BLDG-HVAC-MIB

All MIBs › BLDG-HVAC-MIB

Organization: SNMPCONF working group E-mail: snmpconf@snmp.com

Last Updated: 2003-03-27

Category: Hardware and Environment

Description: Monitors and manages building HVAC (heating, ventilation, and air conditioning) system parameters via SNMP.

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What Is BLDG-HVAC-MIB?

BLDG-HVAC-MIB is an IETF example/standards-track MIB (RFC 3512) illustrating how to model building HVAC (heating, ventilation, and air conditioning) systems and room-level climate policies over SNMP. It exposes a table of HVAC zones keyed by floor and office, including configuration templates, fan speed, current temperature readings, and cumulative cooling/heating run-time minutes. As an environmental-monitoring MIB it is explicitly used to track physical facility conditions rather than network hardware, letting an operator monitor current room temperature, fan operation, and how long heating or cooling has been running, which flags HVAC faults or comfort-policy violations (e.g., a room stuck too hot with the fan off). It depends on standard SNMPv2 SMI conventions including StorageType and RowStatus for row lifecycle management, per general IETF conventions rather than any device-specific MIB. It is deployed in building management systems monitoring facility climate control equipment, sometimes co-located with a data center's environmental monitoring alongside network gear. Engineers implementing or auditing this functionality typically reference the BLDG-HVAC-MIB RFC/standard documentation for the authoritative specification.

IPNetwork Monitor allows you to monitor SNMP objects defined in BLDG-HVAC-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.

Supported Devices

vendor-neutral, standards-based MIB, not tied to a specific manufacturer
building HVAC control unit / building management system

Monitoring Examples

An admin would poll bldgHVACTable/bldgHVACEntry indexed by bldgHVACFloor and bldgHVACOffice to read bldgHVACCurrentTemp and bldgHVACFanSpeed for a given room, comparing against the bldgHVACCfgTemplate policy. If bldgHVACCurrentTemp is far outside the template's target range while bldgHVACCoolOrHeatMins keeps climbing, that indicates the HVAC unit is running continuously without reaching setpoint, signaling a mechanical fault. bldgHVACStatus and bldgHVACStorageType would be checked to confirm the row is active and its configuration is persistent versus volatile.

What Can Be Monitored

current room temperature
fan speed
cooling/heating run-time minutes
HVAC configuration template
zone row status

Imported Objects

From SNMP-FRAMEWORK-MIB

SnmpAdminString

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Gauge32
MODULE-IDENTITY
OBJECT-TYPE
Unsigned32
experimental

From SNMPv2-TC

RowStatus
StorageType
TEXTUAL-CONVENTION
TimeStamp

How to Use in IPNetwork Monitor

Example using bldgHVACCoolOrHeatMins OID:

Select a Building HVAC control units/BM as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type bldgHVACCoolOrHeatMins into the Find box to locate it in the OID tree, selecting the specific row/instance you want to monitor since this is a table column, then select it and click OK. The total number of heating or cooling minutes that have been consumed since the row was activated. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is a Counter32-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases sharply between polls relative to its normal baseline (in minutes), since an unexpected spike often reflects a real change in traffic or activity. Click Finish to create the monitor; you can adjust any parameter later.

