U.S. patent application number 15/691304 was filed with the patent office on 2018-02-08 for air cooled horticulture lighting fixture for a double ended high pressure sodium lamp.
This patent application is currently assigned to IP Holdings, LLC. The applicant listed for this patent is IP Holdings, LLC. Invention is credited to John Stanley.
Application Number | 20180038582 15/691304 |
Document ID | / |
Family ID | 52343431 |
Filed Date | 2018-02-08 |
United States Patent
Application |
20180038582 |
Kind Code |
A1 |
Stanley; John |
February 8, 2018 |
AIR COOLED HORTICULTURE LIGHTING FIXTURE FOR A DOUBLE ENDED HIGH
PRESSURE SODIUM LAMP
Abstract
An air cooled horticulture lamp fixture for growing plants in
confined indoor spaces. The fixture seals the lamp and heat
generated by the same to a reflector interior. Flow disruptors
create turbulence in a cooling chamber thereby enhancing thermal
transfer into a cooling air stream that flows over and around the
reflector's exterior side thereby convectively cooling the lamp
using the reflector as a heat sink. The lamp is effectively
maintained at operational temperatures and the fixture housing is
insulated from the hotter reflector by a gap of moving cooling air,
allowing improved efficiencies of the lamp bulb in confined indoor
growing spaces.
Inventors: |
Stanley; John; (Vancouver,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IP Holdings, LLC |
Vancouver |
WA |
US |
|
|
Assignee: |
IP Holdings, LLC
Vancouver
WA
|
Family ID: |
52343431 |
Appl. No.: |
15/691304 |
Filed: |
August 30, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14662706 |
Mar 19, 2015 |
9752766 |
|
|
15691304 |
|
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|
13945794 |
Jul 18, 2013 |
9016907 |
|
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14662706 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F21V 29/50 20150115;
A01G 7/045 20130101; Y02P 60/14 20151101; F21V 31/005 20130101;
Y02P 60/146 20151101; F21V 7/10 20130101; H01J 61/22 20130101 |
International
Class: |
F21V 29/50 20060101
F21V029/50; F21V 31/00 20060101 F21V031/00; F21V 7/10 20060101
F21V007/10; A01G 7/04 20060101 A01G007/04; H01J 61/22 20060101
H01J061/22; F21V 29/00 20060101 F21V029/00 |
Claims
1. A method of cooling a horticulture lighting fixture, the method
comprising the steps of: providing said horticulture lighting
fixture having a housing 200 with a downward facing bottom opening
205, a first duct 235, a second duct 245, a housing interior 220, a
reflector 100 captured within said housing interior 220, and a pair
of sockets 230A-B, each extending through said housing interior 220
and oriented so that said pair of sockets 230A-B holds a lamp bulb
2 in a substantially parallel orientation in relation to a
longitudinal axis extending between the first duct 235 and the
second duct 245; installing said lamp bulb 2 into said pair of
sockets 230A-B so that operation of said lamp bulb 2 illuminates
surfaces of a reflector exterior side 102 of reflector 100 to
reflect light downward through opening 205; hanging said
horticulture lighting fixture at a predetermined height above
plants to be grown thereunder in a plant growing environment;
attaching a fan to said first duct 235; energizing said fan so as
to flow cooling air between said first duct 235 and second duct
245; energizing said lamp bulb 2 so as to reflect light downward
through opening 205; removing heat from said fixture by flowing
cooling air between said first duct 235 and second duct 245 through
a cooling chamber defined by the space between said housing
interior 220 and a reflector interior side 101, with said cooling
chamber formed so as to substantially prevent cooling air flowing
between said first duct 235 and said second duct 245 from flowing
between said reflector exterior side 102 and said reflector
interior side 101; and allowing said lamp bulb 2 to operate
substantially free from contact with cooling air flowing between
said first duct 235 and said second duct 245, so that operating
temperatures of said lamp bulb 2 are allowed to be higher than if
said lamp bulb 2 were subjected to contact with cooling air flowing
between said first duct 235 and said second duct 245.
2. The method of claim 1 further comprising: connecting intake
ducting to said fan and configuring said fan so as to force cooling
air into said first duct 235.
