U.S. patent number 3,748,997 [Application Number 05/241,567] was granted by the patent office on 1973-07-31 for acoustical insulated fan and temperature conditioning penthouse unit.
This patent grant is currently assigned to Tempmaster Corporation. Invention is credited to Frank J. Dean, Jr., James A. Reese.
United States Patent |
3,748,997 |
Dean, Jr. , et al. |
July 31, 1973 |
ACOUSTICAL INSULATED FAN AND TEMPERATURE CONDITIONING PENTHOUSE
UNIT
Abstract
A penthouse type air conditioning unit has an acoustically
insulated fan which separates the fan motor from the fan discharge
end portion by compartments within the unit. Each compartment is
acoustically insulated with the discharge compartment being
interconnectable with the conventional air conditioning ductwork.
The fan impeller is mounted for exposed rotation without the use of
the usual enclosure directional scroll and creates the pressure
differential for conditioned air flow through the interconnected
air ductwork. A target sound attenuator is mounted in the motor
compartment at a preselected distance from the fan inlet to
attenuate the predominant sound wave frequency generated by the
fan. A second embodiment separates the fan motor and the fan
impeller by an acoustical compartment which encloses the impeller
and interconnects with air conditioning ductwork. A target sound
attenuator is supported a preselected distance away from the fan
inlet, said distance corresponding to the predominant sound wave
frequency generated by the fan.
Inventors: |
Dean, Jr.; Frank J. (Kansas
City, MO), Reese; James A. (Overland Park, KS) |
Assignee: |
Tempmaster Corporation (Kansas
City, MO)
|
Family
ID: |
22911219 |
Appl.
No.: |
05/241,567 |
Filed: |
April 6, 1972 |
Current U.S.
Class: |
454/234; 62/262;
62/296; 454/236; 454/906 |
Current CPC
Class: |
F04D
29/664 (20130101); F04D 17/16 (20130101); F24F
3/00 (20130101); F24F 13/24 (20130101); Y10S
454/906 (20130101) |
Current International
Class: |
F24F
13/00 (20060101); F24F 3/00 (20060101); F24F
13/24 (20060101); F04D 29/66 (20060101); F04D
17/16 (20060101); F04D 17/00 (20060101); F24f
013/00 () |
Field of
Search: |
;62/262,296
;98/4R,33R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wye; William J.
Claims
Having thus described our invention, we claim:
1. An air conditioning penthouse, said penthouse forming a
substantially enclosed structure having side walls and a top cover,
said penthouse comprising
an inlet, said inlet being connectable with return or outside air
conveyance system,
at least one outlet, said outlet being connectable with conditioned
air conveyance system,
a fan means, said fan means having an impeller of the centrifugal
type without a scroll surrounding same and a motor means, said
motor means operable to drive said impeller, and
an acoustical insulating wall, said insulating wall acoustically
separating said motor means from said impeller, said impeller
located in communicating relationship with said outlet and operable
to create conditioned air flow out of said penthouse through said
outlet, said acoustically insulating wall substantially attenuating
objectionable noise produced by said motor means and precluding
same from accompanying said air flow through said outlet.
2. A combination as in claim 1 including a target sound attenuator,
means for mounting said target sound attenuator within said
penthouse on said motor side of said acoustical insulating wall a
preselected distance away from said fan.
3. A combination as in claim 2 including means mounted within said
penthouse on said motor side of said acoustical wall for
conditioning air flow entering said penthouse through said
inlet.
4. A combination as in claim 2 including means for acoustically
insulating said side walls and said top cover of said
penthouse.
5. A combination as in claim 4 including means mounted within said
penthouse on said motor side of said acoustical wall for
conditioning air flow entering said penthouse through said
inlet.
6. A combination as in claim 2 wherein said acoustical insulating
wall has an aperture defined therein, said fan having an inlet
structure interconnecting with said impeller, and means for
resiliently mounting said inlet structure in communicating
relationship with said aperture in said acoustically insulating
wall.
7. A combination as in claim 6 including means mounted within said
penthouse on said motor side of said acoustical wall on
conditioning return air flow entering said penthouse through said
inlet.
8. A combination as in claim 7 including means for acoustically
insulating said side walls and said top cover of said
penthouse.
9. A combination as in claim 6 wherein said penthouse has an
acoustically insulated floor structure interconnected with said
side walls, means for resiliently mounting said motor and said
impeller on said floor.
10. The combination as in claim 1 including means at least
partially enclosing said impeller for producing a uniform velocity
profile for the air leaving through said outlet.
