Re: [EnergyPlus_Support] 3rdOrderBackwardDifference in Energy Plus

[Jeremiah Crossett <jcrossett@xxxxxxxxxxxxxxx>]

Rather then third order backwards- I have been using the analytical solution in my "shoebox" model because my readings in the manual indicated that it was more dynamic, but sticking with the third order backwards my commercial models- would anyone have any insight with regards to the analytical solution, or the Euler Method-such as what type of models might be well suited for these non-default approaches?

Jeremiah D. Crossett  | Senior Analyst  |  Phase Change Energy Solutions

120 E. Pritchard St.  | Asheboro, NC 27203  | Mobile 503-688-8951

www.phasechange.com 

 

  

On Thu, Aug 16, 2012 at 9:12 AM, Richard Raustad <RRaustad@xxxxxxxxxxxx> wrote:

 

E+ saves the previous zone temps in history terms, t-1, t-2, t-3, and
uses those as needed. Of course these are updated every time step (i.e.,
using first in last out).

On 8/16/2012 11:58 AM, bokelai1989 wrote:
> Hi, All,
> In the Engineering Manual of Energy Plus, it mentions a method of "3rdOrderBackwardDifference".
>
> It says "This algorithm requires zone air temperatures at three previous time steps and uses constant temperature coefficients. The assumption is that three previous time steps lengths are the same."
>
> I would like to know in terms of its inner calculation mechanism, how energy plus acquires the zone air temperature at three previous time steps?
>
> Thanks!
> Na
>
>
>

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Richard A. Raustad
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