I used internal mass for a project that was minimally cooled and relied on internal structural mass to keep temperatures within a specified range (over cool at night and stay below an upper bound with a system that does not meet the instantaneous load). While experimenting with the internal mass object I found that it is more sensitive to area, that is doubling the mass for a fixed area had less impact on the results than doubling the mass by doubling the area. Fortunately, we were also the structural engineers and I could get good estimates of both mass and surface areas of the structure I was simulating.
It seems to me that for most models, the envelope mass probably exceeds the content mass, so unless you are simulating a high density storage facility, the impact of internal mass is minimal. It will also have minimal impact with small temperature changes.
Ned Lyon, P.E. (MA)
Staff Consultant
SIMPSON GUMPERTZ & HEGER
781.907.9000 main
781.907.9350 direct
781.907.9009 fax
www.sgh.com
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of James V Dirkes II, PE
Sent: Friday, February 25,
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
__,_._,___