U.S. patent application number 15/041440 was filed with the patent office on 2016-08-18 for low noise micro environmental workspace comfort unit.
The applicant listed for this patent is Air Innovations, Inc.. Invention is credited to Bruce Meissner, Michael Wetzel.
Application Number | 20160238263 15/041440 |
Document ID | / |
Family ID | 56621012 |
Filed Date | 2016-08-18 |
United States Patent
Application |
20160238263 |
Kind Code |
A1 |
Meissner; Bruce ; et
al. |
August 18, 2016 |
LOW NOISE MICRO ENVIRONMENTAL WORKSPACE COMFORT UNIT
Abstract
A low noise micro environmental workspace comfort unit for a
workspace provides an air flow to a person working at the
workspace. At least one ambient air fan is mounted to a wall of the
comfort unit enclosure and electrically coupled to a fan speed
control module, the fan speed control module operatively coupled to
the controller. At least one heated air fan is mounted to the wall
or another wall of the comfort unit enclosure at a different place
than the at least one ambient air fan. A heat reflector reflects
heat radiation away from a rear portion of the low noise micro
environmental workspace comfort unit and directs an air flow from
the at least one heated air fan to the at least one air outlet. A
method for minimizing fan noise of a low noise micro environmental
workspace comfort unit is also described.
Inventors: |
Meissner; Bruce; (Clay,
NY) ; Wetzel; Michael; (Skaneateles, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Air Innovations, Inc. |
North Syracure |
NY |
US |
|
|
Family ID: |
56621012 |
Appl. No.: |
15/041440 |
Filed: |
February 11, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62117231 |
Feb 17, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 2013/205 20130101;
F04D 25/166 20130101; F04D 29/663 20130101; F24F 13/0604 20130101;
F24F 13/32 20130101; F04D 27/004 20130101; F04D 29/601 20130101;
F04D 29/661 20130101; F24F 13/24 20130101 |
International
Class: |
F24F 1/02 20060101
F24F001/02; F24F 13/24 20060101 F24F013/24; F04D 29/66 20060101
F04D029/66; F24F 13/20 20060101 F24F013/20; F24F 13/32 20060101
F24F013/32; F24F 11/00 20060101 F24F011/00; F24F 13/06 20060101
F24F013/06 |
Claims
1. A low noise micro environmental workspace comfort unit for a
workspace comprising: a comfort unit enclosure having a mounting
flange to mount said comfort unit enclosure to a surface of a
workspace; at least one louver mechanically coupled to said comfort
unit enclosure provides an ambient air flow to a person working at
said workspace; a controller to accept a set point from a person
working at said workspace, said set point representing a desired
rate of ambient air flow; at least one ambient air fan mounted to a
wall of said comfort unit enclosure and electrically coupled to a
fan speed control module, said fan speed control module operatively
coupled to said controller; at least one heated air fan mounted to
said wall or another wall of said comfort unit enclosure at a
different place than said at least one ambient air fan, said at
least one heated air fan comprising a heating element mechanically
coupled to said heated air fan, an operation of said heating
element controlled by said controller; at least one air outlet to
flow air heated by said heated air fan provides an air flow to a
person working at said workspace; and a heat reflector having a
curved surface disposed with a center of said curved surface
disposed at about a midpoint between said at least one heated air
fan and said at least one air outlet such that said heat reflector
reflects heat radiation away from a rear portion of said low noise
micro environmental workspace comfort unit and directs an air flow
from said at least one heated air fan to said at least one air
outlet.
2. The low noise micro environmental workspace comfort unit of
claim 1, wherein said curved surface comprises about a circular
shaped curve.
3. The low noise micro environmental workspace comfort unit of
claim 1, wherein said controller comprises a moveable human machine
interface (HMI) controller having a serrated cable clamp.
4. The low noise micro environmental workspace comfort unit of
claim 3, wherein said serrated cable clamp comprises at least one
or more rounded peaks on one side of a cable receiving slot
corresponding to at least one or more rounded troughs on another
side of said cable receiving slot and a cable receiving slot
rounded end.
5. The low noise micro environmental workspace comfort unit of
claim 1, further comprising at least one air cooling coil disposed
behind said heated air fan, said at least one air cooling coil to
flow a cooling fluid or a refrigerant there through said at least
one air cooling coil so that as controlled by said controller, said
heated air fan provides a cooled air flow and/or a heated airflow
to a person working at said workspace.
6. A low noise micro environmental workspace comfort unit for a
workspace comprising: a comfort unit enclosure having a mounting
flange to mount said comfort unit enclosure to a surface of a
workspace; at least one louver mechanically coupled to said comfort
unit enclosure provides an ambient air flow to a person working at
said workspace; a controller to accept a set point from a person
working at said workspace, said set point representing a desired
rate of ambient air flow; at least one ambient air fan mounted to a
wall of said comfort unit enclosure and electrically coupled to a
fan speed control module, said fan speed control module operatively
coupled to said controller; at least one heated air fan mounted to
said wall or another wall of said comfort unit enclosure at a
different place than said at least one ambient air fan, said at
least one heated air fan comprising a heating element mechanically
coupled to said heated air fan; and at least one heated air outlet
to direct air heated by said heated air fan to a person working at
said workspace.
7. The low noise micro environmental workspace comfort unit of
claim 6, wherein said fan speed control module comprises a solid
state relay (SSR), said SSR operatively coupled to an output
terminal of said controller.
8. The low noise micro environmental workspace comfort unit of
claim 7, wherein said SSR is controlled by a pulse width modulation
(PWM) provided by said controller.
9. The low noise micro environmental workspace comfort unit of
claim 7, wherein said ambient air fan is controlled by a phase
angle controlled SSR.
10. The low noise micro environmental workspace comfort unit of
claim 7, wherein said controller is programmed to operate said SSR
at a plurality of pre-determined set points that have an optimized
combination of low fan noise and high air flow.
