Decoding the Ductwork Design Process, Methods and Standards

Today, one of the significant objectives in MEP engineering design for HVAC design engineers is to improve energy efficiency, maintain air quality and thermal comfort. Energy efficiency, air quality and comfort in a building depend on how heating, cooling and air distribution systems are designed and this is where careful ductwork design plays a significant role. Ductwork and HVAC system design are important as it ensures indoor air quality, thermal comfort and ventilation. If the HVAC system and ducts are not designed accurately, it could lead to poor air quality, heat loss and make the conditioned space in the building uncomfortable.

The primary function of the ductwork design system is to ensure a least obtrusive channel is provided through which cool and warm air can travel. When designed accurately, HVAC air distribution systems will play an important role in countering heat energy losses, maintaining indoor air quality (IAQ) and providing thermal comfort.

To understand how ductwork can be designed in a cost-effective and efficient manner, this article decodes ductwork design and provides a brief outline of the design process, methods and standards.

What is Ductwork?

The basic principle of ductwork design is to heat, cool or ventilate a building in the most efficient and cost-effective way. The primary function of ductwork is to design conduits or passages that allow air flow to provide heating, cooling, ventilation and air conditioning (HVAC).

In the duct design process, the basics of air flow must be understood. Return air goes into an air handler unit (AHU), through a filter and into the blower and with pressure it goes through the A coil or heat exchanger and then it goes out into the supply air system. If the ductwork is designed correctly it enables the AHU to produce the right amount of air through the heat exchanger. In a typical air distribution system, ducts must accommodate supply, return and exhaust air flow. Supply ducts provide air required for air conditioning and ventilation, return ducts provide regulated air to maintain IAQ and temperature and exhaust air flow systems provide ventilation.

For ductwork design to be efficient, MEP engineering design teams need to have designers with a mechanical and engineering background. Ductwork design specialists or building service engineers must also possess thorough knowledge of other disciplines such as architectural, civil and structural concepts to ensure HVAC systems are clash free.

The Ductwork Design Process

The ducting system design process is simple, provided that the specifications are clearly mentioned and the inputs regarding application, activity, building orientation and building material are provided. Based on the information provided calculations can be completed to create an energy-efficient and clash-free design. Typically, air conditioning and distribution systems are designed to fulfil three main requirements such as:

• It should deliver air flow at specific rates and velocity to stipulated locations.

• It should be energy efficient and cost effective.

• It should provide comfort and not generate disturbance or objectionable noise.

The process of ductwork design starts once architectural layouts and interior design plans are provided by the client or MEP consultants. Building service engineers then require specification requirements such as application, the number of people, the orientation of the building and architectural characteristics to make calculations on heat load and air flow. Before any calculations are carried out, single line drawings are drafted to showcase the flow of ductwork in the building. Once they are approved, calculations for heat load and air flow are conducted. Once the heat load calculations are complete, the air flow rates that are required are known and the air outlets are fixed. With the calculations, specifications and layout, the ducting system design layout is then designed taking into consideration architectural and structural details of the conditioned space and clashes with other building services such as electrical, plumbing (hydraulic) and mechanical services.

To start the ductwork design process there are inputs required regarding details about the type of application, specification requirements, building orientation, architectural characteristic and material.

• Application type - Ductwork design will vary based on the type of application the building will be used for such as manufacturing, data centres, medical applications, scientific research and comfort applications such as restaurants, offices, residences, institutional building such as schools and universities.

• Specification requirement – To create an efficient duct design, designers need to know what type of activity will be conducted and the average number of people that will use the conditioned space. This will help in calculating the air flow, velocity and heat load required to maintain temperatures and IAQ. In comfort applications, for instance, an office or restaurant will require different duct design and air velocity than a residence.

• Orientation and material of the building - The orientation of building and material used plays a key role in gauging heat absorption which will help determine the cooling and ventilation requirements. Based on whether a building faces north, south, east or west, and where it is geographically located, heat absorption can be calculated. The type of material used for construction also affects the amount of heat gain and loss of the building.

The challenges of incomplete inputs or non-availability of required inputs are discussed in an upcoming article on Ductwork Design Challenges and Recommendations.

