Fan assisted floor ventilation diffuser

Abstract

A fan assisted floor ventilation diffuser includes an enclosed diffuser housing with an air inlet opening and an air outlet opening. A diffuser grille covers the air outlet opening and an inlet fan is mounted at the air inlet opening. The inlet fan pulls air from the underfloor plenum into the floor ventilation diffuser housing and discharges the air through the diffuser grille into the occupied space. A thermostat in each room of the occupied space above the floor controls the operation of the inlet fan for each floor ventilation diffuser in the room and thereby controls the amount of air passing through the floor ventilation diffuser and into an individual room in the occupied space.

Description

FIELD OF THE INVENTION

The present invention relates to a floor ventilation diffuser with an inlet fan. The floor ventilation diffuser is used in an underfloor plenum air conditioning system.

BACKGROUND OF THE INVENTION

In an underfloor plenum air conditioning system, warm or cool air is supplied to the plenum below the floor of an occupied space that is to be heated or cooled. In order to heat or cool the occupied space above the floor, floor ventilation diffusers are mounted in the floor at predetermined locations to allow the warm or cool air in the plenum to flow into the occupied space above the floor. The floor ventilation diffusers are located and oriented to accommodate the configuration of the occupied space to be heated or cooled.

Prior art floor ventilation diffusers include simple boxlike structures with side or bottom air inlet openings. The side inlet openings allowed the floor ventilation diffusers to be rotated in order to control airflow through the floor ventilation diffusers based on the relative position of the diffusers air inlet opening to the flow of air in the plenum. Such side air inlet diffusers usually included sliding dampers for further control of airflow by closing off a portion of the face of the diffuser grilles used with the floor ventilation diffusers. Likewise, floor ventilation diffusers with bottom openings often included rotary dampers to control the amount of air flowing from the underfloor plenum into the occupied space. The performance of such prior art floor ventilation diffusers depended on the air pressure and circulation in the underfloor plenum at the particular location of the floor ventilation diffuser. If the floor ventilation diffuser was located a great distance from the fan column providing the conditioned air to the underfloor plenum, the floor ventilation diffuser might be starved for air even with the damper fully open. Consequently, balancing such a system to provide consistent heating and cooling in the occupied space was sometimes difficult.

SUMMARY OF THE INVENTION

To overcome the problems of the prior art, the present invention is a floor ventilation diffuser with an inlet fan. The floor ventilation diffuser comprises a diffuser housing with an air inlet opening and an air outlet opening. A diffuser grille covers the air outlet opening and an inlet fan is mounted at the air inlet opening. The inlet fan pulls air from the underfloor plenum into the floor ventilation diffuser housing and discharges the air through the diffuser grille into the occupied space.

A thermostat in each room of the occupied space above the floor controls the operation of the inlet fan for each floor ventilation diffuser in the room. Consequently, the thermostat controls the amount of air passing through the floor ventilation diffuser and into an individual room in the occupied space. That individual control improves the comfort in each individual room of the occupied space.

Because the floor ventilation diffuser of the present invention is a variable air volume device, the diffuser will increase and decrease the amount of air delivered to the occupied space depending on the input signal to the inlet fan from the thermostat. This operation makes the floor ventilation diffuser of the present invention more energy efficient than a floor diffuser that has a constant volume based on the pressure in the underfloor plenum.

The inlet fan is a 24 volt direct current (VDC) variable speed fan that consumes a small amount of energy during use when compared to a floor ventilation diffuser with a movable damper for the same task. The inlet fan, the housing, and the diffuser grille of the floor ventilation diffuser generate a low amount of noise. An integrated noise silencer is provide to dampen fan noise.

If the floor plan for the occupied space needs to be rearranged to accommodate a new room layout, the floor ventilation diffuser of the present invention is easily moved because the connections, power and control connections, are all quickly disconnected and reconnected at a new location.

The floor ventilation diffuser of the present invention also includes a feedback alarm signal from the inlet fan. The feedback alarm signal is generated by excess current to the fan and thus warns of jams or blockages.

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.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a floor ventilation diffuser shown mounted in the floor of an occupied space in accordance with the present invention.

FIG. 2 is a perspective view of the floor ventilation diffuser shown mounted in the floor of an occupied space in accordance with the present invention.

FIG. 3 is a perspective view of the floor ventilation diffuser in accordance with the present invention.

FIG. 4 is a perspective view of another embodiment of the floor ventilation diffuser in accordance with the present invention.

FIG. 5 is a top plan view of the floor ventilation diffuser in accordance with the present invention.

FIG. 6 is a section view of the floor ventilation diffuser in accordance with the present invention as seen along line C-C of FIG. 5.

FIG. 7 is a section view of the diffuser grille of the floor ventilation diffuser in accordance with the present invention as seen along line C-C of FIG. 5.

FIG. 8 is a detailed view of the diffuser grille of the floor ventilation diffuser in accordance with the present invention as seen along line C-C of FIG. 5.

FIG. 9 is a section view of the floor ventilation diffuser in accordance with the present invention as seen along line D-D of FIG. 5.

FIG. 10 is a section view of the diffuser grille of the floor ventilation diffuser in accordance with the present invention as seen along line D-D of FIG. 5.

