Information
-
Patent Grant
-
6296478
-
Patent Number
6,296,478
-
Date Filed
Thursday, August 3, 200023 years ago
-
Date Issued
Tuesday, October 2, 200122 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 432 77
- 432 116
- 432 145
- 432 173
- 432 233
- 126 110 A
- 126 110 C
- 126 110 E
- 126 104 A
- 126 116 C
- 310 52
-
International Classifications
-
Abstract
A furnace includes a motor in a motor housing that drives a fan that draws heated air through a heat exchanger of the furnace and also draws a flow of air through the motor housing to cool the motor as well as the motor housing.
Description
BACKGROUND OF THE INVENTION
(i) Field of the Invention
This invention relates generally to furnaces and particularly to cooling a motor that drives a draft inducing fan in a furnace. The invention provides for an improved method of cooling the motor that drives the fan and an apparatus for practicing the method.
(ii) Description of the Related Art
Typically, fans driven by an electric motor are used to induce an air flow in a furnace. These fans are designed to produce a certain amount of air flow which is used to remove the products of combustion in a gas-fired furnace and provide a flow of heated air through a heat exchanger. The air flow induced by these fans does not come in contact with the motor and therefore, does not contribute to the cooling of the motor nor dissipation of the heat generated by the motor.
in typical prior art furnaces, the fan motor is located in the vestibule of the furnace which also houses the electronics and controls for controlling the furnace. The heat generated by the blower motor elevates the temperature within the vestibule. The elevated temperature within the vestibule can shorten the life of the electronics and controls located within the vestibule. Additionally, the excess heat generated by the motor can shorten the life of the motor itself.
Typical prior art furnace fans utilize a motor that has an auxiliary fan attached to the rotating shaft of the motor to cool the motor. The auxiliary fan forces a flow of air to flow across the motor to dissipate the heat generated by the motor. An auxiliary fan, however, has many disadvantages.
One disadvantage is that the auxiliary fan increases the size or height of the motor assembly thereby preventing the streamlining of the motor assembly and the associated furnace within which the motor assembly is used. Another disadvantage is that the use of an auxiliary fan produces an additional load on the motor which can reduce the overall motor efficiency and increase the energy consumption of the furnace in which is it used. Furthermore, the use of an auxiliary fan increases the cost of providing the draft inducing fan. Another disadvantage is that the auxiliary fan can generate additional noise which may require the furnace within which it is used to incorporate additional sound deadening techniques. Finally, because the motor is typically used in a vestibule, the air flow induced by the auxiliary fan is channeled into the vestibule thereby contributing to the elevated temperature of the vestibule and the associated components residing therein.
Therefore, it is an object of the present invention to provide an apparatus and method for cooling the motor that eliminates the need for an auxiliary fan.
SUMMARY OF THE INVENTION
The present invention overcomes shortcomings of prior art furnaces that use an auxiliary fan attached to the motor to cool the motor driving the draft inducing fan by providing a furnace that cools the motor with the flow of air induced by the draft inducing fan. By eliminating the need for an auxiliary fan, the present invention allows for the motor and fan assembly to be more compact and streamlined than the prior art motor, fan and auxiliary fan assemblies. Additionally, the present invention reduces the overall cost of providing a means to cool the motor while reducing the noise associated with cooling the motor with only a minimal load being placed on the motor.
In general, the furnace of the present invention is comprised of a motor which resides in a housing having at least one inlet and at least one outlet. A fan is driven by the motor and resides in a fan housing. The fan housing is operatively connected to and communicates with the motor housing and is configured and adapted to cause a flow of air to flow through the motor housing prior to entering the fan housing, thereby cooling the motor.
