Multi-layer inlet diffuser for a terminal unit

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

an enclosure defining a chamber having a first corner and a second corner opposing the first corner;

a fan disposed in the chamber and configured to provide an airflow through the HVAC system by drawing the airflow into a fan inlet and expelling the airflow out of a fan outlet; and

an inlet diffuser disposed in the chamber upstream of the fan inlet relative to a direction of the airflow, wherein the inlet diffuser is coupled to the enclosure at the first corner of the chamber and at a mid-section of an enclosure wall extending from and partially defining the second corner of the chamber, and the inlet diffuser includes a first layer of perforated metal and a second layer of perforated metal disposed adjacent to the first layer of perforated metal such that the first layer of perforated metal and the second layer of perforated metal are arranged in series relative to the airflow and configured to enable the airflow to pass therethrough.

2. The HVAC system of claim 1 , comprising a terminal unit having the fan and the inlet diffuser.

3. The HVAC system of claim 1 , wherein the first layer of perforated metal includes a concave curvature facing away from the fan inlet.

4. The HVAC system of claim 3 , wherein the second layer of perforated metal includes an additional concave curvature facing away from the fan inlet.

5. The HVAC system of claim 4 , wherein the concave curvature corresponds to the additional concave curvature.

6. The HVAC system of claim 1 , comprising a third layer of perforated metal disposed adjacent to the second layer of perforated metal.

7. The HVAC system of claim 6 , wherein the first layer of perforated metal includes a first concave curvature facing away from the fan inlet, the second layer of perforated metal includes a second concave curvature facing away from the fan inlet, and the third layer of perforated metal includes a third concave curvature facing away from the fan inlet.

8. The HVAC system of claim 7 , wherein the first concave curvature corresponds to the second concave curvature and the third concave curvature.

9. The HVAC system of claim 1 , wherein the first layer of perforated metal is positioned between 0.5 inches and 3 inches from the second layer of perforated metal.

10. The HVAC system of claim 1 , comprising an air balancing valve configured to open a first amount in response to a first pressure drop and configured to open a second amount greater than the first amount in response to a second pressure drop greater than the first pressure drop.

11. The HVAC system of claim 10 , wherein the air balancing valve is disposed upstream of the inlet diffuser relative to the direction of the airflow.

12. A terminal unit of a heating, ventilation, and/or air conditioning (HVAC) system, the terminal unit comprising:

a housing defining an airflow path including a chamber, the chamber including a first corner and a second corner opposing the first corner;

a fan disposed in the chamber and configured to move an airflow through the chamber and into a room; and

an inlet diffuser disposed in the chamber upstream of the fan, wherein the inlet diffuser is coupled to the housing at the first corner of the chamber and at a mid-section of a housing wall extending from and partially defining the second corner of the chamber, and the inlet diffuser includes a first layer of perforated metal and a second layer of perforated metal disposed between the first layer of perforated metal and the fan such that the first layer of perforated metal and the second layer of perforated metal are arranged in series relative to the airflow and configured to enable the airflow to pass therethrough.

13. The terminal unit of claim 12 , wherein the first layer of perforated metal, the second layer of perforated metal, or both comprises a concave curvature facing away from a fan inlet of the fan.

14. The terminal unit of claim 12 , comprising an air balancing valve configured to open a first amount in response to a first pressure drop and configured to open a second amount greater than the first amount in response to a second pressure drop greater than the first pressure drop, wherein the air balancing valve is disposed upstream of the inlet diffuser such that the inlet diffuser is disposed between the air balancing valve and the fan.

15. A terminal unit of a heating, ventilation, and/or air conditioning (HVAC) system, the terminal unit comprising:

a housing defining a first chamber and a second chamber of an airflow path with a separating wall partially separating the first chamber from the second chamber, wherein a conditioned air inlet opening into the first chamber, a return air inlet opening into the second chamber, and an air outlet are formed in panels of the housing;

a fan disposed in the first chamber and configured to bias an airflow from the conditioned air inlet to the air outlet; and

an inlet diffuser disposed in the first chamber of the airflow path adjacent to the conditioned air inlet and between the conditioned air inlet and the air outlet, wherein the inlet diffuser is coupled to a first corner of the first chamber and to a mid-section of a housing wall extending from and partially defining the a second corner of the first chamber, and wherein the inlet diffuser includes a first layer of perforated metal and a second layer of perforated metal disposed between the fan and the first layer of perforated metal such that the first layer of perforated metal and the second layer of perforated metal are arranged in series relative to the airflow and configured to enable the airflow to pass therethrough.

16. The HVAC system of claim 1 , comprising a duct, wherein:

the inlet diffuser is disposed between the duct and the fan;

the first layer of perforated metal includes a concave curvature facing the duct; and

the second layer of perforated metal includes an additional concave curvature facing the duct.

17. The HVAC system of claim 1 , wherein the enclosure defines an additional chamber adjacent to the chamber and partially separated from the chamber by a separating wall, and a return air gap fluidly couples the chamber and the additional chamber between the separating wall and an additional enclosure wall.

18. The HVAC system of claim 17 , comprising a return air inlet formed in the enclosure and opening into the additional chamber.

19. The HVAC system of claim 18 , comprising a duct coupled to a third enclosure wall extending from the first corner to the second corner, wherein the duct is configured to provide a supply air corresponding to the airflow through the HVAC system, and the return air inlet is configured to provide a return air corresponding to an additional airflow through the HVAC system.

20. The HVAC system of claim 19 , wherein the air diffuser is positioned to enable the return air corresponding to the additional airflow through the HVAC system to bypass the air diffuser as the return air corresponding to the additional airflow through the HVAC system enters the chamber through the return air gap.