11. The low noise micro environmental workspace comfort unit of
claim 6, wherein said controller is programmed to prevent a user
from selecting an ambient air fan speed below a predetermined
lowest fan speed associated with fan stall.
12. The low noise micro environmental workspace comfort unit of
claim 6, wherein said controller provides a person working at said
workspace a plurality of ambient air fan speed settings
predetermined to have a low fan noise and high air flow.
13. The low noise micro environmental workspace comfort unit of
claim 6, further comprising a desk surface electric lift mechanism
to set a height of a desk surface.
14. The low noise micro environmental workspace comfort unit of
claim 6, wherein said ambient air fan comprises a static pressure
of about 0.1 inches or greater.
15. The low noise micro environmental workspace comfort unit of
claim 1, wherein said at least one louver is coupled to said
comfort unit enclosure by an air duct mechanically coupled to at
least one hose flange disposed on said comfort unit enclosure.
16. The low noise micro environmental workspace comfort unit of
claim 6, wherein said low noise micro environmental workspace
comfort unit further comprises a proximity sensor communicatively
coupled to said controller and wherein said controller places said
low noise micro environmental workspace comfort unit in a low power
mode when said proximity sensor does not sense a person at said
workspace.
17. The low noise micro environmental workspace comfort unit of
claim 7, wherein said heating element comprises a heated coil.
18. The low noise micro environmental workspace comfort unit of
claim 17, wherein a power level of said heated coil is controlled
by a controller PWM control terminal which is electrically coupled
to a SSR that powers said heated coil wherein said power level is
set by a slider control displayed on a touch screen of said
controller.
19. The low noise micro environmental workspace comfort unit of
claim 6, wherein said low noise micro environmental workspace
comfort unit further comprises at least one accessory outlet
protected by a circuit breaker.
20. The low noise micro environmental workspace comfort unit of
claim 7, wherein said low noise micro environmental workspace
comfort unit further comprises at least one AC powered task light
dimmable by a PWM controlled SSR or a phase controlled SSR.
21. The low noise micro environmental workspace comfort unit of
claim 7, wherein said SSR comprises a DC voltage control input
terminal.
22. A method for minimizing fan noise of a low noise micro
environmental workspace comfort unit comprising: providing a low
noise micro environmental workspace comfort unit comprising a solid
state relay (SSR) fan speed circuit operatively coupled to a
comfort unit controller having a comfort unit controller PWM output
terminal, said comfort unit controller to set a PWM waveform at a
comfort unit controller output terminal; generating a PWM frequency
between about 12 Hz and 250 Hz at said comfort unit controller PWM
output terminal; measuring a fan noise sound level and a fan air
speed at said PWM frequency; repeating said step of generating to
said step of measuring between a fan speed above about a fan stall
speed and about a maximum fan air flow; determining a set of PWM
frequencies having a minimal fan noise and maximum fan air flow for
each of a predetermined number of discrete fan speed settings; and
configuring a firmware or software stored on a non-volatile memory
and that runs on said comfort unit controller, so that said comfort
unit controller provides a person working at said low noise micro
environmental workspace comfort unit, a selection of a fan speed
from a set of discrete fan speed settings.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S.
provisional patent application Ser. No. 62/117,231, LOW NOISE MICRO
ENVIRONMENTAL WORKSPACE COMFORT UNIT, filed Feb. 17, 2015, which
application is incorporated herein by reference in its
entirety.
FIELD OF THE APPLICATION
[0002] The application relates to workstation environmental units
and particularly to fan control and air distribution from a
workstation environmental unit.
BACKGROUND
[0003] There has been an increasing trend away from personal
offices towards workstations in open spaces. With energy
conservation and cost concerns, there is less heating or cooling of
opens spaces. In some industrial settings, such as on a factory
floor, or in a warehouse, it may not be possible to provide a
comfortable office like working environment. Workers at desks in
such open spaces may be uncomfortable for hours at a time leading
to lower morale and lower worker productivity.
SUMMARY
[0004] According to one aspect, a low noise micro environmental
workspace comfort unit for a workspace includes a comfort unit
enclosure having a mounting flange to mount the comfort unit
enclosure to a surface of a workspace. At least one louver is
mechanically coupled to the comfort unit enclosure to provide an
ambient air flow to a person working at the workspace. A controller
accepts a set point from a person working at the workspace, the set
point representing a desired rate of ambient air flow. At least one
ambient air fan is mounted to a wall of the comfort unit enclosure
and electrically coupled to a fan speed control module. The fan
speed control module is operatively coupled to the controller. At
least one heated air fan is mounted to the wall or another wall of
the comfort unit enclosure at a different place than the at least
one ambient air fan. The at least one heated air fan includes a
heating element which is mechanically coupled to the heated air
fan. Operation of the heating element can be controlled by the
controller. At least one heated air outlet directs air heated by
said heated air fan to a person working at said workspace. A heat
reflector having a curved surface is disposed with a center of the
curved surface at about a midpoint between the at least one heated
air fan and the at least one air outlet such that the heat
reflector reflects heat radiation away from a rear portion of the
low noise micro environmental workspace comfort unit and directs an
air flow from the at least one heated air fan to the at least one
air outlet.
[0005] In one embodiment, the curved surface comprises about a
circular shaped curve.
[0006] In another embodiment, the controller includes a moveable
human machine interface (HMI) controller having a serrated cable
clamp.
[0007] In yet another embodiment, the serrated cable clamp includes
at least one or more rounded peaks on one side of a cable receiving
slot corresponding to at least one or more rounded troughs on
another side of the cable receiving slot and a cable receiving slot
rounded end.
[0008] In yet another embodiment, the low noise micro environmental
workspace comfort unit further comprises further comprises at least
one air cooling coil disposed behind the heated air fan. The at
least one air cooling coil flows a cooling fluid or a refrigerant
there through the at least one air cooling coil so that as
controlled by the controller, the heated air fan provides a cooled
air flow and/or a heated airflow to a person working at the
workspace.
