AIRAH QUEENSLANDHigh Induction Air Diffusion

Specialist HVAC Systems

Air Distribution Systems

Tangential Flow

– Coanda attachment– Poor mixing– Poor temp equalisation– Dumping– Draughts– Poor heating– Ventilation effectiveness < 1

MIXED AIRFLOW

TANGENTIAL:

∆Tsupply-return = -8.0 KAirflow = 230 L/s = 6.4 L/(s•m2)

Both: stagnation (v < 0.1 m/s) , and draughts (v > 0.2 m/s)

DIFFUSE:

∆Tsupply-return = -8.2 KAirflow = 360 L/s = 10.0 L/(s•m2)

Comfort : No stagnation, and No draughts

– Rapid temp & velocity equalisation

– Even temp distribution– Draught-free– Good heating– Vent effect ≈ 1

Diffuse Flow

Diffuse Smoke Tests

• High induction

Diffuse • Adjustable Induction Outlet• Twist Outlet• Broad Multiplex Outlet

Broad Multiplex Outlets, InterContinental Hotel

Swirl Smoke Test

Cold Air Diffuser Comparison - ASHRAEHigh Induction – supply air stream temperatures

Nozzle Pre-Induction –

Rapid equalisation

Tsupply = 8 °CTroom = 24 °C

• Krantz swirl Induction –

• Extremely rapid equalisation

• Standard circular diffuser -DUMPING

• Krantz swirl diffuser –UNIFORM TEMPERATURE

• Troom = 23.4 °C ± 0.1 K• ADPI = 97%

Cold Air Diffuser Comparison - ASHRAETsupply = 8 °CTroom = 24 °C

Krantz RA-N3 Ceiling Swirl Diffuser

• Designed for cold air with dT = -15 K • Suitable for VAV with turndown to 30%• 24 radial vanes – pleasant aesthetic with small gaps between vanes• Robust design – face and vanes pressed from one metal sheet• Quiet – sound pressure ≤ NC30 per diffuser (10 dB room absorption)• 2 neck size – provides uniform aesthetic

– DN350 for 16 L/s to 175 L/s– DN500 for 48 L/s to 400 L/s

• Optional collars– to match required airflow range– 2-way blow– 3-way blow

• Optional Round Face

RA-N3: Layout for ADPI ≥ 90%

Airflows Spacing

Low Temperature VAV

Hoyts – Te Awa

Opticlean Smoke Test

Product Movie, Broad Multiplex Outlet BF-A:Animation: Broad Multiplex Outlet, BF-A

High Induction Sidewall Diffuser:

Broad Multiplex, type BF -A

High Induction Sidewall Diffuser:

Broad Multiplex – BF-A

Lengths : 950 mm 1490 mmHeights : Airflow Rates @ 20 Pa (≈NC25) / 30 Pa (≈NC30):134 mm 120 / 145 L/s 190 / 230 L/s173 mm 170 / 200 L/s 260 / 320 L/s212 mm 210 / 260 L/s 340 / 410 L/s251 mm 260 / 320 L/s 410 / 500 L/sThrow: 3 to 9 m (airflow rate and discharge pattern dependent)

Smoke Test: Broad Multiplex Outlet, BF-A

Perforated Sidewall Diffuser, Broad Multiplex Outlet BF-A:

Krantz IN-V2 Induction Diffuser• Designed for dT = -12 K to +5 K; Turndown to 30%

• Variable Discharge Direction

Adjustable Swirl - Horizontal

Adjustable Swirl - Vertical

Heating Tests

Horizontal vs Vertical DischargeTroom warm up from 12°C to 19 °CTsupply = 27°CHdischarge = 6 mHmeasurement = 300 mm above floor∆thorizontal discharge = 2.5 hours∆tvertical discharge = 25 minutes

RA-V

• Manual, Electric

• DN200 – DN500

• Compact

• $

RA-V2

• Manual, Electric, Thermal

• DN250 – DN710

• Bulky

• $$

DD-VL

• Manual, Electric

• DN315 – DN630

• Extremely Quiet

• $$$

DD-VG

• Manual, Electric

• DN315 – DN630

• Very Long Throw

• $$$$

Swirl Diffusers with Adjustable Direction

• Thermally Powered Discharge Direction Adjustment

Adjustable Discharge Direction

DD-VL: Concert Hall, Hamilton, NZ DD-VZ: Sydney Olympics 2000, AU

Adjustable Discharge Direction

DD-VL: South Pacific TV Studios, NZ RA-V2: Exhibition, South Korea

TV Studio: ATP 7, Sydney

Side-blow Swirl – long throw

High Induction Air Diffusionfor

AIRAH Queensland

THANK YOU