[BLDG-SIM] Reduction in Energy consumption?

Leo Rainer lirainer at davisenergy.com
Mon Feb 26 09:13:49 PST 2007


This can happen on the mainland too (and in real situations):

In mild climates, buildings with high nighttime 
internal gains (24 hour call centers, 24 hr 
retail, server farms, etc) and no economizers, 
will exhibit higher cooling energy use with 
higher insulation levels because the insulation 
inhibits the loss of heat to the cooler nighttime 
environment. This is especially true when looking 
at roof insulation levels under highly 
reflective, highly emissive roof coatings as 
these eliminate almost all of the direct solar 
gain, leaving mostly conduction and night-sky radiation.

This should only be a retrofit issue. In new 
construction, with a correctly designed building 
(working economizers) insulation should always 
help, but there is an optimal level.

Regards,

         Leo Rainer
         Senior Engineer
         Davis Energy Group

At 08:05 AM 2/26/2007, Vikram Sami wrote:

>An interesting (or possibly pointless) anecdote:
>
>When I was at ENSAR, we were doing a glazing 
>analysis for a project in Hawaii looking at 
>different glass properties, U-value being one of 
>them. I turn out that not only is there a 
>diminishing return with increased insulation, 
>there are times when you actually lose 
>performance with an increase in insulation. The 
>reduced insulation increased the building 
>balance point enough to allow the outside air 
>temperature to cool the building. Of course - 
>this was in Hawaii, where more than 90% of the 
>year you are within the ASHRAE comfort zone sitting under a tree.
>
>
>
>Vikram Sami, LEED AP
>Direct Phone 404-253-1466 | Direct Fax 404-253-1366
>
>LORD, AECK & SARGENT ARCHITECTURE
>Responsive Design · Technological Expertise · Exceptional Service
>www.lordaecksargent.com
>
>
>
>-----Original Message-----
>From: BLDG-SIM at gard.com on behalf of Gunes Inan
>Sent: Mon 2/26/2007 09:56
>To: BLDG-SIM at gard.com
>Subject: [BLDG-SIM] Reduction in Energy consumption?
>
>Hi Micha,
>
>As Vikram said, it depends. To give an example, 
>we measured the heating consumption of two 
>identical buildings (one bare, the other 
>insulated with 8 cm thick EPS boards) for 6 
>months in Northeastern Turkey, where the annual 
>mean temperature is about 6 Celsius. The average 
>reduction in heating energy was 54 %. Depending 
>on the U-value of the bare wall, this may 
>practically change between 30 and 65 %.
>
>If your building is located at a relatively warm 
>region, increasing the thickness of the 
>insulation will not have much effect on results. 
>Also, ventilation frequency should be realistic.
>
>Gunes Inan
>
>R&D Engineer
>Betek Paint and Chemical Corp., Inc.
>Istanbul, Turkey
>Tel: +90.216.396.2070 / Ext: 177
>Fax: +90.216.396.6989
>
>-----Özgün Ileti-----
>Kimden: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] Yerine Vikram Sami
>Tarih: 26 Subat 2007 Pazartesi 15:36
>Kime: BLDG-SIM at gard.com
>Konu: [BLDG-SIM] Reduction in Energy consumption?
>
>The best answer to this would be "It depends".
>
>There are multiple factors that would affect it 
>(skin dominant v/s core dominant), climate, and possibly even usage.
>
>
>
>Vikram Sami, LEED AP
>Direct Phone 404-253-1466 | Direct Fax 404-253-1366
>
>LORD, AECK & SARGENT ARCHITECTURE
>Responsive Design · Technological Expertise · Exceptional Service
>www.lordaecksargent.com
>
>
>
>-----Original Message-----
>From: BLDG-SIM at gard.com on behalf of micha radi
>Sent: Sun 2/25/2007 17:02
>To: BLDG-SIM at gard.com
>Subject: [BLDG-SIM] Reduction in Energy consumption?
>
>Hello there,
>
>What would the reduction roughly be in energy consumption for using thermal
>insulation? I am trying to figure out whether or not my results are
>correct.. Could anyone give me an estimated percentage of such reduction?
>
>My results show very small impact and I am not able to find where my errors
>might lie.
>
>Many Thanks,
>
>Micha
>
>_________________________________________________________________


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