ApacheHVAC in VE 2012 Cooling tower loop Condenser water loop Electric water cooled chiller Chilled water loop Open cooling tower Towb L T 1 T lct V c Compressor T let V e Cooling tower loop pump Water-to-water heat exchanger Boiler(s) Combined heat and power Air-to-water Heat recovery Common pipe Primary pump Secondary pump Tedb Heating coil Water-to-air Tewt Cooling coil Tewt Water-to-air Heating coil Tewt Water-to-air Cooling coil Heating coil Tewt Water-to-air Cooling coil Tewb Cooling G tower T 2 T T ect owb Condenser Key: water pump water air Condenser Expansion device Primary pump Evaporator Secondary pump Cooling coil or chilled ceiling T ldb g l T edb g e Water source heat exchanger Solar water heater To water source (lake, well, etc.) Key: water air
ApacheHVAC: Flexible modeling of standard and advanced systems Numerous customizable pre-defined systems and equipment options in HVAC library Components based modeling affords exceptional flexibility and controls modeling Pre-define conventional and advanced systems can be modified to match design Supports interaction with thermal models for nat-vent, DSF, labyrinths, UFAD, etc. Multiple systems, models, and VE modules can interact within a single thermal zone. Increasingly user-friendly system setup, sizing, and customization System loads/sizing reports and detailed results analysis options With the addition of a few controls (or using the 07c Mixed-mode VAV system from the HVAC library), a standard VAV system with chilled and hot-water loops can become a mixed-mode system integrated and interacting with natural ventilation at every simulation time step.
Systems and components offer many options simple to detailed Towb HVAC library offers import & export of pre-defined and custom systems, equipment, and controls Predefined conventional multi-zone VAV systems, for example, include Single- and dual-max VAV controls; airflow- or SAT-first cooling control strategies Coil water flow control for LAT-first re-heat control strategy Night-cycle operation with minimum fan flow rate and OA min or off OA economizer: DBT, WBT, or DPT limits, diff enthalpy, mixed temp reset Demand-controlled ventilation (zone CO 2 -based DCV); separate EA & transfer paths Chilled-water, DX, or evaporative (IDE or IDDE) cooling; simple or advanced coil models; Predefined non-standard systems include Mixed-mode (mech/nat-vent), UFAD, active chilled beams, DOAS, DCV, radiant panels, etc. Expanded waterside capabilities cover a broad range of equipment configurations for heating, cooling, pre-heating, pre-cooling, waterside economizes, heat recovery, heat transfer, and more. Cooling tower loop Open cooling tower Cooling tower loop pump Water-to-water heat exchanger Secondary pump Boiler(s) Combined heat and power Air-to-water Common pipe Heating coil Water-to-air Water-to-air Tewt Heating coil Tewt Tewt Tewt Cooling coil Water-to-air Cooling coil Heating coil Water-to-air Cooling coil Heat recovery Primary pump Tedb Tewb Water source heat exchanger Solar water heater To water source (lake, well, etc.) Key: water air
ApacheHVAC in VE 2012 New interface, HVAC systems library, editing tools, and waterside features.
HVAC Systems Library New prototype systems, enhanced selection tree, and mouse-driven placement.
HVAC Systems Library Expanded import options for HVAC equipment, profiles, and fuels/energy end-use.
HVAC Systems Library Export complete systems or any subset to a user library. Export options for selection, HVAC equipment, profiles, and fuels/energy end-uses
System and Multiplex editing System and multiplex containers aid selecting, naming, moving, copying, and export. New options for adding multiplex layers when assigning from room/zone group.
User interface and controller editing Updated and better organized toolbars New system network drawing interface: Drag & drop Move and Copy Select-drag MOVE Select-Ctrl-drag COPY Stretchable controller and sensor leads Start-cusp-end drawing of network paths with minimal mouse clicks using pencil New mouse-keyboard shortcuts
System setup, main input parameters, autosizing, and reports System setup & sizing toolbar in ApacheHVAC System schedules Parameters Zone-level sizing 62.1 ventilation System-level sizing Sizing reports Focus on current HVAC file eliminates need for proposed.asp target file.* *This file naming convention is still autogenerated and required when using the ASHRAE 90.1 PRM Navigator.