3. The method of claim 2 further comprising: connecting exhaust
ducting to said second duct 245.
4. The method of claim 3 further comprising: configuring said
intake and exhaust ducting so that said plant growing environment,
with said lighting fixture oriented above a plant growing space
thereunder, is isolated from cooling air flowing into the first
duct 235 and exhausted through the second duct 245.
5. The method of claim 4 further comprising: substantially
preventing air within said growing environment from mixing with
cooling air flowing between the first duct 235 and the second duct
245.
6. The method of claim 4 further comprising: substantially
preventing air within said growing environment from being pulled in
to said lighting fixture and exhausted through said second duct 245
with a positive pressure between said first duct 235 and said
second duct 245, said positive pressure created by forcing cooling
air from said fan into said first duct 235.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/662,706, filed Mar. 19, 2015, which is a
continuation of U.S. patent application Ser. No. 13/945,794, filed
Jul. 18, 2013, now U.S. Pat. No. 9,016,907.
BACKGROUND OF THE INVENTION
Technical Field of the Invention
[0002] This invention relates generally to horticulture light
fixtures for growing plants indoors, and particularly to an air
cooled fixture used in confined indoor growing spaces that burns a
double ended high pressure sodium lamp.
Description of Related and Prior Art
[0003] Horticulture light fixtures used for growing plants in
confined indoor spaces must provide adequate light to grow plants,
while not excessively raising the temperature of the growing
environment. Removal of the heat generated by the fixture is
commonly achieved by forcing cooling air around the lamp and
through the fixture, exhausting the same out of the growing
environment. The air used for cooling the fixture is not mixed with
the growing atmosphere, as the growing atmosphere is specially
controlled and often enhanced with Carbon Dioxide to aid in plant
development and health.
[0004] Innovations in electronic ballast technology made feasible
for use in the indoor garden industry an improved high pressure
sodium `HPS` grow lamp that is connected to power at each end of
the lamp, thus the term "Double Ended". The double ended lamp as
powered from each end is also supported by sockets at each end,
thereby eliminating the need for a frame support wire inside the
lamp as required in standard single ended HPS lamps. The absence of
frame wire eliminates shadows that commonly plague single ended HPS
lamps. The double ended lamp further benefits from a smaller arc
tube that is gas filled rather than vacuum encapsulated. The
smaller arc tube equates to a smaller point source of light,
thereby improving light projection control and photometric
performance. The double ended HPS lamp proves to be more efficient
than its single ended HPS lamp equivalent, last longer than like
wattage HPS lamps, and produces more light in beneficial wavelength
for growing plants than any single ended HPS lamps of the same
light output rating.
[0005] The double ended HPS lamp, with all of its light output
performance advantages, has a significant particularity in
operation, specifically when cooling the lamp. Operating
temperatures at the lamp envelope surface must be maintained within
a narrow operating range else the double ended HPS lamp's
efficiencies in electrical power conversion into light energy are
significantly reduced. When impacted by moving air, the double
ended HPS lamp draws excessive electrical current which may cause
failure or shutdown of the ballast powering the lamp. When bounded
by stagnant air held at constant operating temperature the double
ended HPS lamp proves more efficient in converting electricity to
light energy and produces more light in the plant usable spectrum.
This particularity in the double ended HPS lamp makes it an
excellent grow lamp, but also thwarted earlier attempts to enclose,
seal, and air cool the double ended HPS lamp to be used in confined
indoor growing application due to the lamp's substantial
sensitivity to moving cooling air.
[0006] Another challenges not resolved by the prior art involves
sealing the glass sheet to the bottom of the fixture. The reflector
interior temperatures when burning a double ended HPS lamp cause
failures of gasket materials. Further, the ultraviolet and infrared
light energies produced by the double ended HPS lamp degrade and
make brittle rubber, neoprene, and most other gasket materials
suitable for sealing the glass sheet.
[0007] Gavita, a lighting company from Holland produces various
fixtures utilizing the double ended HPS lamp. The usual
configuration includes a reflector with a spine, the spine having a
socket on each opposing end such that the double ended lamp is
suspended under a reflector over the plants. The reflector is not
sealed from the growing environment, nor is there a housing
enclosure or ducts to facilitate forced air cooling. The Gavita
fixtures provide the benefit of the high performing double ended
HPS lamp, but lacks air cooling capability which is necessary in
many indoor growing applications as discussed above.
