Variable flow adapters for air diffusers of HVAC systems

A variable flow adapter configured to be positioned within an air diffuser to direct conditioned air from a duct to a conditioned space, comprising:

• at least one pressure-actuated device configured to be in a first configuration in response to a first pressure of the conditioned air and configured to be in a second configuration in response to a second pressure of the conditioned air different than the first pressure of the conditioned air;
• a main body defining an interior volume therein;
• a barrier in which the at least one pressure-actuated device is disposed, wherein the barrier extends across the main body and within the interior volume such that the barrier defines an upstream chamber within the interior volume and a midstream chamber within the interior volume, wherein the midstream chamber is downstream from the upstream chamber;
• a first plurality of nozzles fluidly coupled with the upstream chamber, wherein the first plurality of nozzles is fixed open to fluidly couple the upstream chamber to the conditioned space;
• and
• a second plurality of nozzles fluidly coupled with the midstream chamber, wherein the second plurality of nozzles is configured to fluidly couple the midstream chamber to the conditioned space in response to the at least one pressure-actuated device being in the first configuration and not the second configuration.

A heating, ventilation, and/or air conditioning (HVAC) system, comprising:

• an air diffuser configured to couple to ductwork of the HVAC system;
• a mounting plate of the air diffuser defining an opening configured to receive conditioned air from the ductwork;
• a diffusion plate of the air diffuser configured to direct the conditioned air into a conditioned space;
• a variable flow adapter disposed between the mounting plate and the diffusion plate;
• a main body of the variable flow adapter;
• a barrier extending across the main body such that the barrier defines an upstream chamber internal to the main body and a midstream chamber internal to the main body, wherein the midstream chamber is downstream from the upstream chamber;
• a first plurality of nozzles and a second plurality of nozzles each disposed in the main body, wherein each first nozzle of the first plurality of nozzles is configured to provide a first flow path from the upstream chamber to a downstream chamber outside of the main body and between the main body and the diffusion plate, and each second nozzle of the second plurality of nozzles is configured to provide a second flow path from the midstream chamber to the downstream chamber;
• and
• a pressure-actuated device coupled to the barrier and configured to actuate from a closed position to an open position to supply a portion of the conditioned air to the second plurality of nozzles in response to a pressure of the conditioned air exceeding a threshold pressure.