[0009] According to another aspect, a low noise micro environmental
workspace comfort unit for a workspace includes a comfort unit
enclosure having a mounting flange to mount the comfort unit
enclosure to a surface of a workspace. At least one louver
mechanically coupled to the comfort unit enclosure provides an
ambient air flow to a person working at the workspace. A controller
accepts a set point from a person working at the workspace, the set
point representing a desired rate of ambient air flow. At least one
ambient air fan is mounted to a wall of the comfort unit enclosure
and electrically coupled to a fan speed control module. The fan
speed control module is operatively coupled to the controller. At
least one heated air fan mounted to the wall or another wall of the
comfort unit enclosure at a different place than the at least one
ambient air fan, each of the at least one heated air fan includes a
heating element mechanically coupled to the heated air fan. At
least one heated air outlet flows air heated by the heated air fan
to provide a heated air flow to a person working at the
workspace.
[0010] In one embodiment, the fan speed control module includes a
solid state relay (SSR), the SSR operatively coupled to an output
terminal of the controller.
[0011] In another embodiment, the SSR is controlled by a pulse
width modulation (PWM) provided by the controller.
[0012] In yet another embodiment, the ambient air fan is controlled
by a phase angle controlled SSR.
[0013] In yet another embodiment, the controller is programmed to
operate the SSR at a plurality of pre-determined set points that
have an optimized combination of low fan noise and high air
flow.
[0014] In yet another embodiment, the controller is programmed to
prevent a user from selecting an ambient air fan speed below a
predetermined lowest fan speed associated with fan stall.
[0015] In yet another embodiment, the controller provides a person
working at the workspace a plurality of ambient air fan speed
settings predetermined to have a low fan noise and high air
flow.
[0016] In yet another embodiment, the low noise micro environmental
workspace comfort unit further includes a desk surface electric
lift mechanism to set a height of a desk surface.
[0017] In yet another embodiment, the ambient air fan includes a
static pressure of about 0.1 inches or greater.
[0018] In yet another embodiment, the at least one louver is
coupled to the comfort unit enclosure by an air duct mechanically
coupled to at least one hose flange disposed on the comfort unit
enclosure.
[0019] In yet another embodiment, the low noise micro environmental
workspace comfort unit further includes a proximity sensor
communicatively coupled to the controller and wherein the
controller places the low noise micro environmental workspace
comfort unit in a low power mode when the proximity sensor does not
sense a person at the workspace.
[0020] In yet another embodiment, the heating element includes a
heated coil.
[0021] In yet another embodiment, a power level of the heated coil
is controlled by a controller PWM control terminal which is
electrically coupled to a SSR that powers the heated coil wherein
the power level is set by a slider control displayed on a touch
screen of the controller.
[0022] In yet another embodiment, the low noise micro environmental
workspace comfort unit further includes at least one accessory
outlet protected by a circuit breaker.
[0023] In yet another embodiment, the low noise micro environmental
workspace comfort unit further includes at least one AC powered
task light dimmable by a PWM controlled SSR or a phase controlled
SSR.
[0024] In yet another embodiment, the SSR includes a DC voltage
control input terminal.
[0025] According to yet another aspect, a method for minimizing fan
noise of a low noise micro environmental workspace comfort unit
includes: providing a low noise micro environmental workspace
comfort unit including a solid state relay (SSR) fan speed circuit
operatively coupled to a comfort unit controller having a comfort
unit controller PWM output terminal, the comfort unit controller to
set a PWM waveform at a comfort unit controller output terminal;
generating a PWM frequency between about 12 Hz and 250 Hz at the
comfort unit controller PWM output terminal; measuring a fan noise
sound level and a fan air speed at the PWM frequency; repeating the
step of generating to the step of measuring between a fan speed
above about a fan stall speed and about a maximum fan air flow;
determining a set of PWM frequencies having a minimal fan noise and
maximum fan air flow for each of a predetermined number of discrete
fan speed settings; and configuring a firmware or software stored
on a non-volatile memory and that runs on the comfort unit
controller, so that the comfort unit controller provides a person
working at the low noise micro environmental workspace comfort
unit, a selection of a fan speed from a set of discrete fan speed
settings.
[0026] The foregoing and other aspects, features, and advantages of
the application will become more apparent from the following
description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The features of the application can be better understood
with reference to the drawings described below, and the claims. The
drawings are not necessarily to scale, emphasis instead generally
being placed upon illustrating the principles described herein. In
the drawings, like numerals are used to indicate like parts
throughout the various views.
[0028] FIG. 1 shows an isometric view of an exemplary embodiment of
a low noise micro environmental workspace comfort unit;
[0029] FIG. 2A shows a front view of the low noise micro
environmental workspace comfort unit of FIG. 1;
[0030] FIG. 2B shows a top view of the low noise micro
environmental workspace comfort unit of FIG. 1;
[0031] FIG. 2C shows a side view of the low noise micro
environmental workspace comfort unit of FIG. 1;
[0032] FIG. 2D shows a view of another side of the low noise micro
environmental workspace comfort unit of FIG. 1;
[0033] FIG. 3 shows an isometric of the low noise micro
environmental workspace comfort unit of FIG. 1 mounted in
workstation surface.
[0034] FIG. 4 shows exemplary mounting dimensions for workstation
surface;
[0035] FIG. 5 shows an isometric view of another exemplary
embodiment of a low noise micro environmental workspace comfort
unit;
[0036] FIG. 6A shows a front view of the low noise micro
environmental workspace comfort unit of FIG. 5;
[0037] FIG. 6B shows a top view of the low noise micro
environmental workspace comfort unit of FIG. 5;
[0038] FIG. 6C shows a side view of the low noise micro
environmental workspace comfort unit of FIG. 5;
[0039] FIG. 6D shows a view of another side of the low noise micro
environmental workspace comfort unit of FIG. 5;
[0040] FIG. 7 shows an exemplary installation of a low noise micro
environmental workspace comfort unit of FIG. 5 to the underside of
a workstation surface;
[0041] FIG. 8 shows the relatively small foot print of the low
noise micro environmental workspace comfort unit of FIG. 5 on the
workstation surface.