[0008] Based on the foregoing, it is respectfully submitted that
the prior art does not teach nor suggest an air cooled horticulture
fixture for a double ended HPS lamp suitable for growing plants in
confined indoor growing spaces.
SUMMARY OF THE INVENTION
[0009] In view of the foregoing, one object of the present
invention is to provide an air cooled double ended HPS lamp fixture
for growing plants in confined indoor environments.
[0010] A further object of this invention is to provide a fixture
construct wherein the excessive heat generated by the lamp is
removed using a stream of forced air.
[0011] It is another object of the present invention to provide a
stagnant air space around the lamp that is maintained at constant
temperatures within the reflector during operation to prevent the
lamp from drawing excessive current when subjected to temperatures
differentials, or direct moving cooling air.
[0012] Another object of the present invention is to provide a
positive air tight seal between the fixture and the growing
environment using a gasket that is protected from the lamp's
damaging light.
[0013] This invention further features turbulence enhancement of
the cooling air stream by a diverter that disrupts the air stream
creating eddies over the top of the reflector.
[0014] Other objects, advantages, and features of this invention
will become apparent from the following detailed description of the
invention when contemplated with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Elements in the figures have not necessarily been drawn to
scale in order to enhance their clarity and improve understanding
of these various elements and embodiments of the invention.
Furthermore, elements that are known to be common and well
understood to those in the industry such as electrical power
connection are not necessarily depicted in order to provide a clear
view of the various embodiments of the invention, thus the drawings
are generalized in form in the interest of clarity and
conciseness.
[0016] FIG. 1 shows an isometric exploded view of the preferred
embodiment of the inventive fixture;
[0017] FIG. 2 is a cutaway exploded side view of the fixture in
FIG. 1;
[0018] FIG. 3 is a diagrammatically section end view of the fixture
in FIG. 1;
[0019] FIG. 3A is a perspective exploded view of the flow disruptor
in FIG. 1;
[0020] FIG. 3B is a perspective exploded view of the flow disruptor
in FIG. 3A further including turbulators;
[0021] FIG. 4 is a cutaway corner of the fixture in FIG. 1 showing
the compressively deformed shadowed gasket;
DETAILED DESCRIPTION OF THE DRAWINGS
[0022] As depicted and shown in the FIGs, a "heat sink" is a
component used for absorbing, transferring, or dissipating heat
from a system. Here, the reflector 100 acts as the "heat sink" for
the lamp 2 which is isolated from the cooling air stream 310 within
the reflector interior side 101. The reflector 100 convectively
transfers heat generated by the lamp 2 into the cooling air stream
310. "Convectively transfers" refers to the transport of heat by a
moving fluid which is in contact with a heated component. Here, the
fluid is air, specifically the cooling air stream 310 and the
heated component is the reflector 100. Due to the special
prerequisite criteria that the double ended high pressure sodium
(HPS) lamp 2 be isolated from moving air, and specifically the
cooling air stream 310, the heat transfer is performed convectively
from the reflector exterior side 102 to the cooling air stream 310.
The rate at which the heat transfer can convectively occur depends
on the capacity of the replenish able fluid (i.e. cooling air
stream 310) to absorb the heat energy via intimate contact with the
relatively high temperature at the reflector exterior surface 102.
This relationship is expressed by the equation q=hA.DELTA.T,
wherein, "h" is the fluid convection coefficient that is derived
from the fluid's variables including composition, temperature,
velocity and turbulence. "Turbulence" referring to a chaotic flow
regime wherein the fluid/air undergoes irregular changes in
magnitude and direction, swirling and flowing in eddies. "Laminar"
flow referring to a smooth streamlined flow or regular parallel
patterns, generally having a boundary layer of air against the
surface over which the laminar flow moves. When cooling with a heat
sink device within a cooling medium such as air, turbulent flow
proves more effective in transferring heat energy from the heat
sink into the flowing air. Turbulent flow acts to scrub away the
boundary layer or push away the stagnant layer of air that is
closest to the heat sink, thereby enhancing the fluid convection
coefficient increasing heat transfer. Turbulent flow also increases
velocities and pressures on the surface to be cooled, increasing
thermal transfer. The term "Turbulator" as referenced herein is a
device that enhances disruption of a laminar flow into a more
turbulent flow.
