Flexit Air Handling Units - Elektra

General Technical InformationExample:An air handling unit installed in a standardventilation room.Air flow rate 260m 3 /hTotal pressure100PaSound power level in supply air duct 72dBAMotor power90WExample of sound calculation using the correction tableSupply airHz 63 125 250 500 1000 2000 4000 8000Read off in diagram, LwA 72 72 72 72 72 72 72 72Correction factor 5 3 0 - 1 - 6 - 8 - 17 - 31Sound power level, Lw 77 75 72 71 66 64 55 41Data for supply air is measured in accordancewith ISO 5136, the “In-duct method”.Radiated noise is measured in accordance withISO 9614-2.Bruel & Kjær measuring equipment, type 2260.l/s 0 20 40 60 80 100 120Example of a correction axis for an F5 filter:Calculation example for F5 filter, air flow rate260m 3 /h against 100Paj .Correction for F5 filter + 30Pa, read off thecorrection axis. 260m 3 /h is available against130Pa. To read off the new sound power leveland motor power, move the read-off pointdown 30Pa to k to compensate for reducedresistance. The motor power is reduced from90W to approximately 85W, and the sound isreduced from 72dBA to 70dBA.400Air flow rate 260m 3 /hTotal pressure300Sound power level in supply air ductMotor power230V200100Pa 0190V170V150V120V105V85V60V60V130Pa70dBA77dB(A) 85W230V190V 1170V150V120V275dB(A)105V85V70dB(A)65dB(A)200150100500Wm 3 /h 0 100 200 260 300 400 500Pal/s 0 20 10 40 25608035 100 50 120 651 - 2 = 30Example of a correction axis for a water battery:Calculation example for water battery, air flowrate 260m 3 /h against 100Paj.Correction for water battery -60Pa, read off thecorrection axis. 260m 3 /h is available against40Pa. To read off the new sound power level andmotor power, move the read-off point up 60Pato k to compensate for increased resistance.The motor power is increased from 90W toapproximately 100W, and the sound is increasedfrom 72dBA to 74dBA.400Air flow rate 260m 3 /hTotal pressure300Sound power level in supply air ductMotor power230V200100Pa 0190V170V150V120V105V85V60V60V40Pa74dBA100W77dB(A)230V 2190V170V150V120V75dB(A) 1105V85V70dB(A)65dB(A)200150100500Wm 3 /h 0 100 200 260 300 400 500Pa010 25 35 50 651 - 2 = -607