[0042] FIG. 9A shows an internal front view of one exemplary
embodiment of the low noise micro environmental workspace comfort
unit of FIG. 1;
[0043] FIG. 9B shows a more detailed view of the environmental
workspace comfort unit of FIG. 9A showing more detail of the
section below bulkhead;
[0044] FIG. 10 shows an exemplary graph of PWM frequency and CFM
for various identified fan set points;
[0045] FIG. 11A shows a block diagram of one exemplary embodiment
of a fan speed controller based on a phase angle controlled solid
state relay (SSR);
[0046] FIG. 11B shows a task lighting block diagram element;
[0047] FIG. 12 shows a graph of fan RPM versus DC voltage applied
at the input control terminal of phase angle controlled SSR;
[0048] FIG. 13 shows a side cut away view of an exemplary
embodiment of a micro environmental workspace comfort unit with air
conditioning coils and a heat reflector;
[0049] FIG. 14 shows a dimetric view cutaway drawing of the
exemplary micro environmental workspace comfort unit of FIG.
13;
[0050] FIG. 15A shows an isometric view of the rear side of an
exemplary heat reflector;
[0051] FIG. 15B shows a top view of the heat reflector of FIG.
16A;
[0052] FIG. 15C shows a front view of the heat reflector of FIG.
16A;
[0053] FIG. 15D shows a side view of the heat reflector of FIG.
16A;
[0054] FIG. 16A is a drawing showing an isometric view of an
exemplary HMI controller;
[0055] FIG. 16B shows a top view of the controller of FIG. 17A;
[0056] FIG. 16C shows a front view of the controller of FIG.
17A;
[0057] FIG. 16D shows a front view of the controller frame of FIG.
17A;
[0058] FIG. 16E shows a side view of the controller of FIG. 17A;
and
[0059] FIG. 16F shows a rear view of exemplary HMI controller with
a serrated cable clamp.
DETAILED DESCRIPTION
[0060] As described hereinabove, there has been an increasing trend
away from personal offices towards workstations in open spaces.
Unfortunately, such workstations in open spaces are often less
comfortable because of an overall need for heating ventilation and
air conditioning (HVAC) energy conservation and cost savings. Or,
in other open space work areas, because of an industrial setting,
such as a factory floor or a warehouse, it is not possible to
provide a comfortable office like working environment. Workers at
desks in such open spaces may be uncomfortable for hours at a time
leading to lower morale and lower worker productivity.
[0061] Noise, more particularly fan noise, has been a problem with
prior art comfort systems. Most of the noise is from the fans in or
near the personal environmental unit, which is physically close to
the worker. For example, as described by Demeter, et. al. in U.S.
Pat. No. 4,872,397, the fan noise can be so distracting or annoying
that a white noise generator can be used to help mask noise from
the personal environmental module as well as from nearby
workstations.
[0062] Another problem with prior art personal environmental
modules, such as the unit described by Demeter is the need for
external duct work to convey comfort air from the unit to the
workstation. In densely enclosed workstations, such as, for
example, 911 emergency services operator stations, where there can
be densely packed communications equipment, telecommunications
equipment, and associated interconnecting cables. Retrofitting such
a workstation where external ductwork is needed within the
workstation can be costly, time consuming, and potentially damaging
to the equipment and cables. Therefore, there is a need for a low
noise micro environmental workspace comfort unit without external
ductwork.
[0063] A solution to the problem of fan noise is a new fan power
control system which significantly reduces fan noise while
optimizing air flow. In some embodiments, with various low noise
solutions, the fans can be mounted closer to the worker and exhaust
ports eliminating the need for external duct work. Also, with the
new low noise fan approaches described hereinbelow, the white noise
generator is no longer needed to mask fan noise.
[0064] Another problem with prior art environmental modules is the
need for dampers for active mixing of air streams. For example, in
some prior art solutions, a pre-conditioned source of heated air is
actively mixed with another source recirculated room air to achieve
a desired temperature. Active mixing by controlled dampers adds
extra complexity and cost.
[0065] It was realized that the active mixing system, including
components such as controlled baffles can be eliminated. In a more
cost effective, more efficient, and less complex solution, the new
system solution described hereinbelow uses at least one fan
dedicated to heating and temperature control, and at least one fan
dedicated to ambient air (room air) recirculation. The resultant
new structure has fewer components (e.g. no need for active air
flow mixing as by controllable baffles), while performing the same
functions of temperature control and air recirculation. For
example, in some embodiments, air from one main inlet is split into
two paths, one path for cooling air above the desk and one path for
heating air below the desk. In the new system described in detail
hereinbelow, there is no need for temperature control through
active mixing of air streams because there is a dedicated fan for
air circulation and a dedicated fan for heated air. With separate
dedicated fans for air recirculation and for heated air,
circulation air flow can be direct air above the desk separate from
heated air directed below the desk, there is no need for damper
controlled active air mixing. In other words, the same comfort air
flow functions can be achieved with fewer components.
[0066] Another problem is that workspace comfort systems are
inefficient because of waste heat or waste cooling of the enclosure
cause wasteful heating and/or cooling of the enclosure and lost
energy through the back of the unit. It was realized that a curved
heat reflector installed in a micro environmental workspace comfort
unit can both reflect otherwise lost heat energy to or from a
person working at the micro environmental workspace comfort unit as
well as to more efficiently direct the heating and/or cooling
airflow to the person.
