Berner International has established itself as the leading manufacturer of air curtains/air doors and related products for over 50 years. As the experts in our field, Berner engineers are on the cutting edge of air curtain innovation. Our high performance air curtains have the perfect balance of air volume, velocity and uniformity to properly protect an opening. To validate this claim, Berner engineers have completed research simulations to compare the performance of air curtains to that of vestibules, when it comes to separating environments. Our testing yielded positive results, which were corroborated by a third party, proving that under typical conditions air curtains perform more effectively than vestibules. Below is a summary of our results.
To compare the environmental separation performance of a prototypical Vestibule with two parting automatic doors vs. an Air Curtain in conjunction with one parting automatic door, a structured set of Computational Fluid Dynamics (CFD) simulations were performed. CFD analysis was chosen as the test method because of its ability to model moving solids in numerous scenarios, and to allow measurements to be recorded in a multitude of scalar and vector quantities in a precise and repeatable manner that is impossible with simple mathematical equation or physical lab testing procedures.
The geometry and scale of the test environment was based on the architecture of 3 nationally established pharmacies and 3-D modeled in SolidWorks 2007. The solid model was saved as a parasolid (.x_t), and it was launched into CFdesign v9, a CFD software package developed by Blue Ridge Numerics. The concurrent fluid flow and thermal dynamics simulations used CFdesign’s unaltered CFD code.
The graph below highlights some differences between building configurations and loading scenarios.
1. When compared with other configurations of similar loading, temperature loss is always highest with the Vestibule scenario, (represented by the blue bar). The Vestibule scenario exhibited 71% higher temperature loss than the Vestibule & Air Curtain scenario under High Wind, High Traffic loading.
2. Building configurations share the same performance order (Vestibule most temperature loss, Vestibule & Air Curtain least temperatue loss) regardless of loading.
3. The load scenario of High Wind, High Traffic yields the highest temperature loss values regardless of building configuration. This load scenario created an average temperature drop of 24.6° F, vs. 9.7° F for Low Wind, Low Traffic loading.
4. All other things being equal, wind loading has a more pronounced effect on temperature loss than traffic loading.
5. The Vestibule & Air Curtain configuration showed only a small reduction in temperature loss (avg. 5.3%) when compared with the Air Curtain configuration.
Overall, heat retention was positively correlated to building configurations with Air Curtains. Regardless of door timing or wind load, temperature loss was reduced when an Air Curtain was present.