[Greenbuilding] FW: apples, oranges, and u values

[Douglas E Lamb]

Mr. Abrams,
 
Mr. Straube is correct in the percent of difference between U and R values
in the US vs.. EU.
But as I see it these differences are based upon climate and energy
conditions that are different in EU than in the US and therefore promote the
different data and are only minimal in range.
The main issue is that the glazing products are built different with
different tolerances and configurations. i.e..e. thermal break distance,
glazing thickness, thick of metal and type of coatings coating, etc.
The amount of wood used to enclose the glazing in the EU is often less than
what is used in this country. 
This affects overall size of windows.
Getting the correct window size form the EU window to fit a bedroom by code
for example wood be very costly.
I could see 25% to 50% difference in cost to cover such a condition. 
 
Mr. Straube contention is also correct that approvals by agencies with
performance and quality oversight of imported materials would have a
considerable impact on their availability and pricing also. 
 
Cheers,
Doug Lamb
douglaslamb at columbus.rr.com
 
 

  _____  

From: greenbuilding-bounces at lists.bioenergylists.org
[mailto:greenbuilding-bounces at lists.bioenergylists.org] On Behalf Of Douglas
E Lamb
Sent: Monday, April 16, 2012 1:28 PM
To: 'Green Building'
Subject: Re: [Greenbuilding] apples, oranges, and u values


Mr. Abrams,
 
We simply use different mathematics, and physics symbols to represent the
same thing. (metrics vs. imperial); yards vs. meters, inches vs.
millimeters, etc
This is due to the difference in material thickness 25mm= 1in approx.
Some Eu countries use Joules others use Kilocalories to identify energy
consumption BTU/hr or otherwise energy use in or out, etc.
Whether in the US or EU, though, R=R and U=U.
Some day we will get it correct and every one will be in the same page.
For now however, you can calculate heat loss and heat gain per thickness of
glazing and direction of glare based upon ASHREA formulas regardless of
where you are on the planet.
And I recommend if you own a Pilkington sun (angle calculator) it would be
helpful orienting solar glare direction that best suites Low-E rating of the
glazing for your particular region of the country. 
 
Cheers,
Doug Lamb
douglaslamb at columbus.rr.com
 
 

  _____  

From: greenbuilding-bounces at lists.bioenergylists.org
[mailto:greenbuilding-bounces at lists.bioenergylists.org] On Behalf Of Alan
Abrams
Sent: Monday, April 16, 2012 11:07 AM
To: Green Building
Cc: Greenbuilding at bioenergylists.org
Subject: Re: [Greenbuilding] apples, oranges, and u values


I appreciate all the perspectives, but the question remains, do the
Europeans measure window performance differently, U for U, or R for R, than
we do here in the colonies?  (or are energy stimulated molecules less
excitable here in the new world, than they are, in say, Gay Paree?)

-a

Alan Abrams
Abrams Design Build LLC
A sustainable approach to beautiful space

6411 Orchard Avenue Suite 102
Takoma Park, MD 20912
office  301-270-NET- ZERO (301-270-6380)  
fax      301-270-1466      
cell     202-437-8583
alan at abramsdesignbuild.com
www.abramsdesignbuild.com <http://www.abramsdesignbuild.com/> 



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