OIDs

OID symbolic	OID numeric	Type	Access	Description
bldgHVACMIB	1.3.6.1.3.122			This example MIB module defines a set of management objects for heating ventilation and air conditioning systems. It also includes objects that can be used to create policies that are applied to rooms. This eliminates the need to send per-instance configuration commands to the system. Copyright (C) The Internet Society (2003). This version of this MIB module is part of RFC 3512; see the RFC itself for full legal notices.
bldgHVACObjects	1.3.6.1.3.122.1
bldgHVACTable	1.3.6.1.3.122.1.1		not-accessible	This table is the representation and data control for building HVAC by each individual office. The table has rows for, and is indexed by a specific floor and office number. Each such row includes HVAC statistical and current status information for the associated office. The row also contains a bldgHVACCfgTemplate columnar object that relates the bldgHVACTable row to a row in the bldgHVACCfgTemplateTable. If this value is nonzero, then the instance in the row that has a value for how the HVAC has been configured in the associated template (bldgHVACCfgTeplateTable row). Hence, the bldgHVACCfgTeplateTable row contains the specific configuration values for the offices as described in this table.
bldgHVACEntry	1.3.6.1.3.122.1.1.1		not-accessible	A row in the bldgHVACTable. Each row represents a particular office in the building, qualified by its floor and office number. A given row instance can be created or deleted by set operations upon its bldgHVACStatus columnar object instance.
U32 bldgHVACFloor	1.3.6.1.3.122.1.1.1.1	Unsigned32	not-accessible	This portion of the index indicates the floor of the building. The ground floor is considered the first floor. For the purposes of this example, floors under the ground floor cannot be controlled using this MIB module.
U32 bldgHVACOffice	1.3.6.1.3.122.1.1.1.2	Unsigned32	not-accessible	This second component of the index specifies the office number.
U32 bldgHVACCfgTemplate	1.3.6.1.3.122.1.1.1.3	Unsigned32	read-create	The index (bldgHVACCfgTemplateIndex instance) of an entry in the 'bldgHVACCfgTemplateTable'. The bldgHVACCfgTable row instance referenced is a pre-made configuration 'template' that represents the configuration described by the bldgHVACCfgTemplateInfoDescr object. Note that not all configurations will be under a defined template. As a result, a row in this bldgHVACTable may point to an entry in the bldgHVACCfgTemplateTable that does not in turn have a reference (bldgHVACCfgTemplateInfo) to an entry in the bldgHVACCfgTemplateInfoTable. The benefit of this approach is that all configuration information is available in one table whether all elements in the system are derived from configured templates or not. Where the instance value for this colunmar object is zero, this row represents data for an office whose HVAC status can be monitored using the read-only columnar object instances of this row, but is not under the configuration control of the agent.
G32 bldgHVACFanSpeed	1.3.6.1.3.122.1.1.1.4	Gauge32	read-only	Shows the revolutions per minute of the fan. Fan speed will vary based on the difference between bldgHVACCfgTemplateDesiredTemp and bldgHVACCurrentTemp. The speed is measured in revolutions of the fan blade per minute.
G32 bldgHVACCurrentTemp	1.3.6.1.3.122.1.1.1.5	Gauge32	read-only	The current measured temperature in the office. Should the current temperature be measured at a value of less than zero degrees celsius, a read of the instance for this object will return a value of zero.
C32 bldgHVACCoolOrHeatMinsEx	1.3.6.1.3.122.1.1.1.6	Counter32	read-only	The total number of heating or cooling minutes that have been consumed since the row was activated. Notice that whether the minutes represent heating or cooling is a function of the configuration of this row. If the system is re-initialized from a cooling to heating function or vice versa, then the counter would start over again. This effect is similar to a reconfiguration of some network interface cards. When parameters that impact configuration are changed, the subsystem must be re-initialized. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of bldgHVACDiscontinuityTime.
TIM bldgHVACDiscontinuityTime	1.3.6.1.3.122.1.1.1.7	TimeStamp	read-only	The value of sysUpTime on the most recent occasion at which any heating or cooling operation for the office designated by this row instance experienced a discontinuity. If no such discontinuities have occurred since the last re- initialization of the this row, then this object contains a zero value.
STR bldgHVACOwner	1.3.6.1.3.122.1.1.1.8	SnmpAdminString	read-create	The identity of the operator/system that last modified this entry. When a new entry is created, a valid SnmpAdminString must be supplied. If, on the other hand, this entry is populated by the agent 'discovering' unconfigured rooms, the empty string is a valid value for this object.
STO bldgHVACStorageType	1.3.6.1.3.122.1.1.1.9	StorageType	read-create	The persistence of this row of the table in system storage, as it pertains to permanence across system resets. A columnar instance of this object with value 'permanent' need not allow write-access to any of the columnar object instances in the containing row.
ROW bldgHVACStatus	1.3.6.1.3.122.1.1.1.10	RowStatus	read-create	Controls and reflects the creation and activation status of a row in this table. No attempt to modify a row columnar object instance value in the bldgHVACTable should be issued while the value of bldgHVACStatus is active(1). Should an agent receive a SET PDU attempting such a modification in this state, an inconsistentValue error should be returned as a result of the SET attempt.
bldgHVACCfgTemplateInfoTable	1.3.6.1.3.122.1.2		not-accessible	This table provides unique string identification for HVAC templates in a network. If it were necessary to configure rooms to deliver a particular quality of climate control with regard to cooling or heating, the index string of a row in this table could be the template name. The bldgHVACCfgCfgTemplateInfoDescription contains a brief description of the template service objective such as: provides summer cooling settings for executive offices. The bldgHVACCfgTemplateInfo in the bldgHVACCfgTemplateTable will contain the pointer to the relevant row in this table if it is intended that items that point to a row in the bldgHVACCfgTemplateInfoTable be identifiable as being under template control though this mechanism.