[0067] Yet another problem is the lack of air conditioning in prior
art workstation comfort units. It is contemplated that an air
cooling feature could be added to a micro environmental workspace
comfort unit such as, for example, by chilled water flowing through
one or more coiling coils, or by more traditional air conditioning
means, such as an evaporator direct expansion (DX) coil in the
environmental workspace comfort unit operatively coupled to an
external condenser unit by HVAC techniques know in the art. One
possible problem with plumbing pipe runs to an external condenser
is that the colder liquid return pipe might introduce condensation
problems along the run, such as through sensitive electrical,
electronic, and/or mechanical equipment near the micro
environmental workspace comfort unit. Therefore, a chilled water
type solution is believed to be preferable over a conventional
refrigerant solution because there is no need for long pipe runs to
the external condenser, typically placed outside of the building. A
chilled water solution has plumbed to one or more water cooling
coils any suitable source of water of a low enough temperature to
effect cooling by flowing air over one or more cooling coils
optionally including metal thermal fins. It is contemplated that
such cooling coils could be mounted, for example, behind the heated
air fan with or without additional metal heat transfer fins. In
some installations, an existing cold water source or cold water tap
may be of sufficiently low temperature to provide the needed
cooling. In other installations, a local water chiller of any
suitable type can be used. Such a local water chiller could be
installed within the housing of the micro environmental workspace
comfort unit. A remote water chiller could also be used, however
would have associated possible problems of condensation along a
supply pipe as discussed hereinabove. A chilled water solution
could be open loop with water returning to a water drain or closed
loop where the water continuously circulates, or a combination of
the two techniques. Another additional element could be a local
water condensation drain pipe which may or may not be difficult to
add depending on the proximity of the workstation to a local drain
or exterior wall. Where air cooling is used, usually either the air
conditioning or heating mode is used to cool or heat, however it is
also contemplated that both the heated coil and the cooling coil of
the air conditioner could also be operated simultaneously to effect
changes in humidity. A local water drain would be added to remove
condensation from the local cooling pipes with optional thermal
fins.
[0068] FIG. 1 shows an isometric view of one embodiment of the low
noise micro environmental workspace comfort unit 100. Comfort air
is available at top adjustable louvers 103 of panel 110. Warmed
comfort air is available at lower warm air vents 102. Main power
switch 107 switches low noise micro environmental workspace comfort
unit 100 on or off. Touch screen controller, such as, for example,
a color touch screen controller 105 is programmed to run firmware
and/or software to control the low noise micro environmental
workspace comfort unit 100. Motion sensor 106, is operatively
coupled to touch screen controller 105 so that that the low noise
micro environmental workspace comfort unit 100 can be automatically
powered down by turning off some or all systems of the low noise
micro environmental workspace comfort unit for energy savings when
a person is not in the immediate vicinity of the workstation. On
one side of the low noise micro environmental workspace comfort
unit 100, workstation lighting outlets 133, 134 provide AC
electrical power for workstation lights. The lighting outlets 133,
134 are protected by a lighting circuit breaker 135. Internal fans
and wiring are contained within and protected by front panel 130,
side panels 135, and lower panel 140.
[0069] FIG. 2A shows a front view of the low noise micro
environmental workspace comfort unit 100 of FIG. 1.
[0070] FIG. 2B shows a top view of the low noise micro
environmental workspace comfort unit 100 of FIG. 1. Trim bezel 120
can be used to mount the low noise micro environmental workspace
comfort unit 100 to a workstation surface as well as to provide an
aesthetically pleasing transition between a surface of the
workstation and the low noise micro environmental workspace comfort
unit 100.
[0071] FIG. 2C shows a side view of the low noise micro
environmental workspace comfort unit 100 of the opposite side which
is not visible in FIG. 1. Additional AC power outlets include an
IEC power cord receptacle 142 (typically used to power computer
equipment, such as computer monitors), and auxiliary AC power
outlet 143. Auxiliary AC power outlet 143 is protected by an
auxiliary circuit breaker 144. The low noise micro environmental
workspace comfort unit 100 is protected by main circuit breaker
145. For embodiments with a leg lift, there is also a leg lift
interface connector 146. A motorized lift mechanism, such as, for
example, a Linak.TM. lift control available from LINAK U.S. Inc. of
Louisville K., provides remote electrically controlled desk height
adjustment. The operation of the electric lift mechanism is
typically controlled by the controller 105.
[0072] FIG. 2D shows a view of the other side of the low noise
micro environmental workspace comfort unit 100 including the
lighting outlets 133, 134 which are protected by a lighting circuit
breaker 135.
[0073] FIG. 3 shows an isometric of the exemplary low noise micro
environmental workspace comfort unit 100 of FIG. 1 mounted in
workstation surface 300.
[0074] FIG. 4 shows an example of mounting dimensions for
workstation surface 300.
[0075] FIG. 5 shows an isometric view of another exemplary
embodiment of a low noise micro environmental workspace comfort
unit 500. In the embodiment of FIG. 5, there can be air ducts to
route the ambient air circulation to louvers elsewhere in a
workstation. Any suitable air flow connection system, such as, for
example, exhaust ducts, air ducts, and/or air hoses of any suitable
diameter can be used. Such hoses can be coupled to flanges 513.
Front cover 530 and side covers 531 cover the internal wiring and
components of the low noise micro environmental workspace comfort
unit 500. Another difference is that mounting flange 561 can be
used to mount a low noise micro environmental workspace comfort
unit 500 to a lower surface of a workstation table for an under the
top surface mount, with only upper bezel 520 and the controls
visible above the top surface of the workstation for a lower
profile installation.
[0076] FIG. 6A shows a front view of the low noise micro
environmental workspace comfort unit 500. FIG. 6C shows a side view
of the low noise micro environmental workspace comfort unit 500,
and FIG. 6D, a view of another side of the low noise micro
environmental workspace comfort unit 500. The features on the sides
are the same as were described hereinabove with respect to FIG. 2A,
FIG. 2B, FIG. 2C, and FIG. 2D, except for the under surface
mounting structure (mounting flange 561, and bezel 520) and the
flanges 513 for ambient air distribution.
