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Piping Engineering
HVAC engineering deals with the overall process of planning, designing, installing, commissioning, operating and maintaining heating, ventilating and air conditioning (HVAC) systems for building projects.
It deals with systems that distribute air through preformed or manufactured duct sections. Low velocity, medium velocity and high velocity air flow through ducts are all within the scope of this process.
Six main process stages are considered within the HVAC Engineering lifecycle.
These are shown in the high level process map below as:
- Plan HVAC Systems
- Design HVAC Systems
- Install HVAC Systems
- Test and Commission HVAC Systems
- Operate Elements and Systems
- Maintain Elements and Systems
Plan HVAC Systems [ID:1]
| Type | Task |
| Name | Plan HVAC Systems |
| Documentation | The objective of the planning activity is to: - prepare general outline of requirements (program or brief) and plan future action for the specific planning task concerned, - set up client organisation for programming (or briefing) - obtain program requirements (brief) from the client organisation, - appoint organisations to the project for carrying out work as appropriate to the specific planning task concerned. In this case, the planning activity is concerned with HVAC systems. |
Design HVAC Systems [ID:2]
| Type | Sub-Process (collapsed) |
| Name | Design HVAC System |
| Documentation | The objective of the design activity for a project is the progressive development and refinement of the requirements expressed in the program (brief) and then to propose design solutions to those requirements including construction/installation methods, materials, technical solutions. Design solutions proposed should be validated against the provision of building codes and regulations for the specific location of the project and should be in accordance with sustainability criteria including environmental impact and service life. The cost of the design solutions proposed should be estimated and managed through the progressive development of a cost plan. In this case, the design activity is concerned with HVAC systems. |
Install HVAC Systems [ID:3]
| Type | Task |
| Name | Install HVAC Systems |
| Documentation | The objective of the construct or install activity for a project is to translate proposed design solutions into actual constructed or installed solutions for the project. This activity includes all actions necessary for: - provision of production information including specifications and schedules outlining quality and type of materials and goods required to achieve the objective and constraints applicable to project execution. - planning and scheduling work tasks, - procurement actions for materials, goods and services including tendering actions - execution of construction and installation tasks up to the point at which the work can be tested, commisioned, inspected and/or determined as complete. In this case, the activity is concerned with installation of HVAC systems. |
Test and Commission HVAC Systems [ID:4]
| Type | Task |
| Name | Test and Commission HVAC Systems |
| Documentation | The objective of the test, commisson and complete activity for a project is to: - provide for the testing of technical solutions to ensure that they will function with the required level of safety - set up technical solutions to operate according to the actual operating requirements of a project - ensure that construction or installation work has been properly executed and to remedy any defects - turn over project to the client of the clients operating agent In this case, the activity is concerned with testing, commissioning and completion of HVAC systems. |
Operate Elements and Systems [ID:5]
| Type | Task |
| Name | Operate Elements and Systems |
| Documentation | The objective of the operate elements and systems activity for a project is to perform those actions and adjustments required to ensure the normal day to day operation of a project. |
Maintain Elements and Systems [ID:6]
| Type | Task |
| Name | Maintain Elements and Systems |
| Documentation | The objective of the maintain elements and systems activity for a project is to perform those actions and adjustments required to return elements and systems to a satisfactory state (physical or functional) for continued operation. The activity is concerned both with planned and unplanned maintenance activities and considers requirements that may be state (failure or imminent failure), time or condition based. A maintenance requirement is triggered by an event which may be caused by either: - the amount of time that has elapsed since the previous maintenance operation was carried out has reached the planned interval between maintenance operations, or - the date on which a maintenance operation is planned has arrived, or - the current operating condition of an element, group of elements or system as determined by the values of one or more parameters has reached a level at which maintenance is set to occur, or - an operational failure (either complete or partial) has occurred that requires a maintenance operation to correct. In the context of the above, maintenance is also considered to encompass replacement where an element has reached the end of its working life. |
The stages identified are expected to be approximately mapped to specific project stages according to the table below:
Note that this mapping splits the general project stage 'Construction' between the HVAC stages 'Install' and 'Test and Commission'.
