P3: Laboratory Plug-Load Sizing Factor

Description:

This metric is the ratio of the design value of the equipment load to the peak actual equipment load in the laboratory spaces.

Units: -

P3 = dP2 ÷ dP1
where:
dP2: Laboratory Plug Load: Design Peak (kW)
dP1: Laboratory Plug Load: Actual Peak (kW)

See Required Data for more information on the data items.

Benchmarks:

Stacked bar chart: Laboratory Plug Load Sizing Factor, Potential Efficiency Opportunity: Low 1.4-2.0, Med 2.0-2.5, High 2.5-4.2

Figure. Benchmarks for laboratory plug load sizing factor.

Actions Inferred:

A high value for this metric indicates the opportunity to "right-size" the HVAC systems and improve part load efficiency. Equipment loads in laboratories are frequently overestimated because designers often use estimates based on "nameplate" data, and design assumptions of high utilization. This results in oversized HVAC systems, increased initial construction costs, and increased energy use due to inefficiencies at low part-load operation.

Special Considerations:

The sizing ratio (design/measured) is driven by context specific factors such as reliability and flexibility. The benchmarks provided above are a general guideline. In some situations, unusual requirements for flexibility and reliability may result in a high sizing factor.