Need separate total consumption for different different zones served by same chiller

3 posts / 0 new
Last post

Hi All,

i am modelling building which has residential + commercial areas.whereas
single chiller is serving for both the areas. So i have created different
utility meters for both the system as indicated below:
[image: image.png][image: image.png]
But After Simulation i am not able to find out separate consumption for
cooling,Heating & space rejection.
[image: image.png]
So please help me out to find out separate consumption in every sector & to
find out total consumption to calculate separate EPI for residential &
commercial block.


vishal jagdale's picture
Joined: 2015-05-30
Reputation: 0

The energy is by location of the primary equipment when referring to utility meters, so the chiller is located on one utility meter (as it will be in real life) and pulls kWh from there.

You need to use CHW metering to measure cooling energy consumed by one or more pieces of equipment. You can do this by looking at the AHU/FCU energy usage totals in the output reports, or if you can group several AHUs together on a separate loop of the CHW system you can monitor that loop in the same way. Note that this still won?t directly allocate kWh (neither would the real life system performing this function) but you can use the ratios of cooling consumed by residential and retail secondary equipment to allocate the primary chiller kWh.

Fans and other auxiliary electricity use should be totaled up per utility meter as you described for each AHU or FCU, just like they actually could be fed from certain panels billed to a separate meter and/or account in real life.

If there were zonal packaged systems such as heat pumps in each space then the metering system as described would work with each heat pump being assigned to a meter.

Likewise for heating the primary energy use of a boiler will be on one meter, but could be allocated in post-processing based on the usage of heating energy provided by the AHUs/FCUs or by making a dedicated loop to monitor as a group and use the ratio between residential and commercial to assign gas usage.

If the building had individual furnaces for instance then the metering approach would work.

DSE Mobile

David Eldridge's picture
Joined: 2012-05-08
Reputation: 1

Supplementing David's response - you can additionally:

* Assign individual boilers/chillers/DHW's/Towers/etc to different electrical meters. Look for the meter assignment inputs on the first tab for each piece of primary equipment as you open them in the interface.
* Track energy going to two places from one chiller by:

1. Defining one or more secondary loops
2. Navigate to air-side hvac tab, and you assign what systems/coils are on which secondary loop. Note that you can either assign SYSTEM and/or ZONE coils, if applicable.

[cid:image001.png at 01D53630.6EC03CC0]

1. Simulate, and review secondary loop energies summarized in the SIM reports.
* PS-D summarizes all loops
* PS-H (one per loop) provides a deeper dive. Peaks reported are coincident (considering diversity).
* PV-A reports loops sizing which (adding up capacities for all attached loads/coils w/o diversity).
2. For greater resolution, you can create custom hourly reports to track loads for one or each of your circulation loops, and you?ll then have an hourly profile to work with. For most cases (when for example informing plant design/sizing discussions), I opt for the ?net? load option which is inclusive of pump heat and any other defined circ losses.


[cid:image005.png at 01D515A3.47EDD880]
Nick Caton, P.E., BEMP
Senior Energy Engineer
Regional Energy Engineering Manager
Energy and Sustainability Services
Energy Performance Contracting
913 . 564 . 6361
785 . 410 . 3317
913 . 564 . 6380
nicholas.caton at
15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States
[cid:image006.png at 01D515A3.47EDD880]

Nicholas Caton2's picture
Joined: 2019-03-25
Reputation: 0