Note: Descriptions are shown in the official language in which they were submitted.
CA 02763382 2012-01-09
Attorney Docket No. 010121-8281-US00
GAS-FIRED WATER HEATER WITH AN EXHAUST ASSEMBLY
BACKGROUND
100011 The present invention relates to water heaters, and more particularly
to gas-fired
water heaters with exhaust assemblies.
[00021 Typical gas-fired water heaters produce exhaust gases or products of
combustion
that must be exhausted outside of the residence or other building in which the
water heater is
installed. An exhaust assembly, blower, or fan moves the exhaust gases
generated by the water
heater from the water heater to the atmosphere outside the building.
SUMMARY
[00031 The present invention provides, in one aspect, a gas-fired water heater
including a
storage tank, a combustion chamber, a burner for producing products of
combustion, the burner
positioned in the combustion chamber, a flue including a longitudinal axis,
the flue extending
from the combustion chamber through the storage tank, and an exhaust assembly
positioned
above the flue. The exhaust assembly includes a hood, a motor including a
drive shaft, and a fan
coupled to the drive shaft for rotation with the drive shaft about a
rotational axis. The hood
receives the products of combustion from the flue and directs the products of
combustion at an
acute angle toward the fan. The rotational axis is positioned at the acute
angle relative to the
longitudinal axis.
[00041 The present invention provides, in another aspect, an exhaust assembly
for use
with a gas-fired water heater including a flue having a longitudinal axis, the
gas-fired water
heater producing products of combustion. The exhaust assembly includes a hood,
a motor
including a drive shaft, and a fan coupled to the drive shaft for rotation
with the drive shaft about
a rotational axis. The hood receives the products of combustion from the flue
and directs the
products of combustion at an acute angle toward the fan. The rotational axis
is positioned at the
acute angle relative to the longitudinal axis.
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[0005] Other features and aspects of the invention will become apparent by
consideration
of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is front view of a gas-fired water heater including an exhaust
assembly.
[0007] FIG. 2 is a perspective view of the exhaust assembly of FIG. 1.
[0008] FIG. 3 is an exploded view of the exhaust assembly of FIG. 1.
[0009] FIG. 4 is a sectional view of the exhaust assembly of FIG. I along line
4-4.
[0010] Before any embodiments of the invention are explained in detail, it is
to be
understood that the invention is not limited in its application to the details
of construction and the
arrangement of components set forth in the following description or
illustrated in the following
drawings. The invention is capable of other embodiments and of being practiced
or of being
carried out in various ways. Also, it is to be understood that the phraseology
and terminology
used herein is for the purpose of description and should not be regarded as
limiting.
DETAILED DESCRIPTION
[0011] FIG. 1 illustrates a gas-fired water heater 100. The water heater 100
includes a
water storage tank 105 and a combustion chamber 110 positioned below the
storage tank 105. A
burner 115 is positioned in the combustion chamber 110. A flammable gas is
provided to the
burner 115 by a gas inlet or manifold 120 connected to a gas valve 125. The
gas valve 125 is
also connected to a gas supply. The combustion chamber 110 communicates with
an air supply,
for example, the atmosphere around the water heater 100. A jacket 130
including a cover 135
surrounds the storage tank 105 and combustion chamber 110. Foam insulation is
provided
between the storage tank 105 and jacket 130. A flue 140 extends from the
combustion chamber
110, through the storage tank 105, and through the cover 135. The flue 140
includes a
longitudinal axis 145. The products of combustion or exhaust gases created by
the burner 115
flow through the flue 140 to heat the water stored in the storage tank 105. A
cold water inlet
pipe 150 is connected to a dip tube 155 to supply cold water to the storage
tank 105. A hot water
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Attorney Docket No. 010121-8281-US00
supply pipe 160 is connected to the storage tank 105 to supply hot water to an
end-use location,
for example, a faucet. An exhaust assembly 165 is coupled to the cover 135 and
positioned
above the flue 140. The exhaust assembly 165 receives the exhaust gas exiting
the flue 140. The
structure of the gas-fired water heater 100 other than the exhaust assembly
165 is typical of a
storage or tank gas-fired water heater. The exhaust assembly 165 could also be
used with other
known gas-fired water heaters, including instantaneous or tankless water
heaters or tank-tankless
water heaters. Directional language refers to the exhaust assembly 165 as
installed for normal,
intended use with a gas-fired water heater 100.