[0023] Referring now to FIG. 1-2, the preferred embodiment of the
fixture comprises a reflector 100 captured within a housing 200
defining a cooling chamber 300 within the air space located between
the reflector exterior side 102 and housing interior 220, the
cooling chamber 300 being in air communication with a first duct
and second duct. A cooling air stream 310 is disposed through the
cooling chamber 300 between the first duct 235 and the second duct
245. Two lamp sockets 230A-B located partially through two opposing
reflector apertures 105A-B provide the install location for the
double ended HPS lamp within the reflector interior side 101. A
flow disruptor 160 fixates over each socket 230A-B and aperture
105A-B diverting moving air from entering the reflector interior
side 101 while further creating air eddies and local air turbulence
within the cooling chamber 300 between the sockets over the
reflector top 104 at the reflector's 100 hottest spot,
substantially above the lamp 2. The flow disruptor 160 interference
with the cooling air stream 310 creates air eddies, increases local
vortex velocities within the cooling chamber 300, scrubs away
boundary layers of air proximal to the reflector exterior side 102
that reduce heat transfer, thereby enhancing convective heat
transfer from the reflector 100 into the cooling air stream
310.
[0024] With reference to FIG. 1 and FIG. 2, the fixture 1 includes
a housing 200, a reflector 100 captured within the housing 200, a
cooling chamber 300 defined by the air space between the housing
200 interior and the reflector exterior side 102. The cooling
chamber 300 being in air communication with a first duct 235 and
second duct 245, located substantially on opposite sides of the
housing 200. Between the first duct 235 and the second duct 245
flows the cooling air stream 310 through the cooling chamber 300,
the cooling air stream 310 which is pushed or pulled by remote fan
not shown but commonly used in the prior art, connected by hose or
ducting to the first duct 235.
[0025] Before flowing over the reflector top 104, the cooling air
stream 310 is split or deflected by the flow disruptor 160
enhancing turbulent flow thereby increasing thermal transfer from
the reflector interior side 101, through the reflector 100,
convectively transferring from the reflector exterior side 102 into
the cooling air stream 310. The hottest area of the reflector 100
is the reflector top 104 directly above the lamp 2, which is the
closest structure to the light source. As captured within the
housing 200, the reflector 100 has a reflector top air gap 104A
defined between the reflector top 104 and the housing interior 220.
The reflector top 104 air gap 104A for the preferred embodiment
using a 1000 watt double ended HPS lamp is 3/8 of an inch, which
provides ample cooling chamber 300 space for turbulent air movement
as between the reflector top 104 and the housing interior 220
facilitating adequate cooling while maintaining an acceptably air
insulated housing 200 exterior temperature.
[0026] By cutaway illustration with dashed lines in FIG. 2, the
lamp 2 is shown installed by its ends into the sockets 230A-B
within the reflector interior side 101 near the reflector top 104.
The lamp 2 is shown oriented parallel to the cooling air stream
310, however, the robust design allows for the lamp 2 to be
oriented within the reflector 100 at any diverging angle relative
to the cooling air stream 310.
[0027] As shown diagrammatically by sectioned view in FIG. 3,
cooling air directions being depicted by arrows illustrates the
cooling air stream 310 as impacted by the flow disruptor 160. In
operation, the cooling air stream 310 is being forced to move with
a fan (not shown) either by fan push or fan pull through the first
duct 235, then into and through the cooling chamber 300 to be
exhausted out the second duct 245. The cooling air stream 310 is
diverted and split by a flow disruptor 160 directing part of the
air over one side of the reflector exterior 102, the other part
over the other side of the reflector exterior 102. The diverted
cooling air stream 310 is redirected within the fixture 1 such that
moving air is discouraged from pressuring any apertures, gaps, or
through holes in the reflector 100.
