Experimental and simulation study on bake-out with dilution ventilation technology for building materials.

With recent improvements to living standards and renovations to many residential buildings, a large volume of new building materials have been utilized throughout China. Formaldehyde and other kinds of VOC pollutants, such as benzene, toluene and xylene found in new building materials, however, emit gases that may lead to some direct or potential health problems. Bake-out with dilution ventilation technology has the potential to shorten emission cycles of indoor air pollution, by which off-gassing from building materials can be reduced. In this paper, a test chamber was used to represent a newly renovated residential room in China. Experiments were conducted to study the applicability of the technology for removing of formaldehyde, benzene, toluene and xylene. A numerical method was used to simulate a 1 m3-chamber-TVOC removing amount under different operating conditions and the concentration change of TVOC during the bake-out exhaust dilution process. The effects of bake-out temperatures and times, ventilation times, and air change rates on removal are also discussed. IMPLICATIONS: VOCs are the main study objective in this paper. With higher baking temperature, longer baking time and longer ventilation time, the removal efficiency is higher in experiment. Removal content of TVOC increases with the increasing number of ACH. With the consideration of energy consumption, it is more reasonable to choose a ventilation time of 4 hours if ACH is 1.2 times/h.