Using CFD to Optimise Green Building Design

 

As global warming spreads its tentacles, governments and industries are striving to get things under control again. For the construction industry, the design and creation of green buildings is a major weapon. These buildings need innovative MEP design engineering and a range of proper calculations involving wind analysis and sustainable MEP design to move towards making sustainable building design a widespread reality. Computational fluid dynamics, or CFD, has an integral part to play in the greening of buildings.

 

How do we define sustainable building design? 

Building design that epitomises sustainability aims to reduce the need for and use of non-renewable resources, minimise waste of resources and create healthy environments. Sustainability in construction also includes the creation or development of net-zero buildings, or buildings that produce as much energy as they consume, and natural ventilation methods to optimise air quality while eliminating or reducing the use of energy-inefficient HVAC systems.

 

As CFD is a mix of fluid dynamics, mathematical calculations and computer science, it offers architects a way to optimise sustainable building design. Prime areas targeted by CFD are: 

§  Exhaust system effects on the environment

§  Fire and smoke risks

§  Indoor environment quality

§  Natural ventilation systems

§  Load calculations for heating/cooling

§  Exterior wind loading

 

For HVAC system issues, CFD proves useful in analysing: 

§  Occupants’ thermal comfort

§  Wind loading analysis on a building

§  Acoustic path analysis

§  Airflow equipment

 

There are a number of benefits to using CFD analyses for green building design. However, before gathering data for calculations, it’s important to consider: 

§  Room depth

§  Natural ventilation and open spaces for the wind to deflect

§  Creation of alleys and patios to analyse room thermal pressure

§  Staggered layouts, which can become seasonal calm zones

§  Building envelopes at the entrances for proper indoor airflow

 

Once these factors are carefully considered and data is collated, CFD analysis can provide: 

§  Proper, reliable and affordable representation of fluid dynamics, such as ventilation, wind and smoke

§  Simulation options without physical testing

§  Accurate temperature, pressure, velocity data

§  Easier prediction of fluid movement in advance

§  Determination and improvement on the efficiency of the HVAC system and indoor air quality

§  Optimisation of ventilation to maintain a proper temperature

 

Maintaining a proper thermal flow and ventilation by designing an effective HVAC system is a fundamental goal in creating a green building.

 

As sustainable design gains credibility in global construction milieus, regulatory bodies are laying down guidelines, which may require the adoption of new tools. These tools will show policy compliance and solve energy-efficient design challenges. Using cloud-based simulation lets architects, engineers and other design professionals collaborate efficiently and quickly to make early design decisions.

 

Collaborating with cloud-based simulation and CFD simulation can help achieve sustainable design. How does this happen?

 

§  Building simulation software provides an accurate understanding of the critical relationship between energy needs, policy and a changing climate.

§  CFD simulates and analyses fluid motion through a series of calculations, enabling designers and engineers to model basic heat transfer methods and study the flow of air and water.

§  CFD can be used to test and validate design options so building design professionals can determine the right design to help reduce carbon emissions.

 

Analysis derived from CFD calculations can contribute to optimising thermal comfort, air quality and the conditions of the microclimate in a building, all leading towards the goal of sustainable design.

 

Thermal Comfort

Various complex factors must be considered by building designers to assess a building’s thermal comfort. Variables may include physical aspects and the effects of climate during different conditions, occupancy rate, air velocity and humidity, all of which directly influence the energy demands of the building and its environmental performance. It can be considerably beneficial to use CFD to determine thermal comfort and measure energy consumption. 

Air Quality

Simulation analyses and results can indicate and maintain healthy levels of indoor air quality and ventilation efficiency, while reducing energy consumption. 

Microclimate

The microclimate describes a set of atmospheric conditions that buildings must deal with, such as the effects of wind, sun, other buildings and potential severe weather. The microclimate can have a significant impact on building sustainability. Modelling of the microclimate and wind analysis can help design buildings to ensure occupants’ safety and comfort. 

It is even possible to use CFD to accurately model and evaluate the on-site impact of vegetation. 

