Abstract: A heat exchanger is constructed from a heat-conductive metal foil wound backwards and forwards in sinuous fashion to provide a stack of parallel pockets (1) between neighboring sections (8) of the foil. The pockets (1) contain baffles (5,6) which guide fluid flowing through the pockets to follow a serpentine path of U, S or M shape. The serpentine path in all the pockets is substantially the same shape but the direction of fluid flow (13) in alternate pockets is opposite to the flow direction (14) in the remaining pockets. Two corner regions of the pocket stack are each provided with two manifolds (15,16) one of which communicates with the alternate pockets (1) and the other manifold communicates with the remaining pockets (16). The pockets may be formed from a signal foil or from two or more foils. The manifolds may be arranged on diagonally opposite, or on adjacent corner regions of the stack.

Abstract: Ventilation device for the simultaneous ventilating and exhausting an enclosed room having the capacity for the recovery of heat from the exhaust media current. The exhaust media current is given a longer flow path than the ventilation media current; particularly the flow path of the exhaust media current at the exit side of the heat exchanger has a flow deflection which includes an arc measure of more than 90.degree. degrees and preferably of about 150.degree.. Further, the flow paths of both the exhaust and the ventilation media current extend from their inlets to at least the heat exchanger in an ascending direction.

Abstract: A heat recouperator having a single rotary heat and moisture wheel exchanger uses a random matrix media comprising a plurality of small diameter heat-retentive fibrous material, which provides high thermal efficiency in exchanging heat and moisture between inlet and exhaust air streams.

Abstract: An apparatus is provided which combines in a single, relatively compact housing the necessary components to efficiently exchange stale room air with fresh outside air. The apparatus includes a single, continuous duct having openings at each end. A heat storing matrix is disposed within the duct. A fan is also placed within the duct. The fan is capable of producing a substantially axial air flow through the duct. The fan is moveable between two positions: a first position wherein air flow is in a direction from the first end to the second end of the duct and a second position wherein air flow is reversed. The apparatus includes means for moving the fan from the first position to the second position such as a solenoid.

Abstract: The independent unit for heat exchange particularly for the ventilation of a room or premises is configured like a box (12) wherein are formed two passages (40 and 42) having an undulated shape and wherein circulate in counter-current air drawn in the room and rejected to the outside and outer air introduced into the room. The invention applies particularly to the ventilation and air conditioning of the premises or rooms of a building.

Abstract: In flat heat exchangers for ventilating dwellings, swimming pools, public premises, etc., which are used for air entering and leaving, problems arise when the air entering has low temperature. This results in a cold corner (A) appearing in the heat exchanger and its efficiency thus being reduced. The object of the present invention is to reduce the effect of the cold corner by introducing throttling means (9) along a number of the channels (3) for air leaving. The throttling means (9) are of equal size along one and the same channel, but different in the different channels (3), the channel (3) with the smallest throttling means (9) being located closest to the inlet for the air.

Abstract: There is disclosed an air conditioning unit for location in the wall of a room and which comprises a heat exchanger, an external supply fan operable to blow air into the room through the heat exchanger and an extract fan operable to draw air out of the room through the heat exchanger, in which the heat exchanger comprises a stack of thin flexible plates which are spaced apart from each other so as to define between opposed faces of adjacent plates extract air flow paths and supply air flow paths through the heat exchanger, with the spacing apart of the faces defining the extract air flow paths being greater than the spacing apart of the faces defining the supply air flow paths whereby the depth of the extract air flow paths initially is greater than the depth of the supply air flow paths, but during operation any tendency for the flexible plates to deform under differential pressure action results in the depths of the extract air flow paths and supply air flow paths being substantially equalized, which provid

Abstract: The invention relates to a method and apparatus for controlling the fresh-air, input-air, exhaust-air, waste-air and return-air flows, as well as the air pressure in the input-air duct and the air pressure in the exhaust-air duct, in an air-conditioning system which comprises at least input-air and waste-air flow meters (6, 20), input-air and exhaust-air pressure meters (12, 19), an input-air fan (5) with its air-flow control (13), a waste-air or exhaust-air fan (18) with its air-flow control (14), a fresh-air flow meter (15), a heat recovery exchanger (4), closing and control mechanisms for exhaust air and return air, coupled together as an outlet-air mechanism (10), and closing and control mechanisms for fresh air and fresh-air bypass, coupled together as an intake-air mechanism (3).

