Systems energy
Result – Systems energy
The report gives an overview of energy flows in the HVAC systems. It is divided into the following tables:
Used energy | Heat delivered by the plant and other heat generation/removal devices to the building distribution systems, i.e. presented flows may be reduced by distribution and emission losses before they reach their end use. |
Utilized free energy | Heat at various points that can be considered free, due to recovery or extraction from a free source. Note that the same flow may be represented twice in the table, e.g. both when extracted from the ground and when recovered in the cold tank. |
Generated electrical energy | Locally produced power. This energy is used within the building as far as possible. Only the surplus is sold.. |
Auxiliary energy | Energy for fans, pumps and similar. |
Distribution losses | Energy which is partially or entirely lost within the distribution systems. Some of this heat may be usefully deposited in zones. |
For cases with specified distribution losses, a separate table of distribution losses is presented.
Data for energy is presented in the following categories:
Used energy
category
comment
Zone heating
Heat delivered from the central plant or other, possibly local, heat generation devices to the zones. The distributed heat will normally be reduced by distribution and emission losses before it reaches the occupied space.
Zone cooling
D:o for cooling.
AHU heating
Heating energy supplied to all heating coils of central air handling units. No distribution losses are applied to the circuit between the plant and the AHU. The heating produced by electrical coils in the central AHU is included.
AHU Cooling
Energy removed by all cooling coils of air handling units. Note that a significant part of this energy may be latent due to condensation in coils. No distribution losses are applied to the circuit between the plant and the AHU. The cooling produced by electrical air conditioners in the central AHU is included.
Domestic hot water
Energy delivered to the domestic hot water circuit. The consumption rate is given in Extra energy and losses. Note that actual DHW end use may be smaller due to distribution losses.
Utilized free energy
category
comment
AHU heat recovery
Heating energy recovered in AHU air-to-air heat exchanger or mixing box.
AHU cold recovery
D:o for cooling.
Plant heat recovery
Heating energy that is fed into the hot tank from the brine circuit heat exchanger, e.g. chiller waste heat or direct exchange with another source connected to the brine circuit such as an ambient air heat exchanger.
Plant cold recovery
Cooling energy that is fed into the cold tank from the brine circuit heat exchanger, e.g. heat pump evaporator waste cold or direct exchange with another source connected to the brine circuit such as a ground heat exchanger.
Solar heat
Heat collected from a solar thermal collector.
Ambient heat
Heat extracted from an ambient air heat exchanger and which is fed to the brine circuit.
Ambient cold
Cold extracted from an ambient air heat exchanger and which is fed to the brine circuit.
Ground heat
Heat extracted from a ground source and which is fed to the brine circuit.
Ground cold
Cold extracted from a ground source and which is fed to the brine circuit.
Generated electrical energy
category
comment
Solar (PV)
Power generated by a photovoltaic unit.
Wind power
Power generated by a local wind turbine.
CHP power
Power generated by a local combined heating and power unit.
Auxiliary energy
category
comment
Humidification
Energy used by any central humidification equipment.
Fans
Energy used by fans. Fan electricity consumption is by default based on computed air flows and user supplied pressure heads and efficiencies.
Pumps
Energy used by pumps. Pump electricity consumption is by default based on computed water flows and user supplied pressure heads and efficiencies.
Data for the distribution losses overview is governed by coefficients specified in Extra energy and losses. Results are presented in the following categories:
Distribution losses
category
comment
Domestic hot water circuit
Heat lost from water in domestic hot water distribution systems, either due to permanent circulation or to intermittent tapping.
Heating
Heat lost from water in hot water distribution systems.
Cooling
Cooling energy lost from water in cold water distribution systems
Air ducts
Cooling energy lost from ductwork, both from transmission and air leakage.
A given percentage of each loss is emitted into zones according to floor area.
The data for report is collected by energy meter models (EMETER and EMETER2) that exist in Plant and AHU macros (for fans and pumps – in all macros). When defining custom Plant and AHU macros, the user should add the missing meter models and check (and fix, if required) the connections of EMETER.INPOWER with variables that calculate the power, as described in the table:
category
EMETER model
Typically connected to
Zone heating
Plant.EmeterLocalBoil
Q[2] in boiler model (type SIMBOIL)
EmeterLocHeat (automatically generated when building the advanced level system)
QLOCALUNITS in zone model (type CEDETZON and CESIMZON)
Zone cooling
Plant.EmeterLocalChil
Q2 in chiller model (type SIMCHIL)
EmeterLocCool (automatically generated when building the advanced level system)
QLOCALUNITS in zone model (type CEDETZON and CESIMZON)
AHU heating
AHU.EmeterHeat (in every central AHU and local AHU connected as central AHU)
QHEAT in heating coil (type HCSIMCTR)
Q in heating coil (type HCSIM)
QELACT in electric coil (type HCEL)
AHU Cooling
AHU.EmeterCool (in every central AHU and local AHU connected as central AHU)
QCOOL in cooling coil (type CCSIMCTR)
QTOTOUT in cooling coil (type CCSIM)
Domestic hot water
Plant.EmeterWater
QDOMWAT in chiller model (type SIMBOIL)
AHU Heat recovery
AHU.EmeterRecycle (in every central AHU)
QACTUAL in heat exchange model (type HXSIMCTR)
AHU Cold recovery
Plant Heat recovery
Plant.EmeterHotTank
QHX2TANK in hot tank model (type TANKSTRAT). Implemented in ESBO plant only
Plant Cold recovery
Plant.EmeterColdTank
QHX2TANK in cold tank model (type TANKSTRAT). Implemented in ESBO plant only
Solar heat
Plant.EmeterSolar
QU in solar collector model (SOLTHCOL). Implemented in ESBO plant only.
Ambient heat
Plant.EmeterAmbHX
Q in circuit control model (FREESUPCTR). Implemented in ESBO plant only.
Ambient cold
Ground heat
Plant.EmeterGrndHX
Q in circuit control model (FREESUPCTR). Implemented in ESBO plant only.
Ground cold
Solar (PV)
Plant.EmeterPV
P in PV model (PHOTOVOLT)
Wind power
Plant.EmeterWT
PW in wind turbine model (WINDMILL)
CHP power
Plant.EmeterCHP
PW in boiler model (BOIL1CIRC)
Humidification
AHU.EmeterHum (in every central AHU)
QEL in humidifier model (type STINJCTR)
Fans
AHU.EmeterFans (in every central AHU)
QSUP in fan model (type CEFAN)
PowerSup in axial fan (type AxialFan)
Pumps
Plant.EmeterPump
PPUMP in chiller, boiler, and pump models (SIMBOIL, SIMCHIL, PUMP, PUMPCIRC)