Noise - Acoustic
NCC Class 2 - Class 9 Buildings (high rise apartments, hospitals, hotels, schools, theatres, conference rooms and offices)

Reducing the amount of sound that passes through a door set is a common application for Raven door seals. Sealing door gaps is of prime importance when helping to reduce the amount of sound entering or leaving a room or building. Unlike air, where the amount flowing through a gap changes in proportion to the gap size, sound waves move through these gaps with little loss. Consequently, small gaps around a doorway can let through nearly as much sound as an open door. Because of this, any small clearances not sealed can reduce the effectiveness of a solid core door or acoustically engineered door or partition.

Raven acoustic seals provide an excellent barrier to airborne sound and help ensure that the acoustic attenuation provided by an acoustically sealed door assembly can in many cases be equivalent to the wall or partition into which it is installed.

Raven acoustic seals help isolate buildings from external noise, such as the noise generated from roads, railways and airports. They also help isolate rooms from airborne noise generated within a building. For example; plant and machinery, theatres, cinemas, crèches, dental and doctors’ surgeries, stairwells, passages, interconnecting hotel rooms and adjoining apartments.

In Australia, the NCC Sect. F5.5 and Sect. F2.4.6 mandates that Class 2 buildings; typically apartments, multi-residential and Class 3 buildings; hotels, motels and age care buildings etc., must have entry doors with a minimum sound insulation rating of Rw30. The UK Building Approved Document E states a minimum Rw29 is required.

Raven acoustic seals are used in airports, hotels, offices, hospitals, homes and anywhere noise infiltration occurs through doors. Their effectiveness is best illustrated by the repeated use of Raven seals by architects, acoustic engineers, door fabricators, and project builders.

Raven, the industry leader in door sealing systems, pioneered baseline acoustic testing, utilising “off the shelf” doors and ironmongery to give specifiers proven, cost effective solutions to the growing problem of noise in living and workplace environments.

Acoustic door manufacturers increasingly incorporate Raven door sealing systems with acoustically engineered doors to achieve and maintain the highest Rw ratings up to Rw52 (STC 52).

Improving Rw (STC) Ratings

It should be considered, that the Rw (STC) rating of a door set is only as good as the sum of its parts. i.e. the Rw value of the door and frame fitted with Raven acoustic seals, the wall, the ceiling and floor surface.

The use of soft absorbent furnishings within a room will also help absorb unwanted noise. All these measures will improve the acoustic attenuation of the room and increase the aggregate Rw value of the construction.

Typically, when Raven acoustic seals are fitted to timber solid core doors the Rw rating of the door assembly is increased from around Rw16 up to Rw32. When the assembly is placed into an Rw 55 wall, the overall rating of the door assembly and wall combination drops slightly as a ratio to area. The larger the wall area the less the combined Rw rating will drop.

Class 2 - Class 9 buildings

F5.5 Sound insulation rating of walls

(a) A wall in a Class 2 or 3 building must—
(i) have an Rw + Ctr (airborne) not less than 50, if it separates sole-occupancy units; and
(ii) have an Rw (airborne) not less than 50, if it separates a sole-occupancy unit from a plant room, lift shaft, stairway, public corridor, public lobby or the like, or parts of a different classification; and
(iii) comply with F5.3(b) if it separates—
(A) a bathroom, sanitary compartment, laundry or kitchen in one sole-occupancy unit from a habitable room (other than a kitchen) in an adjoining unit; or
(B) a sole-occupancy unit from a plant room or lift shaft.

(b) A door may be incorporated in a wall in a Class 2 or 3 building that separates a sole-occupancy unit from a stairway, public corridor, public lobby or the like, provided the door assembly has an Rw not less than 30.

Acoustic Standards, Test Methods and Ratings

Test methods used to establish the noise attenuation ability of a door set are AS1191, ISO 140 series, and more recently EN ISO 10140 series standards. Test data from any one of these test methods can be used in EN ISO 717.1 which provides a single number rating across a spectra of frequencies for the noise attenuation ability of the building element. Typically Rw is used for door sets which covers the frequencies of 100hz to 3.125 kHz

Related Building Codes

There are several standards, which refer to seal properties and testing for Weather - Energy:

Requirements are noted in the Australian National Construction Code (NCC) and New Zealand NZ BC Compliance Doc. H.

Requirements are noted in the British Building Regulations Approved Document E.

Requirements are noted in the Building Code and the Residential Code IBC 2000.

For further details, refer to Standards / Authorities.