U.S. patent number 3,692,977 [Application Number 05/100,868] was granted by the patent office on 1972-09-19 for compact combination infra-red heating and ventilating unit.
This patent grant is currently assigned to Panacon Corporation. Invention is credited to Ronald E. Duhamel, James E. Hutten.
United States Patent |
3,692,977 |
Duhamel , et al. |
September 19, 1972 |
COMPACT COMBINATION INFRA-RED HEATING AND VENTILATING UNIT
Abstract
A compact, combination infra-red heating and ventilating unit
for bathrooms and the like. The unit is divided into an upper
compartment containing all the electrical components, and a lower
compartment containing the infra-red lamps. The bulk-head dividing
the said compartments is provided with an aperture for the flow of
air to the ventilating fan in the upper compartment, and the
aperture is shielded from back radiation from the infra-red lamps.
The interior of the lower compartment and the shields are provided
with heat reflective surfaces. A cover plate is provided which has
apertures larger than the outside diameter of the lamps to provide
for air flow, and the apertures in the cover plate have contoured
edges to reflect peripheral radiation into the room. The upper
compartment contains a motor and fan and all the electrical wiring,
and is adapted to be connected to a duct for venting to atmosphere.
A gravity actuated damper is arranged in the vent opening such that
when the fan is not operating, it still permits passage of hot air
by convection.
Inventors: |
Duhamel; Ronald E. (Middletown,
OH), Hutten; James E. (Mason, OH) |
Assignee: |
Panacon Corporation
(Cincinnati, OH)
|
Family
ID: |
22281945 |
Appl.
No.: |
05/100,868 |
Filed: |
December 23, 1970 |
Current U.S.
Class: |
392/347; 362/147;
219/220; 454/347 |
Current CPC
Class: |
F24F
7/06 (20130101); H05B 3/0033 (20130101); F24H
3/0411 (20130101) |
Current International
Class: |
F24F
7/06 (20060101); F24H 3/04 (20060101); H05B
3/00 (20060101); F24h 009/02 (); H05b () |
Field of
Search: |
;219/220,342,343,347,350,351,352,354,357,361,366,367,368,377,370
;250/88,89 ;237/46 ;98/42,43 ;240/2R,2V,47,78H,78HA |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Beha, Jr.; William H.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A compact, combination infra-red heating and ventilating unit,
including an electric motor driven ventilating fan, a discharge
orifice and means for attachment to an exhaust duct, and at least
two infra-red radiant heat lamps, all contained in a sheet metal
housing having a top and sides, and being open at the bottom; said
discharge orifice having a gravity actuated flat damper plate
covering said orifice when said fan is not operating and
discharging air therethrough, said damper plate being hinged at the
top edge and offset by a fixed distance from the face of said
orifice to provide open spaces at the edges of said orifice through
which superheated air inside the housing can escape into the
exhaust duct when said ventilating fan is not operating, the total
area of said spaces being in the range of about 25 percent to about
50 percent of the area of said discharge orifice, whereby heat
build-up within said housing is minimized.
2. A prefabricated combination infra-red heating and ventilating
unit, including an electric motor driven ventilating fan, a
discharge orifice and means for attachment to an exhaust duct, and
at least two infra-red radiant heat lamps, all contained in a sheet
metal housing having a top and sides, and being open at the bottom;
said fan, motor, and the electrical wiring for the heat lamps and
motor being disposed in the upper portion of said housing, and said
heat lamps being disposed in the lower portion of said housing with
their heat-radiating faces directed downwardly, and means behind
the bases of said lamps provided with a highly heat-reflective
surface finish to reflect the back radiation of said lamps
outwardly and downwardly away from said fan, motor, and the
electrical wiring of the motor and heat lamps, said unit also
having a sheet metal cover panel for the open bottom of said
housing, said panel having an aperture for each of said heat lamps,
each of said apertures being larger in diameter than the outside
diameter of the respective heat lamp faces to permit passage of air
to said fan, the edges of said lamp apertures being provided with
an annular downward and outward flare to provide a heat-reflective
contoured surface from which peripheral lateral heat radiation from
said lamps is reflected outwardly from said unit.