Heat transfer loop Extensive control over loop parameters and sizing.
Heat transfer loop Numerous options for heat acquisition/pre-heat and heating equipment sequencing.
Heat transfer loop Cooling tower loop Open cooling tower Towb Cooling tower loop pump Water-to-water heat exchanger Secondary pump Boiler(s) Tewt Tewt Tewt Tewt Combined heat and power Air-to-water Common pipe Heating coil Water-to-air Cooling coil Water-to-air Heating coil Water-to-air Cooling coil Heating coil Water-to-air Cooling coil Heat recovery Water source heat exchanger Primary pump Solar water heater Tedb Tewb To water source (lake, well, etc.) Key: water air Heat transfer loop This conceptual diagram of the new heat transfer loop in ApacheHVAC shows it as configured for zone-level water-loop (water-to-air) s, as well as a range of optional heating and cooling sources. Not all options, such as fluid cooler vs. cooling tower, are shown. Connections to other loops, such as for condenser heat recovery from a CW loop, are also not shown on this diagram.
Heat transfer loop Water-source heat exchanger for heat acquisition and/or rejection. Cooling tower and wet/dry fluid cooler options for heat rejection.
Water-to-air s Water-to-air s (WAHPs) with heating and cooling modes Zone-level devices that attach to a common heat transfer loop
Water-to-air coils New dedicated variants of the simple coil model for use with WAHPs
Waterside modeling Chilled water pre-cooling loop cooling tower fluid cooler water-source heat exchanger Enhanced heat transfer from condenser-water loop to hot water and heat transfer loops Selection of recipient moved to recipient loop (remains displayed on provider loop)
Enhanced Heat Recovery Choice of percentage availability and explicit heat transfer models for both hot-water loop and heat-transfer loops Multiple heat recovery sources (i.e., more than one CW loop) now permitted with percentage availability model Optional WWHP can be used to upgrade heat from each source can to higher HTL or HWL temp Fixed COP (steady-state performance) when used with the simpler percentage availability CHR model
Enhanced Heat Recovery Explicit model for inter-loop heat exchanger Design effectiveness at loop design temperatures Effectiveness varies with delta-t between loops For use with single source and recipient loops Simple WWHP for optional upgrade of recovered heat from CW temperature to higher HTL or HWL temperatures. COP settings for two specified thermal lift (delta-t) data points Linear interpolation of COP between data points
Waterside modeling Radiators and chilled ceilings now see temperature variation of connected water loop (design temp, reset, or off-design temps when underserved ), and are compatible with integrated waterside economizer operation. Defined types have been made scalable via number of units input in the radiator and chilled ceiling dialogs. Autosizable radiators and chilled ceilings will be included in the next feature pack. This will provide autosized water flow rate and number of units, and will also add several related design parameters to the dialogs for radiators and chilled ceilings.
DX Cooling Separation of DX Cooling performance characteristics in type dialog from sizing for each instance Type provides performance curves, rated COP, condenser fan EIR, and rating conditions. Coil dialog includes capacity, coil contact factor, design conditions, and resulting design COP.
Usability enhancements Expanded HVAC network integrity checks with highlighting of opposing flows Separate oversizing factor for fans and new system-level fan min flow rate parameter Specification of infiltration rate in terms of l/s or cfm per unit façade area, rather than floor area (in thermal templates and room data Air Exchanges ) Coupling of OR connections to controllers without sensors Refinements to modeling and controls (behind the scenes) for coils and water loops New pre-defined HVAC systems using VE 2012 capabilities
IES <Virtual Environment> Integrated building performance analysis Cooling Season HVAC System Energy May September Denver, Colorado (TMY climate data) Radiant+DOAS 1.93 0.64 0.26 0.21 Estimated savings = 62 to 71% VAV+WSFC-precool 3.64 4.19 0.49 VAV with WSFC 4.51 4.13 0.36 VAV Baseline 6.41 3.85 0.36 Chillers (VAV only), cooling towers, and chilled water pumps (MWh) Hydronic system pumps and evaporative cooling spray pump (MWh) Fans (including cooling tower fan for waterside free cooling) (MWh) Boilers, natual gas (MWh)