Dear EnergyPlus User Community:
A few thoughts regarding the Rooftop Outdoor Air temperature issue…
1)
It would seem to me that the effect of varying entering outdoor air temperatures (OAT) could be easily seen by trending the known mixed air temperature
(assuming well mixed), known return air temp, and assuming a mass balance based on a (recent?) test and balance report - allowing us to calculate the OAT using these proxies. Not perfect, but still a signal whose uncertainty can be quantified. Better yet,
a direct measurement of OAT (something has to be telling the economizer when to engage) might be available in some units.. Seeing this trend sampled and synchronized to temperatures reported by Weather Underground or other ground station sources would be revealing…
I have not come across anyone who has tried this, but most of my work is in the Northeast US where cooling seasons are relatively short. Once a relationship is established, It also seems like this would be a reasonable approach for FDD logic to determine OA
sensor drift/failure, as the relationship changes over time, but I don’t recall specifically coming across this ‘rule’ either.
2)
Some very interesting and cutting edge work on simulation uncertainty continues at Georgia Tech which may be relevant to this topic – particularly
on developing toolkits to support the exploration of both Meso-Climate and Macro-Climate input uncertainties via automated methods. See this link for more info:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB0QFjAA&url="">
Georgia Tech is sponsoring a conference on BEM Simulation Uncertainty which precedes the IBPSA Simbuild 2014 / ASHRAE Energy Modeling Conference in Atlanta
in September. Stay tuned for more info regarding the program and registration.
3)
Finally, at the joint IBPSA/ASHRAE conference, on Tuesday, Sept 9, there is a one day OpenStudio course covering both measure development and the
uncertainty quantification. The UQ portion of the course will be led by RMI, who will share their experience in using the OpenStudio ecosystem of tools to develop an understanding of modeling uncertainty. Registration for this course is currently open.
All the Best,
_Chris
Chris Balbach, PE, CEM, BESA, CMVP
Vice President of Research and Development
Performance Systems Development of NY
124 Brindley Street, Suite 4, Ithaca, NY 14850
ph: (607)-327-1647
__._,_.___
Posted by: Chris Balbach <cbalbach@xxxxxxxxxxxxxxxxx>
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.
__,_._,___