bldgHVACCfgTemplateInfoEntry	1.3.6.1.3.122.1.2.1		not-accessible	Each row represents a particular template and description. A given row instance can be created or deleted by set operations upon its bldgHVACCfgTemplateInfoStatus columnar object instance.
U32 bldgHVACCfgTemplateInfoIndex	1.3.6.1.3.122.1.2.1.1	Unsigned32	not-accessible	The unique index to a row in this table.
STR bldgHVACCfgTemplateInfoID	1.3.6.1.3.122.1.2.1.2	SnmpAdminString	read-create	Textual identifier for this table row, and, consequently the template. This should be a unique name within an administrative domain for a particular template so that all systems in a network that are under the same template can have the same 'handle' (e.g., 'Executive Offices', 'Lobby Areas').
STR bldgHVACCfgTemplateInfoDescr	1.3.6.1.3.122.1.2.1.3	SnmpAdminString	read-create	A general description of the template. One example might be - Controls the cooling for offices on higher floors during the summer.
STR bldgHVACCfgTemplateInfoOwner	1.3.6.1.3.122.1.2.1.4	SnmpAdminString	read-create	The identity of the operator/system that last modified this entry.
ROW bldgHVACCfgTemplateInfoStatus	1.3.6.1.3.122.1.2.1.5	RowStatus	read-create	The activation status of this row. No attempt to modify a row columnar object instance value in the bldgHVACCfgTemplateInfo Table should be issued while the value of bldgHVACCfgTemplateInfoStatus is active(1). Should an agent receive a SET PDU attempting such a modification in this state, an inconsistentValue error should be returned as a result of the SET attempt.
STO bldgHVACCfgTemplateInfoStorType	1.3.6.1.3.122.1.2.1.6	StorageType	read-create	The persistence of this row of the table in system storage, as it pertains to permanence across system resets. A columnar instance of this object with value 'permanent' need not allow write-access to any of the columnar object instances in the containing row.
bldgHVACCfgTemplateTable	1.3.6.1.3.122.1.3		not-accessible	This table contains the templates, which can be used to set defaults that will be applied to specific offices. The application of those values is accomplished by having a row instance of the bldgHVACTable reference a row of this table (by the value of the former's bldgHVACCfgTemplate columnar instance). Identifying information concerning a row instance of this table can be found in the columnar data of the row instance of the bldgHVACCfgTemplateInfoTable entry referenced by the bldgHVACCfgTemplateInfo columnar object of this table.
bldgHVACCfgTemplateEntry	1.3.6.1.3.122.1.3.1		not-accessible	Each row represents a single set of template parameters that can be applied to selected instances - in this case offices. These policies will be turned on and off by the policy module through its scheduling facilities. A given row instance can be created or deleted by set operations upon its bldgHVACCfgTemplateStatus columnar object instance.
U32 bldgHVACCfgTemplateIndex	1.3.6.1.3.122.1.3.1.1	Unsigned32	not-accessible	A unique value for each defined template in this table. This value can be referenced as a row index by any MIB module that needs access to this information. The bldgHVACCfgTemplate will point to entries in this table.
G32 bldgHVACCfgTemplateDesiredTemp	1.3.6.1.3.122.1.3.1.2	Gauge32	read-create	This is the desired temperature setting. It might be changed at different times of the day or based on seasonal conditions. It is permitted to change this value by first moving the row to an inactive state, making the change and then reactivating the row.
BLD bldgHVACCfgTemplateCoolOrHeat	1.3.6.1.3.122.1.3.1.3	BldgHvacOperation	read-create	This controls the heating and cooling mechanism and is set-able by building maintenance. It is permitted to change this value by first moving the row to an inactive state, making the change and then reactivating the row.
U32 bldgHVACCfgTemplateInfo	1.3.6.1.3.122.1.3.1.4	Unsigned32	read-create	This object points to a row in the bldgHVACCfgTemplateInfoTable. This controls the heating and cooling mechanism and is set-able by building maintenance. It is permissible to change this value by first moving the row to an inactive state, making the change and then reactivating the row. A value of zero means that this entry is not associated with a named template found in the bldgHVACCfgTemplateInfoTable.
STR bldgHVACCfgTemplateOwner	1.3.6.1.3.122.1.3.1.5	SnmpAdminString	read-create	The identity of the administrative entity that created this row of the table.
STO bldgHVACCfgTemplateStorage	1.3.6.1.3.122.1.3.1.6	StorageType	read-create	The persistence of this row of the table across system resets. A columnar instance of this object with value 'permanent' need not allow write-access to any of the columnar object instances in the containing row.
ROW bldgHVACCfgTemplateStatus	1.3.6.1.3.122.1.3.1.7	RowStatus	read-create	The activation status of this row of the table. No attempt to modify a row columnar object instance value in the bldgHVACCfgTemplateTable should be issued while the value of bldgHVACCfgTemplateStatus is active(1). Should an agent receive a SET PDU attempting such a modification in this state, an inconsistentValue error should be returned as a result of the SET attempt.
bldgConformance	1.3.6.1.3.122.2
bldgCompliances	1.3.6.1.3.122.2.1
bldgCompliance	1.3.6.1.3.122.2.1.1			The requirements for conformance to the BLDG-HVAC-MIB. The bldgHVACObjects group must be implemented to conform to the BLDG-HVAC-MIB.
bldgGroups	1.3.6.1.3.122.2.2
bldgHVACObjectsGroup	1.3.6.1.3.122.2.2.1			The bldgHVACObjects Group.

RFC description

SNMP management for building heating, ventilation, and air conditioning systems with policy-based room configuration.

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Download BLDG-HVAC-MIB