As the importance of sustainable building design can only increase in the future, it is vital to find efficient and value-added sustainable MEP design, CFD analysis services and CFD simulation services sourced from reliable CFD consulting services.  

XS CAD has valuable experience providing CFD consulting services, sustainable MEP design, CFD analysis services, CFD simulation services and wind analysis for general contractors.  Our range of services for consultants and manufacturers across the world include HVAC design services.  We create these models and drawings using Revit, AutoCAD and BIM Collaborate Pro for cloud collaboration. 

Plumbing Design Challenges in the UK

 

In the United Kingdom, as in many parts of the world, plumbing or public health design has seen changes, advances and new requirements. Creating plumbing and piping plans can be difficult, as a building’s plumbing system typically consists of a complex network of water supply pipes, drainpipes, vent pipes, etc. Effective public health design can be complicated, and if not developed correctly, it can be one of the most expensive systems to repair. Understanding plumbing system design, both commercial plumbing design and residential plumbing design layouts, is one of the challenges of effective public health design.. 

Any system that enables the movement of fluids, involving pipes, valves, plumbing fixtures, tanks and other such equipment is called plumbing, or public health services. These systems have a variety of functions, such as: 

•   Heating and cooling water
•   Wastewater removal
•  Potable cold and hot water supply
•  Water recovery and treatment
•  Rainwater, surface and sub-surface water drainage 

One of the challenges for M&E engineers is to have access to precise design information to facilitate the effective planning of M&E systems layout. This is important in case of complex systems, especially in congested areas, which can be challenging to plan during the design stage. 

As Building Information Modelling (BIM) is increasingly used in construction, M&E engineers can have access to critical design information while being part of an efficient building workflow, ultimately resulting in fewer on-site errors and optimum systems design. 

Due to the different types of topography in the UK, the source of water depends on the area where it is required. Types of water sources are: 

• Upland catchment (reservoir)
• Ground water (borehole/artisan)
• River extraction

 These sources provide water of differing bacterial and physical qualities, such as: 

•  Hardness
• Bacteria count
•  Minerals

 To a great degree, these qualities are dependent on the environment, and with the effects of climate change and other looming environmental factors in play, households are hoping that technology will lead the way to greater efficiency in building services. 

Typically defined as the careful management and preservation of natural resources and the environment, environmental conservation takes into account climate change, ozone layer destruction and environmental pollution. These factors now have a considerable impact on building design. Regulations have been put in place to help space heating and hot and cold water services design. There is official support for all initiatives to reduce energy use and increasingly rely on renewable energy sources. Plumbing professionals in the UK are more than up for the challenge of deploying new technological advances to fulfil these requirements. 

Advances in technology have helped public health design in a number of ways, from smart pipes to water heaters without tanks. Plumbing professionals can now connect drain rods and pipe cutters to Wifi-enabled tablets and waterproof cameras. Some of the innovations that plumbing professionals are incorporating into public health services design are: 

Smart Pipe Systems: 

• Smart pipe systems, or brain pipes, are part of an increasingly popular home automation system. They help negotiate one of the biggest challenges in plumbing - detecting a leak early enough to prevent a large loss of water.
• Smart pipes monitor water pressure and identify the exact location of leaks, helping to repair the system while preventing significant damage. Thus, consumers avoid expensive repair and mould abatement. 

Hands-Free Faucets & Fixtures: 

• Mainly seen in airports and luxury hotels, motion sensor faucets are common in public restrooms for being more sanitary and reducing wastage of water.
• Now, homeowners are installing hands-free faucets.
• Also popular are no-touch toilets. More consumers want ultra-hygienic toilets that allow hands-free usem, resulting in efficient water use (fewer excess flushes). 

Tankless Water Heater Systems: 

Tankless water heater systems are so efficient that they can supposedly save more than 25% on annual water bills. 

Smart Shower Heads:  

• Today’s shower heads do more than give you decent water pressure.
• Advanced shower heads are Bluetooth-enabled to play music, creating a whole new generation of bathroom singers.
• High-tech shower heads have LED lights for displays of light and sound. 