3. A prefabricated combination infra-red heating and ventilating
unit, including an electric motor driven ventilating fan, a
discharge orifice and means for attachment to an exhaust duct, and
at least two infra-red radiant heat lamps, all contained in a sheet
metal housing having a top and sides, and being open at the bottom;
a bulkhead dividing said housing into upper and lower compartments,
an aperture in said bulkhead for the passage of air, said fan,
motor, and the electrical wiring for the heat lamps and motor being
disposed in said upper compartment, and said heat lamps being
disposed in said lower compartment with their heat-radiating faces
directed downwardly, a sheet metal shield in front of said
aperture, and sheet metal vanes adjacent said aperture between said
aperture and said heat lamps, said bulkhead, shield and vanes in
combination with the top and upper sides of said housing
constituting a heat-protected upper compartment for said motor and
electrical wiring; said discharge orifice being provided with a
gravity actuated flat damper plate covering said orifice when said
fan is not operating and discharging air therethrough, said damper
plate being hinged at the top edge and offset by a fixed distance
from the face of said orifice to provide open spaces at the edges
of said orifice through which superheated air inside the housing
can escape into the exhaust duct when said ventilating fan is not
operating, the total area of said spaces being in the range of
about 25 percent to about 50 percent of the area of said discharge
orifice, whereby heat build-up within said housing is minimized
when said heat lamps are energized but said ventilating fan is not
operating.
4. A prefabricated combination infra-red heating and ventilating
unit, including an electric motor driven ventilating fan, a
discharge orifice and means for attachment to an exhaust duct, and
at least two infra-red radiant heat lamps, all contained in a sheet
metal housing having a top and sides, and being open at the bottom;
said fan, motor, and the electrical wiring for the heat lamps and
motor being disposed in the upper portion of said housing, and said
heat lamps being disposed in the lower portion of said housing with
their heat-radiating faces directed downwardly, and means behind
the bases of said lamps provided with a highly heat-reflective
surface finish to reflect the back radiation from said lamps
outwardly and downwardly away from said fan, motor, and the
electrical wiring of the motor and heat lamps; said discharge
orifice being provided with a gravity actuated flat damper plate
covering said orifice when said fan is not operating and
discharging air therethrough, said damper plate being hinged at the
top edge and offset by a fixed distance from the face of said
orifice to provide open spaces at the edges of said orifice through
which superheated air inside the housing can escape into the
exhaust duct when said fan is not operating, the total area of said
spaces being in the range of about 25 percent to about 50 percent
of the area of said discharge orifice, whereby heat build-up within
said housing is minimized when said heat lamps are energized but
said ventilating fan is not operating.
5. A prefabricated combination infra-red heating and ventilating
unit for ceiling recessed installation, including an electric motor
driven ventilating fan, a discharge orifice and means for
attachment to an exhaust duct, and at least two infra-red radiant
heat lamps, all contained in a sheet metal housing having a top and
sides, and being open at the bottom; a bulkhead dividing said
housing into upper and lower compartments, an aperture in said
bulkhead for the passage of air, said fan, motor, and the
electrical wiring for the heat lamps and motor being disposed in
said upper compartment, and said heat lamps being disposed in said
lower compartment with their heat-radiating faces directed
downwardly, a sheet metal shield in front of said aperture, and
sheet metal vanes adjacent said aperture between said aperture and
said heat lamps, said bulkhead, shield and vanes in combination
with the top and upper sides of said housing constituting a
heat-protected upper compartment for said motor and electrical
wiring, whereby excessive heat build-up within said unit, when said
heat lamps are energized but said ventilating fan is not operating,
is prevented, all interior surfaces of said lower compartment,
including said bulkhead, shield and vanes, being provided with a
highly heat-reflective surface finish, whereby radiant heat from
the bodies of said heat lamps is reflected outwardly and downwardly
away from said upper compartment, said discharge orifice being
provided with a gravity actuated flat damper plate covering said
orifice when said fan is not operating and discharging air
therethrough, said damper plate being hinged at the top edge and
offset by a fixed distance from the face of said orifice to provide
open spaces at the edges of said orifice through which superheated
air inside the housing can escape into the exhaust duct when said
ventilating fan is not operating, the total area of said spaces
being in the range of about 25 percent to about 50 percent of the
area of said discharge orifice, whereby heat build-up within said
housing is minimized.
