) … Second, the inverse relation
of U-value and performance is counter intuitive. As U-value diminishes,
performance increases.”
He also states, “There is good public reason and good technical precedence
for the interchangeable use of R-value and U-factor to describe windows.
With only slight modification to terminology associated with R-value,
the public will be empowered to make smarter, more intuitive energy efficiency
decisions.”
Recently, the National Fenestration Rating Council (NFRC) sent out a bulletin
explaining why it chooses to use U-factors for windows. In the bulletin,
Jim Benney, NFRC chief executive officer, says “From a technical perspective,
there are numerous philosophies about whether R-value applies only to
homogeneous materials and should be measured in terms of surface to surface
heat transfer—i.e., making it the true inverse of conductance—by a guarded
hot plate (ASTM C177). Or, should it be used for composite materials and
measured in a calibrated hot box in accordance with ASTM C236? Or, should
it be measured by means of a heat flow meter (ASTM C 518)?”
Benney continues, “U-factor is not a material property value. It is the
result of a calculation that combines the conductance values of the numerous
materials in a fenestration product. This includes glazing materials,
gas fills, spacer materials, framing materials, weather strips, sealants,
etc. In addition, it includes the convection and radiation elements that
occur within and adjacent to the fenestration product surfaces that dramatically
influence its energy rating.”
Benney adds, “It is critically important that product performance is communicated
consistently to all interested parties. U-factor is the recognized term
for relating the thermal transmittance of windows, doors, skylights, curtainwalls
and fenestration attachment products. NFRC will continue to recognize
U-factor-and U-factor only—for fenestration products.”
Some window and energy experts in the industry also have thoughts on the
matter.
“U-factor takes into account not just conduction but also airflow, absorption
and radiation (emissivity). Unlike most building materials that use an
R-value rating and are made up of a single material component (such as
insulation, roofing materials, etc.), windows are made up of many components
that create the window assembly and the U-factor more accurately measures
the heat transfer of this assembly of components,” says Kerry Haglund,
a senior research fellow with the Center for Sustainable Research, University
of Minnesota.
Tom Culp of Birch Point Consulting LLC adds, “While R-value does have
greater meaning to consumers, there are also technical issues when applied
to windows which have the potential to also mislead consumers if oversimplified
information is given.”
DWM
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