[Equest-users] Water side economizer

[Julien Marrec]

John,

Never did a waterside economizer for RTUs, but a couple of points I think I
remember:

The waterside economizer in eQuest is all or nothing: if it can satisfy the
entire load, then it's on, otherwise it's off. Are you autosizing or
hardsizing it?

It also poses the questions of how you reset the condenser water loop
temperature, and how you reset the rooftop supply air temperature during
low load condition.

What are your current settings?

Julien



--
Julien Marrec, EBCP, BPI MFBA
Energy&Sustainability Engineer
T: +33 6 95 14 42 13

LinkedIn (en) : www.linkedin.com/in/julienmarrec
LinkedIn (fr) : www.linkedin.com/in/julienmarrec/fr
<http://www.linkedin.com/in/julienmarrec>

2015-11-05 15:11 GMT+01:00 John Aulbach <jra_sac at yahoo.com>:

> Hello all and HALP !!
>
> I have an office building in Los Angeles that is looking to go LEED Core
> and Shell. It has some exterior and back of the house lighting, so the
> savings there make sense. But the building has 6 DX 30-50 ton Trane rooftop
> package units, two on the 1st floor and one for each of the other 4 floors.
> These are WATER COOLED units.
>
> These units have a central outside air stream, and have WATER SIDE
> ECONOMIZERS.
>
> My Base model has an air side economizer (still water cooled condensers).
> The proposed model removes the air side and replaces it with the water side.
>
> The units themselves are EER 14+, whereas the Base units are 10.8 EER.
>
> Results show a SLIGHT savings in Space Cooling, which I attribute to the
> EER improvement MINUS the air side economizer removal (Jan and Dec space
> cooling load INCREASES in the Proposed Case).
>
> But the pumping energy skyrockets about 50% (remember, no chilled water).
>
> I am unsure if I am running the water side correctly. There is only the
> one line of data at ever SYSTEM level.
>
> Help??
>
> John R. Aulbach
> Aging engineer (by the minute)
>
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