Revit Families: An Effective Tool for MEP Engineers

Families – they are integral to just about everything in life. This is doubly true for Revit families in the world of MEP (mechanical, electrical and plumbing) engineering. The importance of Revit family creation, especially Revit MEP family creation, is paramount in Revit 3D modelling. So, what is Revit MEP family creation and how beneficial is it?

Since the Revit platform was created by Autodesk, perhaps the more relevant question is: What is Autodesk Revit MEP?

Revit MEP from Autodesk is a building information modelling (BIM) software created specifically for MEP engineers or other MEP professionals. The software enables modifications, additions and communication in intelligent models so that MEP systems, regardless of their complexity, can be precisely designed and documented in a relatively short time. An entire project can be represented as a single model created by Revit MEP and is typically stored in a single file. This way, any changes effected in one part of the model is automatically updated and modified in other parts of the model.

What are the key benefits of using Revit MEP?

Using Revit MEP within a BIM workflow increases productivity, streamlines design and documentation and speeds up project completion from the design stage to the construction stage while automatically updating changes across the model for every single change anywhere in the model. It does so with a range of tools and features designed to improve productivity, such as Building Performance Analysis, Autodesk 360 Integration, Construction Documentation, Pressure and Flow Calculations, Pressure Loss Reports, Parametric Components, etc.

Revit MEP also reduces risks and helps create high quality designs. It can be used to develop detailed BIM-ready product models with a high level of accuracy by an HVAC (heating, ventilation and air conditioning) manufacturing company, for example.

The engineering design process is streamlined with the use of a single model. The single model enables a more efficient communication of design intent before the start of construction. Building performance is improved this way, as project stakeholders can make more informed and precise decisions on design.

A thorough knowledge of creating ‘families’ and ‘types’ can positively influence the length of time it takes to create a model. Families consist of categories and sub-categories. Each category consists of individual families. For instance, consider the Sprinkler Category.

The category of Sprinkler can create several kinds of sprinklers. It is possible for families within this category to perform different functions and use different materials, which makes each of them a family ‘type’. Each family type has a graphical representation. When a specific family and individual family type is used to create a design component, it is known as an ‘instance’. Each instance has its own properties.

The parameters of an element can be changed without changing the parameters of the family type. Only the instance or element or component is affected by the change. When the parameters of the family type are changed, every instance of elements in the family type are changed.

The three main classifications of families are: system, loadable and in-place families.

System families are preinstalled families and create basic MEP elements, such as ducts and pipes. . System family settings include types for levels, grids and drawing sheets.

Loadable families are created elsewhere and then uploaded into the project. They are typically used to create MEP fixtures or other elements that be purchased, moved or fixed in and near a building. Revit MEP helps create and alter loadable families, as they are customisable. External RFA files are used to create them, and then they are loaded into the project. A loadable family with many types uses type catalogs to select a type of family. This family type can be identified and loaded into the project without loading all the family types. Specific kinds of loadable families are nested and shared families.

The third kind of families is the in-place family, which can be used to create customised elements. When a project requires a special individual element, in-place families are created with a specific geometry. The geometry of in-place families will then reference other project geometry and change itself based on the changes of the referenced geometry. Revit can create a family with a single-family type to create an in-place element.

During Revit MEP family creation, Revit 3D modelling can help analyse electrical systems, especially lighting, in a project, since a source of light has its own properties in a modelling setting. Nested families, which are families within other families, can be used to create families with multiple light sources. This is done using the host geometry of the main family. Various lighting fixtures can also be included.

Besides electrical components, Revit MEP family creation includes the creation of elements from other trades too. Some of the examples of Revit MEP family creation components, or elements, are as follows:

Revit Mechanical Family Creation

• HVAC components
• Pipes - valve, strainer and pipe hanger
• Duct hangers
• Air terminals

Revit Plumbing Family Creation

•          Pumps
•          Fixtures - urinals, wash basins, water closets
•          Valves
•          Devices - measuring devices, gauges
•          Fittings

Revit Electrical Family Creation

•          Transformers
•          Distribution boards
•          Switches and sockets
•          Fire alarm devices
•          Lighting fixtures

Revit HVAC Family Creation

•          Fan coil units
•          Air handling units
•          Fire dampers
•          Diffusers, grilles and registers
•          Fittings and valves

Revit Firefighting Family Creation

•          Sprinklers
•          Valves
•          Fittings
•          Fire extinguishers
•          Cabinets

Autodesk’s Revit is BIM software that includes MEP features and is commonly called Revit Bim, but Revit is not BIM. Revit has been created for BIM. The nice thing about BIM, well one of the nice things, is that the data that is stored in BIM throws up a few advantages for users of Revit Bim. Convenient scheduling, marketing that is exclusive, design changes that can be quickly communicated and implemented throughout a project and easy access for MEP designers are some of the advantages of using the information in BIM models.

It’s easy to see why Revit families and their creation are an effective tool for MEP engineers, but since sound technical knowledge is required to create object-based models in Revit Bim, many Western firms opt for offshore Revit modelling services when local talent is either challenging to find or too expensive to afford. Offshore modelling services developed with Revit family creation are increasingly found to be affordable, precise and delivered on time, making it the popular way to go.

Elements to Consider in 3D BIM Coordination

Why is 3D BIM coordination so crucial to building design?