[0077] FIG. 6B shows a top view of the low noise micro
environmental workspace comfort unit 500. Mounting slots 637 can be
used to bolt the low noise micro environmental workspace comfort
unit 500 to the underside of a workstation surface (e.g. under a
desktop surface) using any suitable fasteners, such as, for
example, wood screws or sheet metal screws.
[0078] FIG. 7 shows an exemplary installation of a low noise micro
environmental workspace comfort unit 500 to the underside of a
workstation surface 701. Air ducts 717 connect ambient air flanges
513 to louvers 703. In the exemplary embodiment of FIG. 7, louvers
703 are spaced further apart on the workstation surface 701 than
the width of workspace comfort unit 500. FIG. 8 shows the
relatively small foot print of a low noise micro environmental
workspace comfort unit 500 on the workstation surface 701.
[0079] FIG. 9A shows an internal front view of one embodiment of
the low noise micro environmental workspace comfort unit 100 of
FIG. 1. In the embodiment of FIG. 9A, there are two separate
comfort fans, ambient air fan 971 and heated air fan 951.
[0080] FIG. 9B shows a more detailed view of one exemplary
embodiment of the environmental workspace comfort unit 100 of FIG.
9A showing the section below bulkhead 921. Heating coil 901 can be
seen mounted to heated air fan 951 by heating element brackets 902.
Heating element brackets 902 can use any suitable high temperature
material, such as, for example a ceramic material to support the
heating coil 901. Terminal strips 931 and 932 allow for
environmental workspace comfort unit 100 wiring, such as, for
example, by use of industry standard push on electrical crimp lugs.
The heating coil 901, heated air fan 951 assembly can be seen
mounted to an assembly mounting bracket 961 (e.g. a sheet metal
strap), such as, for example, by bolts 957, nuts 955, and heating
assembly bracket 959. The assembly mounting bracket 961 can be
mounted to a wall of the low noise micro environmental workspace
comfort unit 100 by any suitable fasteners, such as, for example,
by rivets 953.
[0081] In the exemplary embodiments of FIG. 9A and FIG. 9B, the
lower heated air fan 951 is for comfort heating of the desk user's
feet and legs. The top ambient air fan 971 is for sending ambient
air at the desk user's face or torso. Both fans operate
independently of each other. The lower heated air fan 951 can
operate at constant speed while control of its heating element
heating coil 901 can be variable. There are two bottom mounted
rotatable louvers (e.g. 102, FIG. 1) that can direct the warm air
as needed. In the exemplary embodiment of FIG. 9B, the lower heated
air fan 951 is controlled by an on/off control via a solid state
relay (SSR). Generally, no noise reduction circuit is used for
heated air fan 951 because only one relatively low noise fan speed
is used. However, the upper larger air circulation fan is typically
operated at variable pre-determined fixed speeds and does use the
new noise reduction circuitry and techniques. The upper fan
discharges through louvers 103, FIG. 1, or louvers 513, FIG.
6A.
[0082] Fan noise: At least one fan in a micro environmental
workspace comfort unit should have a variable fan speed. One
problem is that prior art methods of micro environmental workspace
comfort unit fan speed control make sounds ranging from an
oscillatory sound to a rumble. Such sounds can be distracting or
even annoying to the worker at the desk or workstation. Also, such
as in the case of a 911 operator or an remotely controlled aircraft
or drone in contact with air traffic controllers, any additional
sounds in the workspace can interfere with efficient error free
communications.
[0083] As described hereinabove, one solution to the fan noise
problem taught by the '397 patent added a white noise generator to
mask fan noise. While helping to mask the unpleasant aspects of
prior art fan control, the white noise generator also increases the
power level of total sounds and noise that the worker must contend
with in trying to most efficiently carry out their assigned task.
While the combination of white noise and fan noise might be less
disruptive than fan noise alone, a better solution is to reduce the
fan noise.
[0084] In some embodiments, one fan speed control technique uses a
pulse width modulation (PWM) output of a controller to control a
zero crossing solid state relay (SSR). Fans of with a suitable
thickness (e g thin fans) with sufficient cubic feet per minute
(CFM) are typically single phase AC fans (typically, not the common
smaller DC (e.g. 12V DC) muffin fans found computers and other
electronic equipment cabinets. Suitable AC fans include air flows
of about 150 CFM or greater and static pressures of about 0.1
inches or greater. This approach effectively chops the AC power to
the single phase AC fan, such as, for example, an AC powered shaded
pole motor muffin fan. The result, depending on the selected fan
speed, is a variety of varying types of fan noise. As one approach
to fan noise suppression, we realized that there are a number of
near optimal PWM settings across a range of fan speeds, for
example, in a range of about 12 Hz to 15 Hz PWM and about 100 Hz to
250 Hz chopping frequency. It was realized that specific PWM
frequencies with certain frequency ranges yield best fan air flow
with minimal emitted fan audio sound power at each of the
pre-determined fan settings to keep fan noise and fan rumble to a
minimum. We also realized that most users do not desire or need a
continuous range of fan speeds and that for some defined number of
fan speeds, e.g. 40%, 60%, etc., low noise, high airflow (e.g.
highest cubic feet per minute (CFM)) lowest noise set points could
be found and defined. Such PWM frequencies can be found for a given
fan type, for example, by manually sweeping the frequency PWM out
of a controller or PLC while monitoring air flow and fan noise
output. Never-the-less, there can still be some audible "grumble"
because of the chopping of the AC sine waveform means the fans are
no longer operating on the more pure 60 Hz waveform for which the
electromagnet structure was originally designed. FIG. 10 shows one
exemplary graph of PWM frequency and CFM for various identified fan
set points of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 100% fan
operation with minimal fan noise audio power emitted and best air
flows for those set points for one exemplary type of single phase
AC powered fan.