6. The structure of claim 5 having two 250 watt, 120 volt heat
lamps, vertically adjustable mounting brackets, a 120 volt, 1550
RPM motor and fan having a rated air delivery of 60 CFm, a spring
held, laterally adjustable cover panel, and having electric
circuitry for the lamps and motor to provide selective operation of
the fan and lamps independently or conjointly.
Description
BRIEF SUMMARY OF THE INVENTION
This invention relates to a prefabricated combination heating and
ventilating unit which employs as the heat source multiple
infra-red electric lamps that generate radiant heat by conversion
of electrical energy. The combination unit of the present invention
is especially suitable for installation recessed between the joists
of the room ceiling, attached to and supported by the joists, with
the heat-radiating lamp surfaces facing downward just below the
ceiling. When installed, the unit box is concealed by an ornamental
cover panel having two circular apertures slightly larger in
diameter than the lamp faces, one opening for each infra-red lamp.
The unit also can be mounted on a vertical or sloping side wall, if
desired. Ventilation is provided by a squirrel cage type blower,
powered by an electric motor enclosed within the unit box, which
may be energized independently of the infra-red lamps or integrated
with electrical circuit for the lamps. The air from the ventilating
fan is discharged through an exhaust duct to the outside of the
building.
The general purpose of this invention is to provide a combination
infra-red heating and ventilating unit for ceiling installation
that is compact, efficient, electrically and mechanically simple,
easy to install, and electrically safe under all operating
conditions.
Ancillary to the purpose of maintaining electrical safety, an
important object of the invention is to arrange the assembly of the
components within the unit box so that the motor and blower and the
electrical wiring for the motor and lamps are separated from and
shielded from the back-radiation of the heat lamps within the
unit.
Another object of the invention, also directly related to the
electrical safety of the installed combination unit, is to provide
all interior surfaces of the unit and the shields for the motor and
other electrical components with a radiant-heat-reflective enamel
surfacing, to minimize the temperature rise of the air within the
unit that might result in deterioration or malfunction of the motor
or wiring or cause an electrical fire.
Another important object is to accomplish both the ventilation of
the room and the cooling of the unit with a single motor and fan,
thereby eliminating the auxiliary cooling fan and motor and its
associated electrical wiring that have previously been required in
similar combination units.
A special purpose of the invention is to provide the combination
unit with a novel offset damper which closes automatically the
orifice through which air is discharged from the fan into the
exhaust duct, so that any back draft of cold air through the unit
into the room when the blower fan is not operating is prevented,
but superheated air within the unit may escape around the edges of
the damper plate into the duct, thereby preventing excessive
temperature build-up within the unit.
A further purpose is to provide the unit with a reflective metal
cover panel for the ceiling installation of the unit, having
circular apertures through which the infra-red lamp faces project,
these openings being larger in diameter than the lamps to provide
an annular air space through which the ventilating air can flow
into and through the unit to the fan intake, the sides of the
apertures being contoured so as to reflect outwardly the radiant
heat from the adjacent peripheral rim of the infra-red lamp.
BACKGROUND OF THE INVENTION
The earliest and simplest method of using an infra-red lamp to
provide heat in a small room was simply to screw the lamp into a
standard electric lamp socket mounted on the ceiling. The lamp then
produced radiant heat, but was exposed to possible breakage and due
to its high surface temperature might cause a painful burn if
touched. The next step was to encase a single lamp in a small
rectangular box having a cover plate with a circular opening in
which the face of the infra-red lamp was exposed; this unit was
then installed within the ceiling structure in the same way as a
ceiling-recessed lighting fixture. A single lamp unit of this kind
may be used either as a lighting fixture or an infra-red radiant
ceiling heater and does not require a cooling fan for electrical
safety nor does it provide any ventilation of the room space.
