Baseline pump efficiencies

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Dear all,

ASHRAE 90.1 appendix G G.3.1.10 defines the base building pump power. I have basic questions regarding this:

1)??? Is 22w/gpm for both primary and secondary pumps put together??

2)??? The user manual defines 22w/gpm as pump operating against a 75 foot head with 60% combined impellar and motor efficiency.
I work on Visual Doe. I have to input impellar efficiency and motor efficiency separately. How do i input these values?

3)??? If 22w/gpm is including secondary pump, then what will be the head and efficiencies for primary pump and secondary pump?

4)??? The condenser water pump power is 19 w/gpm. What is the head, impellar efficiency and motor efficiency?

Looking forward for your replies.

Regards,
Rathnashree

Rathna Shree's picture
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Rathnashree,

1) The ASHRAE baseline pump power requirement has been discussed in
the equest-users forum. There was not a consensus, but the votes were
leaning toward splitting the 22W/gpm between the primary and secondary
pumps, and not assigning 22W/gpm to each pump. See the archives here:
http://lists.onebuilding.org/htdig.cgi/equest-users-onebuilding.org/2010
-November/006942.html and here:
http://lists.onebuilding.org/htdig.cgi/equest-users-onebuilding.org/2010
-December/007044.html

2) I believe the inputs for the chilled water pump power would be
"CCIRC-HEAD = 75", "CCIRC-IMPELLER-EFF = 0.65" and "CCIRC-MOTOR-EFF =
1.0".

3) Again, per the archive threads I provided, there was no
consensus. You need to make a judgment call on how to split the power
up.

4) I believe the inputs for CW pump power would be "TWR-PUMP-HEAD =
60.0", "TWR-IMPELLER-EFF = 0.60" and "TWR-MOTOR-EFF = 1.0".

Regards,

Bill

Bishop, Bill2's picture
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Joined: 2011-09-30
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Hi Rathna,

Pay attention to the total Baseline chiller capacity as well.

1.) Baseline chillers <=300 tons: The chilled water loop is modeled with constant primary/variable secondary flow with the secondary pump riding the curve. Primary chilled water loop (1 constant speed pump) + the secondary chilled water loop (1 constant speed pump) + the condenser water loop (1 constant speed pump); 2.) Baseline chillers >300 & < 600 tons: The chilled water loop is modeled with constant primary / variable secondary flow. Primary chilled water loop (2 constant speed pump interlocked with associated chillers) + the secondary chilled water loop (1 variable speed pump) + the condenser water loop (2 constant speed pump interlocked with associated chillers); 3.) Baseline chillers >= 600 tons: The chilled water loop is modeled with
constant primary / variable secondary flow. Primary chilled water loop (2
constant speed pump interlocked with associated chillers) + the secondary
chilled water loop (1 variable speed pump) + the condenser water loop (2
constant speed pump interlocked with associated chillers);

My understanding is, as long as 22W/gpm and 19W/gpm can be applied to all
baseline water pumps, you can allocate pump energy to each pump based on
your common sense (e.g. 6w/gpm for primary and 16w/gpm for secondary). From
there, you should be able to adjust pump configuration to fulfil its
allocated energy.

Regards,

Cheney

chen yu's picture
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Joined: 2011-10-02
Reputation: 200

Hi everyone,

Simple question I hope. How do we create a ERV with a 4-pipe fan coil
system in eQUEST. For an unknown reason, eQUEST doesn?t allow us to put
heat recovery device with Fan coil systems. Do we have to create a zone and
another system with a ERV that will provide air to the fan coils.

Thanks in advance for any clue.

Marc-Antoine Paquin, ing.

Marc-Antoine Paquin's picture
Joined: 2011-10-02
Reputation: 0

Hi everyone,

We are currently using Comfen 4.0 in one of our project. Is there a way to
import Comfen4.0 datas from one computer to another. In our case we
elaborated approximately 50 scenarios and we need to import those scenarios
on another computer.

Regards,

Marc-Antoine Paquin, ing.

Marc-Antoine Paquin's picture
Joined: 2011-10-02
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Marc-Antoine

The scenarios are stored in the COMFEN database, which is called
comfen.sqlite. If you copy that database onto another computer, you can open
it with COMFEN. You might want to rename it from the default name so that
you don?t overwrite the default database on the computer you are copying it
to. You can change databases from the COMFEN menu, Preferences choice,
Database tab.

Let me know if you need more details about how to do this.

Robin Mitchell

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