Ductwork Design Methods

Ductwork design methods are usually determined based on the cost, requirements, specifications and energy efficiency standards. Based on the load of the duct from air pressure, duct systems can typically be classified into high velocity, medium velocity and low velocity systems. There are three commonly used methods for duct design:

1. Constant Velocity Method – This method, designed to maintain minimum velocity, is one of the simplest ways to design duct systems for supply and return air ducts. However, it requires experience to use this method as the incorrect selection of velocities, duct sizes and choice of fixtures could increase the cost. Moreover, to maintain the same rate of pressure drop in duct runs, this method requires partial closure of dampers in duct runs (except index run) which could affect efficiency.

2. Equal Friction Method – This conventional method used for both supply and return ducts maintains the same frictional pressure drop across main and branch ducts. This method ensures dissipation of pressure drops as friction in duct runs rather than in balancing dampers. However, like the velocity method, partial closure of dampers is required and this could lead to noise generation.

3. Static Regain Method – This method commonly used for large supply systems with long ducts is a high velocity system that maintains constant static pressure before each branch or terminal. While this is a balanced system as it does not involve dampering, longer ducts may affect air distribution to conditioned spaces.

While different duct design methods used vary from application to application, duct system performance and system balancing and optimisation need to be considered. After the air handling unit (AHU) is installed, the system needs to be balanced and optimised to enhance performance. In system balancing and optimisation, air flow rates of supply air outlets and return air inlets are measured, and dampers and fan speed are adjusted. Especially in large buildings, balancing air conditioning systems may be expensive and time-consuming, but it is required as it provides benefits that outweigh the cost incurred in installing the system. To minimise total and operating cost, many optimisation methods are used as such as the T-Method Optimisation described in the DA3 Application Manual of AIRAH (Australian Institute of Refrigeration Air Conditioning).

To design air distribution systems that are energy efficient and cost effective, HVAC system designs must include basic engineering guidelines and adhere to certain design standards. Let us consider some of the guidelines and standards used in the industry in different countries.

Ductwork Design Standards

When designing air conditioning systems, HVAC design engineers must be knowledgeable about the basic methods, guidelines and standards applicable, from the type of units used, calculations required, methods of construction, type of material, duct system layouts, pressure losses, duct leakage, noise considerations to optimisation using testing, adjusting and balancing (TAB). Listed below are some of the standards organisations and associations in the U.S., U.K., Australia and India, that provide manuals, codes and standards for the HVAC industry.

U.S.

• SMACNA (Sheet Metal and Air Conditioning Contractors’ National Association) – It provides a manual on HVAC systems duct design that includes basic yet fundamental methods and procedures with importance on energy efficiency and conservation. While the manual does not include load calculations and air ventilation quantities, it is typically used in conjunction with the ASHRAE Fundamentals Handbook.

• ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) – It is an association that emphasises on the sustainability of building systems by focusing on energy efficiency and indoor air quality. The ASHRAE Handbook is a four-volume guide that provides the fundamentals of refrigeration, applications, systems and equipment. Updated every four years, the handbook includes international units of measurement such as SI (systems international) and I-P (inch-pound).

U.K.

• CIBSE (The Chartered Institution of Building Services Engineers) – is the authority in the UK that sets standards for building services engineering systems. The Codes and Guidelines published by CIBSE are recognised internationally and considered as the criteria for best practices in the areas of sustainability, construction and engineering.

• BSRIA (Building Services Research and Information Association) – is an association that provides services that help companies enhance their designs to increase energy efficiency in adherence to Building Regulations, mock-up testing of systems and BIM support.

Australia

• AIRAH (Australian Institute of Refrigeration Air Conditioning) – provides technical manuals for professionals in the HVAC industry and information ranging from air conditioning load estimation, ductwork for air conditioning, pipe sizing, centrifugal pumps, noise control, fans, air filters, cooling towers, water treatment, maintenance, indoor air quality and building commission.

India

• BIS (Bureau of Indian Standards) – is a national authority that provides standards and guidelines as per the International Organization for standardisation (ISO). The handbooks by BIS stipulates the code of practices applicable to the HVAC industry such as safety code for air conditioning, specification for air ducts, thermostats for use in air conditioners, metal duct work, air-cooled heat exchangers and data for outside design conditions for air conditioning for Indian cities

• ISHRAE (The Indian Society of Heating, Refrigerating and Air Conditioning Engineers) – provides indoor environmental quality standards and testing and rating guidelines based on common IEQ parameters standards and criteria for the classification of buildings based on energy efficiency.