There are several elements to consider in 3D BIM coordination, and one of the first places to start the process is with a 3D coordinated model. Integrating architectural, structural and MEP trades together into a coordinated 3D model is part of the 3D BIM (building information modelling) coordination process. The BIM process is an effective 3D modelling tool that helps generate precise, accurate 3D coordinated models during the design development of a construction project. With a fully coordinated BIM model, users can see just how the architectural, MEP and structural systems have been coordinated in a 3D environment, and making changes becomes easy.

The process of 3D BIM coordination involves recording, using and reviewing detailed data about a building’s physical functions. The information can also be used to prepare task schedules in 4D, calculate project costs and material take-offs and optimise the sustainability of the overall business design. One way of looking at BIM coordination is to think of it as being a grouping together of 3 distinct functions, namely:

• Actual physical construction (building)
• Coordination of detailed data (information)
• Coordination of an accurate 3D model (modelling)

or BIM.

What is interesting about BIM coordination is that it involves much more than just modelling. It includes data and construction management responsibilities and improves efficiency in terms of saving costs and time and enables more informed decision-making.

A useful function of 3D BIM coordinated models is that they are used to perform clash-detection processes. A 3D BIM coordinated model can help find any clashes, interferences or shortcomings between architectural, structural and MEP systems. One of the most popular software used for this process is Revit, which has advanced features to help merge the different disciplines of the model effectively, helping architects, structural engineers and MEP engineers.

Models can also be studied to determine complex space allocation and how the different MEP trades can fit into the available space. Each of the building’s deliverables involving data-related tasks can be easily and clearly identified, tracked and coordinated at any point or stage of the project’s life cycle. Building risers, plant rooms, prefabricated corridors and ceiling modules can also be coordinated using quality checks in the process of BIM coordination.

Management tasks, such as common data environment (CDE) information management processes, are performed to support data exchange and help both model and data integration and coordination. Also included as part of the 3D BIM coordination process are constructability reviews, clash detection reports, virtual/personal coordination meetings with consultants, construction/project managers, sub-contractors, architects and engineers.

There are several benefits to be gained from using 3D BIM coordination, such as:

• Reduced errors by the construction team and design team
• Streamlined workflows in accordance with global standards
• Reduction of construction material waste
• Savings on total costs and project time
• Improved technology and innovative ways to maximise project value

A significant part of 3D BIM coordination involves BIM services, specifically MEP BIM, architectural BIM and structural BIM processes. These BIM services combine data from individual architectural, structural and MEP drawings, using Revit and Navisworks, to help generate intelligent BIM models that feature the following functions and products:

• Coordination
• Fabrication
• Optimisation
• Installation
• MEP engineering
• MEP BIM coordination
• MEP shop drawings
• MEP 3D modelling
• Mechanical room modelling
• Builders work drawings
• As-built drafting
• Piping spool drawings
• MEP quantity take-offs

Since the MEP systems of any building is crucial, it’s critical to be aware of some of the detailed MEP BIM modelling and drafting services available. They include:

• Mechanical equipment modelling
• Diffuser and grill modelling
• Electrical lighting fixture drafting and modelling
• Layout modelling
• Plumbing layout modelling
• Sanitary fixture Revit modelling
• Walk-throughs of MEP/BIM models
• Revit MEP Families Parametric modelling

Common Elements to Consider  

The classification of 3D BIM coordination can be as follows:

MEP BIM

Electrical Systems

• Electrical site plans
• Electrical one-line diagrams (riser diagrams)
• Electrical schematics
• Solar panel detailing
• Electrical, power and lighting plans

Plumbing Systems

• Drafting services for domestic water plumbing
• Plumbing and drainage drafting services
• Location and coordination of pipe sleeve requirements
• Isometrics, riser diagrams, details, schematics and schedules
• Sleeve/Penetration Drawings

HVAC (Heating, Ventilation and Air Conditioning) Systems

• Equipment schedules
• Compressed air and medical gas system plan drawings
• Demolition and existing plan drawings
• Equipment piping sizing and design layout plan drawings
• HVAC system drafting
• Details, schematics, schedules, legends and control diagrams
• As-built drawings, equipment specifications, coordination drawings, shop drawings and addendums
• Mechanical equipment layouts, submittals and elevation drawings

Heating Systems

• Boilers
• Direct vents
• Space heaters
• Indoor coil systems
• Heat pumps
• Wall and floor furnaces
• Forced hot air/water
• Thermostats
• Natural gas heating
• Heat pumps – standard and ground source

Ventilation Systems

• Overhead units
• Ductless split systems
• Sheet metal ducts
• Humidifiers/Dehumidifiers
• Central air systems
• Window/rooftop unit systems
• Air cleaners and filters
• Cooling Systems
• Air conditioners
• Air handlers

Architectural BIM

Using the BIM methodology, architects can develop digital design simulations capable of managing the vast stores of information that is part of an architectural project. Besides the 3D characteristics of models, BIM can incorporate 4D (time) and 5D (costs) associated with a project. Stakeholders can access and manage data intelligently and several processes can be automated, such as programming, conceptual design, detailed design, analysis, documentation, manufacturing, construction logistics, operation, maintenance and renovation/demolition.

Libraries of architectural models are available online, providing elements that can easily be incorporated into a project, saving time. This way, data is loaded, the quality of work can be improved, and the amount of decision-making and modifications made can be reduced, lowering both time and costs. 