11. A self contained fan unit, said fan unit comprising
an acoustically insulated structure, said structure having an inlet
and an outlet,
a fan means, said fan means having an impeller of the centrifugal
type without a scroll surrounding same and a motor means, said
motor means operable to drive said impeller, means for mounting
said impeller within said acoustically insulated structure, means
for mounting said motor exterior of said acoustically insulated
structure, said fan unit thereby operable to acoustically attenuate
noise produced by said impeller and to create an air flow out said
outlet being substantially free of objectionable impeller
noise.
12. A combination as in claim 10 an inlet target sound attenuator,
means for mounting said target sound attenuator exteriorally of
said structure a preselected distance away from said fan.
13. The combination as in claim 11 wherein said structure includes
a means at least partially enclosing said impeller for producing a
uniform velocity profile for the air leaving through said outlet.
Description
BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION
Penthouse type air conditioning and heating units generally operate
to supply conditioned air for the main ductwork of large and small
buildings of all types. The associated air conditioning or heating
system will generally include terminal units or air diffusers in
particular room areas within the building structure and, since the
penthouse unit will include a large fan often generating
objectionable noise, sound attenuating devices are normally in the
air convergance systems located adjacent to the fan unit or
throughout the system in conjunction with the terminal unit and/or
air diffusers. These sound attenuating devices installed in the air
conveyance system are both expensive to construct and are time and
labor consuming in their installation.
The subject invention pertains to unique acoustically treated
penthouse type air conditioning units and to acoustically insulated
fan units which may be separable from the penthouse. The penthouse
air conditioning units will include an acoustically insulated
structure that will have one end portion interconnectable with the
return air conveyance system of a building structure and will have
mounted therein filtering, air conditioning or heating coils which
will condition the return air as it is pulled therethrough by the
fan unit located within the penthouse structure. Immediately
adjacent the air conditioning or heating coils will be a space
within the penthouse unit that is accessible from the exterior and
which has the fan unit motor and target sound attenuator located
therein and mounted on a resilient spring support. The motor drive
shaft is belt connected with the horizontal fan drive shaft, the
latter extending through an acoustically insulated wall and into an
acoustically insulated compartment with air discharge outlets. A
compressible material acts as a compression seal between the
discharge outlet compartment acoustical insulated wall and the
intermediate motor compartment. In this manner, the fan impeller is
completely located within the discharge outlet compartment while
the motor driving same is acoustically insulated therefrom and
located in the intermediate area. the fan impeller has the usual
scroll eliminated therefrom which would normally provide a
directional component to the air flow generated therefrom. One or
more suitable outlet connecting means are provided to enable the
air conditioning or heating ductwork to attach directly to the
discharge outlet compartment.
Further sound attenuation is provided by locating target sound
attenuator a preselected distance away from the fan inlet. This
distance is a function of the quarter wave length of the
predominant noise frequency, which in most cases is related to the
blade frequency of the sound produced by the fan.
The second embodiment of the invention includes an acoustical
insulated fan unit which will include the outlet or discharge
compartments substantially enclosing the fan impeller with the
normal fan scroll removed and with the target sound attenuator
spaced the required distance away from the fan inlet and with the
motor located exterior of the outlet or discharge compartment.
An object of our invention is to provide a substantially improved
penthouse air conditioning or fan unit which has improved sound
level characteristics with little or no reduction in capacity or
efficiency in the normal operative ranges.
Another object of our invention is to provide an improved penthouse
air conditioning unit that is uniquely constructed and which
substantially reduces the normal installation cost either in new or
existing building structures.
Further object of the invention is to provide uniquely constructed
air conditioning or heating penthouse and/or fan unit which
eliminates upstream and downstream sound attenuating devices
normally required. It is a feature of this invention that the unit
will operate to provide a unique source of sound attenuated air for
the temperature conditioning of large or small buildings and
operates in conjunction with both the supply and return air
conveyance systems.
Still further object of the invention is to provide a penthouse air
conditioning unit of the character described which is economically
and acoustically practical to locate same on top of new or existing
buildings and which eliminates further use of upstream or
downstream noise attenuating devices heretofore required by units
of a similar size.
A further object of the invention is to provide a penthouse air
conditioning unit having a uniquely constructed and positioned
target sound attenuator. It is a feature of this attenuator that it
is spaced a preselected distance from said fan structure and is
related with the quarter wave length of the predominant sound
frequency to thereby attenuate objectionable noise levels normally
associated with large fan units.
