Computational Fluid Dynamics (CFD)


Why We Turned to CFD to Validate Heat Pump Performance


Air Source Heat Pumps (ASHPs) are often seen as a go-to solution in the push for low-carbon building upgrades. They’re now being installed almost everywhere, from homes to hospitals to higher education campuses. But while they’re a key tool in the transition to net zero, the reality we’re find is that heat pumps don’t just “work” any-where, no matter the setting.

To perform efficiently, ASHPs rely on sufficient airflow, appropriate placement, and minimal disruption from surrounding structures. In practice, however, these factors are often overlooked, especially in retrofits where space is tight, and system siting is constrained.

This was exactly the challenge we faced on a decarbonisation project for a college building. The site proposed for the new heat pumps was an enclosed courtyard with very limited options for positioning the units. With tight spatial constraints and no obvious "ideal" location, we needed to be sure the system would operate effectively before any installation went ahead.

Computational Fluid Dynamics (CFD) 

Using IES Virtual Environment software, we modelled the airflow and thermal behaviour around the proposed ASHP units. The goal was to test whether expelled cold air would recirculate in the courtyard and be drawn back into the units, undermining performance, reducing efficiency, and increasing energy use.

The CFD simulation was set up under worst-case winter conditions: still air, ambient temperatures at -5°C, and full system operation. The analysis revealed some degree of exhaust air recirculation. However, most of the cold air discharged vertically and dispersed efficiently, minimising the risk of system short-circuiting.

In short, CFD gave us the confidence that, even in a challenging and space-constrained setting, the heat pump installation could perform reliably without compromising on environmental or operational goals.

As more buildings look to decarbonise, CFD offers a vital layer of assurance, helping avoid costly mistakes and ensuring that low-carbon systems actually deliver in real-world conditions.

To find out more about CFD, get in touch with the team.


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More from our Knowledge Share

To ensure that global temperature rise stays within the 2-degree limit set by the Paris Agreement, designers must extend their focus beyond operational energy to also address embodied carbon.

Both the RICS Professional Statement and the London Plan prioritise this aspect of carbon reduction efforts.

Now, for large-scale developments in London, Whole Life Carbon Assessments (LCA) and Circular Economy Statements are mandatory.

What does this mean for your project?

LCA considers every step from raw material extraction through manufacturing, distribution, use, and eventual disposal.

Conducting an LCA allows you to showcase reduced environmental impacts by:

  • Assessing building site options to select the lowest-impact choice.
  • Comparing the environmental impacts of renovation versus demolition and new construction.
  • Evaluating design alternatives to choose the least impactful ones.
  • Identifying environmental hotspots in a building and taking corrective measures.
  • Estimating the lifetime impact of building materials and products to determine the most sustainable options.

How can Futura Bright assist?

The RICS Guidance offers a standardised, science-based methodology for quantifying the lifetime environmental impact of development projects.

We utilise One Click LCA (endorsed by the GLA) to help you meet local and regional requirements. We can compile compliant Whole Life Carbon and Circular Economy Statements to support your development scheme.

With One Click LCA, we guide you through all submission stages, from pre-application to post-construction, facilitating the transition to a holistic carbon approach.

Using this platform enables us to conduct a comprehensive life cycle assessment of the entire building quickly, pinpointing areas requiring action and helping you demonstrate your sustainability credentials to relevant authorities effectively.

Photographic evidence is now required as part of Building Regulations Part L 2021 compliance

Did you know that photographic documentation has become a pivotal aspect of ensuring compliance with the latest Building Regulations Part L 2021? 

This recent requirement marks a significant shift in the construction industry’s approach to verifying adherence to energy efficiency standards.

Under Building Regulations Part L 2021, photographic evidence is now mandated for all newly constructed dwellings undergoing assessment. However, it’s essential to note that this requirement doesn’t extend to non-residential buildings, conversions, or extensions, which are exempt from this provision.

The primary objective behind this mandate is multifaceted. Firstly, it serves to meticulously document the construction processes of each dwelling, offering a comprehensive visual record of the various stages from foundation to completion. This documentation not only provides transparency but also aids in quality assurance, ensuring that every aspect of construction aligns with the original design specifications.

Moreover, the inclusion of photographic evidence is instrumental in identifying any deviations or discrepancies that may arise during the construction phase. By capturing these deviations in real-time, stakeholders can promptly address and rectify any issues, thereby upholding the integrity of the project and minimising potential risks.

Furthermore, the requirement for photographic evidence plays an important role in updating energy modeling to accurately reflect the finished building. By visually documenting key energy efficiency features, such as insulation installations, air sealing measures, and renewable energy systems, stakeholders can enhance the precision of energy performance assessments and ensure compliance with regulatory standards.

Navigating these evolving requirements can be daunting amidst the myriad of changes occurring within the construction industry. 

Check out our handy e-Guide

Maximising Natural Light: Understanding Daylight, Sunlight, and Overshadowing in Building Design

In the pursuit of creating healthy, sustainable, and visually appealing built environments, architects and designers are increasingly prioritising the integration of natural light into their projects. 

Daylight, sunlight, and overshadowing play crucial roles in shaping the quality of indoor and outdoor spaces, influencing everything from occupant comfort and well-being to energy efficiency and architectural aesthetics. Let’s delve into these concepts to understand their significance in building design.

Daylight: Illuminating Indoor Spaces

Daylight refers to the natural light that enters a building through windows, skylights, or other openings, illuminating interior spaces. Beyond its practical function of providing illumination, daylight has profound impacts on human health, productivity, and mood. Exposure to natural light has been linked to improved concentration, enhanced circadian rhythms, and reduced symptoms of Seasonal Affective Disorder (SAD).

In architectural design, maximising daylight penetration is key to creating inviting, visually stimulating interiors. Strategies such as orienting buildings to optimise solar exposure, incorporating large windows and glazed facades, and using reflective surfaces to distribute light can help harness the benefits of daylighting while minimising the need for artificial lighting.

Sunlight: Harnessing Solar Energy

Sunlight, specifically direct sunlight, plays a dual role in building design: it provides natural illumination and serves as a renewable energy source through solar gain. By strategically positioning windows, solar panels, and shading devices, architects can harness sunlight to optimise both daylighting and energy performance.

Sunlight analysis tools allow designers to predict and visualise the path of the sun throughout the day and across seasons, informing decisions about building orientation, window placement, and shading strategies. By balancing the desire for ample natural light with the need to mitigate solar heat gain, architects can create comfortable, energy-efficient spaces that benefit both occupants and the environment.

Overshadowing: Balancing Light and Shade

While maximising natural light is desirable, it’s essential to consider the potential for overshadowing, where adjacent buildings or landscape features block sunlight from reaching certain areas. Overshadowing can have significant implications for building design, affecting everything from daylight availability to solar panel performance.

Through careful site analysis and planning, architects can minimise overshadowing by optimising building massing, height, and orientation. Techniques such as setback and step-backs, building setbacks, and the strategic placement of taller buildings can help mitigate overshadowing effects while preserving access to natural light and views.

Daylight, sunlight, and overshadowing are integral considerations in architectural design, influencing the quality, functionality, and sustainability of built environments. By harnessing the power of natural light, architects can create spaces that promote well-being, enhance visual comfort, and minimise reliance on artificial lighting and mechanical heating and cooling systems.

As stewards of sustainable design, architects have a responsibility to prioritise daylighting strategies that optimise energy performance, enhance occupant comfort, and foster connections to the natural environment. By integrating daylight, sunlight, and overshadowing considerations into their design processes, architects can unlock the full potential of natural light to create buildings that are both aesthetically pleasing and environmentally responsible.