[0028] As depicted in FIG. 3 and shown in FIG. 3A, the flow
disruptor 160 constructed to be deflecting and disrupting to moving
air and arranged to attach over at least one socket 230 and enclose
at least one aperture 105 such that cooling air moving through the
cooling chamber 300 is diverted and disrupted into a more turbulent
flow than a laminar flow regime. The preferred embodiment locates
the flow disruptor 160 to encourage deflection of moving air away
from the sockets 230 and aperture 105 as discussed above,
essentially fulfilling two functions, creating turbulence within
the cooling chamber 300 while also redirecting moving air away from
reflector areas 100 that may be subject to leaks. The flow
disruptor 160 location is not limited to enclosing the sockets 230
or apertures 105, as a flow disruptor 160 located within the first
duct 235 or second annular duct 245, depending on which receives
the incoming cooling air stream 310, is effective at introducing
turbulence into the cooling air stream 310, and depending on which
configuration may be preferred. Additional flow disruptors 160
working independently or in cooperation may be included within the
cooling chamber 300 mounted to the reflector 100 or the housing
200.
[0029] The preferred embodiment design of the flow disruptor 160
shown in FIG. 3A is simply constructed from a first sheet metal
portion 160A and a second sheet metal portion 160B, the preferred
metal being steel over aluminum, as the thermal conductivity of the
flow disruptor 160 is not as important as the costs associated with
manufacture, but in practice both metals are suitable. As shown in
FIG. 3A, the flow disruptor 160 is impervious to moving air to
facilitate the dual function of deflecting moving air away from the
reflector apertures 105 while also creating turbulence within the
cooling chamber 300.
[0030] As shown in FIG. 3B, an enhanced flow disruptor 160 having
turbulators 161 illustratively depicted as rows of through holes.
The turbulators 161 could also be fins, blades, vents, or grating,
most any disrupting structure, redirecting channel, or obstacle for
the cooling air stream 310 will cause turbulence and thereby
increase thermal conductivity from the reflector 100 into the
cooling air stream 310.
[0031] As discussed above, the reflector 100 is a thermally
conductive component of the fixture acting as a heat sink for the
lamp 2. The reflector 100 preferably is constructed from aluminum,
which is the favored material because of its relatively high
thermal conductivity, easily shaped and formed, and highly
reflective when polished. The high thermal conductivity of aluminum
provides beneficial heat transfer between the reflector interior
side 101 to the reflector exterior side 102 thermally transferring
or heat sinking through the reflector 100. Steel is also a suitable
material, however the lower thermal conductivity makes aluminum the
preferred reflector 100 material.
[0032] As shown in the FIGs, openings, gaps, or spaces through the
reflector 100 are filled, blocked, or covered such that the
reflector interior side 101 is sealed from moving air. As assembled
and captured within the housing 200, a first socket 230A is
disposed to fill a reflector 100 first aperture 105A sealing the
first aperture 105A from moving air. A second socket 230B is
disposed to fill the second aperture 105B sealing the second
aperture 105B against moving air. The first socket 230A and second
socket 230B constructed and arranged to cooperatively receive the
ends of the double ended HPS lamp 2 as located within the reflector
interior side 101 between the two sockets 230A-B. As shown from the
side in FIG. 2 and by depiction in FIG. 3, flow disruptors 160
attach over the sockets 230A-B and over both apertures 105A-B
within the path of the cooling air stream 310. In this way, the
flow disruptors 160 enclose any opening or space between either
socket 230A-B and aperture 105A-B respectively, thereby diverting
air moving through the cooling chamber 300 away from any potential
opening into the reflector interior side 101. Filling of each
aperture 105A-B by partial insert of each socket 230A-B requires
precise manufacturing tolerances or specially formed sockets 230 in
order to prevent or substantially stop moving air from traveling
around the socket 230 into the reflector interior side 101. Heat
resistant sealing mediums like metal tape or high temp calk are
available to positively seal the aperture 105 to the socket 230
thereby diverting the cooling air path 310 from entering the
reflector interior side 101. However, high temperature sealing
mediums tend to be expensive, and application of the sealing medium
as performed manually is often messy, slow, and leaves one more
step in the manufacturing process subject to human error. As
discussed herein, the preferred embodiment utilizes flow disruptors
160 constructed from sheet metal that are impervious to air rather
than sealing mediums. However sealing mediums if properly applied
will work in the place of a flow disruptor 160 for the limited
purpose of sealing the reflector interior 101, but lack the
aerodynamic structure necessary to disturb the cooling air stream
310 creating turbulence between the first socket 230A and second
socket 230B for enhanced convective transfer of heat from the
reflector 100 into the cooling air stream 310.