More specifically, the furnace is comprised of a motor in a motor housing having at least one inlet and at least one outlet. A combustion chamber has at least one inlet and an outlet with the at least one combustion chamber inlet being operatively connected to and communicating with the at least one motor housing outlet. A heat exchanger has an inlet and an outlet with the heat exchanger inlet being operatively connected to and communicating with the combustion chamber outlet. A fan driven by the motor resides in a fan housing and the fan housing has an inlet and an outlet. The heat exchanger outlet is operatively connected to and communicates with the fan housing inlet. The fan causes a flow of air to flow into the motor housing through the at least one motor housing inlet, around the motor, and exit the motor housing through the at least one motor housing outlet. The flow of air then flows into the combustion chamber through the at least one combustion chamber inlet, through the combustion chamber, and exits the combustion chamber through the combustion chamber outlet. The flow of air then flows into the heat exchanger through the heat exchanger inlet, through the heat exchanger, and exits the heat exchanger through the heat exchanger outlet. The flow of air then flows into the fan housing through the fan housing inlet and exits the fan housing through the fan housing outlet. The flow of air cools the motor as it flows through the motor housing and around the motor without the need for an auxiliary fan.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objectives and features of the present invention are set forth in the following detailed description of the preferred embodiment of the invention and in the drawing figures wherein:
FIG. 1A
is perspective view of a traditional furnace employing one embodiment of the present invention to cool the motor driving the fan;
FIG. 1B
is a perspective view of the furnace of
figure 1A
wherein the combustion chamber has a single inlet and the vestibule chamber has a plurality of inlets;
FIG. 2A
is a perspective view of a traditional furnace employing an alternative embodiment of the present invention to cool the motor that drives the fan;
FIG. 2B
is a perspective view of the furnace of
FIG. 2A
wherein the air passageway has a single outlet; and
FIG. 3
is a perspective view of another embodiment of the furnace.
DETAILED DESCRIPTION OF THE INVENTION
The furnace, as can be seen in FIG.
1
A and generally indicated as
20
, is basically comprised of a blower
22
which draws a flow of air
24
from the exterior environment and draws the flow of air
24
through a heat exchanger
26
wherein the flow of air
24
is heated and flows out of the heat exchanger and back into the environment which is to be heated by the furnace
20
. The furnace
20
heats the flow of air
24
in the heat exchanger
26
by drawing a flow of combustion heated air
28
through the heat exchanger
26
. The flow of combustion heated air
28
is drawn through the heat exchanger
26
by a fan
30
which is driven by a motor
32
. The flow of air
28
is heated in a combustion chamber
34
by burners
35
or the like, as is well known in the industry, prior to being drawn through the heat exchanger
26
. The flow of combustion air
28
is drawn into the fan
30
and exhausted through an exhaust pipe
36
. In the case of a high efficiency furnace, the air being drawn into the combustion chamber
34
originates from outside the furnace
20
and can be in the room environment or outside the environment which is to be heated and is drawn into the furnace through the inlet pipe
38
. Although, it should be understood that while the exhaust and inlet pipes
36
,
38
have been described as pipes they can be part of a chimney or other air channeling structures as are well known in the industry.
Preferably, the motor
32
resides in a housing
40
having at least one inlet
42
and at least one outlet
44
. The fan
30
which is driven by the motor
32
resides in a fan housing
46
and is operatively connected to and communicates with the at least one motor housing outlet
44
and is configured and adapted to cause a flow of air
48
to flow through the motor housing
40
prior to flowing through the fan housing
46
. The flow of air
48
thereby cools the motor
32
as it flows through the motor housing
40
and around the motor
32
.
Preferably, the combustion chamber
34
has at least one inlet
50
and an outlet
52
. The at least one combustion chamber inlet
50
is operatively connected to and communicates with the at least one motor housing outlet
44
so that the flow of air
48
through the motor housing
40
flows through the combustion chamber
34
prior to flowing into the fan housing
46
. The heat exchanger
36
has an inlet
54
and an outlet
56
. The heat exchanger inlet
54
is operatively connected to and communicates with the combustion chamber outlet
52
and the heat exchanger outlet
56
is operatively connected to and communicates with the fan housing
46
. The flow of air
48
through the combustion chamber
34
flows through the heat exchanger
26
prior to flowing into the fan housing
46
. The fan housing
46
has an inlet
58
and an outlet
60
. The fan housing inlet
58
is operatively connected to and communicates with the heat exchanger outlet
56
and the fan housing outlet
60
is operatively connected to and communicates with the exhaust pipe
36
. The fan
30
causes the flow of air
48
to enter the motor housing
40
through the at least one motor housing inlet
42
, flow around the motor
32
and through the motor housing
40
, and then exit the motor housing
40
through the at least one motor housing outlet
44
. The flow of air
48
then flows into the combustion chamber
34
through the at least one combustion chamber inlet
50
and through the combustion chamber
34
where it mixes with the furnace fuel and is heated by combustion, and then exits the combustion chamber
34
through the combustion chamber outlet
52
. The flow of combustion heated air
48
then flows into the heat exchanger
26
through the heat exchanger inlet
54
and through the heat exchanger
26
, and then exits the heat exchanger
26
through the heat exchanger outlet
56
. The flow of combustion heated air
48
then flows into the fan housing
46
through the fan housing inlet
58
and through the fan housing
46
, and then exits the fan housing
46
through the fan housing outlet
60
. The flow of air
48
then exits the furnace
20
through the exhaust pipe
36
. The flow of air
48
thereby cools the motor
32
as it flows through the motor housing
40
and around the motor
42
.
