Many common software questions are answered in the categories below. If you can’t find a response for yours, try checking our User Forum, or, contact HelpDesk for direct assistance
| MarketManager » Heating and Cooling Equipment |
A:
You probably noticed that there are 4 terms, A, B, C, and D. The coefficients associated with these terms are used in the following equation:
Input Capacity % = A + Bx + Cx^2 + Dx^3
where x = Part Load Ratio, or the load on the equipment expressed as a fraction of maximum.
So that means at 100% load, the
Power Consumption = (A + B + C + D ) * Input Capacity
or (because A + B + C + D = 1)
Power Consumption = Input Capacity
at 100% load.
For specific chillers and boilers found in the library (with a brand name and model number), the part load curve (PLC) comes from manufacturer's data. If the part load curve was not available from the manufacturer, then we used the default. You can always tell if the curve for a given chiller is a default if the PLC is the same as the default for that type chiller.
The default PLC coefficients come from the DOE2 Reference Manual, Version 2.1A, Page V.43 for chillers, V.44 for heating equipment. The Fan PLFs come from DOE2 Engineers Manual Version 2.1A, Page IV.209.
I can’t find the answer to your question ? Try checking our User Forums.
Otherwise feel free to contact our Tech Support staff at (805) 329-6565, or via email at helpdesk@abraxasenergy.com.