[0012] As shown in FIGS. 2 and 3, the exhaust assembly 165 includes a hood
170, a
blower housing 175, a fan, blower, or impeller 180, and a motor 185. The hood
170 includes a
chamber 190 formed by multiple walls 195, including a rear wall 200. The
chamber 190
includes an open bottom portion 205 that is positioned above the flue 140 to
receive exhaust gas
from the flue 140. The flue 140 includes a flue outlet 210. An air inlet 215
is connected to the
chamber 190. At least a portion 220 of the rear wall 200 is angled toward the
flue 140. An
opening, hole, or aperture 225 is formed through the angled portion 220. A
flow path axis 230
passes through the center of the opening 225, is perpendicular to the angled
portion 220, and is
positioned at an acute angle 232 relative to the longitudinal axis 145. An
acute angle is greater
than zero degrees and less than ninety degrees. Preferably, the acute angle
232 is forty-five
degrees. A flow path 235 between the flue outlet 210 and the opening 225 is at
least partially
defined by the walls so that the hood 170 directs the exhaust gas toward the
fan 180 at the acute
angle 232 and through the opening 225 in a direction. substantially parallel
to the flow path axis
230. The direction of flow of the exhaust gas is shown by the arrows in FIG.
4.
[0013] The blower housing 175 includes a chamber 240 formed by a front wall
245, an
outer wall 250, and a cover 255. The outer wall 250 is cylindrical and extends
rearwardly from
the front wall 245. The blower housing 175 is secured to the hood 170 so that
the front wall 245
abuts the angled portion 220. In some embodiments, a gasket or seal is
compressed between the
front wall 245 and the angled portion 220 to create a substantially air-tight
seal between the hood
170 and the blower housing 175. An opening, hole, or aperture 260 is formed
through the front
wall 245. The opening 260 is coaxial with the opening 225 and substantially
the same size and
shape as the opening 225. A blower outlet 265 extends vertically from the
outer wall 250 along
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Attorney Docket No. 010121-8281-US00
an outlet axis 270, with vertical being in the same direction as the
longitudinal axis 145. The fan
180 is positioned within the chamber 240. The cover 255 is secured to the
outer wall 250 at the
distal end of the outer wall 250. The motor 185 is secured to the blower
housing 175 by a motor
housing 275. A drive shaft 280 extends through an opening in the cover 255 and
is connected to
the fan 180 so that that drive shaft 280 and the fan 180 both rotate about a
rotational axis 285.
The rotational axis 285 is parallel to or collinear with the flow path axis
230. Therefore, the
rotational axis 285 is positioned at an acute angle 287 relative to the
longitudinal axis 145.
Preferably, the acute angle 232 is equal to the acute angle 287. The acute
angle 287 is preferably
forty-five degrees.
[00141 In use, exhaust gas exits the flue 140 through the flue outlet 210 in a
now
direction generally parallel to the longitudinal axis 145. The exhaust gas is
received within the
chamber 190 and directed at the acute angle 232 toward the opening 225.
Ambient dilution air is
drawn through the air inlet 215 into the chamber 190. The dilution air mixes
with the exhaust
gas in the chamber 190, thereby reducing the concentration of undesirable
chemicals formed
during the combustion process and lowering the temperature of the exhaust gas
before the
mixture enters the blower housing 175. The mixture of exhaust gas and dilution
air exits the
hood 170 through the opening 225 in a flow direction generally parallel to the
flow path axis
230. The mixture enters the chamber 240 through the opening 260. The rotating
fan 180 moves
the mixture through the chamber 240 to the blower outlet 265 where the mixture
exits in a
direction generally parallel to the outlet axis 270. The blower outlet 265 is
connected to an
exhaust duct that connects the exhaust assembly 165 to the atmosphere outside
the building.
[00151 The rotational axis 285 acutely angled from vertical improves the
efficiency of the
exhaust assembly 165 over known horizontal or vertical exhaust assemblies. A
vertical exhaust
assembly includes a motor and fan oriented so that the rotational axis of the
motor shaft and fan
is parallel with the longitudinal axis 145. This causes the exhaust gas
entering the vertical
exhaust assembly to make a ninety degree turn when transitioning from the flue
to the blower
housing. A horizontal exhaust assembly includes a motor and a fan oriented so
that the
rotational axis of the motor shaft and fan is perpendicular to the
longitudinal axis. This causes
the exhaust gas entering the horizontal exhaust assembly to make a ninety
degree turn when
transitioning from the flue to the hood and a second ninety degree turn when
transitioning from
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Attorney Docket No. 010121-8281-US00
the hood to the blower housing. By acutely angling the rotational axis 285,
the exhaust gas turns
less than ninety degrees before entering the blower housing 175 so that the
efficiency of the
exhaust assembly 165 is improved and the power requirement for the motor 185
is reduced. The
angled design of the exhaust assembly 165 also allows the exhaust assembly 165
to be positioned
between the cold water inlet pipe 150 and the hot water supply pipe 160.
[00161 Various features of the invention are set forth in the following
claims.
