Thermal comfort, IAQ and air distribution analysis in open-space offices with underfloor air distribution

Underfloor air distribution (UFAD) strategy is gaining popularity during the last years, howeverresearches about the performance of such systems still need to be deepened.One of the appreciated features of this technology is the use of an underfloor plenum below a raised floor. This plenum is used to distribute the conditioned air in the rooms and makes possible to avoid large air ducts to be installed. Moreover, this solution allows a large flexibility in the space use.However, the impact of such a system on thermal comfort, indoor air quality and air distribution still needs to be accurately verified.This work shows the results of a field measurement campaign performed at open-space office rooms conditioned by an UFAD system. Main aims of the investigation were: the evaluation of the thermal comfort and air quality at work places, the assessment of the ventilation performances of the HVAC system. The decay tracer gas method was used for assessing the ventilation indices. However, since the ventilation strategy does not make use of air ducts, the applied methodology was suitably adapted to the particular configuration.The experimental campaign has allowed to characterise the performance of the UFAD system in terms of:- global and local air change rates- global and local ventilation efficiencies- global and local thermal comfort- global and local air quality