Computational fluid dynamics (CFD) modeling uses numerical methods to model almost any phenomena related to fluid flow and heat and mass transfer. In the building industry, CFD analyses can be used to analyze interior conditions such as temperature, humidity, and air quality.
In many cases, CFD analyses can reduce the over-conservatism present in the traditional, simplified approaches and significantly reduce first costs of HVAC systems. It can also provide a much higher degree of certainty that a new design approach or geometry will act as expected, thereby reducing risk and liability.
CFD modeling is the best tool for modeling smoke migration and can significantly reduce the size of the smoke control systems in public buildings. It is also successfully applied to laboratory design, data center design, and external environmental flows.
Ignoring condensation analyses can cause extensive damage to a building. With more complicated building designs (i.e. 100% glass facades), the likelihood of comfort and condensation issues is greater.
The advancement of building materials whose properties are either unknown or unforgiving can cause long-term building durability and indoor air quality issues. Building issues may not be fixable or increase operational costs to compensate for the failures of others.
Our clients expect no condensation or mold issues in their buildings. We strive to conduct hygrothermal studies for each project analyzing climate location, building assembly and space condition.
Simply changing the order in which the building materials are constructed in the wall can adversely affect the hygrothermal performance of the assembly. We review problem areas such as where walls meet roofs, balconies, and overhangs. In colder climates, it is important to evaluate the freeze thaw cycle on concrete and masonry to ensure they will maintain structural integrity for the expected lifespan of the building.
An energy model is a predictive tool that relies on the assumption that the building is constructed and operating exactly as designed, which is rarely the case. The best use for energy modeling, especially for new construction, is to evaluate the relative impact of various energy conservation measures to see if they make sense for the client’s goals, both in terms of energy and life cycle cost.
There is still a lot of work to do to make sure energy savings are realized, including proper design, installation, and probably most importantly commissioning. Proper sub-metering also really helps to see what went right or wrong between the predictions of the model and the final installation. Continuous commissioning is the primary indicator in knowing that a building continues to perform optimally, as the best operators will keep a building fine-tuned on a day-to-day basis. For existing buildings, with good utility data, we do have the ability to calibrate models and in that case, a model can become more of a predictive tool for evaluating future measures, assuming these measures are implemented correctly.
Energy analysis is much more impactful if used to inform the design, not just as a rubber stamp at the end of a project. The energy modeler should be a part of the project very early on.