INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

(OP)
This is a challenge given by one of our customers. Here it goes.

We have the following HVAC systems & controls in a building:
1. Water cooled chillers, Primary pumps, Secondary pumps, Cooling Towers, Make up tanks
2. Air cooled chillers, Chilled water pumps
3. Air Handling Units
4. Heat Recovery Units or Energy Recovery Units
5. Variable Air Volume Boxes (for Zone Control)

Type of the building: Software Block & Utility Block

With the controls, we are able to calculate the following:
1. Individual equipment ikW/Tr for Chillers as well as overall plantroom ikW/Tr - Efficiency.
2. Energy Efficiency Index (EEI) of the building - kWh/m2/year
3. Design efficiency of the 3rd party integration equipment like UPS etc.

While we have individual efficiency of each system, the customer wants an aggregate of all this into a single graph with respective to selectable parameters (like efficiency at a certain ambient condition or at a certain load etc.).

Would appreciate if any one of you have done something similar to this and any guidance is highly appreciated.

Regards.

RE: Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

There Are too may variables in this, all interdependent.

RE: Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

(OP)
Yes sir, that's why it was put to us as a challenge. We are also trying to wrap our head around this so we could find something useful for our customers.

RE: Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

Eff=Wout/Win

If it were me, I would get temps, pressures, mass flow rates, and working fluids for each system. Use enthalpies to evaluate the cycle as a whole. If you already have efficiencies of each subsystem, you may be able to use a ratio of mass flows to get overall efficiency, but I'm not 100% sure of that.

I am picturing something similar to combined cycle power plant efficiency where you take data from the Brayton cycle and the steam cycle to get overall efficiency.

RE: Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

Most HVAC software can provide such a graph in energy modeling.
It gives you a profile for the year, month by month.

Get your HVAC guy to model the building (Trace 700, Carrier E20II; Energy Plus, Equest) and fairly simple to get what you're looking for.

RE: Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

With all the variables, sound like something a database would be good at. MS Access maybe?

RE: Aggregated Campus (Building & Utility) Efficiency against fixed baseline (Ambient,load,demand,et

if you have kW/Ton for the plant, why don't you plot that against cooling degree days over the year and that should show you how the plant efficiency varies against the cooling load.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close