Circular Ceiling Diffusers - Air Diffusion

Circular Ceiling DiffusersPerformance Guide Model OD-2L = C + ECv L (m/s)Δt L (C)b 0.2Q (m 3 /h)Δt Z (C)ExampleGiven:Air flow volume: Q = 1000 m 3 /h, L = 2.4mAir jet velocity:V L = 0.3 m/sTemperature difference: Δt z = 5 °CEvL(m/s)v L = 0.2m/sL(m)Solution:From the diagram selected the diffuser OD-2 size 3.Effective discharge velocityV ef = 9.8 m/sΔt L (C)Sound attenuation L WA (dB(A))1413121110987654322000100050020010050020Pressure drop diagram (Valid for volume control damper J2)Q9 (m 3 )Q (m 3 )calculated volume, depending on room reflectanceactual room volumeThe following data are necessary to calculate the volume Q9.1. Normal rooms Q9 = Q2. Rooms with highly reflective walls Q9 = 0.5Q3. Rooms with absorption walls Q9 = 2Q10.7 1 2 3 4Distance from diffuser (m)5Pressure drop diagram (Valid for register J2)Pressure drop diagram (Valid for register E2)10025%Δp celΔp celOpenedOpened50%10025%50%50%Pressure drop Dp cel (Pa)50403010N R = 25 30 35 40 4525 30 35 40 45L WA (dB(A))100%regulation set-upPressure drop Dp cel (Pa)50403010N R = 25 30 35 40 25 L WA (dB(A))35 4545 4540 30 100%regulation set-up552 3 4 5 6 10Effective discharge velocity v ef (m/s)2 3 4 5 6 10Effective discharge velocity v ef (m/s)www.air-diffusion.co.uk 11