Preferably, the furnace
20
also has a vestibule chamber
62
which has at least one inlet
64
. The motor
32
and the motor housing
46
reside in an interior
66
of the vestibule chamber
62
. In a typical furnace, the vestibule chamber interior
66
also contains the electronics and controls (not shown) to control the operation of the furnace
20
. The flow of air
28
being drawn into the furnace
20
by the fan
30
flows through the at least one vestibule chamber inlet
64
prior to flowing through the combustion chamber
34
.
In a preferred embodiment, as can be seen in
FIGS. 1A and B
, the at least one motor housing outlet
44
is connected to and communicates with the at least one combustion chamber inlet
50
by an air passageway
68
. The air passageway
68
channels the flow of air
48
from the at least one motor housing outlet
44
to the at least one combustion chamber inlet
50
. The flow of air
48
flowing through the motor housing
40
flows through the vestibule chamber interior
66
prior to flowing into the motor housing
40
. The flow of air
48
thereby cooling the electronics and controls (not shown) and any other components that reside in the vestibule chamber interior
66
along with cooling the motor
32
.
In one aspect of the preferred embodiment, the at least one motor housing inlet
42
is one of a plurality of motor housing inlets
70
and the at least one vestibule chamber inlet
64
is one of a plurality of vestibule chamber inlets
72
. The flow of air
28
being drawn into the furnace
20
by the fan
30
flows through the plurality of vestibule chamber inlets
72
and into the vestibule chamber interior
66
. The flow of air
48
that flows through the motor housing
40
flows from the vestibule chamber interior
66
and into the motor housing
40
through the plurality of motor housing inlets
70
.
In another aspect of the preferred embodiment, the combustion chamber
34
is sealed, as shown in
FIG. 1B
, and all the air flowing through the combustion chamber
34
flows through the air passageway
68
prior to flowing into the combustion chamber
34
. Because the combustion chamber
34
is sealed, the flow of air
28
being drawn into the furnace
20
by the fan
30
is the same flow of air
48
that is flowing through the motor housing
40
. The flow of air
28
enters the vestibule chamber interior
66
through the at least one vestibule chamber inlet
64
and flows into the motor housing
40
through the at least one motor housing inlet
42
. The flow of air
28
then flows through the motor housing
40
and into the air passageway
68
through the at least one motor housing outlet
44
. The flow of air
28
then flows through the air passageway
68
and into the combustion chamber
34
through the at least one combustion chamber inlet
50
, which is connected to the air passageway
68
and exits the combustion chamber
34
through the combustion chamber outlet
52
. The flow of air
28
then flows through the heat exchanger
26
and the fan housing
46
as previously discussed. Because all of the air being drawn into the furnace
20
by the fan
30
flows through the motor housing
40
, a maximum amount of air flows through the motor housing
40
and a maximum amount of cooling is achieved.
