Upgrading healthcare: Naji Atallah, Autodesk
The building information modelling (BIM) process offers healthcare organisations and building professionals the opportunity to use data-rich models to simulate real-world performance of designs, and computational fluid dynamics (CFD) tools help to quickly and easily evaluate design options. Ultimately, using BIM and CFD can enhance building performance—helping to mitigate healthcare-associated infections, reduce energy consumption and improve patient comfort.
BIM is an intelligent model–based process that helps owners and service providers achieve business results by enabling more accurate, accessible and actionable insight throughout a project lifecycle. Healthcare organisations and building professionals alike are increasingly recognising the role that BIM can play in bringing predictability into the design and construction process. BIM helps design and construction teams create more accurate, coordinated designs faster; improve collaboration and data management; speed decision making among stakeholders; and better manage schedules. Because healthcare buildings are among the most complex project types, working with coordinated, accurate BIM data during the design and construction process can result in substantial cost and time savings.
Beyond design and construction, BIM can also help improve the performance of buildings over their lifecycle, supporting improved patient care and reducing operating expenses. The tight integration of BIM and simulation technology from Autodesk now makes it easier and more cost-effective for healthcare organisations and building design professionals to maximise their investment in BIM. More accurate, data-rich building information models produced by Autodesk’s Revit software for BIM enable healthcare project teams to use advanced simulation tools to help explore the real-world performance and cost of design scenarios early in the design process to achieve more optimal design solutions. In particular, Autodesk BIM 360 simulation capabilities that support the use of CFD can help provide insight into critical environmental factors of healthcare facility designs that influence care and operations, including airflow, thermal comfort, and temperature influences.
Specific healthcare applications for CFD simulation that is enabled by BIM can help mitigate healthcare associated infections, improve patient comfort, and reduce operating expenses over the building lifecycle.
CFD for infection control
The control of healthcare-associated infections (HAIs) presents challenges with severe health and economic consequences for healthcare institutions in the Middle East and across the globe. According to the Centers for Disease Control (CDC), one in 20 people will contract an HAI during the course of receiving treatment at a healthcare facility.
Building design and engineering professionals can play a key role in preventing HAIs through design considerations they undertake before construction begins. Hand-washing is recognised by the CDC as the single most important measure to prevent the spread of infection in healthcare buildings. However, given that an estimated 10 to 20% of HAIs are transmitted by the airborne route, building ventilation systems can play a significant role in preventing the spread of airborne microbial contaminants. Immune-compromised patients who stay in healthcare facilities for prolonged periods of time face the greatest risk of infection and mortality from airborne infections. As an example, mortality rates reported from aspergillosis, an airborne fungus, due to construction activities in healthcare facilities have been reported as high as 95% in bone marrow transplant patients, 13-80% in leukemia patients, and 8 to 30% in kidney transplant patients.
Controlling air quality is critical to minimising infection in operating rooms and other areas of the hospital that support immune-compromised patients. External air supply, operating room staff, and the space itself can all be sources for infections in operating rooms. Aerosol transmission of microorganisms is affected by factors such has increased humidity, temperature, population density, ventilation rate, and room airflow. Room air flow is governed by a combination of air movements caused by ventilation, differences in temperature, moving bodies, and the location and operation of equipment. By designing room airflow to ensure sterility at the surgical site, the risk of post-operative infection can be minimised.
Simulation using CFD tools can help building design teams model designs, such as operating rooms, to visualise and analyse room air flow and temperature distribution to minimise the risk from aerosol-transmitted infections. BIM enables design teams to model equipment and room variables, such as hospital staff, in realistic levels of detail to support more accurate simulations of air flow. Using CFD, project teams can easily test multiple design options to help achieve optimal air flows, humidity levels, and temperature distribution before construction begins.
A study undertaken in Australia validated that fine-tuning a design using CFD can lead to a safer environment for patients and more cost effective ventilation solutions. The study noted that traditional air distribution in operating rooms has not always resulted in the optimal supply of sterile air to the surgical site. Key objectives for controlling the operating room environment are: ensuring sterile air reaches the patient without mixing with air flows over staff and equipment; creating streamline or laminar air flow over the operating area; making sure temperature is controlled and air velocity and temperature do not adversely affect the condition of the patient.
The study found that CFD simulation enabled the design team to model a proposed operating room air distribution system, to test each of the variables to help identify flaws in the air distribution, and make adjustments to achieve the optimum flow and temperature conditions. By using the visual results of CFD simulations, the project team gained a better understanding of how the placement of HVAC system components and equipment affects the environmental conditions in operating rooms. Through simulations, the project team was able to make a positive improvement in the air quality in operating rooms and assist in the reduction of post-operative infection rates.
CFD for energy savings
Hospitals consume more total energy than any other commercial building type, and are second only to retail food establishments in their energy use per square foot. This energy consumption comes at a staggering cost. According to the U.S. Green Building Council, hospitals spend nearly $8.8bn annually on energy. Given that up to 3% of the average hospital budget is spent on energy, reducing operating expenses through energy savings can have a substantial impact on a hospital’s bottom line. According to Energy Star, every $1 a non-profit healthcare organisation saves on energy is equivalent to $20 in new revenues. For-profit hospitals can boost earnings per share by a penny by reducing energy costs by 5%.
Healthcare organisations are increasingly embracing energy efficient solutions. In fact, 84% of hospitals rated energy efficiency as an important attribute of requests for proposals they evaluate. As such, building project teams are turning to simulation solutions such as CFD to help design higher-performing, more sustainable buildings. The seamless integration between design software applications that support BIM and CFD tools helps building project teams incorporate energy efficiency into the design process.
CFD for patient comfort
Simulation can also help project teams design more comfortable healthcare spaces for patients and visitors. Healthcare design teams are increasingly exploring innovative design concepts like underfloor air distributions, displacement ventilation, radiant panels, chilled beams, and different diffuser types. CFD enables exploration of creative design solutions virtually to help teams validate or eliminate them as viable options. This process helps to better ensure the comfort of occupants and visitors in spaces throughout the hospital—lobbies, patient rooms, common areas, atria and dining areas—in a low cost and sustainable way.
In conclusion, healthcare building project teams can take advantage of BIM design data to perform more realistic simulations of building performance—even during the early stages of the design process. With the use of simulation technology for CFD, building project teams can evaluate multiple design options based on various scenarios and environmental conditions, such as temperature and humidity levels.
Now, the Autodesk Revit software for BIM and new cloud-based CFD simulation tools enables project teams to harness the flexible, scalable computing power of the cloud to run an unlimited number of simulations simultaneously and compare results side by side. By offloading computationally intensive studies from local computers, project teams can compress the analysis phase of projects while finding optimal design solutions.
When combined, BIM and CFD tools can offer significant value to healthcare building project teams in helping them plan, visualise, and validate designs. By incorporating simulation early and often in the design process, project teams can help reduce infections, maximise energy efficiency, and create more comfortable spaces for patients.
