Parameters on this tab are displayed for room and plenum templates. They specify system-related information including room-plenum associations.
System tab data for room template with ApSys methodology
System tab data for room template with ApHVAC methodology
System tab data for a Return Air Plenum template
HVAC Methodology
Parameters in this frame relate to HVAC system modelling for rooms.
This parameter is displayed for room and plenum templates.
The methodology to be applied to the modelling of the HVAC system serving the space. The options are ApSys (Apache Systems) and ApHVAC (ApacheHVAC). For plenums HVAC Methodology is forced to ApHVAC, and for voids is it is not relevant.
HVAC methodology specifies the framework for modelling the HVAC system. The ApSys methodology uses a parametric approach based on Apache Systems. The ApHVAC methodology uses component-based ApacheHVAC system models, and is integrated with a set of additional capabilities relating to HVAC zones, plenum spaces and advanced report formats.
The ApSys methodology was applied universally in VE versions prior to VE2017. Rooms with ApSys methodology may feature in ApacheHVAC systems, but they will not have access to the full range of features associated with the ApHVAC methodology.
Conditioned
This parameter is displayed for ApHVAC methodology room templates.
For rooms assigned the ApHVAC methodology, the type of conditioning applied to the room:
-
Yes. Room is conditioned.
-
No (free-floating for Room Loads). Room is not conditioned, and free-floats during Room Loads analyses.
-
No (tempered for Room Loads). Room is not conditioned, but is tempered during Room Loads analyses (as specified on the Room Conditions tab) to emulate its expected behaviour under normal operation.
System Parameters
Parameters in this frame specify systems serving a room. They relate mainly to the ApSys methodology.
In ApacheSim, the system parameters entered here will be overridden (with one exception) in any spaces that feature in an attached ApacheHVAC system. The exception is the setting ‘Auxiliary mech. vent. system’ (which applies to the ApSys methodology). A space served by an ApacheHVAC system may also have one or more auxiliary ventilation air supplies defined on the Air Exchange tab, and for ApSys methodology rooms these are always associated with an Apache System.
HVAC system
This parameter is displayed for ApSys methodology room templates.
The Apache System delivering the conditioning needs of the ApSys methodology room and its supply air.
Auxiliary vent. system
This parameter is displayed for ApSys methodology room templates.
The Apache System used to condition and supply any auxiliary ventilation supplied to the ApSys methodology room.
DHW system
This parameter is displayed for all room templates (ApSys or ApHVAC methodology).
The Apache Systems system delivering domestic hot water to the room.
Heating
Parameters in this frame are are displayed for rooms, and are used for room and system load calculations. For rooms with ApSys methodology they are also used for simulations when there is no attached ApacheHVAC system.
Heating plant radiant fraction
The fraction of radiant heat given out by the heat emitter, e.g. 0.0 for forced warm air heaters and 0.9 for high temperature radiant heaters.
Simulation heating unit capactiy
This is used in dynamic thermal simulation for ApSys methodology rooms. You can either choose unlimited plant capacity or set a limit.
Cooling
Parameters in this frame are displayed for rooms, and are used for room and system load calculations. For rooms with ApSys methodology they are also used for simulations when there is no attached ApacheHVAC system.
Cooling plant radiant fraction
The fraction of cooling that is delivered as radiant energy. 0.0 for an air system.
Simulation cooling unit capacity
This is used in dynamic thermal simulations for ApSys methodology rooms. You can either choose unlimited plant capacity or set a limit.
System outside air supply
For rooms using the ApSys methodology, parameters in this frame are used for room and system load calculations. For rooms with ApHVAC methodology they are used conditionally (subject to options in the ASHRAE Loads dialog) in room and system load calculations.
Minimum flow rate
The supply air condition is set in the Apache Systems dialog. It is the air supply that will be tempered by the system plant and the results will be seen separately from the room load.
Variation profile
This is the variation profile that will be applied to the system air supply. The modulating profile can be set in APpro.
Free cooling flow capacity
For rooms with ApSys methodology this parameter sets the maximum intake of outside air that is available for free cooling in simulations. Free cooling is under the control of the cooling variation profile. It will be supplied when the room temperature exceeds the cooling set point, provided that it is advantageous in terms of reducing room temperature or cooling demand. If mechanical cooling is also available, this will be provided in addition if free cooling is unable to maintain the room temperature at the cooling set point.
If free cooling is not required the free cooling flow capacity should be set to zero. A value of 5 ach would be typical to model ventilation by window opening. In the case of an air conditioned room, where the outside air is brought in via the system, it would be usual to express the value in l/(s·m2) and a value of 0.5 in l/(s·m2) would be typical.