The primary roles shown in the process map diagram (as 'swimlanes') are defined as:
- HVAC Design
- HVAC Construction
- Facilities Management (in this case, concerned with the electrical engineering aspects of facilities management)
Fundamental Design Process
HVAC Engineering design follows the fundamental design process as outlined in the Electrical Emgineering process map.
Stage 1: Plan HVAC Systems
Not currently developed
*Stage 2: Design HVAC Systems* 
Design HVAC Systems (Programming) [ID:2.1]
| Type | Sub-Process (collapsed) |
| Name | Design HVAC Systems (Programming) |
| Documentation | The term "programming" is the process of developing a program. Programming includes the assessment of needs/requirements and delimitations/constraints. These are described as a program (e.g. in Norway usually according to Norwegian Standard NS3451). Delimitations can be physical (e.g. area type and size, space program), technical (e.g. number and type of outlets, or type of materials), time based (e.g. project progress) and financial (e.g. investment budget or LCC). The programming stage accounts for the client's assessment of the requirements to be met by the completed construction and forms the basis for determining the budget. For HVAC, the process includes determining: - Space program requirements for HVAC systems to meet technical requirements - Identification of requirement for technical spaces - Identification of requirement for vertical distribution spaces - Identify what types of system are relevant |
Design HVAC Systems (Sketch) [ID:2.2]
| Type | Sub-Process (collapsed) |
| Name | Design HVAC Systems (Sketch) |
| Documentation | The term "sketch design" is the process of developing an interdisciplinary design where the propositions from the design team describe relevant alternative main principles and main system solutions (in Norway usually according to Norwegian Standard NS3451). The alternatives are presented with pros and cons. The design team's recommended design solutions for further study at the full concept stage are stated, along with proposed reports to be carried out at the full concept stage. For HVAC systems, this process includes determining: - Estimate of load to determine main flow moving device (fan) size - Identify main vertical routes using indicated spaces - Location, sizing and identification of technical spaces - Costing for presentation is by high level aggregation element - Specification of types of system and principles of operation. - Sketch design model showing technical spaces, vertical distribution routes, and key horizontal routes to describe principal routing. Specifics for Norwegian Practice - NS3451, Building element level of systems (down to level of whole system such as all lighting) - Costing uses NS3453 likely to be based on sq.m prices against known previous example buildings. NS3457 is standard table for building categories. |
Design HVAC Systems (Full Concept) [ID:2.3]
| Type | Sub-Process (collapsed) |
| Name | Design HVAC Systems (Full Concept) |
| Documentation | The term "full concept design" is the process of developing an interdisciplinary design where the propositions from the design team describe a recommended solution (in Norway usually according to Norwegian Standard NS3451). At this stage all relevant principles and system solutions for all disciplines are stated, qualitatively and quantitatively. Estimated Life Cycle Cost (LCC) for the design shall be provided. All succeeding stages are in principle regarded as "production stages" (i.e. production drawings / models, the physical building, documentation). The full concept design level of detailing should be sufficient to avert later principle / system decisions with quality, progress or economic implications, unless a change is done in programming requirements. Further detailing and smaller changes of design solutions at later stages are considered to be normal and acceptable. |
Design HVAC Systems (Coordinated) [ID:2.4]
| Type | Sub-Process (collapsed) |
| Name | Design HVAC Systems (Coordinated) |
| Documentation | The term "coordinated design" is the process of developing a detailed interdisciplinary coordinated design where design team deliverables include a building information model that contains characteristic product specification attributes (in Norway usually according to Norwegian Standard NS3420) suitable for a tender process, including supplementary demands for test procedures, component labeling, documentation etc. A number of additional reports may also be required (e.g. environmental issues reports, LCC according to Norwegian Standard NS3454, waste handling procedures, universal (handicapped friendly) design documentation etc). |
*Stage 21: Design HVAC Systems (Programming)* 
Estimate Load [ID:2.1.1]
| Type | Task |
| Name | Estimate Load |
