A register box for an HVAC installation has a body with a plurality of side panels arranged in a generally rectangular or square configuration and a wall extending in generally transverse relation to the plurality of side panels, and an expandable polymeric material affixed to an inner side of the side panels and across the wall. The wall has a plurality of concentric circular areas cut into the wall. Each of the concentric areas is formed of a first partial circle having ends in spaced relation to a second partial circle. The circular area can be removed from the wall so as to allow a user to cut through the polymeric material at the wall so as to form a hole opening to an interior of the register box. This hole can receive a collar therein. The collar can be connected to the HVAC system.

A process for forming an insulated register box includes forming an insulation across the interior surface of a register box, placing a locating collar onto an outer surface of the register box, marking the outer surface of the register box so as to present a representation corresponding to an inner diameter of the collar, separating a portion of the outer surface of the register box from a remainder of the register box corresponding to the marked representation, penetrating the exposed insulation with the collar until an end of the collar opens to an interior of the insulated register box, and positioning the flange against the outer surface of the register box.

A process for forming an insulated register box includes forming an insulation across the interior surface of a register box, placing a locating collar onto an outer surface of the register box, marking the outer surface of the register box so as to present a representation corresponding to an inner diameter of the collar, separating a portion of the outer surface of the register box from a remainder of the register box corresponding to the marked representation, penetrating the exposed insulation with the collar until an end of the collar opens to an interior of the insulated register box, and positioning the flange against the outer surface of the register box.

A UFAD system with bifurcated air towers. The air towers are bifurcated in the sense that the air columns are fan-less and coil-less, and fans for delivering pressurized air to the air columns, and hence to the underfloor plenum of the UFAD system, are in overhead ceiling air ducts and spaced away from the air columns. Cooling coils could be located in a remote air handling unit that feeds conditioned air to the overhead ceiling air ducts to be pressurized by the fans.

A UFAD system with bifurcated air towers. The air towers are bifurcated in the sense that the air columns are fan-less and coil-less, and fans for delivering pressurized air to the air columns, and hence to the underfloor plenum of the UFAD system, are in overhead ceiling air ducts and spaced away from the air columns. Cooling coils could be located in a remote air handling unit that feeds conditioned air to the overhead ceiling air ducts to be pressurized by the fans.

An air control system 20 and associated methods including a flexible duct 30 having air exit holes 40, 42 and a flexible liner 50, 60 sheet within the duct 30 and extending longitudinally along the duct, the liner 50 sheet having opposite longitudinal edges 52, 54 connected to the duct 30 along the longitudinal length of the duct 30, the liner 50 sheet being permeable in one aspect and regulating air flow through the exit holes 40, 42 when the sheet is pressed against the portion of the duct having the exit holes, and an air exit hole positioned in the duct downstream a terminal end of the liner sheet such that air exits the duct through the air exit hole to reduce or eliminate retrograde airflow along a length of the duct.

An air control system 20 and associated methods including a flexible duct 30 having air exit holes 40, 42 and a flexible liner 50, 60 sheet within the duct 30 and extending longitudinally along the duct, the liner 50 sheet having opposite longitudinal edges 52, 54 connected to the duct 30 along the longitudinal length of the duct 30, the liner 50 sheet being permeable in one aspect and regulating air flow through the exit holes 40, 42 when the sheet is pressed against the portion of the duct having the exit holes, and an air exit hole positioned in the duct downstream a terminal end of the liner sheet such that air exits the duct through the air exit hole to reduce or eliminate retrograde airflow along a length of the duct.

A diffuser for a heating, ventilation, and air conditioning (HVAC) system includes a housing defining a plenum chamber, where the housing comprises a diffusion plate configured to direct a first air flow into the plenum chamber and to discharge a second air flow from the plenum chamber and a plenum plate disposed within the housing, where the plenum plate extends from a first side of the housing to a second side of the housing opposite the first side, and the plenum plate divides the plenum chamber into a first chamber and a second chamber. The diffuser includes a plurality of apertures disposed along the plenum plate, where the plurality of apertures is configured to direct a third air flow from the first chamber into the second chamber to draw the first air flow into the plenum chamber and to force the second air flow out of the plenum chamber.

A diffuser for a heating, ventilation, and air conditioning (HVAC) system includes a housing defining a plenum chamber, where the housing comprises a diffusion plate configured to direct a first air flow into the plenum chamber and to discharge a second air flow from the plenum chamber and a plenum plate disposed within the housing, where the plenum plate extends from a first side of the housing to a second side of the housing opposite the first side, and the plenum plate divides the plenum chamber into a first chamber and a second chamber. The diffuser includes a plurality of apertures disposed along the plenum plate, where the plurality of apertures is configured to direct a third air flow from the first chamber into the second chamber to draw the first air flow into the plenum chamber and to force the second air flow out of the plenum chamber.

An indoor unit includes a housing, an air duct member, and a thermal insulation tube. The housing has an accommodating cavity. the air duct member is detachably mounted in the accommodating cavity. A mounting space is formed at a side of the air duct member in a length direction of the air duct member. The mounting space has a mounting opening facing an outside of the housing. The thermal insulation tube includes a tube section extending along a direction perpendicular to the length direction of the air duct member. The tube section is at least partially arranged in the mounting space.