AHU Economizer Performance Report

Overview

This report evaluates Air Handling Unit (AHU) economizer operation (free cooling), outside airflow, and provides a score based on the effectiveness of both. Fault conditions contributing to the score are:

Weather conditions permit free cooling but it is not being fully utilized.
Excessive outside air is entering the building resulting in additional heating and cooling.

A relative cost is calculated to project the impact of these conditions.

Intent of Report

This report intends to identify improper economizer operations. The focus is on whether the economizer is not maximized (i.e. mechanical cooling is being utilized when it's more advantageous to the economizer) or when there is excess ventilation when it is not advantageous to economize.

Requirements

The AHU equipment type must include the following input points to appear on the report.

OaHumidity and OaTemp or OffPremWeatherStation Humidity and OffPremWeatherStation Temp
DaFlow and OaFlow or MaTemp and RaTemp or OaDmprCmd
OaFlowMinSp and DaFlow or OaDmprMinPosSp
At least one ColdDeckTempSp, ColdDeckTemp, DaTempSp, DaTemp

Primary Metrics

Key metrics in evaluating the operation of the equipment within the report.

Hours economizer is not maximized
Hours of excess ventilation
Cost impact

Scored KPIs

Additional cooling costs for not maximizing economizer.
Additional heating and cooling costs for running in economizer when not advantageous.

Input Points

To appear in a report, each piece of equipment of the appropriate type and with the appropriate equipment tag constraints, must have at least one input point.

Standard Points

A standard input point is typically a proxy point with time-series data that is retrieved at regular intervals from a remote data source such as Niagara using a Resolute Connector. Below are the Standard Input Points for the AHU Economizer Performance Report.

Name	Positional Requirements	Optionality
DaFanSts	The point must be a direct child of the equipment	Mandatory
ClgCmd	The point must be a direct child of the equipment	Mandatory
ColdDeckTemp	The point must be a direct child of the equipment	Optional if ColdDeckTempSp, DaTempSp, or DaTemp are available
ColdDeckTempSp	The point must be a direct child of the equipment	Optional if ColdDeckTemp, DaTempSp, or DaTemp are available
DaFlow	The point must be a direct child of the equipment	Optional if MaTemp and RaTemp or OaDmprCmd are available
DaTemp	The point must be a direct child of the equipment	Optional if ColdDeckTempSp, ColdDeckTemp, or DaTempSp are available
DaTempSp	The point must be a direct child of the equipment	Optional if ColdDeckTempSp, ColdDeckTemp, or DaTemp are available
EconMode	The point must be a direct child of the equipment	Optional
HtgCmd	The point must be a direct child of the equipment	Optional
MaTemp	The point must be a direct child of the equipment	Optional if DaFlow and OaFlow or OaDmprCmd are available
OaDmprCmd	The point must be a direct child of the equipment	Optional if DaFlow and OaFlow or MaTemp and RaTemp are available
OaDmprMinPosSp	The point must be a direct child of the equipment	Optional if OaFlowMinSp and DaFlow are available
OaFlow	The point must be a direct child of the equipment	Optional if MaTemp and RaTemp or OaDmprCmd are available
OaFlowMinSp	The point must be a direct child of the equipment	Optional if OaDmprMinPosSp is available
OaHumidity	The point must be a direct child of the equipment	Optional if OffPremWeatherStation Humidity and OffPremWeatherStation Temp are available
OaTemp	The point must be a direct child of the equipment	Optional if OffPremWeatherStation Humidity and OffPremWeatherStation Temp are available
OffPremWeatherStation	The point must be a direct child of the equipment	Optional if OaHumidity and OaTemp are available
RaHumidity	The point must be a direct child of the equipment	Optional
RaTemp	The point must be the direct child of the equipment	Optional if DaFlow and OaFlow or OaDmprCmd are available