DSO

removable central disc)

PART 1 – GENERAL

1.1 SUMMARY

A. Round plaque supply diffuser(s) providing 360-degree air diffusion pattern; suitable for heating, ventilating, and cooling applications and VAV systems.

B. Construction: heavy-gauge aluminum; removable central disc for easier installation and maintenance.

C. Mounting: duct mounted or drywall mounted, as scheduled. Where installed in false ceilings, provide DSO-MOD square face configuration as scheduled.

D. Application limits: suitable for temperature differentials up to 22°F (12°C) and ceiling heights 8.5 to 13 ft (2.6 to 4.0 m), unless otherwise indicated.

E. Optional accessories (as scheduled): plenums PLRR and PLXP; air equalizing grid (EQ); dampers R3G, OBD, RSBD.

1.2 SUBMITTALS

A. Product Data: Manufacturer’s data for scheduled neck sizes and configuration, including:

1. Free area; minimum and maximum airflow.
2. Pressure loss and diffuser-generated NC.
3. Published throw data (with and without ceiling effect where published).
4. Damper correction information (pressure loss and sound correction where applicable).
5. Finish and mounting details.
6. Optional plenum/damper selections (if scheduled).

B. Shop Drawings: Show model designation (DSO or DSO-MOD), neck size, mounting type, finish/color, and scheduled options (PLRR/PLXP, EQ, and damper type).

C. Airflow Prediction Report (Required – SelectiV): Provide a manufacturer-generated SelectiV airflow prediction report for each diffuser type and each distinct room condition using manufacturer performance data and recognized airflow physics corrections. Report shall include:

1. 3D room model with diffuser locations.
2. Predicted airflow visualization views: plan (top), section (side), elevation (front).
3. Throw distances for terminal velocities of 150, 100, 60, 50, 40, 30, and 20 fpm.
4. Pressure loss at scheduled airflow.
5. Diffuser-generated NC at scheduled airflow.
6. Perceived NC at room center (5 ft height) from all sources combined across 63–8000 Hz octave bands; include key assumptions used.

D. Verified CFD Validation (When Indicated): Provide EffectiV Verified CFD validation and summary report for spaces indicated and/or when operation is outside published selection limits (airflow, ΔT, mounting height, geometry).

1.3 SUBSTITUTIONS

A. Substitutions per Division 01. Proposed equals shall provide a line-by-line compliance matrix including all Part 1 deliverables, including the SelectiV Airflow Prediction Report deliverables.

PART 2 – PRODUCTS

2.1 BASIS OF DESIGN

A. EffectiV DSO architectural aluminum round plaque diffuser with removable central disc.

2.2 SIZES AND AIRFLOW (AS SCHEDULED)

A. Provide scheduled neck diameter(s) and airflow within published ranges:

1. 6 in (160 mm): free area 0.215 sq ft; 106 to 212 cfm
2. 8 in (200 mm): free area 0.338 sq ft; 166 to 332 cfm
3. 10 in (250 mm): free area 0.527 sq ft; 259 to 519 cfm
4. 12 in (315 mm): free area 0.839 sq ft; 412 to 823 cfm

2.3 MATERIALS AND CONSTRUCTION

A. Diffuser: heavy-gauge aluminum.

B. Removable central disc: provide for installation and maintenance access.

C. Configuration (as scheduled):

1. DSO: round face.
2. DSO-MOD: square face for false ceiling.

2.4 FINISH

A. Factory powder coat, TGIC-free, white M9016 unless otherwise scheduled.

2.5 OPTIONAL PLENUMS AND OPTIONS (AS SCHEDULED)

A. PLRR plenum: optional plenum used to equalize air (including EQ option), to use an oversized face with a given duct diameter, and/or to add a special damper. Plenum shall include anti- seismic tabs.

B. PLXP plenum: optional side-connection plenum used where ceiling space is limited, where acoustical performance is important, and/or to add a special damper.

C. EQ option: air equalizing grid (perforated plate) where scheduled.

2.6 DAMPERS (AS SCHEDULED)

A. Provide damper type as scheduled:

1. R3G integrated butterfly volume damper
2. OBD opposed blade damper
3. RSBD radial sliding blade damper

B. Apply manufacturer damper correction factors to published pressure loss and NC where required.

PART 3 – EXECUTION

3.1 INSTALLATION

A. Install per manufacturer instructions; coordinate duct-mounted versus drywall/false-ceiling mounting as scheduled.

B. Provide access for removal/reinstallation of the central disc for maintenance.

C. Where optional plenum is scheduled, install plenum square/true and attach diffuser per manufacturer method; coordinate anti-seismic tab attachment where applicable.

3.2 ADJUSTING

A. Balance to scheduled airflow.