Importantly, these elements, with unique characteristics, can be parametrically related to other project elements, which means that any changes on one element will effect automatic changes to other elements that are connected to or dependent on the first element. Thus, architects can interact with clients, builders and engineers in a shared process.

Structural BIM

The methodology of structural BIM modelling enables design analysis and review of structural elements in a project to further improve the overall design process. Structural BIM services consist primarily of 3D modelling, detailing and drafting. The analysis of these services results in cost-effective design and improves the safety of the design. Building geometry, location and space data, building properties, building materials and resources are better understood with structural BIM services. Some of the major structural BIM services are the following:

• Structural analysis
• Structural design
• 3D modelling 
• Steel structure detailing
• Creation of 3D, 4D and 5D BIM services
• Extraction of structural components
• High-quality construction documents
• Clash detection and risk management
• Intelligent parametric library development
• Precise quantity take-offs and cost estimates

With the help of BIM services, design errors are reduced from the improved coordination and communication of decisions. Thus, the main benefits of BIM services include:

• Better communication
• Faster approvals
• Improved coordination
• Easy modifications of design 
• Reduced errors
• Reduced time to create drawings and revisions
• Improved performance analysis, evaluation
• Improved project efficiency 

There are many elements to consider in 3D BIM coordination, and there are many ways to utilise and optimise the benefits resulting from 3D BIM coordination. Typically, the processes of 3D BIM coordination require the expertise and experience of several stakeholders, sometimes separated by countries. Many Western construction firms opt to outsources these processes to countries further east, such as India, since they have large groups of technically qualified, experienced, English-speaking personnel who deliver these BIM services accurately, clash-free, on schedule and cost-effectively. Bringing together clash-free MEP, structural and architectural systems after careful consideration of its many elements, high-quality 3D BIM coordination services remain an essential part of modern construction.

How Architectural Rendering Contributes to Design Development

What you see is what you get – how many times has that been said? In the field of architecture, this could be said about architectural rendering in the Design Development phase. The Design Development phase of architectural design can be of considerable importance in the ongoing communication process between designers and customers or owners. Visuals help keep this communication clear and transparent, and one of the key visual representations in this phase, rendering, is versatile, photorealistic and accurate when depicting the final structure. Here’s why high-quality architectural rendering services can move a project forward.

Useful both for new constructions and for renovations, rendering software’s prime objective is to provide a simulation of a building from a range of angles and distances, in the most accurate way possible. When the rendered image is accurate, it helps locate dimensional problems, it can help assess the usage of available space, and it enables the customer to be happy (or not) with both the inside and outside of their building . . . and these functions occur before construction commences.

During the Design Development phase, the architect and client work closely together to choose interior finishes, appliances and materials for windows, doors and fixtures. The initial drawings from the Schematic Design stage are modified, adding details from revised sketches. At the conclusion of this stage, the interior and exterior building design is finalised by the owner and the architect. The plans and elevations are reviewed and revised to include specifications and details needed for construction.

Project elements detailed in the Design Development stage include:

• Building materials and finishes used for the interior and the exterior
• Furniture and equipment choices and locations
• Cabinet and custom fabrications
• Lighting and technological design
• Mechanical, electrical and plumbing systems
• Miscellaneous issues that affect project constructability and that may require changes to the project or to the budget

At the end of the Design Development stage, design drawings and specifications are almost complete. The building's size, purpose, materials, configuration and spaces and the use of equipment and materials used for the structures and systems are defined. Then, the project’s budget, schedule and all building plans are decided.

So, how does rendering fit into this process?

Rendering can be done during the Schematic stage of design, but it is during the Design Development stage that many of the details of the design can be easily and comprehensively communicated to the customer through rendered images. These visual assets can be used to sell the project’s key features.

Photorealistic images are generated by rendering 3D models that include the basic mechanical and architectural details of the project design. Rendered images can be updated during the Design Development stage as changes occur. Though previously created in-house, an increasing number of engineers and designers are using external rendering specialists to create these images.

Models are endowed with a range of visual effects with rendering, such as shading, texture mapping, shadows, reflections and motion blurs. Improved rendering algorithms and hardware acceleration have made software more powerful than before. 

The key five ways rendered images are beneficial during the Design Development stage are as follows:

1. Design Flaw Identification

To picture a building in its entirety by only looking at 2D drawings has its limitations. A 3D model of a building helps see the structure from all angles. Due to this, a significant number of design flaws can be identified, which may otherwise have slipped through. These flaws can be amended before construction begins. By doing so, unnecessary expenses are minimised and construction time is shortened.

2. Effective Communication 

Architects typically aim to give customers a building that they want, as much as possible. Sometimes what the customer desires may not match with the architect’s understanding. With this 3D view of exteriors and interiors, the customer has a more informed understanding of building functions, materials and appearance. If the design seems to clash with what the customer wants, modifications can be made at this point.

3. Promotes Saleability

The view of both exteriors and interiors in 3D can help the architect display his work to the customer and convince him of why the design works efficiently for his needs. Realty developers use them to convince potential stakeholders of the project’s worth and to invest in the project. Rendered images help market houses, condominiums and villas to potential clients.

4. Walk-throughs

A walk-through is essentially a video developed from a series of rendered images so that the viewer can see external views of the building project and also has the ability to exist inside the building and actually walk through it. This lets the viewer experience a feel of the layout and experience different aspects of the building – to virtually imagine how to navigate the interiors of the building before the building has been constructed.

