Patent Application
20090061757
This invention relates to a modular floor terminal having an adjustable basket with a light weight horizontal diffuser grille for use with an HVAC system with an under floor air plenum.
In an HVAC system having an under floor air plenum, cool or warm air is supplied to the plenum below the floor of an occupied space to be cooled or heated. In order to cool or heat the occupied space above the floor, modular terminals with diffuser grilles are mounted in the floor at predetermined locations to allow the cool or warm air in the plenum to flow into the occupied space above the floor. The terminals are located and oriented to accommodate the configuration of the occupied space to be cooled or heated.
Typically the floor terminal includes a basket mounted in the floor of an occupied space for delivering air from the under floor air plenum to the occupied space above the floor through a diffuser grille. In some installations, the modular floor terminal basket includes a stationary round basket and rotatable internal round basket. Both the stationary basket and the rotatable basket have openings in their sides and bottoms. Rotation of the internal basket within the stationary basket opens and closes the openings thereby controlling the amount of air that flows through the terminal basket, through the diffuser grille, and into the occupied space. The internal rotatable basket is connected to the diffuser grille so that rotation of the diffuser grille opens and closes the openings and thereby controls the amount of air flowing through the floor terminal. Walker U.S. Pat. No. 6,361,432 discloses a modular floor terminal with a stationary basket and a rotatable basket connected to the diffuser grille.
In certain cooling applications, it is advantageous to have a diffuser grille that diffuses the cooled air in a low velocity horizontal swirl pattern that remains tight to the floor as the cooling air from the under floor plenum displaces the air in the occupied space. The low velocity cooling air mixes slowly with the air in the occupied space rising slowly as the heat load from people and equipment is absorbed. H. Krantz-TKT GmbH has manufactured and sold at a metal horizontal diffuser grille shown in
Therefore, it is an object of the present invention to provide a modular floor terminal having an adjustable terminal basket with a lightweight plastic horizontal diffuser grille. The modular floor terminal has a stationary basket fixed to the floor and a rotatable basket nested inside of the stationary basket. The relative rotation between the stationary basket and rotatable basket opens and closes the openings in the baskets, which in turn controls the air flow from the under floor air plenum, through the lightweight horizontal diffuser grille, to the occupied space above the floor. Moreover, the lightweight horizontal diffuser grille of the present invention is connected to the rotatable basket so that that rotation of the lightweight horizontal diffuser grille controls the amount of air flowing through the modular terminal to the occupied space.
The lightweight horizontal diffuser grille has an I-beam like structure with a top plate and a bottom plate spaced apart by means of a series of radially extending hollow pillars. Each of the pillars has a radially extending slot that extends through the pillar from the top plate to the bottom plate. The pillar configuration of the lightweight horizontal diffuser grille lends itself to a single step molding process. The radially extending slots are oriented at an angle from an axis oriented perpendicular to the top plate and the bottom plate. As conditioned air passes through the radially extending slots in each of the pillars, the angle of the slots from the perpendicular imparts a swirling motion to the conditioned air, which in turn, spreads the conditioned air horizontally along the floor of the occupied space. The diffuser grille also has a series of holes in the top plate near the center of the lightweight horizontal diffuser grille. The holes exhaust the conditioned air vertically at low velocity in order to inhibit the mixing of the room air with the conditioned air spreading horizontally from the radial slots of the diffuser grille. In order to ensure adequate structural support for the diffuser grille at its center, a series of support ribs is formed below the holes to support the top plate.
Further objects, features and advantages will become apparent upon consideration of the following detailed description of the invention when taken in conjunction with the drawing and the appended claims.
The rotatable basket 18 is nested within the stationary basket 16 for relative rotation. Rotating the rotatable basket 18 within the stationary basket 16 opens and closes the circumferential openings 26 and 28 and the bottom openings 36 and 38. A setpoint mechanism 40 consists of an adjustable post 42 on the stationary basket 16 that engages the edge of an enlarged setpoint opening 44 in the bottom 32 of the rotatable basket 18. The setpoint mechanism 40 sets the minimum degree of opening when the modular floor terminal is set at its minimum flow rate.
The lightweight horizontal diffuser grille 14 is mounted on top of the rotatable basket 18 so that control slots 46 in the lightweight horizontal diffuser grille 14 engage pins 48 on the top of the internal rotatable basket 18 (
The lightweight horizontal diffuser grille 14 (
The diffuser grille 14 also has a series of holes 58 in the top plate 50 near the center 62 of the lightweight horizontal diffuser grille 14. The holes 58 are oriented in concentric rings 60 around the center 62 of the lightweight horizontal diffuser grille 14. The holes 58 exhaust conditioned air vertically at low velocity through the lightweight horizontal diffuser grille 14 into the occupied space. The low velocity conditioned air exiting the diffuser grille 14 through holes 58 inhibits the mixing of the room air with the conditioned air spreading horizontally from the radial slots 56.
The pillars 54, the top plate 50, and the bottom plate 52 create an I-beam like structure providing rigidity to the diffuser grille 14. In addition, the separate pillars 54 allow for injection molding of the diffuser grille 14 in a single operation. In order to ensure adequate structural support for the diffuser grille 14 at its center 62, a series of support ribs 64 is formed below the holes 58 to support the top plate 50. The support ribs 64 include radially extending ribs 66 and cross ribs 68. Such ribs 64 provide the needed support for the center of the lightweight, plastic embodiment of the diffuser grille 14 of the present invention.
While this invention has been described with reference to preferred embodiments thereof, it is to be understood that variations and modifications can be affected within the spirit and scope of the invention as described herein and as described in the appended claims.