A further object of the invention is to provide a uniquely
constructed penthouse air conditioning fan unit which both
acoustically attenuates objectionable noise levels produced by the
fan located therein but at the same time provides an easily
accessible repair and service area for the entire unit.
Another object of the invention is to provide a uniquely
constructed air conditioning penthouse unit and/or fan unit which
has eliminated the normal directional scroll from the centrifugal
fan impeller. Accordingly, the above structure enables an
acoustically insulated outlet compartment (having a plurality of
outlets) to be utilized with the interconnection with normal
ductwork optionally located at any position or several places with
respect to said compartment.
Another object is to provide essentially uniform air velocity
leaving the unit discharge so that downstream duct performance at
fittings and takeoffs in close proximity will provide predictable
results.
Still further object of the invention is to provide a unique
structure for acoustically insulating and separating the fan
impeller and the fan motor from the enclosure. It is a feature of
the object that the fan is mounted on a resilient structure and
further permits and compensates for the pressure differential
between the fan inlet and outlet or discharge compartment.
Other and further objects of the invention, together with the
features of novelty appurtenant thereto, will appear in the course
of the following description.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view of the penthouse air conditioning unit with
portions thereof broken away to indicate the general construction
of the unit including the inlet, the air conditioning coils, the
intermediate or access section which is occupied by the fan motor
and the target sound attenuator, the acoustical wall and structure
separating the intermediate section from the outlet section and the
fans impeller, the solid line arrows indicating the normal air flow
while the broken line arrows indicate the sound travel pattern;
FIG. 2 is a rear elevational view of the target sound attenuator,
the fan motor, the resilient fan mount and the portion of the wall
separating the fan motor section from the outlet section;
FIG. 3 is a sectional view taken generally along the line 3--3 of
FIG. 1 in the direction of the arrows and showing the inlet to the
fan;
FIG. 4 is an end elevational view taken from the outlet or
discharge end portion of the fan;
FIG. 5 is a side elevational view of a fan unit utilizing the
target sound attenuator with two fan impellers located within the
acoustically insulated outlet or discharge section and with the
solid line arrows indicating the air flow;
FIG. 6 is a view similar to FIG. 5 but with a single inlet, target
sound attenuator and fan impeller located within the acoustically
insulated outlet or discharge compartment and with the solid line
arrows indicating the air flow to and out of the fan unit;
FIG. 7 is an enlarged sectional view taken generally along the line
7--7 of FIG. 1 in the direction of the arrows and showing the
construction of the acoustically insulated wall separating the
outlet compartment from the intermediate compartment;
FIG. 8 is a view similar to FIG. 7 but showing the upper wall
opening construction and is an enlarged view of the same elements
shown in FIG. 1; and
FIG. 9 is a view similar to FIG. 8 but showing the lower separating
wall construction.
Turning now more particularly to the drawings, reference numeral 10
generally represents the completely enclosed box-like penthouse
unit which will be constructed of sound attenuating material such
as glass fiber matting enclosed steel siding. The housing 10 will
have an inlet 11 which is provided with a grillwork 12 and which is
interconnectable with the return air ductwork of a building heating
or air conditioning system. The initial air flow, as indicated by
the solid arrows, is through the inlet end and air conditioning
coils generally indicated by the numeral 14. It should be pointed
out that these air conditioning coils may be arranged vertically or
on the incline and may take on various forms such as filters and/or
heating or air conditioning coils and the showing in FIG. 1 is
merely representative of any one or all of the above.
Numeral 14 represents the intermediate section which is accessible
through an access door (not shown) and which will enclose the fan
motor and target sound attenuator described infra. In any event,
the intermediate section will be terminated in the left to right
direction by sound insulating wall generally indicated by the
numeral 15. As will be seen, this insulating wall 15 has a large
opening defined therein which assists in the flexible mounting of
the fan unit and motor/target support.
The fan, which will be described in more detail later, is mounted
on a framework generally indicated by the numeral 16. For example,
FIGS. 1 and 2 indicate the angle structurals which form a portion
of framework 16 and which support fan motor 17 thereon. The exact
shape and structural form of the framework may be varied; however,
it is contemplated that the structurals 16a may be mounted to
extend through the opening of the wall 15 and will further have the
cross structural 16b weldedly connected thereto for reinforcing
purposes. Located near the forward portion of wall 15 upright
structurals 16c extend vertically upwardly and terminate in the
horizontal shaft supporting structurals 16b which spans the two
upright members.