5. Planning and Strategy

Views generated by 3D rendered images help plan for how the interior designs of the building can be handled. Designers and architects can prepare 3D interior strategy that they can use to communicate with the task force on site and show other stakeholders. This way, they can see potential defects and rectify them.                                 

These are some of the key reasons for architectural rendering services becoming an essential tool for architects and interior designers worldwide during the Design Development phase. With several overseas firms offering 3D architectural rendering services at affordable prices and delivering 3D rendering and walk-throughs on schedule, they are becoming an increasingly preferred choice for Western firms in need of such services.

Design Considerations for Different House Types

One of the nicest things about houses is that they are uniquely designed, and each unique design calls for unique considerations. Design considerations for houses include several factors, but since the final set of design drawings, also known as construction drawings or working drawings, guide the actual construction, these residential construction drawings are critically important. Let’s try and understand exactly what construction drawings are and how they may change according to the different type of houses under construction.

What construction drawings aim to do is provide contractors, fabrication suppliers and even owners an accurate dimensional and graphical representation of the finished structure. The contractor uses these for the actual construction, the suppliers can use these to fabricate, assemble or install components, and the owners can view in detail what their building will look like. These drawings include ‘production information’, specifications and bills of quantities provided by designers to the construction team. Residential construction drawings are part of tender documentation and contract documents. They are legally important and constitute a major part of the agreement between employers and contractors.

What makes construction drawings so crucial is their accuracy and the fact that they are concise and coordinated. Details specified include the materials, standards, techniques, etc. needed to start and maintain construction. Graphic details include component arrangement, detailing, dimensions, layouts and installation methods. All of the details are drawn to scale as part of elevations, plans, sections and detail drawings.

Construction drawings typically contain separate trade drawings, e.g. mechanical, electrical, plumbing and fire. Standard architectural hatchings and symbols enable trade professionals to easily decipher and understand them.

Using Building Information Modelling (BIM) facilitates the development of coordinated 3D models with sufficient information to manufacture, install or construct each element represented in the models, and these models help develop clash-free drawings.

In brief, construction drawings include the following information:

• Foundation Plans – plans that include footing dimensions and locations
• Wall Framing Plans – plans that include lumber sizes - usually 2x4 or 2x6
• Sub-floor Plans – plans that show the arrangement of services
• Roof Plans – plans of the building’s roof, including type, pitch and framing
• Interior Elevations - drawings of interior walls
• Detail Drawings – drawings of built-in shelving, mouldings and columns
• Schedules – lists of the quantities of each element, such as windows and doors
• Structural Layouts
• Electrical and Telecoms Drawings - plans that show where outlets, TV sockets, switches and fixtures are located and where electric lines should run
• Plumbing Schematic Drawings – plans that show piping and plumbing fixtures

An additional type of drawing included in the set of construction drawings for most projects

are reflected ceiling plans. A reflected ceiling plan is a view while looking up at the ceiling, involving the location of light fixtures, ceiling level changes and moulding locations.

Considering the major drawings in detail, we look at exactly what information lies within.

Exterior & Interior Elevations

Exterior elevations are straight scale drawings of exterior sides – front, rear and both sides. Information included are the exterior shapes, floor-to-floor heights, building height, openings, exterior wall doors or windows, the fall of the land, exterior finishes, ridge heights, roof pitches and exterior architectural styling details. Interior elevations include the inside view of each wall, room height, wall openings, finishes, cabinets and wall-mounted elements.

Building & Wall Sections

The view resulting from an imaginary vertical cut or cross section of a house’s interior is known as a section. These include internal finishes, ceiling height, ceiling type (flat or vault) and window and door dimensions.

Exterior & Interior Details

Exterior and interior details consist of elements, materials and information resulting from zooming into specific exterior or interior areas through a horizontal cut, vertical cut or elevation.

Schedules

Information about materials used in a specific area defines a schedule. An example would be a door schedule. This would represent information such as the total number of such doors, different door types, their location and material types on a single drawing. Similarly, there are schedules for windows, room finishes, cabinetry, plumbing fixtures and appliances.

Framing & Utility Plans

Structural drawings that show the floor and roof framing members, the material size and the location of the weight acting on the framing members (or loads) are known as framing plans. Elements of the major trades – mechanical, electrical, plumbing and fire – and the element locations and appliances are part of the utility plans.

Site Plans

A view of the building from the top that includes the construction site, lot boundaries, location of utility services, setback requirements, easements, driveways, walkways and topographical data with the terrain slope make up the site plans.

Floor Plans

This overhead view shows wall width with scaled parallel lines, room dimensions, doors, windows, built-in elements, such as plumbing fixtures, cabinets, water heaters and furnaces. Floor plans can include data regarding finishes, construction methodology or electrical element symbols.

Completing a set of construction drawings involves regular and constant dialogue between the project’s stakeholders and depend on the type of house being constructed. The considerations vary for different types of houses, such as: single story vs multi story, built on site vs prefab, smart houses vs traditional houses, environment friendly, etc. Types of houses can also be dependent on the number of stories they have. For instance, single-storey houses consist of just one floor, and a multi-storey building features multiple storeys and has vertical circulation, such as ramps, stairs and lifts.

