[Equest-users] Water-Cooled Condenser Loop -no attached primary cooling equipment

[Pasha Korber-Gonzalez]

Hi Elliott,

I took a quick look at your model files.  The error is correct, you do not
have a heat rejection piece of equipment indicated in your Plants Tab.  This
will cause an error.


Where you are indicating on the air-side taht you have a water-cooled
condenser for your PSZ systems, we need to understand what that input is
assuming in DOE2--from the help file for this topic I found the following:

CONDENSER-TYPE

Takes a code-word that specifies the type of condenser in packaged systems
with direct-expansion cooling (and optional heating.)  Note that the program
changes the default performance data (such as EIR) when you change the
condenser type; if the unit being modeled is atypical nput data
representative of the unit should be used to replace the default performance
parameters.

AIR-COOLED                The condenser is air cooled.

WATER-COOLED          The condenser is water cooled. You must attach the
condenser to a CIRCULATION-LOOP of TYPE = CW or WLHP via the CW-LOOP
keyword. For PSZ, PVAVS and PVVT, use of this value indicates that a
water-to-air heat pump (WLHP) is to be modeled.

EVAP-PRECOOLED        The air-cooled condenser on a RESYS2, PSZ, PMZS,
PVAVS, PTAC, PIU or PVVT system includes an evaporative precooler. The
precooler is controlled by a time and/or temperature controller that decides
if the unit should operate (see EVAP-PCC-SCH, EVAP-PCC-EFF, and
EVAP-PCC-ELEC). When this unit doesn't operate, the condenser returns to
CONDENSER-TYPE = AIR-COOLED. The evaporative precooler is only active during
cooling mode. If no operation schedule is specified using EVAP-PCC-SCH, a
default operation is assumed that provides for cooling mode operation
whenever the outside dry-bulb temperature is more than 2F (1.1K) above the
value of COOL-FT-MIN.

EVAP-COOLED             The condenser on a RESYS2, PSZ, PMZS, PVAVS, PTAC,
PIU or PVVT system is evaporative. Note that this is different than an
EVAP-PRECOOLED condenser, which is an air-cooled condenser with evaporative
precooling media.

Since an evaporative condenser responds to the outdoor wetbulb temperature,
not the outdoor drybulb, the nominal capacity and power consumption,
together with off-rated performance curves, must be defined relative to the
outdoor wetbulb. The ARI rating point is 95°F outdoor drybulb and 75°F
outdoor wetbulb. Therefore, the COOLING-CAPACITY and COOLING-EIR must be
specified relative to a 75°F outdoor wetbulb (and 67°F indoor wetbulb). The
performance curves COOL-CAP-FT, COOL-SENS-FT and COOL-EIR-FT must all be
normalized to a 75°F outdoor wetbulb. The program includes generic default
curves for these functions. Normally, the COOLING-EIR and COOL-EIR-FT should
include the compressor power as well as the condenser fan and spray pump.
Is this what you were intending to model with your specified input?  If so,
then you will need to add a heat rejection equipment to the loop.   See
attached screen shot for how to add a water cooled heat rejction device.

To get the window to appear (as in the screen shot) you want to RIGHT click
on your mouse at the top highlighted item on your project navigation tree.

Pasha

On Wed, Nov 3, 2010 at 12:47 PM, Elliott Knotts <eknotts at wt.net> wrote:

>  I have a building designed in eQUEST 3-64 with a Water-Source HP System,
> when I run the Compliance Analysis, the system generates a LEEDS-based Bldg
> but also generates a "CW-LOOP = *UNDEFINED*" error for each of the four
> systems. After defining the Condenser Water Loop from the library as
> "DEFAULT_CW" for each system, I get the following error:
>
>
> ***ERROR***********************************************************************
>
> Loop: DEFAULT-CW has no attached primary cooling equipment.
> I have tried creating a Circulation Loop with a Pump, but I still get the
> no attached cooling equipment error. What am I doing wrong or How do I
> attach cooling equipment. I am about to go bald pulling my hair out.
>
> I have attached the *.inp and *.pd2 files:
>
> Any and all advice will be appreciated.
>
> Elliott
>
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