| Documentation | For the project as proposed, make an estimate of the expected overall HVAC load so that a preliminary estimate of the size of the flow moving device (fan, pump etc.) can be made. Information for estimating loads at the programming stage will typically be derived from previous, similar projects or from collected 'rules of thumb' (which are effectively aggregated data from multiple previous, similar projects). Such calculations will make broad assumptions about contributions to load resulting from lighting or other energy sources rather than using information contributed to the building model from other roles. |
Estimate Space Requirements for Technical Spaces [ID:2.1.2]
| Type | Task |
| Name | Estimate Space Requirements for Technical Spaces |
| Documentation | Makes a preliminary estimate of the space required for major technical spaces to serve the HVAC systems on a project. Major technical spaces are spaces that have a substantial impact on building consideration either in terms of their overall size or their structural implication (special floors etc.). Other (minor) technical spaces will be determined at the sketch design stage. Estimate of the space requirement may include height requirement (e.g. need for 5m height for the type of equipment being considered). Example: A major technical space could be for a chiller or cooling tower plant space or plant room. The estimate is based on experience, knowledge of previous projects, industry guidance etc. Typically, it is determined on a factor based method that takes into account total space area and space function. Non indicated spaces such as circulation space, storage space etc. may be accounted for in total building space by further parameters. This can also be used in accounting for space required to accommodate further expansion that may be mandated by the space program. |
Define Special Spaces [ID:2.1.3]
| Type | Task |
| Name | Define Special Spaces |
| Documentation | Special spaces are spaces that may require more detailed elaboration at the programming stage. Typically, they are spaces that have particular, detailed requirements and are not represented as a space type within a libray of such types held by a client. Example: A 'Ship Simulation Room' at Tromso College is used to train ships officers by providing simulated views from the bridge of a ship. This space is modelled in detail even at the programming stage to enable consideration of the particular design requirements of the space. |
Agree Location and Size of Technical Spaces [ID:2.1.4]
| Type | Task |
| Name | Agree Location and Size of Technical Spaces |
| Documentation | Propose the location and size of major technical spaces - from previous process (not minor technical spaces). This should be based on the space requirements previously identified. Location of spaces includes the configuration relative to adjacent spaces in the case of there being any constraints or requirements as to room type X adjacent to room type Y. E.g. plant room and fan chamber should be adjacent to each other. |
Estimate Cost [ID:2.1.5]
| Type | Task |
| Name | Estimate Cost |
| Documentation | For the project as proposed, make an estimate of the order of magnitude cost of the electrical systems. Order of magnitude costing will largely be based on cost information from previous projects. Specifics for Norwegian Practice - Costing uses NS3453 and is likely to be based on sq.m prices against known previous example buildings. - NS3457 is standard table for building categories. |
*Stage 2.2: Design HVAC Systems (Design Stages)* 
Define Spaces [ID:2.2.1]
| Type | Sub-Process (expanded) |
| Name | Define Spaces |
| Documentation |
Confirm Requirements, Location, Shape and Size for Technical Spaces [ID:2.2.1.1]
| Type | Task |
| Name | Confirm Requirements, Location, Shape and Size for Technical Spaces |
| Documentation | The task confirms and agrees the requirement for, location, shape and size of technical spaces as proposed at the previous project stage. This is based on the space requirements previously identified but expands the requirement in terms of the extended geometry information available for the space including height requirement where relevant, Technical spaces includes plant rooms, plenum chambers etc. as well as vertical distribution spaces. |
Identify Fire Compartmentation [ID:2.2.1.2]
| Type | Task |
| Name | Identify Fire Compartmentation |
| Documentation |
Zone Spaces into Systems [ID:2.2.1.3]
| Type | Task |
| Name | Zone Spaces into Systems |
| Documentation | Identify spaces and group them into zones within which all entities of a given class (or range of classes) are grouped together to belong to a particular system. |
Determine Air Requirements [ID:2.2.1.4]
| Type | Task |
| Name | Determine Air Requirements |
| Documentation | Establish the requirement for supply or extraction of air from spaces. Distribute this requirement to be met by terminals within spaces. |
Select and Locate Equipment [ID:2.2.2]
| Type | Sub-Process (collapsed) |
| Name | Select and Locate Equipment |
| Documentation | For main items of equipment, select generic types and estimate their size, location and weight. |
