IMPROVEMENTS IN VENTILATING PRO
Year: 1881

page_text: LETTERS PATENT to Franz Lönholdt, Architect, of Frankfort a/m, in the
German Empire, at present of the Midland Hotel, St. Pancras, in the
County of Middlesex, for an Invention of “IMPROVEMENTS IN VENTILATING
PROVISIONAL SPECIFICATION left by tho said Franz Lönholdt at the Office
of the Commissioners of Patents on the 25th November 1881.
FRANZ LÖNHOLDT, Architect, of Frankfort a/m, in the German Empire, at
present of the Midland Hotel, St. Pancras, in the County of Middlesex.
"IMPROVEMENTS IN VENTILATING BUILDINGS AND IN APPLIANCE OR APPARATUS
THEREFOR"
This Invention relates to improvements in ventilating buildings and rooms,
and in apparatus therefor, the object being to heat ventilation shafts by a special
construction of heating chambers or wall boxes, to provide cowls on the said shafts
to prevent down draught or the wind from blowing down, and to increase and
regulate up draught; also to provide apparatus by which fresh air can be introduced
without causing a draught.
To secure an equal heat in the ventilation shafts, and to cause the air within the
full cross section of the shaft to rise with equal rapidity, metal heating chambers or
wall-boxes of plan equal to the section of the shaft, and open top and bottom, are
placed at suitable positions in the height of the shaft.
In these heating chambers are fitted a number of gas burners, and these are
surrounded by copper sheet walls or diaphragms arranged at angles to each other,
which catch, and reflect, and radiate the heat communicating the same to the rising
air within the shaft. These vertical copper walls divide the heating chamber, and
consequently the cross section of the shaft into separate portions within which the
air rises, impinging on the hot surfaces and becoming highly heated.
The heating of the exterior wall and the walls of the shaft is provided against
by a space between the lining of the wall boxes, and the whole of the heating
chamber rests on thin deep bars, so that the free area of cross section of the
opening is but immaterially reduced.

page_text: In front of the heating chambers are double doors through which the gas or
petroleum oil burners is or are lighted, or in some cases the gas lighting. can be
effected from the bottom where the heating chamber is over a draught hole.
Upon the outlets of the ventilation shafts cowls are placed for the purpose of
provision against the entry of wind and rain, and to increase the draught, and they
may be equally advantageously employed for ordinary chimneys. These cowls
consist of a socket portion which fits into the shaft or chimney opening, above
which are fixed louvre screens arranged at different angles of obliquity from the
vertical line, and a cover plate is employed above these, and in the socket portion
vertical partition plates dividing up the area are provided so as to break up any
air or wind which inny pass the louvres, and prevent a stream or current passing
down so as to create renction.
For ventilating by existing chimnies, wall boxes are used, which are fitted
interiorily with regulating closing traps or valve doors, and a cast iron grating
forms the front of the wall opening, said grating being fitted with a small
revolving wheel or circular mica plate, which by its action indicates how the
ventilation is going on, which can be regulated as required by operating the valves
or traps by cords the heating chamber ventilating apparatus underneath, but in
cases where fitted to a chimney that is not heated, and a glimmer plate is
introduced to screen the flames from observation.
The regulating closing traps by their own weight in normal condition hang
closed, and are raised as required by their cords.
The heating chambers can be arranged to burn either petroleum oil or
gas. For oil to be burned without chimney glasses the floor of the chamber is
nade nearly the full width of the front of the heating chamber, and the lamp
rests upon transverse bars resting on ledges so that the lamp or lamps stand
free, and accessible all round to air and cannot be heated. The air for com-
bustion is led downwards by means of a tin plate screen fixed on the inside
of the door, which also prevents the light from being seen through the opening
in the door, said opening being regulated by a push slide.