Two-lamp ceiling fixtures of similar construction have also been
produced; this type enables the use of a light bulb in one lamp
socket and an infra-red radiant heat lamp in the other.
Infra-red radiant ceiling heaters with multiple lamps (two or
three) have been produced and these also are installed as
ceiling-recessed fixtures. Such multiple units produce more heat
build-up within the unit box than a single lamp heater and for
electrical safety must be provided with a small electric powered
cooling fan inside the unit box. Since the purpose of the fan is
merely to disperse the heated air inside the unit so as to maintain
safe internal temperatures when the lamps are in operation, this
type of unit does not require a duct discharging the air outside
the building, nor does it provide any ventilation of the room. If
the fan motor fails while the lamps are operating the unit
overheats and becomes unsafe, therefore the electrical circuitry
for the lamps and motor are integrated so that the motor operates
when the lamps are energized, but if the motor fails the lamps are
shut off.
The combination unit, which provides both infra-red radiant heat
and air ventilation to the room in which it is installed, is a
recent development in this field; the present invention is
concerned with an improved and simplified combination unit of this
type. When a ventilating fan is added to the infra-red heating unit
it then becomes a ventilating unit and Building Code regulations
provide that the fan exhaust air must be discharged into a duct to
the outside of the building. Prior to the present invention, such
combination units have incorporated two electric powered fans: (1)
a "large" squirrel cage fan for ventilation having a capacity of
about 50 CFM and (2) a "small" fan within the unit box for cooling
the infra-red lamps. Usually the ventilating fan is mounted on the
outside of the unit box, with its motor inside the box so that the
motors of both fans and all their electrical wiring are directly
exposed to back-radiation from the infra-red heat lamps. Because
the ventilating fan and the lamps can be used separately, the
infra-red heat lamps may often be energized when the ventilating
fan is not operating, therefore it is necessary that the cooling
fan be included in the lamp circuit so that it operates
continuously while the lamps are on, otherwise excessively high
internal temperatures will result and create an electrical safety
hazard.
Examination and comparative analysis of the design features and the
structural arrangements of the components in various combination
infra-red heating-ventilating units that are now commercially
available made it clearly evident that improvement is needed and
particularly, to eliminate the auxiliary "cooling" fan. When it is
made possible to accomplish both infra-red heating and ventilating
by a unit having a single motor and fan, this enables making it
more compact, simpler mechanically and less complicated
electrically, more efficient, less subject to possible malfunction,
more durable so as to provide a longer service life, possessing
complete electrical safety, and at a lower cost.
The improved combination unit herein disclosed has been found
particularly suitable for heating and ventilating small rooms such
as bathrooms and bath-dressing rooms, to provide personal comfort
for the occupants and to ventilate the air and remove excessive
moisture. It is also effective as a supplemental heat source in
motel rooms, mobile homes and small apartments, particularly in the
spring and fall when the main heating system may not be in
operation. For rooms of greater area, multiple units may, of
course, be installed. An important advantage of the infra-red
heating unit is that it provides almost instantaneous radiant heat
when the unit is turned on, with none of the delay that is typical
of air convection heating systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general perspective view of the complete unit, showing
the unit box with its attachment brackets, exhaust duct fitting,
electrical junction box, cover panel and the infra-red lamps in
place.
FIG. 2 is a detail bottom plan view of the unit box, showing the
locations of the motor mounting bracket, lamp sockets, air guide to
the exhaust opening, radiant heat shield between the motor base and
the infra-red lamps, and the radiant heat reflector vanes between
the motor base and the lamp sockets.