Select, Size and Connect Distribution Routes [ID:2.2.3]
| Type | Sub-Process (collapsed) | |
| Name | Select, Size and Connect Distribution Routes | |
| Documentation | Selection of distribution method, estimate of load and diversity, routing and sizing of ducts. | 
|
Select Distribution Method [ID:2.2.3.1]
| Type | Task |
| Name | Select Distribution Method |
| Documentation | Decide on the distribution method of the HVAC system. E.g. central air/air distribution, local air/water system etc. Note that several alternative sketch designs may be proposed, each design using an alternative distribution method. Final choice of the selected method is made at the full concept design stage. |
Decide Distribution Routes [ID:2.2.3.2]
| Type | Task |
| Name | Decide Distribution Routes |
| Documentation | Using spaces allocated to systems decide main distribution routes. This is for main air ducts throughout the project only; branch ducts are not routed at this stage. The objective of determining the distribution route is to ensure awareness of main routes and sizes for distribution.. |
Estimate Loads at Significant Points [ID:2.2.3.3]
| Type | Task |
| Name | Estimate Loads at Significant Points |
| Documentation | Estimate the load to be met at significant points along the main distribution routes. |
Sum Loads [ID:2.2.3.4]
| Type | Task |
| Name | Sum Loads |
| Documentation | Add the estimated loads progressively back to the estimated point at which the fan will be located. This will provide an estimated load on each section of the main distribution route and a total estimated load which the fan(s) is required to meet. |
Calculate Distribution System Sizes [ID:2.2.3.5]
| Type | Task |
| Name | Calculate Distribution System Sizes |
| Documentation | From the loads determined for the main distribution routes, estimate the required largest duct size. This is used for allocation of space within distribution zones and also for coordination purposes. |
Estimate Diversity Factor [ID:2.2.3.6]
| Type | Task |
| Name | Estimate Diversity Factor |
| Documentation | Estimate a diversity factor for HVAC supply that considers the expected maximum simultaneous load on the system given that not all HVAC distribution may be required at the same time. |
Model Typical Space Layouts [ID:2.2.3.7]
| Type | Task |
| Name | Model Typical Space Layouts |
| Documentation | Detailing of equipment layouts and duct branch routes in typical 'spaces' that enable cost models to be better informed. |
Connect System Elements [ID:2.2.3.8]
| Type | Task |
| Name | Connect System Elements |
| Documentation | Make connections between distribution system elements and allocate flow directions. |
Regulate Systems [ID:2.2.3.9]
| Type | Task |
| Name | Regulate Systems |
| Documentation | Deals with the selection,placement (where not already done through a prior process), sizing (by reference to the distribution elements to which regulating elements are connected) and establishment of regulation setting to achieve the degree of regulation required. For example, to achieve the required air flow through a branch air duct, a balancing damper must be set to be 30% closed. Note that the settings established by design at this stage may be subject to field modification when HVAC systems are commissioned. |
Assign Operational Information [ID:2.2.4]
| Type | Task |
| Name | Assign Operational Information |
| Documentation | Preliminary assignment of operating and maintenance data about the systems and distribution routes that forms the basis for later operating and maintenance instruction information. |
Analyze System [ID:2.2.5]
| Type | Task |
| Name | Analyze System |
| Documentation | Analyze the system in terms of flow requirements. The type of calculation (algorithm used) should be driven by the extent of information available from the model. The more information that is available then the more comprehensive the method that is expected to be used in analysis. Sizing Balancing Acoustics inc cross talk |
Estimate Cost [ID:2.2.6]
| Type | Task |
| Name | Estimate Cost |
| Documentation | Estimate the cost of the proposed construction/installation at the current design stage Specifics for Norwegian Practice - NS3457 is standard table for building categories. |
Stage 2.3: Design HVAC Systems (Full Concept)
Considered as a cyclical stage within the process at stage 2.2 above
Stage 2.4: Design HVAC Systems (Coordinated)
Considered as a cyclical stage within the process at stage 2.2 above
Stage 3: Install HVAC Systems
Not currently developed
Stage 4: Test and Commission HVAC Systems
Not currently developed
Stage 5: Operate Elements and Systems
Not currently developed
Stage 6: Maintain Elements and Systems
Not currently developed
Specification of Data Objects
HVAC Requirements
| Type | Data Object |
| Name | Electrical Requirements |
| Documentation | Requirements for the provision of HVAC services. |
Previous Project Guidance
| Type | Data Object |