If gas is burned the cross bars are not used, but instead a tin plate bottom
is placed on the supporting ledges, which carries the zig-zag grooved metal walls
for heating purposes. The air is forced to descend by reason of the door plate
screen, and expands under the tin plate all around coming into contact with the
copper heating sheets, and passes under a standing plate in the ventilating box
and into the outlet shaft or chimney, carrying with it the air of the upper box
which is supplied from the room or other apuce, and thus is formed a heating
stove of great power by utilizing a few gas jets in the most effectual way to hoat
large masses of air.
For carrying fresh air into rooms without causing a draught, the wall boxes are
employed, closing peculiarly by means of a hinged pendulum trap, which is to be of
the full width of the box, and hinged at the bottom edge to the front of the inside
of the box.
This box is fitted against the wall opposite to an opening communicating with
the air to be brought in, and the box first becomes full of the entering air which is
deflected by the hinged plate towards the back of the box and to an opening at the
top, whence it is discharged into the room in a film or sheet, which spreads up the
face of the wall and disperses, falling by its gravity, and mixing with the hot air
in the upper part of the room or building.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Franz Lönholdt in the Great Seal Patent Office on the
25th May 1882.
FRANZ LÖNHOLDT, Architect, of Frankfort a/m, in the German Empire, at
present of the Midland Hotel, St. Pancras, in the County of Middlesex.
IMPROVEMENTS IN VENTILATING BUILDINGS AND IN APPLIANCE OR APPARATUS
66
THEREFOR
"
This Invention relates to improvements in ventilating buildings and rooms and
in apparatus therefor, the object being to heat ventilation shafts by a special
construction of heating chambers or wall boxes, to provide cowls in the said shafts
to prevent down draught or the wind from blowing down, and to increase and
regulate up draught; also to provide apparatus by which fresh air can be introduced
without causing a draught.
To secure an equal heat in the ventilation shafts, and to cause the air within
the full cross section of the shafts to rise with equal rapidity, metal heating
chambers or wall boxes of plan equal to the section of the shaft and open top and
botton are placed at suitable positions in the height of the shaft.
In these heating chambers are fitted a number of gas burners, and these are
surrounded by copper sheet walls or diaphragms arranged at angles to each other
which catch, and reflect, and radiate the heat, communicating the same to the rising
air within the shaft. These vertical copper walls divide the heating chamber, and
consequently the cross section of the shaft into separate portions, within which the
air rises, impinging on the hot surfaces and becoming highly heated.
The heating of the exterior wall and the walls of the shaft is provided against
by a space between the lining of the wall boxes, and the whole of the heating
chamber rests on thin deep bars, so that the free area of the cross section of the
opening is but immaterially reduced.
In front of the heating chambers are double doors, through which the gas or
petroleum oil burners is or are lighted; or in some cases the heating can be effected
from the bottom when the heating chamber is over a draught hole.
Upon the outlets of the ventilation shafts cowls are placed for the purpose of
provision against the entry of wind and rain and to increase the draught, and they
may be equally advantageously employed for ordinary chimneys. These cowls
consist of a socket portion which fits into the shaft or chimney opening, above
which are fixed louvre screens arranged at different angles of obliquity from the
vertical line, and a cover plate is employed above these, and in the socket portion
vertical partition plates dividing up the area are provided, so as to break up any
air or wind which may pass the louvres, and prevent a stream or current passing
down so as to create reaction.
For ventilating by existing chimneys or by ventilating shafts wall boxes are
used, which are fitted interiorily with regulating closing traps or valve doors, and
a cast iron grating forms the front of the wall opening, said grating being fitted
with a small revolving wheel or circular mica plate, which by its action indicates
how the ventilation is going on, which can be regulated as required by operating
the valves or traps by cords, and by the heating chamber ventilating apparatus
underneath, but also in cases when fitted to a chinney that is not heated a glimmer
plate is introduced to screen the flame from ohservation.
The regulating closing traps by their own weight in normal condition hang
closed, and are raised as required by their cords.
The heating chambers can be arranged to burn either petroleum oil or gas. The
oil to be burned without chimney glasses, the door of the chamber is made nearly

page_text: the full width of the front of the heating chamber, and the lamp rests upon
transverse bars resting on ledges, so that the lamp or lamps stand free and accessible
all round to air and cannot be heated.