FIG. 11 is a detailed view of the diffuser grille of the floor ventilation diffuser in accordance with the present invention as seen along line D-D of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, in which like reference numerals represent like parts throughout the several views, FIG. 1 discloses a floor ventilation diffuser 10 in accordance with the present invention mounted in a floor opening 14 of a floor 12. Conditioned air is supplied to a closed underfloor plenum 16 by means of a fan column (not shown). The floor ventilation diffuser 10 includes a diffuser housing 20 with side walls 21 and a bottom wall 19. The diffuser housing 20 has with an air outlet opening 22 and an air inlet opening 26 in one of side walls 21. A diffuser grille 24 is mounted over the air outlet opening 22. An inlet fan 28 is mounted in the air inlet opening 26.

The diffuser housing or plenum box 20 is constructed of galvanized steel or other suitable material to prevent oxidization after installation in the field. The diffuser housing 20 has a lip 30 on all four sides to allow the floor ventilation diffuser 10 to rest within the opening 14 in the raised floor 12. The inlet fan 28 is a plastic brushless direct current (DC), variable speed fan. The inlet fan 28 in one embodiment is affixed to the outside of the side wall of the diffuser housing 20. An integrated silencer 32 in the shape of a small acoustical channel 34 is located at the air inlet opening 26 within the diffuser housing 20. Acoustical dampening material (not shown) lines the inside surfaces 36 of the diffuser housing 20. An electrical enclosure 38 is provided to cover the electrical components within the diffuser housing 20. The electrical enclosure 38 has a perforated top 40 to allow heat generated from the components within the electrical enclosure 38 to flow out of the diffuser housing 20. The electrical enclosure 38 houses a power transformer, a circuit board, and a terminal block. An electrical plug 42 is connected to a power cable 43 that passes through one of the side walls 21 of the diffuser housing 20 and into the electrical enclosure 38. A socket 23 is located on the side wall 21 of the diffuser housing 20 to accept a signal cable (not shown) which conducts control signals from a thermostat or other control module to the ventilation diffuser 10.

Turning to FIGS. 5-11, the diffuser grille 24 consists of end frames 44 and side frames 52. A removable grille core section 58 is constructed of thick gauge extruded grille blades 54 that are mechanically locked together with a mandrel tube 56. Grille openings 50 are formed between the grille blades 54 to allow air into the occupied space above the floor. The grille core section 58 rests on end ledges 64 of the end frame 44 and on side ledges 66 of the side frames 52. Below the ledges 64, support bars 46 are welded to the end frames 44. The support bars 46 in turn support directional vanes 48 (FIG. 11). The directional vanes 48 are captured between the side frames 52. The directional vanes 48 are oriented at 90 degrees from the grille blades 54 of the core section 58 of the diffuser grille 24. A painted steel baffle 62 is attached to the bottom of the diffuser grille 24.

The lips 30 of the diffuser housing 20 rest on the edge of the floor opening 14 cut into the raised floor 12 (FIG. 3). The diffuser housing 20 penetrates into the underfloor air plenum 16. Consequently, the floor ventilation diffuser 10 can be installed from the room side of the floor 12. Also, the diffuser grille floor 24 is removable from the room side of the diffuser housing 20, thereby allowing access to the diffuser housing 20 for cleaning. Likewise, the core section 58 of the diffuser grille 24 is removable to allow for internal cleaning of the diffuser grille 24.

The inlet fan 28 is attached to the side wall 21 of the diffuser housing 20 and is wired to an internal circuit board (not shown) located in the electrical enclosure 38. The circuit board receives a control signal either from a computerized Building Management System (BMS) or directly from a thermostat located in the individual room of the occupied space via socket 23. If the inlet fan 28 becomes jammed or blocked, the circuit board receives an alarm signal from the inlet fan 28, sends a control signal to the inlet fan 28 to halt its operation, and relays the alarm signal back to the BMS via socket 23. The incoming control signal from the BMS or from the individual thermostat and the output alarm signal are transmitted through a provided cable (not shown) to socket 23, which connects to the floor ventilation diffuser 10 via modular connections (such as socket 23). There are also modular connections to allow the floor ventilation diffusers 10 to be daisy chained together. The power cord 43 passes into the electrical enclosures 38 and is connected to the power transformer. The transformer provides the power to the circuit board. The control signal from the BMS or from the individual thermostat is then relayed to the inlet fan 28 to provide an appropriate airflow as demanded in the occupied space. The inlet fan 28 pushes air through the integrated silencer 32 and into the lined diffuser housing 20. The conditioned air is then directed upwards by the pressure created by the inlet fan 28 towards the air outlet opening 22. The baffle 62 mounted on the back side of the diffuser grille 24 equalizes the air speed and direction as the air passes through the diffuser grille 24. The air then passes through directional vanes 48, which are individually adjusted to deflect the air, as set by the user. The core section 58 of the diffuser grille 24 then directs the air at an angle specified by the user.

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.

Claims

1. A fan assisted floor ventilation diffuser for an underfloor air plenum air conditioning system for diffusing heated or cooled air into an occupied space above a floor, the heating and cooling system comprising: a. a diffuser housing with an air inlet opening communicating with the underfloor air plenum and an air outlet opening communicating with the occupied space; b. a fan mounted to the housing and in communication with the air inlet opening; and c. a diffuser grille covering the air outlet opening.

2. The diffuser of claim 1, wherein the diffuser housing has sidewalls, and the fan is mounted in one of the sidewalls.

3. The diffuser of claim 1, wherein the air inlet includes an acoustical channel located inside the housing.

4. The diffuser of claim 1, wherein the fan is controlled by a control signal that relates to the temperature within the occupied space.

5. The diffuser of claim 1, wherein the diffuser grille includes directional vanes for directing flow of the heated or cooled air into the occupied space.