Maximum recommended acoustical design criteria for air conditioning systems and duct work:

Guest Rooms 35*NC

Meeting Rooms 35 NC

Circulation Areas 40 NC

Lobby and Foyers 40 NC

Coffee Shop and Dinning Areas 40 NC

Recreation 50 NC

Offices 40 NC

Service work areas 45 NC

*NC = Noise Criterion

Sound Barrier Construction

Installed ratings: (to be certified by approved test of installed construction)

Guest Room to Guest Room *STC 50

Guest Room to corridor STC 45

Mechanical equipment room STC 54

Mechanical equipment room adjoining
occupied public spaces & offices STC 60

Operable walls (Ballroom &
Meeting Rooms) STC 50

Kitchen/dance high sound level music
areas over/under/adjacent to
Guest Rooms STC 70

*STC = Sound Transmission Class

The following are common acoustical problems experienced in hotels.

Guest Rooms
- Lack of seals at interconnecting doors
- Lack of seal under main door into Guest Room
- Noise from flushing system from one bathroom to the next
- Not offsetting penetrations in walls
- Single glazed Guest Room windows
- Traffic noise from adjacent streets
- Wind noise through poorly sealed penetrations
- Lack of insulation to fan coil unit
- Absence of acoustic underlayment under tiles
- Poor sealing of walls at cornice and skirting
- lack of hollow wall acoustic material
- Noise from poorly insulated mechanical and hydraulic ducts
- Water hammer
- Sound leakage through poorly sealed pipe and duct penetrations
- Noise from elevator shafts
- Poorly maintained air conditioning or fan coil unit

Public Areas
- Noise into Public Areas from adjoining tiled spaces such as Kitchens, bathrooms
- Air conditioning ductwork noise
- Crowd noise from open pre-function and reception areas
- Lack of acoustic seals to Ballroom doors
- Noise from B.O.T.H. into Ballroom
- Absence of acoustic treatment over Ballroom operable walls
- Poorly performing operable walls and wind up-seals
- Noise and vibration from mechanical equipment, Laundry equipment
- Particular care in location of noise sensitive areas such as Ballrooms
- Noise from activity areas such as Health Clubs, Workshops and Nightclubs, particularly when adjacent to above or below quieter spaces such as Function Rooms, Guest Rooms and Restaurants
- Lack of attenuation of emergency generator room, generator, generator exhaust etc
- Noise from dimmers in Ballroom audio areas
- Wind whistle in lobbies, especially when doors not sealed properly
- Rain noise on metal roofs
- Poor air balancing