While HVAC design engineers must keep relevant standards in mind and ensure that local codes are applied in designs, energy efficiency is a primary objective as well. Ductwork design plays a significant role in regulating indoor air quality, thermal comfort and ventilation. The key function of ductwork design is to provide the least obtrusive channel through which cool and warm air can travel in the most efficient and cost-effective way.

Inaccurate duct designs could result in poor indoor air quality, heat loss and uncomfortable conditioned space in the building. A well-designed air conditioning HVAC system will ultimately optimise costs. By regulating pressure loss, selecting the right duct size, balancing air pressure and controlling acoustics, ductwork designers could optimise manufacturing, operational, environmental and commissioning costs.

 

Trends That Set You Apart: SEO Techniques That Every Web Designer Should Know

If it was a decade back, then the term ‘SEO’ and web designing wouldn’t have gone parallel. But today the thing is something different. The web-smart world wants more from us and being exclusive is the first requirement of the customers. Webbing the business in a smart way along with decorating and designing the website for a fresh promotion is the new in nowadays.

Web designing incorporates a lot of strategical tasks and implementing them one by one enhances the front-end beauty of the website. It combines a lot of work with the frameworks, the programming languages, CMS or Content Management System, pre-decorated templates, web designing tools and hosting platform. On the other hand, it takes a lot of planning, sketch, graphical designing and strategy building for designing websites. A web design company deploys professional and experienced web designers who will perform all these tasks single-handedly.

The major job of a web designer is to produce the perfect UI & UX designs that will allure the viewers with its unique design. But, today, most of the web designers need to know about a little bit of SEO that will help them to understand its significance in terms of generating traffic to the website and allows them to comprehend its importance in the designing field.

SEO or Search Engine Optimization involves the process of optimizing the website by analyzing the site itself. This is connected to the designing and coding of the website for which the designers should be in the practice of these methods. So, that is why the designers should keep in mind certain things before designing the website.

Mobile Responsive Design
The demand for the mobile first designs has taken the interest of the consumers due to the major shift of searching methods from desktop to mobile. As the huge number of customers is using the smartphones nowadays and search almost everything from their smartphones instead of switching on their desktops and PCs, designing responsive websites has become a necessity for the entrepreneurs for increasing the visibility of their websites. The emergence of Google’s mobile-friendly algorithm has also facilitated the mobile responsive search results, pushing backward the nonresponsive websites in terms of amenity.

This has invoked the designers to use the mobile responsive templates and tools. The designers should use coding & programming that is utterly suited for mobile. The contents should be fit in the screen resolution of the mobile and the layout should be mobile first for the smooth access from the smartphones or cross platform devices.

URL Orientation
Search engines can’t find ambiguous and vague URL identity. The clear format of the URL makes your website SEO-friendly. With a perfect URL, the chances of getting the visibility to the viewers are more. Moreover, incorporating keyword phrases with the URL allows your users to identify and find the URLs easily and quickly. A designer should know about this so that they can easily collaborate with the SEO team of their respected companies.

Enhancement of the Website Speed
Improving the site speed is the major part of the SEO. Google’s algorithm supports the websites that have a good loading speed and disapproves the sites whose loading speed are worst! This is because the users don’t like websites with low loading speed and chances of the increase in the bouncing rate also raises up. Thus, improving the speed of your site is a much-needed thing, which can’t be optimized without the help of the designers. The speed augmentation process lies within the back-end service provided by the designers which include optimizing the database, minimizing HTTP requests, compressing images, reducing server requests, minifying resources, enabling the browser caches and accessing a CDN or Content Delivery Network.

Without the perfect knowledge of SEO and without the comprehension of the importance of site loading speed on SEO, the designers won’t understand its significance. So, for a perfect collaboration, the knowledge of site loading speed is required for the designers.

Pertinent Title Tags
Exclusive & relevant title tags are important for phrasing up an online document and those title tags are only used in the rich snippets aftermath. These title tags are displayed in the SERPs, on the browser, and on the external websites and should be smaller in size so that Google can easily catch them up.