| Name | Previous Project Guidance |
| Documentation | Previous projects of a similar nature from which guidance can be obtained. |
Industry Technical Guidance
| Type | Data Object |
| Name | Industry Technical Guidance |
| Documentation | Industry technical guidance from which guidance can be obtained. |
Building Program
| Type | Data Object |
| Name | Building Program |
| Documentation | This is the document that sets out what needs to be taken into account during the HVAC design process. It does not set down data requirements but it does set down the overall expectations that the client has of the HVAC engineer and therefore acts as a 'quality assurance' document. States the clients preferences. |
Space Regulations
| Type | Data Object |
| Name | Space Regulations |
| Documentation | Local regulations on size and placement of technical spaces. |
Equipment Data
| Type | Data Object |
| Name | Equipment Data |
| Documentation | Generic equipment size and weight specifications enabling testing of space allocation, structural provision and enabling preliminary coordination. |
Cost Data
| Type | Data Object |
| Name | Cost Data |
| Documentation | Stored cost information from suppliers or other cost planning sources |
Task Data
| Type | Data Object |
| Name | Task Data |
| Documentation | Stored information about operation and maintenance tasks that should be undertaken on systems and equipment, the skill expected to be able to undertake tasks, the expected frequency of tasks (enabling a proposed maintenance plan to be able to be derived). |
Exchange Requirement Data Objects
er_exchange_HVAC_model [programming]
| Type | Data Object |
| Name | er_exchange_HVAC_model [programming] |
| Documentation | HVAC model at the programming stage that can be added to overall building information model. Information at this stage is advisory based on speculative design. It includes the following advisory information provision: - overall size (area) of major technical spaces required, - minimum height requirement for technical spaces, - location of major technical spaces including constrained relationships to any other spaces that may be required for reasons of noise, safety, environmental considerations or other aspects, - required adjacency between major technical spaces considered to be in the vertical as well as in the horizontal plane; this may indicate the required strength of the adjacency (must be, should be, could be), - estimated HVAC load for the project, - indications of major equipment items to be located in identified spaces and information that may impact on regulation processes (e.g.planning), - list of special spaces for which special design provisions may apply. |
er_exchange_HVAC_model [space]
| Type | Data Object |
| Name | er_exchange_HVAC_model [space] ** applicable to design stages cyclically ** |
| Documentation | Exchange of information about technical spaces for HVAC plant and equipment and how other spaces are grouped for system development and fire compartmentation. Used to coordinate with general zoning and spacing requirements with other roles. |
er_exchange_HVAC_model [equipment]
| Type | Data Object |
| Name | er_exchange_HVAC_model [equipment] ** applicable to design stages cyclically ** |
| Documentation | Exchange of information about shape, size and location of HVAC components. HVAC systems information can then be brought together with equivalent information from other roles to ensure that items of equipment are in proper spatial and functional relationship to each other taking into account their size and location in terms of space allocation and structural provision. Information provided for equipment includes all that provided for prior exchange requirements including spaces information with the addition of: - types of component to be used and sizes - allocation of type information to occurrences of components - size of type and/or occurrence of component - shape representation of component (using an appropriate representation form that may be symbolic, 2D, 3D boundary representation etc.); the form of representation to be used and the extent of detail that is provided for the component may differ at different stages of the project. - location of occurrences of components. |
er_exchange_HVAC_model [systems]
| Type | Data Object |
| Name | er_exchange_HVAC_model [systems] ** applicable to design stages cyclically ** |