In a similar manner, the discharge outlet compartment 18 has a
transverse structural 16b' interconnected between the longer
structural 16a discussed above. Likewise, uprights 16c' vertically
locate the horizontal cross shaft supporting structural 16d' at the
proper location within the outlet or discharge compartment 18. In
both situations, the framework 16 is supported on heavy duty
compression springs which are indicated by the numeral 19. As will
be seen, the compression vibration isolators 19 support the entire
fan assembly including the later described target sound
attenuator.
A pair of upright angle structurals, identified by the numeral 20
in FIGS. 1 and 2, is supported by the framework 16 within the
intermediate compartment area 14 before acoustically insulated wall
15. Brackets 20a extend horizontally therefore and operate to hold
a target sound attenuator 21 a pre-selected distance away from the
fan input (extremity of 27) as will be described in more
detail.
The fan is generally represented by the numeral 22 and is supported
with its axis lying in a substantially horizontal plane by the
upright structurals 16c and 16c' as mentioned above. Further, the
upright structurals 16c and 16c' are spanned by the fan shaft
supporting structurals 16d and 16d' respectively. A suitable
bearing mount 23 will be located on the inlet side of wall 15 and
is bolted or otherwise fixedly attached to the structural 16d. A
similar bearing mount 24 is located on the outlet side of wall 15
within the outlet compartment 18 and in the same horizontal plane
as bearing mount 23. The rotatable fan shaft 25 extends through the
two bearing mounts with the inlet end of the shaft having the belt
pulley 26 fixedly located thereon. Motor 17 through belt 17a drives
pulley 26 and rotates shaft 25 for appropriate fan action.
In the disclosed embodiment, the fan inlet is represented by the
numeral 27 and is frustoconically shaped to channel the air flow
(as shown by the solid arrows) into contact with the rotating
impeller 28. The impeller operates in a centrifugal fashion to
impart a velocity to the air flow which will change to a pressure
differential under the influence of outlet compartment 18. It
should be pointed out that the location of ductwork 29 and the
outlet 18a within compartment 18 is entirely variable and can be
made dependent solely upon the structural requirements of the
particular building being temperature conditioned. Also, with the
acoustically insulated compartment 18 and the later described
isolating structure for the fan impeller 28, no scrolls or other
air flow directional means which would normally circumscribe wheel
28 are needed.
Turning now once again to FIG. 1, it was mentioned above that the
communicating opening in wall 15 (between compartments 14 and 18)
was substantially rectangular and centrally located. As shown in
FIGS. 1 and 3, wall 15 both structurally and acoustically separates
the intermediate compartment 14 from the outlet compartment 18 save
for the location of the fan inlet 27 in the rectangular opening.
This rectangular opening (in wall 15) is further occupied by the
structure, now to be described, which gives some degree of
flexibility to the enclosure and around the fan inlet 27 in the
remainder of the wall 15.
The FIGS. 1 and 7-9 detail the general construction of the
remainder of the wall enclosure. For example, each vertical side of
the rectangular (or other suitable shape) opening in wall 15 has an
angled structural 30 extending substantially the length thereof. A
similarly shaped (in section) angular structural 31 is offset
toward the compartment 18 and is substantially parallel to each
structural 30. The structurals 31 include a sheet metal backing 32
with a circular opening (or aperture) cut therein to be engaged
over the frustoconical inlet 27 of the fan 22. Finally, a
compressible rubber (or other suitable material) strip 33 occupies
the space between flanges 30a and 31a of the structurals 30 and 31
respectively. This compressible rubber strip 33 permits the two
above-described structures to move towards each other as the
pressure or force within outlet compartment 18 begins to build up
during operation of the fan. The upper portion of the sheet metal
strip 32 has structural 34 attached to and extending along the
horizontal edged portion thereof. The corresponding or mating
horizontal edge of the opening in wall 15 supports structural 35
with the downturned flange 35a permitting the rubber strip 36 to be
located between same and the upturned flange portion 34a of the
structural 34. Finally, FIG. 1 discloses the lowermost
interconnecting section which will include the lower structural 37
being fixedly attached to the floor of penthouse 10 and having the
upturned flange 37a extending vertically up and into the
rectangular opening space. The lower edge portion of the circularly
apertured sheet metal strip 32 has structural 38 weldedly connected
thereto with the downturned flange 38a forming an overlapping
relationship with the upturned flange 37a. This permits the
location of the compressible rubber stripping 39 to be located
therebetween to completely enclose the rectangularly opening with a
resiliently mounted centrally apertured sheet metal structure that,
under the forces acquired within compartment 18, is permitted fore
and aft movement with respect to wall 15. In this manner the
differential pressure acting on plate 32 and fan inlet 22
compresses the rubber strip and makes the seal.