In yet another aspect of the preferred embodiment, as can been seen in
FIG. 1A
, the at least one combustion chamber inlet
50
is one of a plurality of combustion chamber inlets. The plurality of combustion chamber inlets include a main combustion chamber inlet
76
and secondary combustion chamber inlet
78
. The main combustion chamber inlet
78
is connected to and communicates with the air passageway
68
so that the flow of air
48
flowing through the motor housing
40
flows through the air passageway
68
and into the combustion chamber
34
through the main combustion chamber inlet
76
. The secondary combustion chamber inlet
78
is open to and communicates with the vestibule chamber interior
66
. Because the combustion chamber
34
has a plurality of inlets that communicate with both the motor housing
40
and the vestibule chamber interior
66
, a first portion
80
of the flow of air
28
being drawn into the furnace
20
by the fan
30
will flow from the vestibule chamber interior
66
and into the motor housing
40
and through the air passageway
68
and then enter the combustion chamber
34
through the main combustion chamber inlet
76
. A second portion
82
of the flow of air
28
being drawn into the furnace
20
by the fan
30
will flow from the vestibule chamber interior
66
directly into the combustion chamber
34
through the secondary combustion chamber inlet
78
. The first and second portions
80
,
82
join together in the combustion chamber
34
and are drawn through the rest of the furnace
20
as described above. Because the flow of air
24
being drawn into the furnace
20
by the fan
30
will follow the path of least resistance, the resistance encountered by the first and second portions
80
,
82
of the flow of air
28
must be designed and balanced so that a sufficient amount of air flows through the motor housing
40
to cool the motor
32
. The resistance to the first portion
80
of the air flow
28
is determined generally by the number, size, location and spacing of the plurality of motor housing inlets
70
and the spacing and restrictions experienced between the motor housing
40
and the motor
32
and any obstructions encountered within the air passageway
68
prior to flowing the combustion chamber
34
. The resistance encountered by the second portion
82
of the air flow
28
is generally determined by the size, dimension and location of the secondary combustion chamber inlet
78
. While the secondary combustion chamber inlet
78
has been shown as being a single inlet, it should be understood that the secondary combustion chamber inlet
78
can be one of a plurality of secondary combustion chamber inlets without departing from the scope of the invention as defined by the claims.
In an alternate embodiment, as shown in
FIGS. 2A and B
, the at least one vestibule chamber inlet
64
is connected to and communicates with the at least one motor housing inlet
42
by an air passageway
84
having at least one inlet
86
and at least one outlet
88
. The air passageway
84
causes the flow of air
48
through the motor housing
40
to originate outside of the vestibule chamber
62
and flow through the at least one vestibule chamber inlet
64
and the at least one air passageway inlet
86
prior to entering the motor housing
40
. The at least one air passageway outlet
88
is connected to the at least one motor housing inlet
42
and the flow of air
48
flowing through the motor housing
40
flows from the air passageway
84
through the at least one air passageway outlet
88
and into the motor housing
40
through the at least one motor housing inlet
42
. The flow of air
48
then exits the motor housing
40
through the at least one motor housing outlet
44
and flows into the vestibule chamber interior
66
. The vestibule chamber interior
66
is operatively connected to and communicates with the at least one combustion chamber inlet
50
so that the flow of air
48
exiting the motor housing
40
and entering the vestibule chamber interior
66
flows through the vestibule chamber interior
66
and then into the combustion chamber
34
through the at least one combustion chamber inlet
50
. Preferably, the vestibule chamber
62
is sealed so that the entire flow of air
28
being drawn into the furnace
20
by the fan
30
flows through the at least one vestibule chamber inlet
64
and through the air passageway
84
. Because the vestibule chamber
62
is sealed, all air flowing through the vestibule chamber interior
66
flows into the combustion chamber
34
through the at least one combustion chamber inlet
50
.
In one aspect of the alternate embodiment, as can be seen in
FIG. 2A
, the at least one air passageway outlet
88
is one of a plurality of air passageway outlets. The air passageway
84
has a primary air passageway outlet
90
and at least one secondary air passageway outlet
92
. The primary air passageway outlet
90
is connected to the at least one motor housing inlet
42
and the at least one secondary air passageway outlet
92
is open to the vestibule chamber interior
66
. Because the air passageway
84
has a plurality of outlets, the flow of air
28
being drawn into the furnace
20
by the fan
30
will be split into a plurality of flows of air. A first portion
94
of the flow of air
28
will be channeled through the air passageway
84
and into the motor housing
40
through the primary air passageway outlet
90
. The first portion
94
of the flow of air
28
is the same as the flow of air
48
flowing through the motor housing
40
. The first portion
94
of the flow of air
28
exits the motor housing
40
through the at least one motor housing outlet
44
and flows into the vestibule chamber interior
66
. A second portion
96
of the flow of air
28
will be channeled through the air passageway
84
and into the vestibule chamber interior
66
through the at least one secondary air passageway outlet
92
. Because the vestibule chamber
62
is sealed, the first and second portions
94
,
96
of the flow of air
28
can mix together in the vestibule chamber interior
66
and are both drawn into the combustion chamber
34
through the at least one combustion chamber inlet
50
. The first and second portions
94
,
96
then flow through the heat exchanger
42
and the fan housing
46
and are exhausted from the furnace
20
through the exhaust pipe
36
.