The air for combustion is led downwards by means of a tin plate screen fixed on
the inside of a door, which also prevents the light from being seen through the 5
opening in the door, said openings being regulated by a push slide. If gas is
burned the cross bars are not used, but instead a tin-plate bottom is placed on the
supporting ledges which carries the zig-zag grooved metal walls for heating
purposes. The air is forced to descend by reason of the door plate screen, and
expands under the tin plate all around, coming into contact with the copper heating 1
sheets, and passes under a slanting plate in the ventilating box and into the outlet
shaft or chimney, carrying with it the air of the upper box which is supplied from
the room or other space, and thus is formed a heating stove of great power by
utilizing a few gas jets in the most effectual way to heat large masses of air.
For carrying fresh air into rooms without causing a draught, the wall boxes are 1
employed peculiarly by means of a hinged pendulum trap which is to be of the
full width of the box, and hinged at the bottom edge to the front of the inside of
the box.
This box is fitted against the wall opposite to an opening communicating with
the air to be brought in, and the box first becomes full of the entering air, which
is deflected by the hinged plate towards the back of the box and to an opening at
the top, whence it is discharged into the room in a film or sheet, which spreads up
the face of the wall and disperses, falling by its gravity and mixing with hot air
in the upper part of the room or building.
I will further describe the Invention in reference to the accompanying Drawings.
Fig. 1 represents in sectional view arrangement of ventilation shafts as applied to
the several floors of a building. Doors are provided for access to the burners for
lighting the gas.
Hitherto gas flames were placed in or before the shafts in a sort of funnel to
create draught. These flames acted inefficiently, inasmuch as they did not heat:
the air in all parts of the cross section of the shaft uniformly, but this is effected
according to this Invention by vertical metal walls, which become heated by the
flames, and give their heat again to the rising air.
A heating chamber constructed according to this Invention is shown in Figs. 2,
3, and 4. d are the exterior walls thereof, which are separated from the walls of
the ventilation shaft, and leave a free space all around. In the boxes d are sheets c, c,
arranged in a zig-zag manner, the height of the said walls or sheets being according
to the size of the shaft.
In the inner angles are burners for the gas or oil. The air streams up in the
channels e, e, as well as in those in which the gas burns, and thereby the air is
heated by means of the hot walls and gas flames.
The space e is arranged to prevent the heating of the walls of the shaft in a
dangerous degree, and the adjoining wood-work is kept cool.
The said heating chamber, which does not make the cross section of the shaft
much narrower, rests on iron bars f rivetted into the shaft.
If the door through which the gas is lighted is underneath the heating chamber,
then the walls d can divide the section of the cross shaft in chequer shaped
compartiments, as shown by the dotted lines, Fig. 4.
Figs. 5, 5, and 6, 6, show in vertical and horizontal sections a ventilation shaft
fitted according to this Invention, in which the heating chamber is in that part of
the shalt which draws through the rooms to be ventilated, the heating chamber
being constructed as above described.
In every room that is to be ventilated there are two ventilation openings, one
on the floor, the other at the ceiling, and these ventilators can be opened or closed
by hinged traps. If the room gets too hot the lower one is closed and the upper
opened; if it gets too cold the bottom one is used for letting air out.
Figs. 7, 8, and 8 show a ventilation shaft which begins or opens at the top of or

page_text: above the space to be ventilated and not right through the same, and can in like
manner to that shown in Figs. 5 and 6 ventilato two adjoining rooms at the same
time.
The door h serves for regulating the up draught and at which to light the gas
(with a taper), and here is provided the heating chamber between the beams, but
no danger will arise from heating for reasons before described; this arrangement
is specially applicable for such rooms where excessive heat is to be carried
away.
The construction of the shaft top or cowl is shown in Figs. 9, 9, and 10, 10ª.
Many apparatus have been made which narrow the section of the exit opening of
the shaft, which is most undesirable, and they are so complicated and expensive as
not to be within reach of general adoption.