The penthouse air conditioning unit described above has an internal
air flow substantially as shown by the solid arrows in FIG. 1. In
other words, the air flow is through the inlet 11, past the air
conditioning coils 13, and in through the fan inlet 27. The fan
impeller 28 accordingly creates a sufficient pressure differential
within the compartment 18 that the air flow is through outlet 18a
down through the building system ductwork 29.
With the airflow pattern described above, should be pointed out
that arrows shown in broken lines represent the sound level path
that is created by the various rotating and motor elements. But for
the penthouse being constructed of sound-deadening acoustically
insulating material, the sound level would be transmitted both
through the return air and the downstream ductwork. However, even
further sound attenuating benefits are obtained by the utilization
of the target sound attenuator 21. As suggested above, this
attenuator (which may assume various shapes and sizes) is supported
by the upright brackets 20 a preselected distance away from the end
extremity of the inlet 27 of fan 22. This preselected distance is
based on the predominant noise frequency produced by the fan. It
has been further found that the third octave band is generally (for
centrifugal fans) the predominant noise frequency. For example,
when the frequency is found to be in the order of 200 cycles per
second, a five foot wave length may be ascribed to such an octave
band. By locating the target sound attenuator a quarter wave length
away (or approximately 14 inches for a 5 foot wave length) the
maximum fan noise attenuation is obtained that would otherwise very
likely tend to be transmitted in terms of an objectionable decibel
level into the return air ductwork. This target sound attenuator
has further enabled the subject acoustically insulated penthouse
air conditioning unit to eliminate the use of downstream or return
air sound attenuating devices throughout the entire system.
Alternative embodiments are shown in FIGS. 5 and 6. This structure
pertains to an acoustically insulated fan unit which may or may not
be utilized with the penthouse construction described above. It is
contemplated that a similar type of framework will support the fan
unit and said framework is generally represented by the numeral 40.
Spring mounts 40a support the framework 40 and provide for the
mounting of motor 17 in the manner described above. The motor shaft
25 extends into and through an acoustically insulated sound
deadening box generally indicated by the numeral 41. As shown in
FIG. 5, a pair of target sound attenuators 21a and 21b are mounted
with respect to the inlets of the sound deadening box 41. These
inlets, hereinafter identified by the numerals 41a and 41b, are
immediately adjacent and in communicating relationship with the
inlets of two fan impellers 28a and 28b respectively, same being
rotated by the single shaft 25. The box outlet 41c permits the
usual interconnection with the outlet ductwork for the building
heating or air conditioning system. It is contemplated that an
alternative arrangement may include two motors 17 with each motor
arranged to rotate a separate shaft 25. However, in either case
both target sound attenuators would be utilized at a preselected
distance corresponding to the predominant sound frequency way from
the inlets to the sound deadening box 41.
The embodiment shown in FIG. 6 is again similar to that shown in
FIG. 5, however, a single fan is utilized with inlet 41a with
respect to the sound deadening box 41. It should be pointed out
that in both cases the airflow into inlets 41a (or the combined
inlets 41a and 41b) may be through suitable filtering, heating
coils and/or air conditioning coils and will be in and around the
motor and target sound attenuators until transmitted through the
outlet and into the ductwork. However, this structure results in a
significant lowering of the sound to a suitable level obviating the
utilization of a downstream or return air sound attenuator as
heretofore required by such units.
Both the penthouse construction, as well as the sound deadening
boxes, have been found to reduce the typical noise levels in air
conditioning and heating systems by 10 to 20 decibels (db). This is
a substantial noise reduction made possible by the overall
construction of the unit. Further, this modular type construction
permits substantial prefabrication and requires only that hookup be
accomplished directly on the building top or at other prescribed
locations, depending upon the available and desired duct
facilities.
From the foregoing, it will be seen that this invention is one well
adapted to attain all of the ends and objects hereinabove set forth
together with other advantages which are obvious and which are
inherent to the structure.
It will be understood that certain features and subcombinations are
of utility and may be employed without reference to other features
and subcombinations.
As many possible embodiments may be made of the invention without
departing from the scope thereof, it is to be understood that all
matter herein set forth or shown in the accompanying drawings is to
be interpreted as illustrative and not in a limiting sense.
* * * * *