[0033] In FIG. 4 a sectional view with a close up of the bottom
corner of the fixture 1 showing by illustration the cooling chamber
300 as defined between the reflector 100 and the housing 200. The
cooling chamber 300 is shown in cross section demonstrating from
top to bottom the relative size of air space between the reflector
100 and the housing 200 for the preferred embodiment. As shown,
there is only one continuous cooling chamber 300, however several
smaller cooling chambers 300 split by disruptors 160 or mounting
fins between the housing interior 220 and the reflector 100 provide
greater control of the movement of the cooling air stream 310
through the fixture 1.
[0034] The lower left close up view shown in FIG. 4 of the bottom
corner of the fixture 1 demonstrates the lower lip 103 of the
reflector 100 location as captured within the housing 200, wherein
the lower lip 103 is adjacent to and slightly extending below the
housing lower edge 210. As captured, the reflector's 100 lower lip
103 and housing lower edge 210 thermally transfer heat energy. This
heat sinking occurring between the reflector's 100 hotter lower lip
103 and the housing 200 cooler lower edge 210 makes the lower lip
103 the coolest part of the reflector 100, making for the most
suitable place to seal the reflector 100 using a gasket 31. A
specially formed reflector lip 103 protectively shadows the gasket
31 from damaging light energy produced by the double ended HPS lamp
2 thereby preventing premature failure of the gasket 31 during
operation. As compressed, the gasket seals against the housing edge
surface slightly deforming 31A to further seal against the
reflector lip 103. In this way, a double redundant seal is provided
between the fixture interior and the growing environment, while
also providing a positive air tight seal between the cooling
chamber 300 and the reflector interior side 101 that is not as
susceptible to premature seal failure.
[0035] As shown in FIG. 4, the compressive sealing between the
glass sheet 30 and the housing edge 210 with a gasket 31 sandwiched
in between thereby seals the growing environment from the fixture
interior. The gasket 31 being located relative to the reflector 100
such that the reflector lower lip 103 shadows or blocks direct
light 2A produced by the lamp from impacting the gasket 31. As
shown, the glass sheet 30 is held in place compressively by at
least one latch 32 with enough compressive force to deform the
gasket 31. The deformed gasket 31A sealingly contacts the lower lip
103 making a second redundant seal against the coolest part of the
reflector 100 at the lower lip 103 which is shadowed and protected
from the direct light energy produced by the lamp 2. For the
preferred embodiment the gasket 31 is constructed of a porous
neoprene material, however many suitable heat resistant gasket
materials may be used to construct the gasket 31.
[0036] The inventive fixture as shown may have the cooling air
pushed or pulled through the cooling chamber 300 by fan or other
forced air apparatus. The robust fixture 1 cools effectively with
either a negative pressure or positive pressure within the housing
200 due to the isolated reflector 100 interior side 101. Two fans
used in cooperation may be implemented without diverging from the
disclosed embodiment, and linking fixtures together along one
cooling system is also feasible, similar to current `daisy
chaining` configurations.
[0037] The foregoing detailed description has been presented for
purposes of illustration. To improve understanding while increasing
clarity in disclosure, not all of the electrical power connection
or mechanical components of the air cooled horticulture light
fixture were included, and the invention is presented with
components and elements most necessary to the understanding of the
inventive apparatus. The intentionally omitted components or
elements may assume any number of known forms from which one of
normal skill in the art having knowledge of the information
disclosed herein will readily realize. It is understood that
certain forms of the invention have been illustrated and described,
but the invention is not limited thereto excepting the limitations
included in the following claims and allowable functional
equivalents thereof.
* * * * *