Multi-storey buildings can be classified as:

• Low-rise - buildings of 4 storeys or less
• Mid-rise - buildings of 5 to 10 storeys, with lifts
• High-rise - more than 10 storeys
• Skyscraper: 40 storeys or more
• Super-tall: more than 300 m
• Mega-tall: more than 600 m

 These multi-storey buildings must consider the design of the following features in great detail: 

• Access and circulation
• Fire safety and evacuation
• Structural design
• Ventilation
• External air movement
• Shading, views and right to light
• Construction methods
• Access for maintenance and cleaning

Houses built on site and prefab houses are different in a number of ways and thus must be designed accordingly. Site-built homes are built entirely on the site. They typically use 2 by 4s and 4 by 6s precut wood for framing and trusses and follow all state, local or regional codes at the site’s location. Prefab homes or modular homes are manufactured in sections at a factory, transported to the site and joined by contractors. These homes can be built on non-removable steel chassis.

Modular homes are becoming an increasingly popular choice for several reasons. They are manufactured with sustainable materials and have many features, such as house orientation, good ventilation, insulation and shading, designed during the early stages. Solar power and greywater systems can be easily incorporated into modular homes during design, resulting in less time and money being spent on the actual construction.

Modular houses can be created using recyclable materials and do not typically use timber, making them environmentally friendly. Also, modular houses can use ‘green’ lighting and HVAC options. These homes can be designed for further future expansion, helping to relocate them, if required.

For all its advantages, design considerations for modular homes must take into account certain restrictions imposed by the location of its site and the incompatibility of luxury buildings. Some zones specify that only brick houses can be constructed there, mainly in housing estates, though it is possible to build a modular home with a brick façade. Some sites are not easy to access, making it difficult to transport modular houses to the site. The materials and style that are compatible with modular houses may not depict luxurious design.

Besides prefabricated homes, trends indicate an upward trajectory in the use of smart buildings. A building that employs automation to remotely/automatically control heating, ventilation, air conditioning, lighting, security and other systems can be considered a smart building.

These buildings use sensors, actuators and microchips to collate and manage data for the functions and services of a house. Intelligent and adaptable software is installed to link the core systems of lighting, power meters, water meters, pumps, heating, fire alarms and chiller plants with sensors and control systems. Smart houses are fully integrated and can have automated/sensor-driven elevators, access systems and shading.

Energy use can be minimised by utilising chilled water systems to continuously monitor HVAC set points, heat loads and demands. Smart systems connected to weather stations can use information on heat, humidity, wind, rain and cold for optimum and energy-efficient HVAC usage. Occupants of a smart home enjoy a higher quality of life with smart lighting, thermal comfort, improved air quality, security and sanitation, with lower costs and leaving a smaller carbon footprint than those living in a traditional home.

An important part of residential construction drawings is ensuring conformity to codes and standards of specific areas. In general, there are few restrictions on site-built houses other than minimum sizes and restricted covenants. Developments are increasingly allowing modular houses and smart homes.

To conclude, accurate and precise drawings for building design can be created by experienced and technically qualified professionals, which helps to ensure that any kind of house type can be developed with adequate design consideration. With the ease of outsourcing procedures, high-quality building and planning drawings are affordable and technically near-flawless.

Design HVAC for Modern Office Facility

Much like office practices and workflows, modern offices are changing. They are designed to be more open than in the past, which consisted of a ring of private cabins or offices surrounding clusters of cubicles in the centre of the office floor. The open plan design calls for alternative considerations for heating, ventilation and air conditioning, or HVAC duct design.

Cubicles are increasingly replaced with workspaces created for specific activities, such as team lounges, fitness centres and large work tables for discussions and collaboration on team projects. The HVAC system consumes a significant portion of all energy needs in a building, and changes in the office layout will impact the HVAC design. Thinking and planning for HVAC design in an office space needs to begin as early as possible when considering renovation or a new project to save energy costs.

Design goals for office buildings are based on the fundamental principle of ensuring health and safety to those occupying those buildings. Ventilation, therefore, is required at all times and must eliminate or minimise pollutants. The measure of air flowing in or out of a space is cubic feet per minute or cfm. Generally, a person needs up to 30 cfm of outdoor air, and an ideal comfortable temperature is between 20 and 24ºC with 20-60% relative humidity. The efficiency of HVAC systems design makes these conditions possible.

Some of the key strategies for efficient HVAC systems design in modern offices include:

Reduction of Cooling Loads

Well insulated walls, floors and windows are a must. The use of natural light for a healthier workplace is becoming increasingly accepted as the norm and for the reduction of heating loads during the winter season. For warmer climates, tinted low-e glass can help avoid solar gain (solar heat gain or passive solar gain), which is the increase in thermal energy resulting from the absorption of solar radiation, and reduce cooling loads. Low emissivity glass, or low-e glass has a super-thin transparent coating that reflects infrared energy or heat. This glass minimises both ultraviolet and infrared light passing through it without affecting the visible light that is transmitted.
Lights that automatically switch off during sufficient daylight conditions are a useful energy-saving idea, which can work as a complement to cooler lighting options and will generate less heat, thus reducing cooling loads on the HVAC system.

HVAC System Size

It’s important not to install an HVAC system that is too big for the energy needs of the office concerned. Oversized air conditioning systems typically create discomfort during the day. Such systems generally switch on and off continuously and are not efficient in removing humidity, resulting in an office area that is predominantly humid and dotted with hot and cold spots. More than just square footage needs to be considered in calculating HVAC load requirements. Computer simulation can accurately analyse building materials, daylight, lighting design and space activities affecting HVAC loads.