These improved protection caps or cowls consist of the neck or socket pipe g
which is of equal section of the shaft and fits therein or thereon, and is furnished
with louvres or inclined screens over which the air can enter and leave freely at
all sides, and so that horizontal and upwards directed wind currents rise up in
the screens along the lower edge of the lid and carry the air that rises in the
shaft with it.
Acting against wind blowing downwards in the shaft there are the cross
plates dividing the shaft into a number of equal sized openings. These
divisions g¹ prevent downward blowing winds as indicated by the arrows to such
degree as to prevent down puffs or burst of down draught by dividing them and
breaking their force, so that they will be carried by the existing draught in the
shaft upwards into the open air.
These cowls also serve as exhausters, as constructed according to Figs. 9 and 9,
wherein the bell shaped cover g² allows free current of the wind and offers the
least possible frictional resistance.
To give the greatest possible cross space for the exit of the air over the bell g³,
there is a rim g³ inserted between the bell and the lid, so that for the leaving air
there are three out-flow openings.
The exhaust bell g and rim and the cover are fixed on straps which are
rivetted on vertical bars attached to the socket piece g, and these cowls are
applicable for protecting chimnies from damp and cold as well as for ventilating
chimnies and general ventilation shafts, and for air draughts in railway carriages
and smoke and steam pipes of every kind.
The improved means for the introduction of fresh air is shown in Figs. 11, 12,
13, and 14. To warm the air before it enters the room a similar heating chamber
as above described is placed in the supply pipe and is made in the shape of a flat
pillar or box of metal set into the wall with the grating Fig. 14. The said supply
pipe is a covered horizontal pipe k and is fixed with screws near the top into
position.
In the lower part of the said pillar is the heating chamber similar to that already
described, only that the flames are lighted through the door m, which forms at the
same time the cut off for exterior air and room air circulation is admitted through
perforations nt m².
Above the heating chamber the channel is carried up a short distanco vertically
to effect a better mixture of the air which is discharged into the room, and can be
heated more or less by regulating the flame.
As this apparatus is only used in conjunction with suitable air draught arrange-
ment (for exit of air) the air contamination through the gas is not perceptible but
is neutralized by the favorable counter ventilation.
Cold air can be carried into rooms through vertical pipes without causing direct
draught, but these pipes require space and are unsightly, therefore in Figs. 15
and 16 I have shown an elegant design for such a pipe fitting which will be fitted
to rest a short distance from the floor on a bracket, and is constructed so as to
carry cold air into the room without causing direct draught which is effected by
the peculiar construction for closing the supply pipe.

page_text: The apparatus is fixed on a horizontal channel k in the wall fitted outside with
an ornamental grating, Fig. 14, and is fixed at the top to the wall with screws and
forms a cabinet. Inside the channel is a vertical register plate which may be let
down, as shown in dotted lines in Fig. 15; with this the air draught velocity can
be increased or decreased as the chamber is opened or closed, and the air is thus
forced up and deflected against the wall to mix with the air and then to distribute
in the room.
The regulation of the register is done by cord n.
In cases where existing smoke pipes or chimnies have to be used apparatus is
employed, as shown in Figs. 17, 18, 19, and 20, and consists of an air extracting
flap level with the wall and fitted with a heating chamber as above described.
One or more burners are provided and surrounded with copper sheets, so that the
gas impinges thereon and they are strongly heated.
Through the front door p the flames are lighted. Underneath the door is floor f'
set into the heating chamber, and on this rest the vertical copper heating sheets.
The bottom f¹ is pierced or perforated, through which the combustion air arrives
to the flame and for heating against the copper sheets, and thence passes up at the
inner side of the heating chamber door, and prevents the same getting hot and also
the radiation of heat.
These apparatus are made in different sizes with gas jets, or where there is no
gas with petroleum burners, and are suitable for existing chimnies. The whole
apparatus is made of cast iron, so as to make it durable and cheap.
