Question

وانم دوراد و A maximum of 10 smokers are anticipated in a smoking room and each is expected to contribute about 150 g/min of environmental tobacco smoke (ETS) to the space. It is desired to hold the particulate level of ETS below 180 g/ m using filters with an effective efficiency of 80 percent and an intake of outdoor air at a rate of 20 cfm per person. Assuming a ventilation effectiveness of 0.85 and the filter located downstream of the mixed recirculated and outdoor air. Determine the required rate of supply air to the room. -10 [8 points) 150 Malmin E = 80% (on Nani

Answer 1

rate required The is objective to to determine the the room. of supply air Giyen data all the tobacco present in ait ef: 807 en Naque eter 2017- Ventilation effectiveness Evs 0.85 Der gli contamination rate Csa 180 mg (m3 to outdoor contamination 6-0 [clean air] 23 sa Air intake ito rate rate edo efm pessor Recirculations and filteration As per ASHRAE: (1-R) Qr El & Ricerrota to QSLIM) outpord, Done (19) of , Q & in

where diagram from above the Q> Volumetric How ca contaminate concentration E. Efficrency coll Effectiones flow reduction reactor No contaminate generation rate Ra recirculation flow factor o the "filter which is y located down stream of the mixed re-circulated al will be located at B The Egn for constant air flow rate supplied to the room for filter located at 'B' in Ev. RQ; Ef. es Evlc- Cinee) 6] > Where air outdoor 29, re circulated an Na Contanminant rate = Average rate of contaminant. condition 10 smokers the rate of tobacco smoke generated given have we N = 10 x 150 Mg/min = 1500 outdoor air = 10*20cfm

1 rearranging The above flow rate Equation - do Ev [CG - CINEA) co] R. Q = Ex Ef & C o in the air Substitulag all balancing the known values Equation.. (1-0.80 20*10 *085 im 150 100 3008 ft som lo lombowe dl) - 2014 10 * 0.3s (120-1-08) Rodran 0.86 0.85 * 180 52972-000 - 30566 0.8 0.85*180 22 406 122.4 air to in Raja 183.05 ft 3 (min the required rate of supply room & 183.05 ft3/min