7/28/2019 Selection of Diffusers

http://slidepdf.com/reader/full/selection-of-diffusers 1/4

Some Guidelines for Resid~ntial Air Distribution

1.Location of diffusers should effectivelycontrol load areas sucbas Doors, Windowsand OutsideWalls. .

2.Avoid lo«atingDiffusers in the direct lineof traffic such as in front of sliding doors.

How to S~I~ctDiffusers

1. LocateDiffuseruniformly.

2. Co-ordinatewith locationof light Fittings.

3. Diffusersneed not be in the center of the area being served by any particular

diffuser as 1,2 & 3 way patterns are availaNe.

. t t=.+.~+.~~ ~ .' ~ ~

4 WAYWAY 2 WAY 3 WAY

4. Data required for s~lection

a. TotalAir flow (CFM) for area served.

b. Suggested locations.

c. CeilingHeight.

d. Type of Ceilin~.

e. Type of Application.

f. Horizontal through required.

7/28/2019 Selection of Diffusers

http://slidepdf.com/reader/full/selection-of-diffusers 2/4

Selecting DIFFUSER Sizes according to CFM*

Selecting GRILL Sizes according to CFM*

*Note: The Sizesmayvary frommanufacturesto manufacturesdepends uponthe cfm and fpm

I

CFM SAD / RAn SIZE

Upto 150 6" x 6"

151 to 300 9" x 9"

301 to 500 12"x 12"

501 to 700 - 15"x 15

701 to 1000 18'x 18"

1001 to 1400 24"x 24"

CFM SAG / RAG SIZE,

50 to 150 10" x 6"

175 to 350 20" x 6" or 16" x 8"

400 to 500 24" x 6" or 20" x 8"

505 to 600 30" x 6" or 24" x 8"

605 to 750 40" x 6" 'Or 30" x 8"

755 to 900 48" x 6" or 36" x 8"

905 to 1000 40" x 8"

1025 to 1200 48" x 8"

7/28/2019 Selection of Diffusers

http://slidepdf.com/reader/full/selection-of-diffusers 3/4

Recommended Maximum Duct Velocities for Low Velocity System(FPM)

CONTROLLINGFACTOR CONTROLLING FACTORDUCT FRICTION

APPLICATIONS NOISE GENERATION

MAIN DUCT

MAIN DUCT

SUPPLY IRETURN

Residences 600 1000 800 600 600

Theaters

Auditoriums

800 1300 1100 1000 800

General Offices

High class RestaurantsHigh class StoresBank

1500 2000 1500 1600 1200

Average StoresCafeterias

1800 2000 1500 1600 1200

Industrial 2500 3000 1800 2200 1500

ApartmentsIotel Bed rooms 1000 I 15()0 11300 11200 11000

Hospital Bed rooms

Private Offices

Directors rooms I 1200 12000 11500 11600 11200

Libraries

7/28/2019 Selection of Diffusers

http://slidepdf.com/reader/full/selection-of-diffusers 4/4

Recommended Noise Criteria @!}

AUDITORIUMS

Concert& OperaHalls, Studios for sound reproductionTVAudience Studios

Lobbies

20 - 25

30 - 35

35 - 45

SCHOOLS-

Libraries, Schools& Class roomsRecreationHalls, Corridors

30 - 40

35 - 50

HOSPITALS & CLINICS

Private rooms

Operationrooms,WardHalls, Corridors,Labs, Lobbies&WaitingRoomWashrooms &Toilets

25 - 35

30 - 4035 - 45

40 - 50

RESTAURANTS 40 - 50

SUPER MARKETS & STORES 30 - 50

HOTEL INDIVIDUAL ROOMS 30 - 40

OFFICES

Conferencerooms

General open officesHalls & Corridors

25 - 30

35 - 45

35 - 55