| Documentation | Exchange of information about configuration, size, location, connection and technical data of HVAC systems including both the components and the distribution elements. HVAC systems information can then be brought together with equivalent information from other roles to ensure that items of equipment are in proper spatial, functional and technical relationship to each other taking into account their size and location in terms of space allocation and structural provision. Information provided for systems includes all that provided for prior exchange requirements including spaces and components information with the addition of: - estimated or calculated loads for systems and for the project (the definition of estimate or calculation being dependent on project stage and the available technical detail to enable calculation to occur), - form of HVAC distribution (e.g. low velocity, high velocity etc.) - airflow requirements at components - simultaneous load diversity information required by the power supplier. - types of ductwork to be used and sizes - allocation of type information to occurrences of ductwork - types of flow terminal outlet (grille/diffuser) to be used, sizes and technical data - allocation of type information to occurrences of flow terminal outlet - types of flow control (dampers etc.) to be used, sizes and technical data - allocation of type information to occurrences of flow control - types of flow moving device (fan etc.) to be used, sizes and technical data - allocation of type information to occurrences of flow moving device - allocation of components and distribution elements to systems - types of flow treatment (filters etc.), heat exchange devices and other air distribution devices to be used, sizes and technical data - allocation of type information to occurrences of other air distribution devices - allocation of components and distribution elements to systems - distribution routes - connection details and flow directions The extent of system information exchanged will vary depending on the project stage, (1) Sketch design is expected to include only major routes and may be topologically represented (lines in 3D space) including edges as routes and vertices to represent changes in direction and with main components indicated. (2) Full concept design is expected to represent linear segments, fittings and components. Relevant information about routes is expected together with load information. Technical data will be provided but this may not be sufficiently complete for specification and procurement. (3) Coordinated design will include all system elements including jointing detail and connectivity and all associated detailed technical data required for specification and procurement. |
+*Coordination Point Gateways*+
Coordinate_plan
| Type | Coordination Point |
| Name | Coordinate_plan |
| Documentation | Coordination and approval (or otherwise) of all planning work undertaken. |
Coordinate_design
| Type | Coordination Point |
| Name | Coordinate_design |
| Documentation | Coordination and approval (or otherwise) of all design work undertaken. ** This coordination point may be considered as being synonymous with the 'Coordinate_coordinated_design' coordination point. |
Coordinate_program_design
| Type | Coordination Point |
| Name | Coordinate_program_design |
| Documentation | Coordination and approval (or otherwise) of speculative design work undertaken at the programming stage. |
Coordinate_sketch_design
| Type | Coordination Point |
| Name | Coordinate_sketch_design |
| Documentation | Coordination and approval (or otherwise) of design work undertaken at the sketch design stage. |
Coordinate_full_concept_design
| Type | Coordination Point |
| Name | Coordinate_full_concept_design |
| Documentation | Coordination and approval (or otherwise) of design work undertaken at the full concept design stage. |
Coordinate_coordinated_design
| Type | Coordination Point |
| Name | Coordinate_coordinated_design |
| Documentation | Coordination and approval (or otherwise) of design work undertaken at the coordinated design stage. |
Coordinate_equipment_location
| Type | Coordination Point |
| Name | Coordinate_equipment_location |
| Documentation | This purpose here is to represent a point at which the model of the HVAC systems is brought together with equivalent models from other roles for coordination and approval. Coordination is concerned with ensuring that items of equipment are in proper spatial and functional relationship to each other taking into account their size and location in terms of space allocation and structural provision. For example: (1) major items of equipment applying a significant load on the structure need to have suitable structural support, (2) equipment requiring maintenance action should not have access restricted by other technical systems components, (3) visible items should be in appropriate locations for functional and aesthetic coordination. |
Coordinate_space
| Type | Coordination Point |
| Name | Coordinate_space |
| Documentation | The purpose here is to bring together information that is currently available about the spaces as required for the technical systems designs to ensure that requirements are coordinated and that space allocations as required are made. |
Coordinate_systems
| Type | Coordination Point |
| Name | Coordinate_systems |
| Documentation | At this point, the aim is to coordinate the HVAC systems design with other systems information and make adjustments that are necessary. The possibility for such adjustments is described by feedback provisions. |