[0085] Another problem is fan stall. It was found that below some
fan speed settings, it was possible to have a fan stop in a
particular point of its rotation, where it was difficult to restart
it (i.e. the fan blade stopped turning). In the embodiment
described hereinabove, by locking out fan speeds below a certain
lower threshold (e.g. 20%), we were able to substantially solve the
fan stall problem.
[0086] In another embodiment, it was realized that single phase
analog switching can be used to control fan speed instead of a PWM
controlled SSR to chop the 60 Hz mains power waveform. One
exemplary implemented control scheme uses phase angle SSRs
available from Carlo Gavazzi, Incorporated of Buffalo Grove,
Illinois. In one exemplary implementation, a type RM1E 1 phase
analog switching SSR (part no. RM1E23V25) was used to control both
the cooling fan and task lights.
[0087] Heater Coil Control: The heated fan, heat element can be
controlled by a PWM control system. In some embodiments, heating
power of the heated element (e.g. heated coil 901) is controlled by
a pulse width modulation (PWM) control terminal of a controller
which controls a zero crossing solid state relay (SSR) that powers
the heating coil. In some embodiments, the PWM controlled heated
coil power is set to a desired heating power by a user control,
such as, for example, a slider control displayed on the LCD touch
screen of the workstation controller (e.g. controller 105). It was
realized that rather than setting a desired temperature, the person
at the workstation can more simply slide the heating coil power
side control set a heated air flow that is most comfortable to them
at that moment.
[0088] example: FIG. 11A shows a block diagram of one exemplary
embodiment of a fan speed controller based on 1 phase analog
switching. A controller 1010, here a Unitronics controller, makes a
variable PWM output control waveform in the usual way as known to
those skilled in the art. The PWM output control waveform is
converted to a DC voltage in a range of 0 to 10 VDC by low pass
filter 1012. The phase angle controlled solid state relay 1014, in
this exemplary embodiment, a Carlo Gavazzi part number RM1E23V25
phase angle controlled solid state relay which is powered by a +24
power supply and controls by phase angle control a 115 VAC power
source to provide a phase angle controlled (partial sinusoidal
waveform) via wire 1021 to AC fan 1016 which also has connected
thereto an appropriate AC neutral return wire path for the phase
angle controlled AC waveform.
[0089] FIG. 11B shows a task lighting block diagram element. The
same circuit of controller 1010, low pass filter 1012, and phase
angle controlled solid state relay 1014 can be used power a
dimmable an AC light bulb 1026 by applying a phase angle controlled
(partial sinusoidal waveform) via wire 1022 to AC light bulb 1026.
It is understood that the controller can have two or more PWM
output terminals and that the circuit from controller 1010, low
pass filter 1012, and phase angle controlled solid state relay 1014
can be replicated two or more times to control the fan speed of one
or more fans and/or one or more dimmable AC powered lamps.
[0090] FIG. 12 shows a graph of fan RPM versus DC voltage applied
at the input control terminal of phase angle controlled solid state
relay 1014 by low pass filter 1012. Testing of the exemplary
circuit shows less fan noise and no low perceptible fan rumble or
growl compared with the technique of directly using the PWM signal
from the controller to fire a conventional SSR.
[0091] It is also contemplated that another suitable phase angle
controlled solid state relay, for example, is the NuWave
Technologies part number SSRMAN-1P-HR-xSS-1% available from NuWave
Technologies, Inc. of Norristown, Pa. The SSRMAN series mount on
top of standard Panel Mount Solid State Relays and provide phase
angle and burst firing based on the selected command input (e.g. a
0-10 VDC input control voltage range).
[0092] In the example described hereinabove, 0-10 VDC was used to
control the phase angle of the phase angle controlled solid state
relay. However any suitable control signal can be developed using
known techniques from a PWM output of a controller, directly via a
low pass filter such as an RC filter to develop a 0 to 10 VDC
control signal, or by other such known techniques directly or with
or more intervening active stages (e.g. amplifier gain, offset,
and/or voltage to current conversion or current to voltage
conversion, to develop a current control signal (e.g. the standard
4-20 mA control range), any suitable voltage control range (e.g.
0-5 VDC), an equivalent resistance control range, etc. It is also
contemplated that instead of the PWM controller output, the
controller could also provide an analog voltage or analog current
control signal directly to an input terminal of a phase angle
controlled solid state relay. As with one or more PWM output
controls, there could be two or more of any suitable type of analog
output control terminal (e.g. output voltage, and/or output
current) programmatically controlled (e.g. by firmware and/or
software) by the controller.
[0093] Applications: Typical applications for a low noise micro
environmental workspace comfort unit include multi-tiered desks,
such as are used in 911 call centers and control stations used in
industrial and military settings. However, a low noise micro
environmental workspace comfort unit can also be used at any desk,
such as in a traditional, cubical, or open area workspace.
[0094] example: One exemplary low noise micro environmental
workspace comfort unit provides a cooling ambient air stream above
desk of about 0-40 CFM delivered through directional louvers.
Heating air stream below the desk with an air flow of about 40 CFM
heat the air by a about a 0-350 watts heating element, where the
heated air can be delivered through directional louvers. One
exemplary unit includes: an integral Linak.TM. lift control,
integral variable task lighting, integral ON/OFF power outlet to be
used for any miscellaneous device (Andon status light, phone
charger, radio, etc), controller memory for storing unique user
settings, and an integral motion sensor to shut the unit off when
desk is not occupied. Some embodiments with integral top air
louvers serve as a complete one-piece drop-in unit. Other
embodiments having air duct flanges allow for placement of the
cooling ambient air supply louvers or grills farther away from the
controller control panel.
