How quiet is an air curtain?
Comparing apples with apples
Which is the most quiet air curtain? How big an entrance will the air curtain cover? For customers to make accurate comparisons, all manufacturers need to measure in the same way. So that you can compare apples with apples, quite simply. The air curtain industry has now made it easier for the customer to make good choices for their particular needs.
Frico is the initiator of a Eurovent group called “European Air Curtains” that focuses on air curtains. Its purpose is to develop new guidelines. An important part of this is to define common measurement methods that allow customers to compare products with each other. The group includes representatives from twelve different companies.
Previously, the usual way to indicate the sound level was the sound pressure level, a value that is dependent on the characteristics of the room and how far from the product the measurement was taken. Some manufacturers, such as Frico, have clearly stated the conditions under which sound levels were measured, while other manufacturers have used measurements taken in an unrealistic way and have been able to claim lower sound levels than were actually the case.
From July 2017, all manufacturers will report sound power levels (in accordance with ISO 27327-2) on their products. Sound power is the objective value and is not dependent on the characteristics of the room. This makes it easier for customers to compare different products with each other, which Frico has long wanted and supports. This value is higher than the sound pressure level, partly due to being based on a different logarithmic scale to the one used for sound pressure.
From 1 July 2017, both sound power and sound pressure levels for all air curtains will be specified in Frico's documentation.
There are many different methods for measuring airflow and air volume. Unfortunately, it is common in the industry not to report the conditions under which their airflow data was obtained. This results in nominal or free-blowing values (which are much higher) being reported and compared with actual values for the airflow coming out of the unit, giving a misleading comparison. There is now an agreement in the Eurovent group to measure airflow and thus obtain airflow data in accordance with ISO 27327-1 Labratory methods of testing for aerodynamic performance rating, which Frico has been doing for a long time. This ensures that all manufacturers will shortly be reporting values that can be compared.
There are a number of different ways to measure air velocity. The measurement of the air barrier’s velocity and uniformity is also part of the ISO standard 27327-1. Frico is already measuring all its air curtains according to this standard, and the results can be found in the air velocity profile for each of its products.
At Frico, we have one of the most modern and advanced air and sound laboratories in Europe to assist us and we measure according to the ISO standard. Our products do what we promise they will do. Thanks to the work with Eurovent, it is now also easier to compare our products with those of others.
Product Area Director - Air Curtains and Heating