Validated HTML5 And CSS3 Usage
HTML5 & CSS3 enables your website to fit in any resolution. HTML5 is advanced with much more features than the HTML and CSS3 enhance the downloading speed of the page. Authenticated HTML5 & CSS3 helps in implementing good coding that will optimize on-page SEO easily.

In most of the web design companies, the perfect collaboration of SEO and web designing teams is the major requirement because their harmony optimizes the entire website which results in bringing clarity on the front-end website with an aim of increasing more traffic and enhancement of conversion rate.

 

The Ultimate eCommerce Web Designers Trick

Either you’ll be able to go with freelance web designers or can hire total service web designers to get your internet presence, also called website. The very first reason to have your website is your engagement with the internet. There are lots of web designers out there. So when you’re looking to locate a fantastic web designer, the very first thing you’ve got to check is designing services that are quality oriented. Most reputable web designers know not to pick an internet host simply because they’re definitely the most popular or since they supply the cheapest web hosting.

The site designer may get the job done freely or even as a member of a company which is particularly into designing proficient stores. For instance, if you want non-profit website then non-profit website designers are the ideal choice for you. Moreover, flash designs might also be incorporated within the site to make it even more alluring to the clients. Designing an eCommerce website is an extremely professional undertaking. In case the website design of your site cannot pull and convert visitors, then it means your site needs improvement.

Being an owner of a company, you should select an eCommerce web designer that could comprehend the tasks of designing an eCommerce shop. A great designer is going to know that design and SEO go hand-in-hand. They are being snatched by agencies and large projects. They are creative people that need to think out of the box. A superb web designer ought to be in a position to comprehend the emerging trends in the market, the expected changes in web design, current and future trends as well as the most recent web development tools.

Your website design provider should use the ability of Social Media Marketing. Any expert web design company would help the consumers in many respects. An excellent web design company will have great search engine optimisation skills to publicize your website. It’s always preferable to opt for a great web design company that comprises of dedicated and seasoned employees.

So as to create a web site or an internet presence, one wants to employ a website design company. Also, make certain that the website design company ought to have a group of experienced web designers, developers, programmers and testers etc so that you are able to secure all kinds of services under one roof. A seasoned web design company is going to have a good portfolio of internet sites that they’ve created for different customers. New web design businesses are springing up all of the moment, but don’t be tricked by shiny sites loudly proclaiming their amazing services.

The Advantages of eCommerce Web Designers

The Web lets us market our services and products any place in the Earth, but to be able to actually earn a sale, we have to set a relationship that generates a sufficient amount of trust, confidence, loyalty and passion. Environmentally-friendly web hosting is getting more and more popular for business web sites appearing to implement an eco-policy. To rival a number of the biggest bands on the planet, websites have allowed bands the capacity to grow massive online fan bases through pay per view. The site ought to be downloaded as fast as possible. For example, the site of a company making and selling luxury goods needs to seem luxurious also.

If all the sites look alike there’s hardly any chance of the visitor remembering a specific website. Your website ought to have the ideal architecture with easy navigational keys. To acquire the excellent traffic at the site, it is necessary to create the website attractive. First and foremost you must seek out the video sites that will supply you the resources to make your own video. It is due to the fact that the site has to be unique. An eCommerce website is as fantastic as a digital store. eCommerce websites are designed in order to do the business needs.

A specialist site designer if technically sound enough may give a wholly different get until the site. A web site is your internet address which aids you reach customers in every corner of earth, no matter which corner you’re sitting in. In different cases you may employ your website for a lead generation tool where you don’t conduct financial transactions online. Yeah it’s true, your website is online but still you want to give a fantastic customer service online. There are several kinds of websites like eCommerce sites, social media sites, template-based sites, CSS websites and several more.

The Basics of eCommerce Web Designers

Our site brings you different types of explanatory videos to select from. Therefore, in case it’s not possible for the website to be made fully compatible with all browsers due to coding limitations, then the developer needs to understand the numerous types and versions of internet browsers employed by the majority of the website visitors. Creating your web site may be a tricky practice. Building an internet site is a very technical procedure, while designing an internet site is a very creative procedure. The internet site and social networking pages should complement one-another.