eQUEST Model Calibration Against Hourly Data

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Hello,
I have been asked by one of my clients to do calibration of eQUEST model against hourly energy data of different systems. They will send me 60 to 90 days energy data for various equipment such as pumps, cooling towers, air conditioning units, lighting...etc and they want me to calibrate the model against these hourly data. These hourly data will be collected during ASHRAE Level III energy audit.
I have done many calibration against the monthly energy data from the actual bills but this is the first time I have been asked to do it against the hourly data so, can you please explain to me how to do it against the hourly data? Thanking you in advance.
Is it done by adding up the hourly data from the energy audit measurements to make it monthly data and then compare it against the data for each system in PS-F simulation report? But how we can do that if the customer providing only 60 to 90 days hourly data and not for a full year?
Your help will be highly appreciated.
Regards
Ahmad

Ahmad Fraij's picture
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I would follow the IPMVP protocol, which is a statistical correlation.? My experience - you'll spend a lot of time working on schedules.Shaun
-------- Original message --------From: Ahmad Fraij via Equest-users Date: 8/25/23 5:56 PM (GMT-08:00) To: equest-users at onebuilding.org Subject: [Equest-users] eQUEST Model Calibration Against Hourly Data Hello,I have been asked by one of my clients to do calibration of eQUEST model against hourly energy data of different systems. They will send me 60 to 90 days energy data for various equipment such as pumps, cooling towers, air conditioning units, lighting...etc and they want me to calibrate the model against these hourly data. These hourly data will be collected during ASHRAE Level III energy audit.I have done many calibration against the monthly energy data from the actual bills but this is the first time I have been asked to do it against the hourly data so, can you please explain to me how to do it against the hourly data? Thanking you in advance.Is it done by adding up the hourly data from the energy audit measurements to make it monthly data and then compare it against the data for each system in PS-F simulation report? But how we can do that if the customer providing only 60 to 90 days hourly data and not for a full year?Your help will be highly appreciated.RegardsAhmad

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Shaun Martin's picture
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Hello Ahmad.

Calibration of an hourly simulation against hourly data is non-trivial. There are several reasons for this.

First, do you have the basic envelope properties? Can you create an accurate envelope model.

Next, do you have the description of the secondary HVAC systems, AHU, etc.

Then, the primary systems, boiler, chiller, etc.

Finally, can you match part or all of the hourly date and justify your calibration.

At the whole-building level, matching the whole building data at specific seasons of the year is instructive: cooling season, heating season, non-heating-cooling season.

Coincident weather data is important as well. Without it, you can only compare certain values. If you can get it, then you can go much further.

There are many methods published in the literature. Many were published in the 1990s in ASHRAE. Several are included in Guideline 14. Others are in various papers.

With proper measured data you can calibrate specific periods to good accuracy, +_ 20%. Without measured data you?re flying blind.

Jeff

Jeff S. Haberl, Ph.D., P.E.inactive, FASHRAE, FIBPSA
Department of Architecture
Texas A&M University
College Station, Texas 77845-3581
Office: 979-845-6507, Lab: 979-845-6065
Fax: 970-862-2457, jhaberl at tamu.edu, www.esl.tamu.edu

Jeff Haberl2's picture
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Ahmed,

I?m happy to chat about specifics. As an educator, that?s my job.

Jeff

Jeff S. Haberl, Ph.D., P.E.inactive, FASHRAE, FIBPSA
Department of Architecture
Texas A&M University
College Station, Texas 77845-3581
Office: 979-845-6507, Lab: 979-845-6065
Fax: 970-862-2457, jhaberl at tamu.edu, www.esl.tamu.edu

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