[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [EnergyPlus_Support] Re: How to change the solar radiation calculation model in Energyplus





Some of this information is garbled.

1. The Perez Model is just one of many solar models developed to estimate the direct/diffuse split in solar radiation.

2. ASHRAE Design Day procedures use the ASHRAE Clear Sky Model that was completely redone in 2009 and then further improved in 2013.�� Like situation 1 above, there are also other Clear Sky Models that could be used.

3. The Zhang-Huang Model is a full sky model that estimates the solar radiation under both clear and cloudy sky conditions based on the Cloud Cover and other climate variables.� The ZHM was never intended and should not be used for deriving design day solar radiation.

4. I led an effort at LBNL 6-8 years ago to develop doe2ep (actually a modification of DOE-2.1E) that can read a DOE-2.1E input file and produce a complete EnergyPlus IDF file, assuming that's what was being referred to as
"
some initial E+ conversion from doe2.1e."

Joe
Joe Huang ���
White Box Technologies, Inc.
346 Rheem Blvd., Suite 108D
Moraga CA 94556
yjhuang@xxxxxxxxxxxxxxxxxxxxxxxx
http://weather.whiteboxtechnologies.com for simulation-ready weather data
http://www.whiteboxtechnologies.com
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"



On 11/5/2013 8:26 AM, Jeremiah Crossett wrote:


�I think that the solar model is a function of the weather file, from memory solar is measured in global horizontal witch is split into direct and diffuse�using a modified version of the perez�model.�

The design day info has model options that are not weather file based. �One of witch was developed by�ZhangHuang. Huang has done a lot of work on weather data and some initial E+ conversion from doe2.1e.�


The solar calculations in Energy Plus solar distribution FullInteriorAndExteriorWithReflections is more useful for calculations of solar heat gain for specific interior surfaces, however it requires convex zones and does not work well with window multipliers.�

Solar can be effected by ground and snow reflectivity, as well as transmittance schedules of shading surfaces.�

The material properties setting for solar absorbency (inverse of reflectivity) also have effects.

Yes it would be interisting to have solar modeling options, but I m not sure what would be useful in addition to what is currently available.�







Jeremiah D. Crossett��| Senior�Analyst��| �Phase Change Energy Solutions
120 E. Pritchard St. �| Asheboro, NC 27203 �| Mobile�503-688-8951
��





On Tue, Nov 5, 2013 at 8:00 AM, Jill Dalglish <jill.dalglish@xxxxxxxxxxxxxxxxxxxxx> wrote:
�
I am interested in this question.� How are you measuring the solar radiation?




__._,_.___


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.




Your email settings: Individual Email|Traditional
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

__,_._,___