Note: Descriptions are shown in the official language in which they were submitted.
635
1 According to the invention there is provided a
convector heater comprising a cabinet having top and
bottom air vents and a partitionless interior;
electrically heated heat exchanger means mounted within
the cabinet for inducing a convection air flow to flow
through the cabinet and the air vents and for heating the
convection air flow, the convection air flow occurring as
a single flow occupying the entire interior of the
cabinet; a supplementary air inlet means, provided in a
face of the cabinet, for allowing additional air to enter
the cabinet and to supplement the convection air flow; >
and inwardly and upwardly inclined deflector means,
integral with the face at the foot of the inlet means and
sloping upwardly in the cabinet into the path of the
convection flow, for diverting the convection air flow
impinging thereon from below and for directing the
additional air entering through the inlet means into the
convection air flow to mix therewith.
A supplementary air inlet may be provided level with
or below the heat exchanger for allowing additional air
to flow into the cabinet and be heated by the heat
exchanger. Additional air from this inlet assists in
maintaining the mean convection air flow temperature at
the top vent, and indeed the top vent itself, at an
acceptably low level.
A supplementary air inlet may be provided above the
heat exchanger for allowing additional air to flow into
the cabinet to cool air therein already heated by the
heat exchanger. Preferably this supplementary air inlet
is provided immediately below the top edge between the
top vent and the said face for allowing additional air to
flow into the cabinet to cool the top edge. Thus the top
edge is kept at an acceptably low temperature.
Z635
In a preferred embodiment, both such supplementary air
inlets are provided.
Preferably each supplementary air inlet extends
horizontal across the face and the upward-direction of each
such inlet is effected by inclining a deflector, integral with
the face at the foot of the inlet, inwardly of the cabinet.
The deflector may be surmounted by a strip angled up to be
parallel with the side having the supplementary air inlet.
In oraer that the invention may be more readily
understood, a specific embodiment thereof will now be
described with reference to the accompanying drawings in
which:-
Figure 1 is a perspective view of a convector heateraccording to the invention,
~ 15 Figure 2 is a cross-section viewed in the direction of
arrow A in Figure 1 and taken half-way along the cabinet, and
Figure 3 is an end view in the direction of the arrow A
in Figure 1.
The illus~rated convector heater has a cabinet 1 with
finned grilles in top and bottom vents 2, 3. A heater
exchanger 4 (see Figure 2) of the kind described in Canadian
patent 1,077,113 is mounted in the cabinet 1 near the bottom
thereof by means o brackets 5. The heat exchanger comprises
an elongate electrically heated element, a spine surrounding
the element and a pair of banks of parallel fins extending
upwardly from the spine in Vee formation, each fin being
planar, disposed perpendicular to the heat source and in
alignment with the convection air flow.
Supplementary air inlets 6, 7 extend horizontally
; 30 in the front face 8 of the cabinet. These air inlets
are given an upwards direction by deflectors 9, 10
which are integral with the face 8, being bent inwardly
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~22635
of the cabinet nt the bottom of each inlet. To steady
the top ed$e of the deflectors integral tabs 11 inter- _
connect with the face immediately above the inlets.
Clearly~ these tabs ~ust not extend more than n short
distance along the inlet in order not to obstruct it;
they Are provided only at the endq thereof.
In operation, the heat exchanser induces a con-
vection air flow within the cabinet. Air passing up the
cabinet close to the inlet 7 which is on a level with
heat exchanger 4, will be at a reduced pressure (on
account of t1le convection flow) in comparison with the
! ambient pres~ure outside the inlet 7. Accordinsly9
there will be an additional flow of air into the cabinet.
This results in the air leaving the heater via the top
grille 2 being at a lower temperature than it would
have been in the absence of inlet 7, since more air is
being heated by an electrically heated element having a
given heating capacity. Similarly~ further additional
air flows throu~h the inlet 6 to cool the top-front
edge 12 of the cabinet. As there i~ less scope for
this additional air to mix with the general flow out of
the top vent 2, its coolin$ effect is restricted to the
vicinity of the edge 12.
The cabinet 1 includes a number of other notewor*hy
featureq. The front face panel 8 has turned back end
portions whereby it i6 fastened by self tapping screws
13 to the ends of the cabinet. To ob~cure the screw
heads and sive the cabinet a neat appearance, cover
plates 14 of pla tics material are clipped to the ends
of the cabinet over the screws and the end portions.
To alleviate the problem of convection-air-borne dust
soiling the wall above the heater, the illustrated heater
being intended for wall mountinS~ the back panel has a
deflectin~ portion 15 for deflecting the convection air
away from the wall. Controls for the heater are
~2263S
accommodated behind the top left hand corner of the
cabinet. As shown the control comprises an on/off switch
16 and a thermostat controlled by thumbwheel 17.
To avoid overheating the controls, the heat
exchanger 4 does not extend below the controls.
The illustrated heater has a length of 700 mm and a
height of 180 mm. When fitted with a 1 kw heater element
the temperature of the cabinet nowhere - including at the
edge 12 - exceeds 90 degrees C under normal operating
conditions except that the temperaure of the air flow at
the top vent 2 - and the top grille - reaches 115 degrees
C. This can be compared with a top vent temperature of
around 240 degrees C without the supplementary air
inlets. A further comparison can be maae with another
similar heater without supplementary air inlets but
having its height increased to 300 mm. In this instance,
the top vent temperature is 115 degrees C. Thus in terms
of temperature of the cabinet, a heater of height 180 mm
including supplementary air inlets is equivalent to a
heater of height 300 mm high without the supplementary
air inlets. The saving of space and material can be
appreciated.
The invention is not intendea to be restricted to
the details of the above described embodiment. The number
ot supplementary air inlets can be varied. For instance
four inlets, two in each face, may be employed in a free
stan~ing as opposed to wall mounted heater. Further,
heat exchangers other than that described in Canadian
patent 1,077,113 may be utilised.
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