When the air passageway
84
has both a primary air outlet
90
and at least one secondary air passage outlet
92
, the flow of air
28
being drawn into the furnace
20
by the fan
30
will follow the path of least resistance when being drawn into the combustion chamber
34
. Therefore, the resistance experienced by the first portion
94
of the flow of air
28
and the second portion
96
of the flow of air
28
must be designed and balanced to ensure that the first portion
94
of the flow of air
28
which flows through the motor housing
40
is adequate to cool the motor
32
. As was discussed above, the general factors that effect the resistance experienced by the first and second portions
94
,
96
of the flow of air
28
include the size, location and obstructions experienced by both the first and second portions
94
,
96
of the flow of air
28
as they follow their respective flow paths.
In another aspect of the alternate embodiment, as can be seen in
FIG. 2B
, the at least one air passageway outlet
88
is a single air passageway outlet
98
and is connected to the at least one motor housing inlet
42
. The air passageway
84
channels the flow of air
28
being drawn into the furnace
20
by the fan
30
through the single air passageway outlet
98
and into the motor housing
40
through the at least one motor housing inlet
42
. The entire flow of air
28
through the furnace flows through the motor housing
40
. A maximum amount of air flows through the motor housing
40
to cool the motor
32
and a maximum amount of cooling occurs.
In yet another alternate embodiment, as can be seen in
FIG. 3
, the at least one vestibule chamber inlet
64
is connected to the at least one motor housing inlet
42
by a first air passageway
100
. The first air passageway
100
causes the flow of air
28
being drawn into the furnace
20
by the fan
30
to originate outside of the vestibule chamber
62
and flow through the at least one vestibule chamber inlet
64
, through the first air passageway
100
, and into the motor housing
40
through the at least one motor housing inlet
42
. The at least one motor housing outlet
44
is connected to the at least one combustion chamber inlet
50
by a second air passageway
102
. The second air passageway
102
causes the flow of air
28
to flow from the motor housing
40
, through the at least one motor housing outlet
44
, through the second air passageway
102
and into the combustion chamber
34
through the at least one combustion chamber inlet
50
. The flow of air
28
then flows through the heat exchanger
28
, through the fan housing
46
and exits the furnace
20
through the exhaust pipe
36
.
While the present invention has been described by reference to specific embodiments, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention as defined by the following claims.
Claims
- 1. A furnace comprising:a motor in a motor housing, the motor housing having at least one motor housing inlet and at least one motor housing outlet; a fan driven by the motor and residing in a fan housing, the fan housing being operatively connected to and communicating with the at least one motor housing outlet and configured and adapted to cause a flow of air to flow through the motor housing prior to entering the fan housing to thereby cool the motor; a combustion chamber configured and adapted to alter the temperature of air passed therethrough, the combustion chamber being operatively connected between and communicating with the at least one motor housing outlet and the fan housing and configured and adapted to cause the flow of air to flow through the combustion chamber after exiting the at least one motor housing outlet and before entering the fan housing; and the furnace is a high efficiency furnace.
- 2. A furnace comprising:a motor in a motor housing, the motor housing having at least one motor housing inlet and at least one motor housing outlet; and a fan driven by the motor and residing in a fan housing, the fan housing being operatively connected to and communicating with the at least one motor housing outlet and configured and adapted to cause a flow of air to flow through the motor housing prior to entering the fan housing to thereby cool the motor; the fan housing has a single fan housing inlet and a single fan housing outlet, the single fan housing inlet being operatively connected to and communicating with the at least one motor housing outlet and the flow of air enters the fan housing through the single fan housing inlet.
