A ventilation panel for a soil gas barrier system includes: an insulating foam body having first and second opposing faces and a plurality of grooves to define, in cross-section, an interconnected plurality of ventilation channels having walls that extend into the ventilation panel from the second face toward the first face; and a film of substantially gas-impervious material attached to at least one of the first face and the second face.

A ventilation panel for a soil gas barrier system includes: an insulating foam body having first and second opposing faces and a plurality of grooves to define, in cross-section, an interconnected plurality of ventilation channels having walls that extend into the ventilation panel from the second face toward the first face; and a film of substantially gas-impervious material attached to at least one of the first face and the second face.

A structure comprises at least one outer wall having an internal wall section and an outer wall section with an air flow passage therebetween. A circulation system circulates air through the flow passage to inhibit moisture accumulation and mold growth. A sensing system determines the presence of moisture in the flow passage and generates a signal in response thereto. A controller receives the signal from the sensing system and controls the circulation system to maintain a predetermined temperature and relative humidity in the flow passage.

An under-floor HVAC system for a building includes a pliable air duct lying upon a subfloor. A matrix of pedestals resting upon and extending upward from the subfloor supports a set of floor panels, which thus creates a plenum between the subfloor and the set of floor panels. The air duct extends through the plenum to convey conditioned air from a supply air duct to a series of registers in the floor panels. The registers disperse the conditioned air to a room or area just above the panels. To help keep the air duct from repeatedly extending, retracting, and otherwise sliding freely along the subfloor in response to changes in air duct pressure, the air duct is held taut by anchoring a distal downstream end of the duct to one or more of the floor-supporting pedestals. Various air duct configurations can be assembled from a predefined assortment of duct components.

An under-floor HVAC system for a building includes a pliable air duct lying upon a subfloor. A matrix of pedestals resting upon and extending upward from the subfloor supports a set of floor panels, which thus creates a plenum between the subfloor and the set of floor panels. The air duct extends through the plenum to convey conditioned air from a supply air duct to a series of registers in the floor panels. The registers disperse the conditioned air to a room or area just above the panels. To help keep the air duct from repeatedly extending, retracting, and otherwise sliding freely along the subfloor in response to changes in air duct pressure, the air duct is held taut by anchoring a distal downstream end of the duct to one or more of the floor-supporting pedestals. Various air duct configurations can be assembled from a predefined assortment of duct components.

An example welding system includes: a downdraft table having: a work surface; and a suction source configured to create a negative pressure through at least one of the work surface or a second surface adjacent to the work surface; and a positive pressure source configured to direct a positive pressure airflow around at least a portion of a periphery of the downdraft table.

An example welding system includes: a downdraft table having: a work surface; and a suction source configured to create a negative pressure through at least one of the work surface or a second surface adjacent to the work surface; and a positive pressure source configured to direct a positive pressure airflow around at least a portion of a periphery of the downdraft table.

A three-dimensional laser cutter can be disposed in a machining room. The machining room includes a ceiling and a plate member. The ceiling is provided with a suction port connected to a suction device. The plate member is disposed below the ceiling with a gap therebetween. The plate member forms a space with the ceiling.

A three-dimensional laser cutter can be disposed in a machining room. The machining room includes a ceiling and a plate member. The ceiling is provided with a suction port connected to a suction device. The plate member is disposed below the ceiling with a gap therebetween. The plate member forms a space with the ceiling.

An under-floor HVAC system for a building includes a pliable air duct lying upon a subfloor. A matrix of pedestals resting upon and extending upward from the subfloor supports a set of floor panels, which thus creates a plenum between the subfloor and the set of floor panels. The air duct extends through the plenum to convey conditioned air from a supply air duct to a series of registers in the floor panels. The registers disperse the conditioned air to a room or area just above the panels. To help keep the air duct from repeatedly extending, retracting, and otherwise sliding freely along the subfloor in response to changes in air duct pressure, the air duct is held taut by anchoring a distal downstream end of the duct to one or more of the floor-supporting pedestals. Various air duct configurations can be assembled from a predefined assortment of duct components.