[Bldg-sim] radiation through glazing

[Joe Huang]

Larry,

I'm not ready to dismiss this effect totally. When I look at a plot of Low-E 
transmissivity, it's shown to block anything from 800 nanometers on up, although the plot 
stops at 2400 (see 
http://www.leyboldoptics.com/cms/upload/downloads/S_Low_E_Coating_Apollon.pdf page 2).  
Out of curiosity, I did a Google Search for "Low-E windows block cell phone signals"  and 
found this question raised in various web pages.  Expanding on what I had said previously, 
I do know of a building in Beijing (China Academy of Building Research) that did a facade 
retrofit a few years back, after which the staff reported they could no longer get cell 
phone signals.  I think I'll send my colleagues an e-mail to ask for more details.

Joe

Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 108D
Moraga CA 94556
yjhuang at whiteboxtechnologies.com
http://weather.whiteboxtechnologies.com for simulation-ready weather data
(o) (925)388-0265
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On 3/4/2014 7:26 AM, ldegelman at suddenlink.net wrote:
> I don't see how there could be any effect at all.  The wavelengths are totally 
> incompatible.  Low-e coatings block the near-infrared radiation at wavelengths of 700 to 
> 2400 nanometers.  Even at the ultraviolet end, the wavelengths are around 100 to 400 
> nanometers.  The 3G and 4G networks that cell phones use are way off from this.  
> Typically, cell phone wavelengths (at 0.8 to 2.4 Ghz, the RF portion of the spectrum) 
> are about one foot long (or around 300 million nanometers) - not even in the same ball 
> park.
>
> \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
> Larry O. Degelman, PE, FIBPSA, ASHRAE
> Professor Emeritus of Architecture
> Texas A&M University
> //////////////////////////////////////////////////////////////
> -----Original Message----- From: Russell Richman
> Sent: Monday, March 03, 2014 10:00 PM
> To: leen peeters
> Cc: BldgSim Mailing List
> Subject: Re: [Bldg-sim] radiation through glazing
>
> these types of glazing systems will help reduce EMF's from the exterior.  As such, they 
> 'may' reduce cell phone wave lengths as well.  I have not come across any studies, but 
> the physics says it is possible.
> -russell
>
> On 2014-03-03, at 6:47 PM, leen peeters wrote:
>
>> Dear all,
>>
>> is there anyone aware of a negative impact of triple glazing or foils used in triple 
>> glazing on the transmittance of mobile phone signals?
>>
>>
>> Any input is welcome ...
>>
>> leen
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