- 3. A furnace comprising:a motor in a motor housing, the motor housing having at least one motor housing inlet and at least one motor housing outlet; a combustion chamber having at least one combustion chamber inlet and a combustion chamber outlet, the at least one combustion chamber inlet being operatively connected to and communicating with the at least one motor housing outlet; a heat exchanger having a heat exchanger inlet and a heat exchanger outlet, the heat exchanger inlet being operatively connected to and communicating with the combustion chamber outlet; and a fan driven by the motor and residing in a fan housing, the fan housing having a fan housing inlet and a fan housing outlet, the fan housing inlet being operatively connected to and communicating with the heat exchanger outlet, the fan causing a flow of air to flow into the motor housing through the at least one motor housing inlet around the motor and exit the motor housing through the at least one motor housing outlet and flow into the combustion chamber through the at least one combustion chamber inlet and exit the combustion chamber through the combustion chamber outlet and flow into the heat exchanger through the heat exchanger inlet and exit the heat exchanger through the heat exchanger outlet and flow into the fan housing through the fan housing inlet and exit the fan housing through the fan housing outlet, the flow of air thereby cooling the motor as it flows through the motor housing.
- 4. The furnace of claim 3, further comprising:a vestibule chamber having at least one vestibule chamber inlet, the motor and the motor housing residing in an interior of the vestibule chamber, and the flow of air flows through the at least one vestibule chamber inlet prior to flowing into the combustion chamber.
- 5. The furnace of claim 4, wherein:the at least one motor housing outlet is operatively connected to and communicates with the at least one combustion chamber inlet by an air passageway, the air passageway channeling the flow of air from the at least one motor housing outlet to the at least one combustion chamber inlet.
- 6. The furnace of claim 5, wherein:the at least one motor housing inlet is one of a plurality of motor housing inlets and the at least one vestibule chamber inlet is one of a plurality of vestibule chamber inlets.
- 7. The furnace of claim 5, wherein:the combustion chamber is sealed and configured and adapted so that the only air flowing through the combustion chamber flows through the air passageway.
- 8. The furnace of claim 7, wherein:all of the air flow entering the motor housing through the at least one motor housing inlet flows through the vestibule chamber inlet without circulating in the vestibule chamber before entering the motor housing.
- 9. The furnace of claim 5, wherein:the at least one combustion chamber inlet is one of a plurality of combustion chamber inlets and the air passageway is connected to at least one of the plurality of combustion chamber inlets.
- 10. The furnace of claim 5, wherein:the furnace is a high efficiency furnace.
- 11. The furnace of claim 5, wherein:all of the air flow entering the combustion chamber through the at least one combustion chamber inlet flows through the motor housing before entering the combustion chamber.
- 12. The furnace of claim 4, wherein:the at least one vestibule chamber inlet is operatively connected to and communicates with the at least one motor housing inlet by an air passageway having at least one air passageway inlet and at least one air passageway outlet, the air passageway being configured and adapted to cause the flow of air to originate outside of the vestibule chamber and flow through the at least one vestibule chamber inlet and the at least one air passageway inlet, the at least one air passageway outlet being operatively connected to and communicating with the at least one motor housing inlet so that the flow of air is channeled by the air passageway into the motor housing through the at least one motor housing inlet, the flow of air then exiting the motor housing through the at least one motor housing outlet and flowing into the interior of the vestibule chamber, the interior of the vestibule chamber being operatively connected to and communicating with the at least one combustion chamber inlet so that the flow of air flowing out of the motor housing into the interior of the vestibule chamber flows into the combustion chamber through the at least one combustion chamber inlet.
- 13. The furnace of claim 12, wherein:the vestibule chamber is sealed except for the at least one vestibule chamber inlet so that only air flowing into the vestibule chamber interior through the vestibule chamber inlet flows into the combustion chamber through the at least one combustion chamber inlet.
- 14. The furnace of claim 13, wherein:the furnace is a high efficiency furnace.
- 15. The furnace of claim 13, wherein:the at least one air passageway outlet is one of a plurality of air passageway outlets comprised of a primary air passageway outlet and at least one secondary air passageway outlet, the primary air passageway outlet being operatively connected to and communicating with the at least one motor housing inlet and the at least one secondary air passageway outlet communicating with the interior of the vestibule chamber, the primary air passageway outlet channeling the flow of air into the motor housing and the at least one secondary air passageway outlet channeling air into the interior of the vestibule chamber.