Recycling Dishwasher Water: 

• Plumbing is changing how dishwashers use water.
• Dishwashers save significant amounts of water, and the latest dishwasher technology offers an option that recycles rinse water, reducing water usage by nearly 700 gallons annually.

 Greywater Recycling: 

• Greywater recycling technology recycles waste water from the shower and kitchen sink and uses it for gardening.
• Installing greywater systems can also reduce water bills and leave a smaller environmental footprint.

Smart Irrigation Systems: 

• These smart irrigation systems track the weather forecast and not water the lawn if rain is expected.
• Smart sprinklers turn off automatically during rain, conserving water.
• Smart irrigation systems factor in the type of plants, soil conditions and other environmental data to function effectively.
• Smart irrigation systems can connect to a mobile app for easy access to the data. 

The systems mentioned above can be cloud-based and can be connected through 3G and 4G wireless networks for precision and reliability. Challenges for plumbing professionals lie in delivering accurate, error-free and efficient design drawings and models to ensure a smooth installation process. 

Challenges to Standard Bathroom Plumbing Layouts

Plumbing, or public health, design would be somewhat incomplete without discussing bathrooms, the scenes for most design challenges. When redesigning, repairing or renovating existing bathrooms, one of the most challenging situations in the UK involve small spaces. In addition there are a few other common challenges, such as: 

Challenge:

Small bathrooms give professionals little room to work and to fit in the fittings required. 

Solutions:

•  Plastic fittings mean flexible pipes can be threaded through joists and around corners, without needing joints, making retrofit easier.
•  Copper or plastic adaptors can be used to extend existing systems.
•  Plastic components can be installed faster, leading to reduced labour costs.

 

Challenge:

Problems due to waste pipe fall are messing up the new layout design.

 

Solutions:

• Install waste pipes that slope down to ensure the right path for water, such as 10mm fall for every 4m of pipe.
• The floor level can be raised to create a void.
•  Run the wastewater between and below joists, boxing it in at the ceiling level of the room below.
•  Construct a plinth to raise the bath or shower above floor level and place the pipework below.

 

Challenge:

• Bathroom remodelling is affected by plumbing in awkward spaces, such as adding a basement bathroom or a bathroom that is far from the main drain.

 

Solution:

 Typically, bathrooms are connected to a 100mm soil pipe. When this is difficult to do, bathrooms can be installed in awkward spaces with a flexible small-bore waste pipe and a pump with a macerator.

 

Challenge:

A power shower’s water is not draining properly, resulting in standing water in the shower tray.

 

Solutions:

• §  First, check the waste pipe width, which should be big enough for the increased amount of water generated by a powerful shower.
• §  Use a 50mm waste pipe to handle the high flow rate in a large shower head or a power shower.

 

Challenge:

A shower has low water pressure, resulting in a weak, disappointing shower.

 

Solutions:

• §  Check the pressure on the hot and cold supply – most shower and tap mixers need 3-bar or more.
• §  Consider a special shower head or a high-pressure electric shower for low water pressure systems.
• §  Install a pump to boost the mains water pressure from a gravity-fed system.
• §  For mixer showers, the combi-boiler must be able to deliver a sufficient hot water flow.

 

Challenge:

It takes too long for hot water to reach the faucet, as the bathroom is at the end of a long plumbing run.

 

Solution:

 Connect a hot water cylinder to the end of the run and instal a bronze pump on the loop, with a timer, so hot water keeps circulating and faucets will provide instant hot water. 

Most of the challenges mentioned above for bathrooms can be solved by adding value to standard bathroom plumbing layouts through the support of high-quality, accurate plumbing design services and plumbing design drawings services. When these services become difficult to source in the UK, many firms are looking for offshore plumbing system design support, both for residential plumbing design layouts and commercial plumbing design. 

XS CAD has valuable experience providing design for plumbing system design and plumbing design drawings services for general contractors and design consultants.  Our range of services for building design firms across the world and specifically in the UK include standard bathroom plumbing layouts, residential plumbing design layouts, commercial plumbing design and other plumbing design services.  We create these models and drawings by using Revit, AutoCAD and BIM Collaborate Pro for cloud collaboration.