Zones

Multiple zones with independent temperature controls within a large open space translates to greater efficiency and comfort. Different areas in open spaces have different temperature requirements, such as:

• Perimeter areas, which need separate controls, as they are more susceptible to weather
• Computer rooms, which have special temperature needs and controls
• Conference rooms and other areas that host large gatherings of employees, which need more cooling while in use and less when empty 

Modern offices with fewer internal walls make these design details tricky.

Sensors
Smart buildings use sensor technology, mainly with two types of sensors – light sensors and occupancy sensors. These can be incorporated with HVAC design early in the design stages. Light sensors sense the amount of daylight available and adjust lighting accordingly. They can be connected to the HVAC system to maintain heating and cooling. Occupancy sensors track the number of people in a given space at a given time. They communicate with HVAC controls to regulate temperatures. During a large meeting, for example, occupancy sensors help increase cooling for the area concerned.


A ‘Sensible’ Option
Environmental sensors lead to cleaner, healthier air. Sophisticated sensors provide real-time data on air quality, revealing the surprisingly unhealthy current conditions of most offices worldwide and a related reduction in productivity. Studies show that a 670-sq ft office with 15 employees can generate CO2 levels of 1,000 parts per million (ppm) in under 8 hours. This is equivalent to 2.5 times atmospheric carbon dioxide levels and at a level that may cause 15% decrease in cognitive performance in employees. Meeting and conference rooms, naturally, are even worse, with 3,000 ppm, significantly decreasing productivity.
Organic compounds from furniture and carpets combine with these high levels of carbon dioxide to increase fatigue in employees and decrease productivity. In some cities, windows cannot be opened due to the toxicity of the smog outside. Indoor air quality could be improved with HVAC systems that react to carbon dioxide and airborne particles. This could be achieved by pulling in fresh air and filtering out pollutants.


Under-floor Air Distribution
Typically, air conditioning cools a space using overhead air distribution. This method may not be ideal and less energy efficient in open spaces with high ceilings. Use of under-floor air distribution is a popular trend today. Diffusers are installed under a raised floor, transmitting cool, air-conditioned air throughout the space. Stratification moves warm air upwards to the ceiling and cooler air-conditioned air replaces it at ground level. This method has been found effective in providing continuously comfortable conditions and maintaining better air quality.

Ventilation
An effective HVAC design must control humidity, eliminate odours and remove dust, carbon dioxide, bacteria and viruses that may contaminate the space and spread illness. In an open-plan office, this is critically important. The correct indoor air quality must be regulated and maintained for the well-being of employees and their productivity. Sufficient intake and distribution of outside air and the controlled circulation of conditioned air is a mandatory requirement of efficient HVAC design.

Experts’ Design
Whether renovating or creating from scratch, professionals from the field, such a HVAC mechanical engineering consultants, must be taken on board right from the early stages to avoid costly errors at later stages. Consultants will utilise their professional HVAC design and drafting skills to produce high quality HVAC shop drawings, which can then be coordinated with other trades.

Open Windows
Decades ago, offices had windows that could be opened. Currently, most offices worldwide are air conditioned and air tight. Windows that can be opened help control energy consumption and give people greater control over their work environments. But skyscrapers with offices don’t have windows that open or have access to fresh air during a work day. Why? Well, some of the reasons for permanently closed windows are:

1. To prevent cooled, air-conditioned air from escaping and unfiltered air, noise, rain and insects from entering
2. That offices are wary that people may fall out or jump out, resulting in the offices and management being held responsible
3. That some employees may open windows on a hot day, making the air conditioner work harder
4. That in keeping with modern architecture, open windows are unfashionable and they disturb the lines of the building
5. That with many employees on any floor, natural ventilation is near impossible
6. That energy is saved, increasing productivity

Facts show that these concerns are no longer concerns. A naturally ventilated, intelligently designed office building can halve the energy consumption of constantly air-conditioned buildings. A naturally ventilated building need not support intense and constant HVAC system needs. Ventilation that is natural and access to fresh air contributes to an increase in productivity. A connection to the outdoors, a perception of control and better overall health are beneficial side effects of natural ventilation. The design of HVAC systems in an office facility thus has a direct bearing on the productivity of the office’s inhabitants.

With the help of qualified and experienced HVAC mechanical engineering consultants, a comfortable, safe and secure office building may be constructed with the right HVAC shop drawings. In the global environment of outsourcing MEP (mechanical, electrical, plumbing) design services, the quality, expertise and experience required can be found overseas, resulting in cost-effective, precise HVAC design and drafting.

The Challenges of Coordinating Risers

For modern buildings, risers carry the very life blood of a comfortable space. Much like an arterial system, different kinds of risers perform various necessary functions for the health of a building. They are conduits or carriers of fluids, fuel or air. Coordinating risers is critically important within the workflow of MEP coordination and clash detection, and this can be challenging at times. Challenges generally occur with hydraulic services design during renovation of older buildings. Let’s look at how that may happen.

Well, first off, what is a riser?