[0095] Air Conditioning: FIG. 13 shows a side view cutaway drawing
of one exemplary micro environmental workspace comfort unit 1300
having heating coils 1303 mounted behind fan 1351 by any suitable
mechanical and thermal mounting means. Fan 1351, similar to fan 951
of FIG. 9A and FIG. 9B typically includes one or more heating
elements as well for full range temperature control. Micro
environmental workspace comfort unit 1300 is shown mounted below a
table or desk surface 1360.
[0096] FIG. 14 shows a dimetric view cutaway drawing of the
exemplary micro environmental workspace comfort unit 1300.
[0097] Heat Reflector: It was realized that a micro environmental
workspace comfort unit can more efficiently transfer heat to and
from a worker sitting or standing near the unit by installing a
curved reflector. FIG. 13 shows an exemplary curved reflector 1301.
The curved reflector 1301 is mounted adjacent to a back wall 1315
between the back wall 1315 and fan 1351. In the heating mode, the
curved reflector 1301 reflects heat, including infrared (IR)
radiation from a heating element (e.g. heating coil 901, not shown
in FIG. 13) from the heating coil to the heated air stream flowing
out of the micro environmental workspace comfort unit 1300 towards
the user, as well as towards the front of the unit and air vents
102. In contemplated embodiments of a micro environmental workspace
comfort unit having an air conditioning feature such as exemplary
micro environmental workspace comfort unit 1300, the reflector
helps to direct heat energy and IR radiation from the user side of
micro environmental workspace comfort unit 1300 to the cooling
coils. A curved reflector 1301 can also help to more efficiently
direct airflow from fan 1351 to air vents 102 by, for example,
directing air flow along the curved path defined by the curved
surface of reflector 1301. The air flow so directed, avoids some of
the turbulence associated with the otherwise squared corner
surfaces of the micro environmental workspace comfort unit
enclosure.
[0098] A heat reflector 1301 can be formed from any suitable
material, such as, for example, any suitable sheet metal by any
suitable metal forming means.
[0099] FIG. 15A to FIG. 15D show several views of an exemplary
micro environmental workspace comfort unit reflector 1301. FIG. 15A
shows an isometric view of the rear side of an exemplary reflector
1301. Two sides of the reflector 1301, here the top and bottom
sides, are bent at more than 90 degree angles form mounting flanges
1511. In the exemplary embodiment of FIG. 15A, each mounting flange
has two mounting holes 1513 for fasteners. Any suitable fastener or
fastening system can be used, such as for example, PEM.TM. nuts,
which can be press fit into the mounting holes. FIG. 15B shows a
top view, FIG. 15C a front view, and FIG. 15D a side view of the
reflector 1301 of FIG. 15A.
[0100] Example: In one exemplary embodiment, the heat reflector was
about 11 inches wide by about 8 inches high. The flanges were about
1.4'' wide with the two mounting holes spaced about 4.5'' apart on
each mounting flange. The curve approximated a section of a circle
with a radius of about 6''. As shown in FIG. 13 and FIG. 14, the
midpoint of the curve was located about half way between the back
of fan 1351 and the back of air vents 102. The top of the curve was
placed at about the height of the top of the fan 1351, and the
bottom of the curve was placed about at the bottom of the air vents
102. In addition to efficiently reflecting heat towards the user
which would otherwise have been lost by radiation to other parts of
the micro environmental workspace comfort unit 1300, the curve of
the heat reflector 1301 also more efficient directed air flow from
fan 1351 to air vents 102.
[0101] Exemplary Desk human machine interface (HMI) controller:
FIG. 16A shows an isometric view of an exemplary HMI controller
1600. One difference between the HMI controller 1600 of FIG. 16A
and the color touch screen controller 105 of FIG. 1 which is fix
mounted into panel 110, is that the moveable HMI controller 1600 of
FIG. 16A can slide freely over a desk surface to any available
desired position on the desk. The HMI controller 1600 can have an
acrylic front sheet with button labels for the touch sensitive
buttons (e.g. capacitive touch buttons which are well known in the
art) and other labeling such as pertaining to a numeric display,
along with arrows to select functions. FIG. 16B shows a top view,
FIG. 16C a front view, FIG. 16D a front view of a frame to hold the
controller front panel, and FIG. 16E shows a side view. FIG. 16F
shows rear view of HMI controller 1600 with a more detailed view of
serrated cable clamp 1601. In this exemplary embodiment, serrated
cable clamp 1601 is a tabbed element on the back of HMI controller
1600 which secures and holds an attached HMI controller
communication cable (not shown in FIG. 16F). Serrated cable clamp
1601 prevents the communication cable from being tugged out of a
socket 1602 on the back of the front panel of HMI controller 1600
when someone moves the HMI controller 1600 around the desk. In the
exemplary embodiment of serrated cable clamp 1601, a slot 1611
receives the communication cable includes rounded peaks 1613 on one
side of the slot 1611 corresponding to troughs 1615 on the other
side of slot 1611. Then end of slot 1611 is finished with a rounded
end 1617. The features of serrated cable clamp 1601 including
rounded peaks 1613, corresponding to troughs 1615, and rounded end
1617 serve both to positively capture the communication cable as a
cable strain relief, as well as to prevent chaffing or other damage
to the communications table as the HMI controller 1600 is moved
around the desk.
[0102] The firmware and/or software which controls a low noise
micro environmental workspace comfort unit is typically provided
on, or stored on, a computer readable non-transitory storage
medium. A computer readable non-transitory storage medium as
non-transitory data storage includes any data stored on any
suitable media in a non-fleeting manner Such data storage includes
any suitable computer readable non-transitory storage medium,
including, but not limited to hard drives, non-volatile RAM, SSD
devices, CDs, DVDs, etc.
[0103] It will be appreciated that variants of the above-disclosed
and other features and functions, or alternatives thereof, may be
combined into many other different systems or applications. Various
presently unforeseen or unanticipated alternatives, modifications,
variations, or improvements therein may be subsequently made by
those skilled in the art which are also intended to be encompassed
by the following claims.
* * * * *