Annual cooling load VS total equipment cooling load

asked 2018-06-20 14:30:20 -0500

BORM gravatar image

updated 2018-06-20 17:06:11 -0500

I'm working on a SketchUp model with OpenStudio.

The model includes:

  • Heating loop with electric boiler and water baseboard;
  • Cooling loop with electric chiller and cooling coil in HVAC loop;
  • Somes electric preheat coil, VAV reheat, electric baseboard, PTAC and DX cooling coil.

The objective is to compare the loads from:

  1. Heating (2208 MBtu) and Cooling (1001 MBtu) annual loads from HVAC Load Profiles from OpenStudio Report

to:

  1. Sum of heating equipement + Boiler load (efficiency = 1) (heating coil loop)
  2. Sum of cooling equipement + Chiller load (COP = 6.5) (Cooling coil loop)

I noted that annual heating load (2208 MBtu) equal to Boiler load (1155 MBtu) + heating equipment excluding heating coil (1054 MBtu).

The problem is for the cooling load. Annual cooling load (1001 MBtu) dot not equal to Chiller load (959 MBtu) + cooling equipment excluding cooling coil (324 MBtu).

What can explain this disparity?

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