Also known as a vertical riser, a riser is a void that contains a duct, pipe or conduit or a combination of all services that rises through a building to carry or transport gases, fluids or electrical signals in the form of piping. In general, a dry riser is an empty, or dry, pipe used to carry water for firefighting systems, and a riser cable can deliver electricity or communications between several floors. Looking at risers in more detail, they can be:

1. Vertical Riser Ducts
As mechanical pipes and electric cables are aesthetically unappealing, typically they are hidden away in vertical riser ducts. These ducts must be strategically placed to minimise pipe lengths and cable runs, thus cutting costs. Pipes must run unhindered vertically in ducts, especially sanitary waste pipes, so that this waste water need not navigate bends in pipes. Since vertical risers cut through floors and can be vulnerable for the spread of fire, they must adhere to strict guidelines.

2. Vertical Riser Cables and Pipes
Sometimes, it is practical to have risers exposed. Servicing becomes easier. Cables connect to sockets and light fittings to riser conduits mounted on walls and columns. Cables and pipes that travel through floors are covered with fire-protected collars, to prevent the spread of fire through them. Increasingly, services pipes are becoming part of the décor.

3. Wet and Dry Risers
Vertical pipes, that are both wet and dry risers, run the full height of a building and are built near stairs to provide a direct water feed to each floor in case of fire. Dry risers have ground coupling pipes outside the building that can be connected to an external water source in case of emergency. Wet risers are connected to the building’s water supply.

4. Dry Risers in Fire Fighting
A dry riser usually includes the following:
Inlet Box

1. Made of galvanised sheet steel, for recessed mounting, with architrave
2. Has a hinged, lockable door with a panel glazed with wired glass, so that the lock can be opened after breaking the glass. 
3. Hoses can be connected to inlets without opening the door.
4. Large enough to access for maintenance and operate the drain valve

Inlet Breeching

1. A two-inlet breeching, with instantaneous male coupling, back pressure valve, blank cap and chain
2. Has a gunmetal gate valve for drain purposes, with plug and chain

Landing Valves

1. Straight or oblique gunmetal gate pattern valves, with flanged inlet, instantaneous female outlet with blank cap and chain, fixed with a leather strap and padlock
2. Lined and coated with woven synthetic fibre hose and diffuser branch pipe nozzle
3. Valve, hose and nozzle in a box, on purpose-made hangers

Air Release Valves

1. Brass automatic air release valve, with a rubber ball inside

For a tall building with the same floor layouts (e.g. apartments), the riser equipment/elements will change size as they move down or up the building. As such, a section of each riser will show slightly different sizes, especially for ductwork, which is why a drawing is created for every floor, even when the rest of the floor is the same.

With a variety of risers to deal with in the MEP (mechanical, electrical and plumbing) sector, it is crucial that the MEP systems coordination workflow, especially with regard to hydraulic design of liquid or water piping systems, is efficient. Technological advances and the innovations they enable have been a prime factor in fuelling this efficiency. In the construction industry, BIM (Building Information Modelling) has been driving immense change in the MEP coordination process and the delivery of MEP coordination drawings.

The use of BIM technology has made equipment tracking and task monitoring easier. Covering almost every aspect of a construction project, the BIM process involves project managers, subcontractors, designers, architects and other construction professionals participating in controlling individual processes and project phases, with a smooth exchange of information during the larger MEP coordination process.

Increasingly, the trend in the AEC (architecture, engineering, construction) sector is to design 3D models for 2D construction documentation and 3D trade coordination. Generally, the trade design or MEP design follows the architectural design stage. Trade professionals, such as HVAC mechanical engineering consultants and others, collaborate with architects to design mechanical, electrical, plumbing, fire prevention and fire protection services. A consultant or MEP contractor ensures that the MEP design is efficient, clash-free and installation-ready. At this point, fabricators who create ductwork or pipework components, electrical ladders or module sprinklers share their input. Thus, a fully coordinated 3D model is developed that can be used for clash detection.

Subcontractors (for the different trades) can virtually place systems as shown on detailed design drawings with individual elements, which include risers, offsets, hangers, conduits with required radius bends and cable trays. Other elements to consider include data communication lines, fire protection system controls and process piping.

At this point, challenges may arise, especially during the renovation of an existing structure. Some of the circumstances that may contribute to challenges in installation of risers include:

• Riser replacement in an existing building – opening up walls creates a mess, dust and debris throughout the premises and destroys expensive decorative finishes that were lovingly installed. In older buildings, asbestos can be destroyed, as well as lead-based paint that has peeled off.
• Existing plumbing risers may be difficult to handle after years of corrosion, because rust makes steel pipes brittle.
• As hot and cold risers behind kitchens and bathrooms are replaced, tiles, cabinets and walls must be removed.
• Risers must be replaced entirely or not at all, since new risers attached to old risers can break.
• Accessing risers takes time and money.

Signs that risers need replacement are hard to miss. Upper floors will experience low water pressure. Debris will appear in the water – bits of corroded pipe in sinks, showers and bathtubs. Time is an indicator. Galvanised steel pipes last for about 50 years, accumulating scale and rust inside, while brass lasts for nearly 70 years. Copper pipes last even longer. Coloured water is a definite indication of rust and scale accumulation. Also, excessively hot showers are a result of clogged plumbing risers that reduce the flow. The need to replace existing risers during renovation introduces different kinds of challenges for coordination.

- For example, during the renovation of an existing building, one of the chase walls was opened, and a large conduit was installed inside a duct chase against an exhaust duct riser, causing a clash in the planned duct connection. A coordinated model showed ductwork and risers in the limited space and how their placement could be manoeuvred to avoid the clash, guiding the fitting of components to meet the design requirements.