FIG. 3 is a schematic cross sectional view, taken on the line 3--3
of FIG. 2, of the complete unit under actual operating conditions,
showing the locations of the motor, blower wheel, air guide to
exhaust, exhaust damper, lamp socket and lamp, radiant
heat-reflective shields between the motor base and lamps, the
bulkhead separating the lamps from the electrical wiring and fan;
and particularly, the air flow pattern around the lamps, around the
motor shields, into the air guide channel and to the exhaust
orifice.
FIG. 4 is a schematic representation of the electrical wiring
diagram for the two-lamp infra-red heating and ventilating
combination unit of the Typical Example of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The infra-red radiant heat lamp is designed to project most of the
radiant heat that it produces outwardly from the face and adjacent
rim areas of the lamp. However, this lamp also radiates a great
deal of heat from the body and stem of the bulb which is inside the
unit box. The heat thus radiated is termed, for the purposes of
this disclosure,-"back radiation", and it is this back radiation
which creates the problem of overheating of the combination unit
when the ventilating fan is not operating. Under such conditions
the glass of the body and stem of the lamp becomes extremely hot.
It has been determined that when two infra-red radiant lamps are
operated continuously in a closed space without ventilation, the
surface temperature of the glass body may rise as high as
470.degree. F.
Several means are disclosed herein by which the objectionable
temperature rise from the back radiation of the lamps can be
prevented or minimized so that a combination unit having a single
motor and fan can be made electrically safe and reliable. These
novel means vary in effectiveness; therefore in the preferred
constructions of the unit two or more are used conjointly, although
each of them if used independently contributes much improved
performance in respect to temperature control. Stated briefly,
these are:
A. separation of the fan motor and the electrical wiring for the
motor and lamps, within the interior space of the unit, from the
radiant heat source (the infra-red lamps) by a
radiant-heat-reflective sheet metal bulkhead and heat radiation
shields, these constituting a heat-protected compartment for the
electrical components in the upper part of the box.
B. arrangement and design of the components in the lamp compartment
(lower part of the unit box) to reflect radiant heat outwardly from
all interior surfaces, including the motor shield and reflectors,
and from the periphery of the infra-red lamp face.
C. provision of an automatic, offset damper, integral with the fan
exhaust orifice of the unit, that closes by gravity when the
ventilating fan is not operating, but provides a spaced opening
around its edges that enables superheated air to escape into the
exhaust duct when the damper is closed.
As best seen in FIG. 1, the unit is enclosed in a housing 10 of
sheet metal. The housing 10 (with its bottom facing the viewer in
the Figure) has a top wall and side walls 11 and end walls 12. The
top wall is indicated at 13 in FIG. 3. The cover element 14 is
separate and is attached to the casing by means of spring 15 (FIG.
3).
One of the side walls 11 is provided with a fitting 16 for
attachment to a duct venting to the atmosphere. A bracket 17
carries the junction box 18 for electrical connection of the unit.
Mounting brackets 19 are provided for mounting the unit to the
joists.
Basically, the housing 10 is divided into upper and lower
compartments. The upper compartment is indicated generally at 20
and the lower compartment at 21. The dividing wall is in the form
of a sheet of metal 22 which carries the socket 23 for the heat
lamps 24. The bulkhead 22 also mounts the motor bracket 25 as at 26
and 27 and secured to the bracket 25 is a circular plate 28.
Coaxially with respect to the circular plate 28 is a circular
aperture 29 in the bulkhead 22. The electric motor 30 is mounted on
the bracket 25 above the circular plate 28 and the motor 30 drives
the ventilating fan 31 which is coaxial therewith.
Adjacent the aperture 29 in the bulkhead 22 there are provided the
sheet metal vanes 32 which protect the aperture 29 from direct back
radiation from the base portions of the heat lamps 24. The plate 28
similarly shields the compartment 20 from back radiation.