The exit air opening A is fitted with regulating hinged register plate b, and in
front is a cast iron grating on the wall face, in the centre of which there is a wind
wheel c, which should by its quick or slow turning indicate how the ventilation is
working, and by these means the regulation of ventilation can be effected by
setting the register plate b, or by regulating the heating flames.
The lower heating apparatus need not actually be combined with the upper air
exit apparatus portion, and especially where the air exit register A is placed in
combination with a heated chimney or pipe.
The flap b turns at b, and falls by its weight against the ledge d in the direction
indicated by the dotted line, and will rest against a round edge e when closed.
The front grating is fixed, but to obtain access to the flap the wind wheel is
removable.
The wind wheel has round the edge a brass spring frame with four indents or
recesses corresponding to the size of four balls cast on the grating, so that it is 3
held by the spring, as will be readily understood.
The incline of ledgo d will prevent soot collecting behind the round bar e, which
otherwise would get into the room when the flap bopens from the slanting surface f,
which also acts to screen the lights from observation.
4
When a lamp is used it rests on two or more narrow cross bars on the floor f', {
thus the lamp rests free surrounded by air and cannot get hot.
The air on entering is conducted downwards by the fixed sheet g, and this sheet
also prevents the flame being seen.
The door has several openings p which can be regulated by a sliding plate, and
hangs hinged so as to be opened by inward pressure.
If gas is used for heating the cross bars are left out, and instead a sheet bottom
plate may be substituted and be laid on projections at the sides, and the zig-zag
copper heating sheets will be carried thereon. Batswing burners are preferable.
The air which is conducted downwards by sheet g disperses under the bottom
on all sides, and coming thus in close contact with the heating sheets is heated
thereby and passed under the slanting wall through the slots o in the chimney
and inducing the air current. As the copper sheets, as well as the slanting wall f
were heated by the flame, the heat will be radiated from a large surface and the
heat of the fame fully utilized.
The purposes of the constructions of these devices are:-
(1) To simplify the cost of manufacture; (2) provision of air exits of large cross
section for the nubaustel
105

page_text: minimise the exhaust effect of the wind draughts; (4) positive protection against
the wind entering into the ascending pipes from whichever direction it might
impinge or be driven.
Having now described the nature and particulars of the said Invention, I
claim,―
Firstly. The herein described construction of heating chambers which divide the
cross section of the shaft by vertical copper sheet walls, between which open
flames burn which heat the sheets on which the air impinges in its passage, as
herein set forth and shown by the respective Figures of the Drawings.
Secondly. In the shaft covers or cowls as described, the combination of the free
overlying screens or louvres, and open lid or cover with the dividing walls g¹, by
which the mouth of the shaft is divided in several parts, as set forth and shown by
the respective Figures of the Drawings..
Thirdly. The apparatus for introducing fresh air, as described in reference to and
shown by Figs. 11, 12, and 13 of Drawings.
Fourthly. The air supply apparatus with the pendulum trap k across the cross
section for narrowing the space and deflecting the air stream towards the wall, as
herein set forth and shown by Figs. 15.and 16.
Fifthly. The air-exhausting apparatus shown in Figs. 17, 18, 19, and 20 with
the exhaust trap, which can be regulated, and the same also in combination with a
heating chamber placed under it with its zig-zag shaped copper sheets and the
pierced or open bottom plate, as set forth.
Sixthly. The construction of an air supply apparatus, as shown in Figs. 17
and 18, with the indicating wind-wheel attachment c with the balls and sockets to
fix it, as set forth.
Seventhly. The construction of the exhaust covers or cowls as specified, the bell
shaped sucking-hood and open louvres or screens, with the open case or lid fixed or
rivetted on the vertical supports or bands, with or without dividing plates gl, as
and for the purposes set forth.
In witness whereof, I, the said Franz Lönholdt, have hereunto set my hand
and seal, this Eighteenth day of May, in the year of our Lord One thousand
eight hundred and eighty-two.
FRANZ LÖNHOLDT. (L.S.)