Abstract: A vertically situated head exchanger is mounted externally of a building and insulated relative to the ambient air. Fan units are situated within the building preferably between adjacent joists and in the basement and in alignment with the connections to the heat exchanger. One fan unit draws fresh air from outside the building, through the heat exchanger and into the building. Another fan unit draws exhaust air from the building and passes this through the heat exchanger thus giving up heat to the cool incoming air and is then exhausted externally of the building. A controlled duct may draw warm air from the building and pass it through the heat exchanger to defrost same when necessary.

Abstract: A rotary heat regenerator comprises a regenerator matrix mounted for rotation in a central aperture of a housing wall, and an improved seal disposed in the annular gap between the matrix and the housing wall. The seal includes (a) a first portion of pile-like material which is secured to the peripheral surface of the matrix, and (b) a second portion of pile-like material which is secured to the housing wall such that the two interact to provide a seal while allowing the matrix to rotate in the aperture.

Abstract: An apparatus including a ventilation conduit mounted within a ceiling structure of a dwelling, with an exhaust fan and intake fan arranged at ninety degrees relative to one another, with an intake pipe and exhaust pipe arranged contiguously about their major extent relative to one another to effect heat exchange minimizing cold air entering the dwelling.

Abstract: A ventilating heat recovery system is used for exchanging heat between fresh air introduced to a building and stale air exhausted from the building. The system is designed to provide a long, counterflow heat exchange path. The system includes a stack of rectangular plates coupled to arcuate duct sections to provide to interleaved sinuous air paths in heat exchange relation with one another.

Abstract: An air to air heat exchange system for removing undesirable air from an enclosed structure. The heat exchanger provides for the removable of air containing pollutants, toxics gases and odors while providing for the recovery of heat from the exhaust air. The system utilizes a plurality of tubes within a larger tube so that air can flow freely over and around the smaller tubes thus providing for maximum heat transfer between the incoming air in the smaller tubes and the exhaust air in the larger tube. The smaller tubes, if used for the incoming air, permit the air to be distributed to various selected locations throughout the structure.

Abstract: A heat exchanger according to the present invention comprises a housing for containing an upper and a lower layer of fluid, means for preventing intermixing of the two fluid, and heat transfer means for enhancing the transfer of heat between the layers. Specifically, the heat exchanger means is in form of a plurality of elongated cylinders extending into both layers, each of said cylinders containing a convective fluid. Preferably, the convective fluid is a liquid; and the preferred liquid includes water. Where the fluid in each of said upper and lower layers is a gas, the preferred orientation of the cylinders is vertical. The hotter fluid should be beneath the cooler fluid so that heat from the hotter fluid is first transferred to the liquid in the lower ends of each cylinder. The buoyancy of the heated liquid sets up convection currents which carry the heated liquid upwardly in the vertical cylinders where the heat is given up to the cooler fluid.

Abstract: The main air stream (1) in a room is cooled by passing it along the dry duct (3) and simultaneously passing the auxiliary air stream (7) that has been taken from the atmosphere in a countercurrent flow along the moist duct (9), which is in heat-exchange interaction with the dry duct (3). To provide more intensified cooling the auxiliary stream (7) is precooled in another dry duct (8), which is in heat-exchange interaction with another moist duct (6), by passing a part (5) of the precooled air taken up from the main stream (1), while a part (4) of air is returned to the room. The auxiliary stream (7) is flowing with the aid of an air exhauster (10).

Abstract: The textile machine has a cooling fluid circuit for dissipating heat from the heat-emitting parts of the textile machine. The cooling circuit has a coil disposed within an air duct of the textile machine from which the air can be blown to the outside. A longitudinally extending fly suction duct may also be used for cooling the cooling fluid of a cooling circuit used to cool the motor and convertor of the textile machine. The fly duct thus serves to remove heat as well as fly from the machine.

Abstract: A plate-type air-to-air heat exchanger is provided with a control device disposed directly adjacent the corner of the heat exchanger located between the cold air inlet and the warm air outlet. The control device includes a swingable baffle plate positioned adjacent the corner for partially closing off the cold air inlet directly adjacent the corner to deflect the inflowing cold air away from the corner to prevent build up of frost or ice. The baffle is controlled by a motor which in turn is preferably controlled in response to the outside air temperature.

Abstract: For lowering the energy requirement for a room (2) ventilated by a ventilating system (11 to 17) of a building (1), windows (4) and opaque wall parts of the outside wall (3) are designed so that the heat transfer numbers (kF and kW, respectively) are smaller than 1 W/m.sup.2.K. In addition, the supply air flows into the room (2) near the floor (9) at the comfort temperature of at most 20.degree. to 22.degree. C. and an input velocity which does not exceed a maximum air velocity which is permissible for comfort conditions in an occupied zone.