A damper is provided in the exhaust fitting 16 and is indicated at
33 in its closed position and 33a in its open position. The damper
33 is hinged at the top and closes by gravity against an abutment
or stop 34. Under the influence of exhaust air when the fan is
operating, the damper moves to the position 33a to permit air to
flow out to the exhaust duct. When the fan is not operating, the
damper does not close the opening entirely by virtue of the stop
34. There is always a space around the periphery of the orifice
which preferably amounts from about 25 percent to about 50 percent
of the full opening of the orifice. The purpose of this structure
is to permit superheated air to pass out to the exhaust duct when
the lamps are operating and the exhaust fan is not operating.
The cover plate 14 which is exposed in the room in which the unit
is installed, may be decorative in character. It is of sheet metal
and as indicated above is attached by means of a spring which hooks
on to a hook 35 which may be struck out from the plate 28. The
cover plate 14 has apertures for the heat lamp 24 which are larger
than the diameter of the heat lamp so as to allow an annular space
around the edges of the heat lamp for passage of air to the
ventilating fan. As best seen in FIG. 3, the edges of these
orifices are configured as at 36 for a purpose to be described
hereinafter.
From the detailed description above given, it will be seen how the
three means described above may be applied to a unit of this
character. As to the means indicated above as A, it will be seen
that the interior space of the housing has been separated into the
lamps compartment 21 and the motor and wiring and fan compartment
20. The circular sheet metal heat radiation shield 28 between the
motor mount and the motor and the vanes 32 between the lamps and
the motor shield the motor compartment from the aforementioned back
radiation. In this way, the top and upper sides of the unit
together with the bulkhead, the motor shield, and the reflector
vanes constitute the heat protected motor compartment 20. It will
be understood that the separate motor shield and reflector vanes
could be combined into a single piece if though to be
desirable.
From the foregoing description, it will be understood how back
radiated heat from the lower body and stem of the infra-red lamps
impinges on the interior surfaces of the lamp compartment to
produce elevated temperatures of the air and the box walls and the
components when the ventilating fan is not operating. The
application of the means identified as B and described above
involves the provision for all the interior surfaces of the lamp
compartment, including the walls, the bulkhead, the motor shield
and the reflectors, of a highly heat-reflective surface, preferably
white enamel. Alternatively, the radiant heat-reflective surfaces
may be of bright plated non-corrodible metal or metal foil. In this
way the back radiated heat is reflected outwardly and downwardly
away from the bulkhead and motor compartment which minimizes the
temperature rise within the unit. It also increases the heating
efficiency of the unit since a greater part of the total heat
produced enters the room space instead of being wasted by
overheating the unit box and its components.
The outward reflection of the back radiated heat is further
enhanced by forming the bulkhead with an angular heat reflecting
panel of about 45.degree. inclination at each end where it is
attached to the walls of the unit box. This is the preferred
construction for maximum efficiency of temperature control.
Additionally, the configuration of the cover panel described above
constitutes an additional means by which back radiation is
reflected outwardly. The cover panel may be of sheet metal having a
heat reflective surface finish such as white enamelled steel, but
it is preferably of polished aluminum.
FIG. 3 also illustrates the application of the third means C. The
rectangular exhaust orifice from the fan discharge into the sleeve
of the duct fitting is covered by the flat damper plate as
previously described. The offset mounting provides a free opening
along the sides and lower edge of the damper plate through which
the superheated air which may accumulate within the housing when
the fan is not operating can escape into the exhaust duct and
thereby prevent excessive heat build up.
The purpose of a damper in this type of unit is to prevent a back
draft blast of cold air from outside the building entering the room
when the heating unit is operating but the ventilating fan is not.
The offset damper described herein accomplishes this purpose but
still permits superheated air to escape. The objects of this damper
could be accomplished by various means and the particular offset
damper is shown by way of example. It will be understood that the
edges of the opening might be provided with serrated metal
projections to determine the offset distance instead of the single
bumper stop or small apertures could be made in the damper plate to
permit the escape of superheated air.
