Chiller EIR

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Dear All,

I have selected a water cooled chiller for the HVAC system. But I get
Cooling EIR as Zero in the SV-A file, system design parameters. Can anyone
tell me why?

Thanks in advance


anura perera's picture
Joined: 2011-09-30
Reputation: 0

The SV-A report is a system report. In the SV-A report EIR refers to system level cooling efficiency. For example, the DX efficiency of a packaged unit. Look at the PV-A report for the efficiency of the chiller.


Jeremy McClanathan, LEED(r) AP BD+C

Jeremy McClanathan's picture
Joined: 2011-09-30
Reputation: 200

Anyone know how to shut off primary air flow to VAVS or PIU zones on a schedule?

I am modeling a high-rise building with a central AHU and floor-by-floor isolation dampers.

5 floors of the 40 operate at night, and their isolation dampers remain open 24/7.
The remainder of the floors have isolation dampers that are commanded shut at 6pm and opened at 6am.
(Heating is provided by separately controlled perimeter systems.)

The strategy I've been using is to schedule the zone MIN-FLOW-SCH to be 0 during the night and -999 during the day.
Then set an artificially aggressive setback / setup temp in the hopes that the tstats will close the VAV boxes automatically.

However, this isn't resulting in the airflow / kWh savings I was expecting...


Aaron Dahlstrom , PE, LEED(r) AP

Dahlstrom, Aaron2's picture
Joined: 2011-09-30
Reputation: 4


I don't think MIN-FLOW-SCH can force zonal air flow to shut off
completely. I suggest creating custom hourly reports to track zonal
supply air flow of a few zones, to verify how the system is actually
being simulated.

One option would be to model a separate system for the floors that
operate at night. Then you could force the fans off at night for the
other 35 floors using the system fan schedule.

Unfortunately, you can't isolate the operation of the baseboards (unless
you create shallow perimeter zones separated from the interior portion
of the zones by air walls). If you set their control to "Thermostatic",
they will come on to meet the heating load first, followed by system
heating if needed. It may help to enter the actual baseboard capacities
rather than letting eQUEST autosize them.

What are you comparing to for your expected savings? If you have an
unrealistic setback/setup in both options that you are comparing, you
won't capture all of the potential savings.


William Bishop, PE, BEMP, LEED(r) AP

Bishop, Bill2's picture
Joined: 2011-09-30
Reputation: 0