Abstract: An apparatus for ventilation, recovery of heat, dehumidification and cooling of air or industrial gases for use in industrial processes and in air conditioning of residential, commercial and industrial building comprises a highly effective valveless periodic flow type dehumidifier-heat exchanger in which a countercurrent flow of two gaseous streams through a stationary matrix of a desiccant and a solid heat exchanging material is achieved by an air fan controlled by a variable timer controller. The stationary matrix may include a single bed or two beds of solid materials with distinguished mositure and heat sorption properties, a heater and a wet filter to provide simultaneously an effective transfer of heat and moisture, removal of particulates and adiabatic cooling of the two gaseous streams.The released sorption heat is temporarily stored within the matrix material and then used in reactivation of the desiccant.

Abstract: An air circulating apparatus includes a housing which is separated into a front room and a rear room. A heat exchanging wheel is rotatably disposed in one side of the housing between the front room and the rear room. An induced draft fan and an exhaust fan are disposed in another side of the housing and respectively located within the front room and the rear room. Indoor air is drawn through a lower portion of the heat exchanging wheel by the exhaust fan, and flows out of a building. Outdoor air is drawn through an upper portion of the heat exchanging wheel by the induced draft fan and flows into the building.

Abstract: A rotary regenerative heat exchange assembly comprises (1) heat exchange wheel means including a heat exchange wheel having a rotation axis and rotably mounted for rotation about said axis and means for rotating said wheel about said axis; and (2) cabinet means comprising openings for securing said assembly to a source of relatively cool air and to a source of relatively warm air so that when said assembly is properly located in an operative position in said cabinet means a portion of said wheel intercepts the flow of said relatively cool air and another portion of said wheel intercepts the flow of said relatively warm air, said cabinet means including means for slidably supporting said heat exchange wheel means and an opening so that said heat exchange wheel means can be slid into said cabinet means to said operative position, and at least partially moved out of said cabinet means so that said wheel can be maintained and/or replaced.

Abstract: Disclosed are a heat exchange element obtained by forming a sheet material or honeycomb structure having a shape required for a heat exchange element from an organic filler-filled sheet made from an acid-resistant glass fiber, dipping the formed sheet material or honeycomb structure in a suspension of an inorganic filler, at least a part of which is composed of scaly particles, and fixing the inorganic filler applied by the dipping treatment to the sheet material or honeycomb structure by a binder, and a process for the preparation of this heat exchange element and a heat exchange apparatus comprising this heat exchange element. A high acid resistance and a high gas-intercepting property can be maintained even by using a thin and light sheet material.

Abstract: An apparatus and method for exchanging air within building in order to exhaust air contaminated with radon gas or other pollutants. The apparatus includes a heat reclaim exchanger to recapture building heat which is dimensioned to be mountable between standard spaced and sized floor joists of a dwelling basement ceiling. A solar panel is used to produce electric power for system operation and cooperates with a trickle charge unit including a storage battery to provide power when there is insufficient light energy available to operate the device. A control unit operates one or more fans or blowers to provide a positive differential pressure within a basement area with respect to outside air pressure so as to inhibit and arrest the influx of radon or other gaseous pollutant into the basement or other confined space of device use.

Abstract: A heat pipe type heat-exchanger for ventilation is disclosed, having a plurality of heat pipes affixed with widely spaced fins provided internally in a box like case and arranged horizontally relative to the case, a partition plate dividing the inside of the case into two chambers on the right and left is provided crossing the heat pipes, an inlet and an outlet are formed for the respective chambers of the case, and fans for circulating the air to the respective chambers in opposite directions through the inlets and outlets are provided to make one chamber always an air-supplying chamber and other chamber always an air-discharging chamber. The connection point of power source wires of the fan motors is placed in the air-supplying chamber.

Abstract: A heat exchange device including a number of panels formed from a flexible frame forming a window and having parallel air paths through the frame, a thin flexible plastic film secured to one side of each frame to form a heat transfer surface across the window, the panels being stacked with each alternate panel turned 90.degree. to form first and second air flow paths through the spaces between the plastic films, the frame being made of corrugated cardboard or fluted plastic.

