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Perforated Ceiling Air Distribution System

Perforated Ceiling Air Distribution System

Perforated Ceiling Air Distribution System

(OP)
Has anyone used a perforated ceiling air distribution system? Results? Advantages? Problems?

RE: Perforated Ceiling Air Distribution System

What are you using it for and what airflow are you trying to achieve?

Friar Tuck of Sherwood

RE: Perforated Ceiling Air Distribution System

(OP)
10,000 cfm in a 1000 sq. ft. area.  The area is used for precision machining.

RE: Perforated Ceiling Air Distribution System

Thats about 60AC. I assume its a clean room then?

If so, you can use someone like AAF American Air Filters who I believe do special ceiling systems with lay in filters. The filters lay in a non-setting glue or gel that provides the seal.

the ceiling is also high strength to take the higher ceiling space pressures that you may experience, though I dont think it will be much with such a relatively low volume flow and face velocity.

You will also need to extract air at low level to achieve a more effective room airflow

do you know what clean room classification you are after?

Friar Tuck of Sherwood

RE: Perforated Ceiling Air Distribution System

(OP)
This is not a clean room application.  It is a precision machining operation.  Temperature must be controlled +- 0.5 *F.

RE: Perforated Ceiling Air Distribution System

Design your ceiling grilles to have less than 5Pa PD and you shouldn't get any tile movement problems.

Friar Tuck of Sherwood

RE: Perforated Ceiling Air Distribution System

PS Swirl diffusers give good draft free conditions and are worth considering

Friar Tuck of Sherwood

RE: Perforated Ceiling Air Distribution System

Hello, I too get into perfed ceilings in small(100-300) sq.ft. controlled temp. (CT) rooms.  SMACA's HVAC System Duct Design has a table 14-17 on page 14.48 that gets into a a coefficient factor for doing calculations regarding pressure drop and air flow.  We use Hunter-Douglas steel perf panels and Norton Industries NLBE hex cell louver.

RE: Perforated Ceiling Air Distribution System

How much percentage of the ceiling is perforated? With high percentage penetration you will have problems with air stratification(not thermal, I mean). For example, with Laminar Air Flow Workstations,(i.e 100% face area) I found the drop in velocity at 30fpm per one foot. My idea is to keep atleast 50 fpm face velocity.

You also need to carefully design your duct work to avoid short circuiting of the air. I will prefer static regain method in this case.

Regards,

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