- 16. The furnace of claim 13, wherein:the at least one air passageway outlet is a single air passageway outlet and is operatively connected to and communicates with the at least one motor housing inlet, the air passageway channeling the flow of air through the single air passageway outlet and into the motor housing.
- 17. The furnace of claim 13, wherein:all of the air flow entering the combustion chamber through the at least one combustion chamber inlet flows through the motor housing before entering the combustion chamber.
- 18. The furnace of claim 17, wherein:all of the air flow entering the combustion chamber through the at least one combustion chamber inlet circulates in the vestibule chamber before entering the combustion chamber.
- 19. The furnace of claim 4, wherein:the at least one vestibule chamber inlet is operatively connected to and communicates with the at least one motor housing inlet by a first air passageway, the first air passageway being configured and adapted to cause the flow of air to originate outside of the vestibule chamber and flow through the at least one vestibule chamber inlet and into the motor housing through the at least one motor housing inlet; and the at least one motor housing outlet is operatively connected to and communicates with the at least one combustion chamber inlet by a second air passageway, the second air passageway being configured and adapted to cause the flow of air to flow from the motor housing through the at least one motor housing outlet and into the combustion chamber through the at least one combustion chamber inlet.
- 20. A method of air cooling a furnace blower motor comprising the steps of:providing a motor in a housing; providing a fan driven by the motor and positioning the fan in a fan housing; operatively connecting the fan housing to the motor housing so that the fan housing communicates with the motor housing and draws a flow of air through the motor housing to cool the motor; and providing a fan housing having a single fan housing inlet and a single fan housing outlet and operatively connecting the single fan housing inlet to the motor housing to cause the flow of air to flow through the motor housing prior to flowing into the fan housing through the single fan housing inlet.
- 21. A method of air cooling a furnace blower motor comprising the steps of:providing a motor in a housing; providing a fan driven by the motor and positioning the fan in a fan housing; operatively connecting the fan housing to the motor housing so that the fan housing communicates with the motor housing and draws a flow of air through the motor housing to cool the motor; providing the fan housing having a single fan housing inlet and a single fan housing outlet and operatively connecting the single fan housing inlet to the motor housing to cause the flow of air to flow through the motor housing prior to flowing into the fan housing through the single fan housing inlet; providing a combustion chamber that is operatively connected between and communicates with the motor housing and the fan housing and is configured and adapted to cause the flow of air to flow from the motor housing and through the combustion chamber prior to flowing to the fan housing; providing a heat exchanger that is operatively connected between and communicates with the combustion chamber and the fan housing and is configured and adapted to cause the flow of air to flow from the combustion chamber and through the heat exchanger prior to flowing into the fan housing; and providing a vestibule chamber having an interior and at least one vestibule chamber inlet which is operatively connected to and communicates with the motor housing, the motor and the motor housing residing in the vestibule chamber interior so that the flow of air flowing through the motor housing passes through the at least one vestibule chamber inlet prior to entering the motor housing.
- 22. The method of claim 21, wherein:the vestibule chamber is sealed except for the vestibule chamber inlet; the vestibule chamber interior is operatively connected to and communicates with the combustion chamber and the motor housing so that the flow of air flowing through the motor housing exits the motor housing and flows through the vestibule chamber interior and into the combustion chamber; and the motor housing is operatively connected to and communicates with the at least one vestibule chamber inlet by an air passageway that causes the flow of air to originate outside of the vestibule chamber and flow through the at least one vestibule chamber inlet, the air passageway channeling the flow of air to the motor housing without mixing with the air flowing through the vestibule chamber interior prior to flowing through the motor housing.
- 23. The method of claim 21, wherein:air flowing through the vestibule chamber interior enters the vestibule chamber interior through the at least one vestibule chamber inlet; the motor housing is operatively connected to and communicates with the combustion chamber by an air passageway that channels the flow of air from the motor housing directly to the combustion chamber and prevents the flow of air flowing through the air passageway from mixing with the air flowing through the vestibule chamber interior; and the flow of air flowing through the motor housing flows through the vestibule chamber interior prior to entering the motor housing.
US Referenced Citations (9)