VRF System EER

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Hello everyone,

We have been modeling VRF units through PVVT by eQUEST for some time now.
One of the most asked question is how we would be incorporating the System
EER in lieu of the Equipment EER. Most of our designers size their outdoor
units larger by at least 10% than the connected load to assure the system
to operate at a much higher EER (part load). With this in mind, from what
report can we see the System EER during part load operation?

Please correct me if I?m wrong, but the usual modeling process is to input
the Full load EER in the EIR section of the detailed design interface, and
let the curves take care of the part loading. We have of course used some
of the manufacturers part load curves as reference which showed a greater
savings in cooling energy than the default eQUEST curves. Is there a report
perhaps that we can use to see the part load EER in a particular time?

Thank you for your time.

Regards,

Jude

*Joel Jude A. Tadeo, *ME, MEng-ME, LEED Green Associate

Senior Mechanical Consultant (PH) | Arcadis Philippines, Inc

T. +63 2 8112971 | M. +63 997 549 9377 | F. +63 2 8112071

www.arcadis.com

*Be** green, leave it on the screen.*

via Equest-users's picture
Joined: 2016-07-15
Reputation: 400

Hi Joel,

The place from where one can get the EER versus part load ratio is the
water side tab from where one can know the EIR versus the part load ratio.
There is a relation between EIR and EER for the HVAC system you can know.
The snapshot is here-below:

[image: Inline image 1]

Here the a, b, c, d are the coefficients to determine the relation between
the part load and the EIR.
X is the part load ratio in fraction. With this data you can plot the
relation between the prat load ratio and the EIR with the help of curve
formula.
As such there is no such report or plot to determine the relation directly
from eQUEST.
As you have got the manufacturers data so in the same way one can have a
plot or have the plot from the manufacturers.

*Thanks,*
*Sharad.Kumar.*
*India.*

---------- Forwarded message ----------
From: Joel Jude Tadeo via Equest-users
To: equest-users at lists.onebuilding.org
Cc:
Bcc:
Date: Wed, 19 Jul 2017 15:00:39 +0800
Subject: [Equest-users] VRF System EER

Hello everyone,

We have been modeling VRF units through PVVT by eQUEST for some time now.
One of the most asked question is how we would be incorporating the System
EER in lieu of the Equipment EER. Most of our designers size their outdoor
units larger by at least 10% than the connected load to assure the system
to operate at a much higher EER (part load). With this in mind, from what
report can we see the System EER during part load operation?

Please correct me if I?m wrong, but the usual modeling process is to input
the Full load EER in the EIR section of the detailed design interface, and
let the curves take care of the part loading. We have of course used some
of the manufacturers part load curves as reference which showed a greater
savings in cooling energy than the default eQUEST curves. Is there a report
perhaps that we can use to see the part load EER in a particular time?

Thank you for your time.

Regards,

Jude

*Joel Jude A. Tadeo, *ME, MEng-ME, LEED Green Associate

Senior Mechanical Consultant (PH) | Arcadis Philippines, Inc

T. +63 2 8112971 | M. +63 997 549 9377 | F. +63 2 8112071

www.arcadis.com

*Be** green, leave it on the screen*

via Equest-users's picture
Joined: 2016-07-15
Reputation: 400