[Equest-users] all input values

Sami, Vikram Vikram.Sami at perkinswill.com
Fri Aug 6 15:46:19 PDT 2010


Katie,
Assuming you are looking for the definition for the model, the place to look is the inp file. If you've not changed the default values, all you'll see (in the space deffinition) is:

  INF-METHOD       = ASHRAE-ENHANCED

When you change the defaul Flow Coefficients and Stack coefficients you'll see this as well:

   FLOW-COEF        = XXXXX
   STACK-COEF       = YYYYY

Here's what the help files say about this:


FLOW-COEF

For INF-METHOD = ASHRAE-ENHANCED, specifies the flow coefficient 'c' in the equations:

          Qs = c * Cs * dTn

          Qw = c * Cw * (sf*Wlocal)2n

          Qnet = [ Qs2 + Qw2 ]1/2

where
          Qs      infiltration due to the indoor/outdoor temperature differenial, cfm
          c         flow coefficient, cfm/(in. H2O)n
          Cs       stack coefficient, (in. H2O/°F)n
          dT       absolute value of the indoor/outdoor temperature differential, °F
          n        pressure coefficient
          Qw      Infiltration due to wind, cfm
          Cw      wind coefficient, (in. H2O/mph2)2n
          sf        Shelter factor, modifier of local wind speed based on immediate surroundings
          Wlocal local wind speed as modified by the SITE-PARAMETER terrain parameters, mph
          Qnet   Net infiltration due to the combined effect of temperature and wind, cfm

Stack and wind coefficients vary according to the number of stories in the house, whether a flue exists, and whether the house has a crawl space.  The default FLOW-COEF is based on the first example given in the 2005 ASHRAE Handbook - Fundamentals, pp. 27.22; scaled by the square root of the ratio of the SPACE:VOLUME divided by the volume in the example, 12,000 ft3.

Because the units are dependent on the pressure exponent 'n', this keyword is dimensionless in the input, and this method currently cannot be used with metric input.  If simulated in metric, this keyword must still be defined in English.


________________________________
From: equest-users-bounces at lists.onebuilding.org [equest-users-bounces at lists.onebuilding.org] On Behalf Of Katie Mac [kmacken2 at email.smith.edu]
Sent: Friday, August 06, 2010 4:43 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] all input values

Hey everyone!

I need access to all the input values for a given model, specifically for infiltration calculations.  I've searched through the INP file but it doesn't show every parameters.

I'm studying the ASHRAE Enhanced infiltration method and seeing the effects of altering the coefficients.  You can alter these values by going through Detailed Mode.  Within Properties of any spc or plnm zone, select Infiltration and change the Infiltration Method to 'ASHRAE Enhanced'.   I need to be able to read these values for further calculations and later use in a MATLAB program.

The only files I've been able to read have been the INP, SIM, and CSV (_EG_MoEU_ED) files.

Thanks so much,
Katie



--
Katie MacKenzie
Smith College, Engineering 2011
Cell: 503.730.6354
E-mail: kmacken2 at smith.edu<mailto:kmacken2 at smith.edu>
Website: www.ktmackenzie.com<http://www.ktmackenzie.com>

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