Air Curtains
Three times more effective against the infiltration of outside air, and far more energy efficient than vestibules. This was the result when air curtains were tested by the world's leading authority on air movement and system equipment for air.
Today's standard for many new builds is to try to eliminate the problem of infiltrating air and energy loss. Instead of being content with a normal entrance, a vestibule is built for additional protection. A costly solution that takes up too much space at the part of the building that customers and staff pass every day.
AMCA (Air Movement and Control Association ) has conducted a comprehensive study that has measured a building's overall energy consumption and compared the results obtained at an entrance without an air curtain, with an air curtain and also with a vestibule, a two door entrance.
The results show that an air curtain provides approximately 65% protection against the infiltration of outside air. Compared with the second most effective protection - a vestibule, which only provides 23% protection against infiltration. AMCA have thus proved that air curtains really reduce the energy consumption of a building.
AMCA have proved that air curtains really reduce the energy consumption of a building.
The study is based on previous work with both real-world testing and CFD analyses developed in the 90's when a building code for America's colder provinces was established regarding entrances with vestibules. The result led to vestibules becoming the norm in new builds to save energy. These conclusions and methods have now been reused and some 350 different simulations have been carried out to answer the question of how best to protect entrances and buildings once and for all.
The simulations took a variety of scenarios, such as climate zones, summer and winter, balanced / unbalanced ventilation, wind stresses and number of people passing through the entrance per hour, into account. Part of the analysis focuses on examining the amount of infiltration of outside air through the entrance. The analysis clearly shows that an air curtain across the opening clearly provides better protection from infiltrating air than a vestibule.
The study also tested pure energy savings and calculated and analysed a model of a medium sized office building, among other things. The building had a balanced ventilation system and an average of 100 people passing per hour. The results show that the total energy consumption of the building was less with an air curtain at the entrances of both buildings with a normal entrance, and with a vestibule.
Above all, the air curtain was superior in colder climates where energy savings were achieved both through less infiltration and through savings in the form of less heating. The cases in the study show that the air curtain is not only more efficient than a vestibule but it also has a much lower installation cost and takes significantly less space at the building's entrance.
The complete study can be found here
Air Movement and Control Association International (AMCA) is a non-profit, international association for manufacturers of system equipment for air - mostly fans, shutters, dampers and air curtains used in commercial buildings and industrial processes.