TYPICAL EXAMPLE OF A PREFERRED EMBODIMENT
FIG. 1 shows the complete two-lamp combination unit, in perspective
view, and FIG. 2 is a detailed plan view from the lower (lamp
compartment) side. It can be seen that the unit is very compact and
that the only components outside the box are the mounting brackets,
the exhaust fitting sleeve, the electrical junction box and the
wiring raceway. The unit box dimensions of the Typical Example are:
71/8 inches .times. 73/8 inches .times. 141/4 inches overall. Due
to its small dimensions the unit may be installed either parallel
to or across the joist direction of a ceiling with standard 16 inch
joist spacing.
INSTALLATION - All four sides of the unit box are provided with
vertical slots for attachment of the mounting brackets, so that the
unit can be placed either parallel to or across the joist
direction. The mounting brackets are adjustable vertically to allow
for variations in the ceiling thickness. Flat support bars are
inserted through the brackets and then nailed to the joists.
Spacing of the unit from any vertical wall surface should be at
least 12 inches.
INFRA-RED LAMPS - The infra-red heat lamps used are standard 250
watt-R40 type, for operation with 120 volt, 60 Hz electric current.
Two lamps therefore consume about 500 watts and provide about 1700
BTU of radiant heat.
VENTILATING FAN AND MOTOR - The fan is a "squirrel cage" blower
wheel, 5 3/16 inches diameter and 1 3/4 inches high, powered by a
120 volt, 0.90 Amp., 60 Hz, 1550 RPM, thermal protected motor. In
continuous operation, the fan consumes about 55 watts and has a
rated air delivery of about 60 CFM. The total electrical load for
the unit with two lamps and the fan operating continuously is about
560 watts.
COVER PANEL - The cover panel is of formed, polished sheet
aluminum, 9 7/8 inches .times. 16 7/8 inches overall, with two
apertures each 5 inches in diameter. The walls of the apertures are
contoured outwardly to a diameter of about 6 5/8 inches and a
height of 7/8 inch. The base diameter of the aperture provides an
annular opening of about 5/16 inch width around the rim of the
infra-red lamp through which the fan draws its intake air from the
room. The cover panel is held in place over the ceiling recess by a
tension spring at its center point, attached at its other end to
the motor mount bracket inside the lamp compartment of the unit.
This enables the panel to be adjusted laterally so that each lamp
is properly centered in its aperture, to ensure uniform air flow
around the lamps to the fan intake.
ELECTRICAL CIRCUITRY - The combination unit is internally pre-wired
as shown in the schematic wiring diagram of FIG. 4. The motor
terminals are wired to a parallel blade, snap-in type connector.
The internal leads of the wiring are carried through a plated steel
tubing raceway to the junction box for field splicing to the house
circuit.
This combination unit offers numerous optional conditions of
operation which are provided by wiring to one, two or three
standard off-on wall switches. With a single switch, both lamps and
the fan operate simultaneously. Two switches enable operating the
fan and the lamps separately. With three switches the options are:
1 lamp; 2 lamps; 1 lamp and fan; 2 lamps and fan; fan only. Or one
infra-red lamp may be replaced by an incandescent light bulb for
more light. If desired, a timer switch may be used to energize or
de-energize the heat lamps at a predetermined time.
UNDERWRITERS' LABORATORIES, INC. LISTING - The combination
heating-ventilating unit of the Typical Example, above described,
has been tested and meets all the requirements of Underwirters'
Laboratories, Inc. for the components and their assembly in the
complete unit in respect to electrical safety and performance
reliability, under their "Standard for Electric Space Heating
Equipment", UL 573-1968. These tests included: measurement of power
input, temperature rise with the ventilating fan not operating,
dielectric withstand, over-voltage, and motor locked-rotor tests.
The combination infra-red radiant heating and ventilating unit
having the novel features herein disclosed has been listed by U.L.
under the above-identified Standard.
The invention having now been fully disclosed and its novel
features set forth in detail, it is evident that numerous
variations and combinations can be made as to the shape and
dimensions of the combination heating-ventilating unit and the
arrangement of the components, therefore no limitations are
intended except those defined by the following claims.
* * * * *