- In another building, the floor-to-floor height was 20 feet, generally enough for ductwork and piping from air handlers to central core chases. In this case, a chilled water piping that was routed only 10 feet above the floor and close to the AHUs (air handling units) and supply and return ducts, next to the shafts, made for difficult coordination. Ductwork from 2 AHUs had to pass above the chilled water piping and between hanger rods. Coordinated design drawings showed a more efficient duct placement.

- Yet another example involved duct and pipe routing between an existing main electrical room and adjacent AHUs. The electrical room had floor-mounted AHUs right outside, and the adjacent AHUs had disconnect switches and variable frequency drives (VFDs). Coordinated MEP drawings and 3D modelling showed that the chilled water piping to the electrical room AHUs had to be moved, as did the larger AHUs and VFDs, allowing the ductwork and piping to be placed with the correct amount of clearance.

Easing MEP Coordination
Forming a key part in setting up and laying out design, MEP coordination is a key means to connect building elements and make the structure functional. Earlier during MEP coordination, drawings were overlaid and compared and spatial and functionals interferences, or clashes, were dealt with by multi-trade professionals. This method needed countless revisions before the finalisation of the coordinated drawings, but BIM processes changed all that. The BIM workflow involves a 3D approach and data-based reasoning to help MEP contractors plan, design and install equipment, including risers, efficiently.

Using BIM technology, a once-prolonged and tedious process fraught with delays, insufficient data and miscommunication, is now smooth and efficient. A building’s MEP systems are seamlessly integrated and coordinated with architectural and structural systems, creating clash-free models.

The placement of elements of MEP design, such as risers, can be intelligently designed and laid out. Tools, such as Navisworks, enable clash-free designs, with multi-disciplinary integration in one work environment. Flawless MEP coordination drawings are produced.

The Revit Solution
Creating a 3D model with Revit software enables easy coordination during design, and clash detection can be performed with Navisworks. So, early on in the design process, the model can be coordinated with architectural design and MEP design that includes risers. The models of new buildings and those of existing buildings will have differing degrees of efficiency, since existing buildings contain unknown elements, spaces and conditions which may not be represented in models.

The good news is that with BIM-enabled MEP coordination, most of the challenges concerning the design, layout and clashes of risers in MEP systems is eliminated and smooth coordination results. Those firms that find it difficult to provide hydraulics and plumbing design services and MEP coordination services may consider online collaboration and outsourcing, which is efficient, accurate and cost-effective, for the delivery of precise MEP coordinated drawings as part of the hydraulics and plumbing design services and MEP coordination services. Managers can retain full control of the project, resulting in faster delivery.

Advantages of Revit Family Creation in BIM Technology

Similar to biological families, Revit families follow a certain order. For instance, a door is a ‘category’ of different components. There are different kinds of doors, and these different kinds of doors are different ‘families’. An example of a ‘family’ name would be a ‘flush door’. Within the family of the flush door, there are options for the flush door, based on dimension, material, etc. A flush door of a particular dimension is a ‘type’ of flush door. All the elements in a project’s design are created using families, including walls, roofs, doors, columns, beams, trusses, windows, fixtures, annotation, mechanical components, plumbing fixtures, lighting fixtures and other detailed components, and they can be created using Revit for BIM (Building Information Modelling) requirements in architectural design drafting.

Revit family modelling within the BIM context provides a range of advantages, namely:

• Improved layout plans
• Increased communication of plans
• Impressive Revit 3D modelling for marketing
• Detailed scheduling
• Customisation of projects

The creation of BIM models requires the extensive use of families. Walls, doors, windows, stairs, etc. may be of multiple types in the same project. A prime advantage of Revit families is that any change to a type will be updated in every instance of that type throughout the project design. For example, when the height of a window type is changed in one place, all windows of the same type will be modified instantly and automatically throughout the entire design.

The intelligent model-based process of BIM technology helps plan, design, construct and manage buildings and infrastructure and results in delivering specific outcomes with time and cost savings. Revit families and BIM content can be created for architectural, structural, mechanical, electrical and plumbing design. The process to deliver Revit families with high standards includes:
 

1. Selection of the family template
2. Planning the parameters
3. Creation of the model geometry
4. Assigning of the object subcategories according to requirements
5. Setting up visibility rules
6. Creation of family type

Revit allows created families of components to be stored and reused in other projects. They can be used as reference material by architectural designers to show prospective clients.

Builders, manufacturers, designers, engineers and other stakeholders in a project are dependent on model creation services for intelligent and parametric models that can host a complete group of components or equipment for BIM construction. Besides displaying the parameters of actual equipment and geometric components of windows, boilers, columns, etc. through graphics, Revit family modelling has other advantages, such as:

• Formula and imported data result in effective component design
• Regardless of size and design, the models created are accurate
• Resizing of models is both possible and economical
• Relationships and coordination between various elements of a unit are maintained
• Enabling building analysis and estimating

Revit modelling can create additional items like curtain wall panels, furniture, plumbing fixtures, electrical fixtures, machine parts, elevators and HVAC pumps. Family creation services include the following types:

• Structural
• Architectural
• MEP
• Building systems
• BIM
• Related custom and supporting content

Revit family creation, like real-life families, provides many benefits due to the inter-relationships they provide in a model. They are the driving force behind the success of BIM projects. With skilled Revit BIM practitioners available globally, accurate, cost-effective and viable project design services can be ensured.