음향 투과 등급, STC (Sound Transmission Class)

음향 투과 등급, STC (Sound Transmission Class)

 

벽체 등의 차음투과손실을 나타내는 단일지표로 1/3 옥타브밴드 125~4000Hz 사이의 투과손실 그래프와 규정된 기준 곡선과 아래 조건을 검토하여 STC 등급을 정의한다.

 

 

➤ STC 등급은 ASTM 3413에서 규정된 기준곡선을 상하로 조정하여 결정됨

• 조건 1: 기준 곡선 아래의 모든 주파수 대역별 투과손실과 기준곡선값의 차이의 합이 32dB 이하
• 조건 2: 단 하나의 투과손실 값도 기준곡선 밑으로 8dB를 초과하지 않는 조건
• 상기 2가지 조건을 만족하는 기준곡선 500Hz에서의 차음값을 STC 등급으로 정의함
• 아래 그림에서 STC 투과손실 등급은 STC 38으로 정의됨

 

[ STC 등급 평가 예시 ]

 

STC 음향투과등급(Sound Transmission Class) 은 건축물 내 벽체 차음성능의 실 용도별 기준을 정의하는데

사용되며, 아래 표에서는 벽체 위치에 따른 일반적인 STC 등급을 제안하고 있다.

 

[ 벽체의 위치에 따른 STC 등급 ]

Interior wall type	Minimum STC
소음이 심한 공간과 다른 재실 공간 사이	60
회의/교육/수면실과 다른 재실 공간 사이	55
조용한 공간(집중/독서/휴게)과 조용한 공간 사이	50
집중이 필요한 공간과 다른 재실 공간 사이	45
통로와 정기적 재실 공간 사이	40

 

 

한편, 아래 표에서는 실제 적용되는 실 용도별 벽체 차음성능 기준에 대한 STC 등급을 명기하고 있다.

 

[ STC Ratings for Wall, Partition, or Panel Between, * ]

Type of Occupancy	Room Being Considered and Adjacent Area		STC Ratings
Executive areas, doctors’ suites, confidential privacy requirements	Office	- Adjacent offices - General office areas - Corridor or lobby - Washrooms and toilet areas - Exterior of building - Kitchen and dining areas - Manufacturing areas and mechanical equipment rooms	47 42 47 47 42 47 52
Normal officeareas, normal privacy requirements	Office	- Adjacent offices - General office areas - Corridor or lobby - Washrooms and toilet areas - Exterior of building - Kitchen and dining areas - Manufacturing areas and mechanical equipment rooms	37 37 37 42 37 42 47
Any normal occupancy, using conference rooms for group meetings or discussions	Conference rooms	- Other conference rooms - Adjacent offices - General office areas - Corridor or lobby - Washrooms and toilet areas - Exterior of building - Kitchen and dining areas - Manufacturing or other noisy interior areas	42 42 42 42 47 37 47 47
Normal business offices, drafting areas, banking floors, etc.	Large general office areas	- Corridors or lobby - Exterior of building - Data Processing areas - Manufacturing areas and mechanical equipment areas - Kitchen and dining areas	32 32 37 42 37
Offices in manufacturing, laboratory, or test areas	Shop and laboratory offices	- Adjacent offices - Manufacturing, laboratory, or test areas - Washrooms and toilet areas - Corridor or lobby - Exterior of building	37 42 37 32 32
Motels and urban hotels	Bedrooms	- Adjacent bedrooms, separate occupancy - Bathrooms, separate occupancy - Living rooms, separate occupancy - Dining areas - Corridor, lobby, or public space - Mechanical equipment rooms - Exterior of building: Normal street or highway noise - Exterior of building: Heavy highway traffic - Exterior of building: Airport noise	47 47 47 47 47 52 42 47 47

* 참고 문헌: Sound, Noise and Vibration Control, 2nd edition, Lyle F. Yearges

 

 

 

[ STC Ratings for Wall, Partition, or Panel Between, * ]

Type of Occupancy	Room Being Considered and Adjacent Area		STC Ratings
Apartments, multiple dwelling buildings	Bedrooms	- Adjacent bedrooms, separate occupancy - Bathrooms, separate occupancy - Bathrooms, same occupancy - Living rooms, separate occupancy - Living rooms, same occupancy - Kitchen areas, separate occupancy - Kitchen areas, same occupancy - Mechanical equipment rooms - Corridors, lobby, public spaces - Exterior of building	47 47 37 47 42 47 42 52 47 42
Apartments, multiple dwelling buildings	Living rooms	- Adjacent living rooms, separate occupancy - Bathrooms, separate occupancy - Bathrooms, same occupancy - Kitchen areas, separate occupancy - Kitchen areas, same occupancy - Mechanical equipment rooms - Exterior of building	47 47 42 47 42 52 37
Private, single-family residences	Bedrooms	- Adjacent bedrooms - Living rooms - Bathrooms, not directly connected with bedroom - Kitchen areas - Exterior of building	37 42 42 42 37
Private, single-family residences	Living rooms	- Adjacent bathrooms - Kitchen areas - Exterior of building	42 42 37
Normal school buildings without extraordinary or unusual activities or requirements	Classrooms	- Adjacent classrooms - Laboratories - Corridor or public areas - Kitchen and dining areas - Shops - Recreational areas - Music rooms - Mechanical equipment rooms - Toilet areas - Exterior of building	37 42 37 42 47 47 47 52 42 37
Normal school buildings without extraordinary or unusual activities or requirements	Large music or drama areas	- Adjacent music or drama rooms - Corridor or public areas - Practice rooms - Shops - Recreational areas - Laboratories - Toilet areas - Mechanical equipment rooms - Exterior of building	52 47 47 47 47 47 47 52 47
	Music practice rooms	- Adjacent practice rooms - Corridors and public areas	47 47
	Language laboratories	- Same as for theaters, concert halls,  auditorium, etc.	-
	Counseling offices	- Same as for executive offices	-
Any occupancy where serious performances are given. Requirements may be relaxed for elementary schools or noncritical types of occupancy	Theaters, concert halls, lecture halls	- Adjacent similar areas - Corridors and public areas - Recreational areas - Mechanical equipment spaces - Classrooms - Laboratories - Shops - Toilet areas - Exterior of building	52 47 52 52 47 47 52 52 52
Any occupancy where serious amateur or any professional work is done	Radio, TV, recording studios	- Use professional consultants. This is an extremely critical type of area	-

 

* 참고 문헌: Sound, Noise and Vibration Control, 2nd edition, Lyle F. Yearges

 

 

 

▷투과손실 평가 

투과손실 (차음성능, Transmission Loss, TL) 평가

 

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