Indoor Air Quality Modeling Purpose of Indoor Air

Indoor Air Quality Modeling

Purpose of Indoor Air Quality Modeling n n n To estimate the indoor air pollutant concentration in a building To determine the indoor air quality inside a building For development and evaluation of source-to-dose models of persistent pollutants

Types of Air Quality Models n One – Compartment models n Multi Compartment models n Empirical models

Mass Balance Model n n Given by Q 0+Q 2=Q 3+Q 4 Mass Balance Indoor Outdoor Model Infiltration from outdoors Q 2 Re circulation Q 1 Make Up Air Q 0 F 1 Room Volume (V) Mixing factor k Source S Decay R Exfiltration Q 3 F 0 & F 1 are filter efficiency Exhau st Q 4

Pollutant Mass Balance n n n V(d. C 1 / dt) = k x Q 0 x C 0(1 – F 0) + k x Q 1 x C 1 (1 – F 1 ) + k x Q 2 x C 0 + S – R- k (Q 0 + Q 1 +Q 2 )Ci For t = 0 , Ci = C R = E x Ci Also t tends to infinity Ci, ss = ((k x [Q 0 x C 0 (1 – F 0) + Q 2]C 0) + S) / ((Q 0 + Q 1 +Q 2) + E) Where, Ci, ss = Steady State concentration

Notations n n n n Q 0 = Make up air Q 1 = Indoor air Recirculation Q 2 = Infiltration from outdoors Q 3 = Exfiltration Q 4 = Exhaust F 0 = Filter efficiency F 1 = Filter efficiency Co= Outside Concentration

Notations n n n Ci = Indoor Concentration V = Room Volume K = Mixing factor S = Source emission rate R = Decay of Pollutant