An Experimental Investigation on the Air Permeability of Passive Ventilation Grilles
Abstract The need of increasing both energy saving and acoustic insulation has leaded to the design of lowest air permeability frames resulting in the worsening of indoor air quality. Moreover, sometime in several civil-use existing buildings (i.e. schools or houses, historical buildings) mechanical ventilation systems cannot be installed due to non-removable constraints. In these cases, passive ventilation grilles are a cheap and effective solution for the ventilation. This work deals with an in-depth experimental analysis about the air permeability values measured over a set of passive ventilation grilles available on the market. Obtained results often showed performances very far to thos…
Mean Radiant Temperature Measurements through Small Black Globes under Forced Convection Conditions
One of the most critical variables in the field of thermal comfort measurements is the mean radiant temperature which is typically measured with a standard 150 mm black globe thermometer. This is also the reference instrument required for the assessment of heat stress conditions by means of the well-known Wet Bulb Globe Temperature index (WBGT). However, one of the limitations of this method is represented by the relatively long response time. This is why in recent years there has been a more and more pressing need of smart sensors for controlling Heating Ventilation and Air Conditioning (HVAC) systems, and for pocket heat stress meters (e.g., WBGT meters provided with table tennis balls). …