Re: [EnergyPlus_Support] Insulating the roof

["David Scheer - L+U" <david@xxxxxxxxxxxxxx>]

Always, always export your DB model to IDF and run from EnergyPlus native and check inputs and summary tables before trusting the DB model.  DB is a black box with too many unknowns, while E+ is as transparent as it can get.  Use both to take advantage of the clarity of E+ and the data management of DB.

 

----- Original Message -----

From: Richard Raustad

To: EnergyPlus_Support@xxxxxxxxxxxxxxx

Sent: Tuesday, June 24, 2008 8:14 AM

Subject: Re: [EnergyPlus_Support] Insulating the roof

Check the construction properties of the roof in the E+ input file
generated by DB. Changing the roof insulation in DB should result in a
change in the roof properties. If this does not happen you will not see
a change in results. Also look at the cooling and heating energy instead
of the total energy if you have not done so already. With increased roof
insulation, cooling energy use should be reduced and heating energy use
will increase. Although I find it hard to believe that changes in
cooling and heating energy offset each other in hot dry climates, it is
possible that the total energy did not change significantly.

Daniel Solís wrote:
>
> Hi E+,
>
> I simulated a house with DesignBuilder in a very hot and dry climate.
> I insuated the roof with EPS polyestyrene. No matter how much
> insulation I used, the results were almost the same.
>
> In DB forum I got the answer that no matter the climate, the
> temperature and HVAC consuption is entirely driven by internal gain
> and so there is no difference insulating the roof.
>
> It's all the opposite I have read in the state of the art. Even, in
> that specific city I got the weather file from, there is a government
> support for people to insulate their roofs because they have a lot of
> measurements proving an HVAC reduction of 15-20%.
>
> Since DB uses E+ as core program, I'm asking you directly what's
> happening,
>
> Thanks,
>
> Daniel
>
>

--
Richard A. Raustad
Senior Research Engineer
Florida Solar Energy Center
University of Central Florida
1679 Clearlake Road
Cocoa, FL 32922-5703
Phone: (321) 638-1454
Fax: (321) 638-1439 or 1010
Visit our web site at: http://www.fsec.ucf.edu

UCF - From Promise to Prominence: Celebrating 40 Years

__._,_.___

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 not allowed -- please post any files to the appropriate folder in the Files area of the Support Web Site.

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

__,_._,___