[Equest-users] HHW reset controls in eQuest

[Dominique Michaud]

Fellow eQuest modelers, 

 

I am experiencing a great deal of grief trying to model HHW/boiler energy
efficiency measures using eQuest. I am trying to model HHW temperature
resets based on outside air temperature and boiler lockout strategies.

 

Under the DD Wizard, "Hot Water System Control and Schedule > Setpoint is:"
drop-down list I've selected "OA Reset" and allowed the resulting hi/low
temperature values to default, namely HW Max Temp: 180.0F and HW Min Temp:
140.0F (see attached screenshot).

 

Digging into the BDL, I noticed this issue:

 

     *5356 * "B5HW Lp Heat Reset Sch-D" = DAY-SCHEDULE-PD

     *5357 *    TYPE             = RESET-TEMP

     *5358 *    SUPPLY-LO        = 140

-CAUTION-------------------------- ===
-------------------------------------------------------

-CAUTION--- VALUE GREATER THAN MAXIMUM OF 0.1200E+03

     *5359 *    SUPPLY-HI        = 180

-CAUTION-------------------------- ===
-------------------------------------------------------

-CAUTION--- VALUE GREATER THAN MAXIMUM OF 0.1200E+03

     *5360 *    OUTSIDE-LO       = 30

     *5361 *    OUTSIDE-HI       = 65

     *5362 *    ..

 

However, it looks as though the values are accepted for the reset schedule:

 

-NOTE- - -         DATA FOR     B5HW Lp Heat Reset Sch-D

-INPUT - - - - - - - - - - - - - - - - - - - - - - - -  TYPE             =
RESET-TEMP

-INPUT - -                                              OUTSIDE-HI       =
65.0000 F

-INPUT - -                                              OUTSIDE-LO       =
30.0000 F

-INPUT - -                                              SUPPLY-HI        =
180.0000 F

-INPUT - -                                              SUPPLY-LO        =
140.0000 F

-DEFAULT - - - - - - - - - - - - - - - - - - - - - - -  DAY-HOURS        =
1.0000

-DEFAULT -                                              DAY-HOURS        =
24.0000

 

 

When I run the model I end up negative natural gas savings (i.e. more gas
usage than in my baseline case). No matter what dials I try to turn with
this EE measure, I consistently end up with negative savings. Even more
frustrating, when I try to run a OA temperature lockout for the boiler, I
get even more energy use than my baseline model!

 

Can anyone provide me with some guidance on what I need to do to get my
model to run these EEMs correctly? Help put me on the path to solving these
problems and I will buy you a beer.

(Note: I am using eQuest 3.64 Build 7130 - the latest release)

 

Thank you for any assistance you can provide.

 

Yours,

 

Dominique Michaud | Project Engineer

 <http://www.scengineers.net/> SC Engineers, Inc. 

 
<http://maps.google.com/maps?hl=en&cp=40&gs_id=2&xhr=t&q=17075+Via+Del+Campo
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&wrapid=tljp132371020953200&um=1&ie=UTF-8&hq=&hnear=0x80dbf72707811bcf:0xafd
a74b7e473e651,17075+Via+Del+C> 17075 Via Del Campo, San Diego, CA 92127

P: 858.946.0333 | C: 858.436.4213 |F: 858.946.0334

 <mailto:dominique at scengineers.net> dominique at scengineers.net |
<http://www.scengineers.net/> www.scengineers.net

 

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