Abstract: The specification discloses an air-to-air, polymeric heat exchanger having a housing and a core removably mounted within the housing. The housing includes four generally indentical duct units, which are secured to one another, and a top and a bottom, which are secured to the duct units. The core includes a pair of end walls and a plurality of tubes extending between, and opening through, the end walls. Each end wall includes a plurality of tubular projections or pockets extending from the end wall in a common direction. Opposite ends of the tubes are secured within the tubular pockets in the opposite end walls. A method of constructing the core includes the step of severing the tubular projections after the tubes are positioned therein to expose the tube interiors through the end walls. Preferably, the tubular projections are severed using a hot wire to also fuse the tubes within the end walls.

Abstract: A tube-within-a-tube, counter flow, air-to-air heat exchanger utilizing a rigid outer tube and a continuous, flexible inner tube. The corrugated, flexible inner tube is spiralled longitudinally around a center core and creates turbulence in the air which permits a rapid exchange of heat between the exhaust and fresh air streams.

Abstract: Air to air heat exchanger structure and method including a helical heat exchange coil having a lower portion and an upper portion, refrigerant in the lower portion of the heat exchange coil, a first chamber surrounding the upper portion of the heat exchange coil, a second chamber surrounding the lower portion of the heat exchange coil, structure connecting the bottoms of the coil portions and the tops of the coil portions to each other, and motor and blower structure for passing warm air over the lower portion of the heat exchange coil to boil the refrigerant therein and for drawing cool air over the upper portion of the heat exchange coil to heat the cool air whereby the boiled refrigerant in the upper portion of the heat exchange coil is condensed and flows by gravity back to the lower portion of the heat exchange coil. The air to air heat exchange structure is adapted for utilization in a window opening to ventilate a dwelling space.

Abstract: A plate fin heat exchanger is provided having: a core having a plurality of warm layers for conducting a warm fluid and a plurality of cold layers for conducting a cold fluid, the warm layers making a first pass parallel to at a front face of the exchanger, the front face being first exposed to the cold fluid, and then passing in an essentially counterflow pattern to the flow of the cold fluid through the exchanger from a back of the exchanger to near the front face thereof; and a baffle disposed at the back face of the heat exchanger, the baffle being adapted to create a high pressure profile at the front face such that the cold fluid is distributed upon the front face in such a manner that snow and ice build-up upon the front face is minimized.

Abstract: An air-conditioning system including an air conditioner incorporating a heat exchanger and a fan therein, and duct assembly connecting to the air conditioner for supplying conditioned air to a specific room equipped with the air conditioner and to another room, the duct assembly comprising an auxiliary duct removably attached to a front cover of the air conditioner and a main duct separably connected to the auxiliary duct to extend from the specific room to said another room and having air outlet portions for supplying air to the respective rooms, the auxiliary duct having an air channel for guiding the air discharged from the air outlet of the front cover into the main duct.

Abstract: The present invention relates to a heat exchange machine for removing the excess of the heat during the summer period and the excess of humidity during the cold period. The machine comprises two tubes, one inside the other, an intermediate frame with two sets of blades attached to the frame from inside and outside thereof and driven by a common reversible motor in the same direction. One of these sets is the set of blades rigidly fixed to and the other one is swingingly mounted in the frame, so that the change of the direction of the fixed set of blades induces the change of the direction of the air flow in one of the tubes, meanwhile the direction of the air flow along the other tube induced by the other set of swingable blades remains the same regardless of the direction of rotation of this set.

Abstract: An air conditioning system includes a first indoor unit having a heat exchanger separating the inside space of a case in which air drawn from an air inlet is passed through the heat exchanger and then discharged from a plurality of air outlets, and a second indoor unit having no heat exchanger and connected with one of the air outlets via an intake duct. With this construction, the air to be distributed to a plurality of rooms is cooled or heated by a common heat exchanger. The air conditioning system thus constructed can be installed easily and has a relatively small number of structural components.

Abstract: A ventilator has a body in which an air-intake passage for introducing outdoor-air indoors and an air-discharge passage for introducing indoor-air outdoors are defined. An air-intake fan and an air-discharge fan are arranged in the passages, respectively. A filter is provided in the air-intake passage to filtrate air flowing through the air-intake passage. The flow resistance in the air-discharge passage is set higher than that in the air-intake passage.

Abstract: A room ventilator for insertion within a wall of window of the room comprises two fans mounted side by side, and a heat exchanger located inwardly of the fans. The construction of the heat exchanger is such that counter flow heat exchange occurs between the incoming and outgoing air streams.

Abstract: The present invention comprises an air to air heat exchanger having a circular outer housing and a circular exhaust duct lying there within a long the longitudinal central access thereof. A plurality of cone shaped turbulators are secured to a rod supported within and extending along the longitudinal central axis of the exhaust. The outer housing is made of a heat insulating plastic, and the exhaust duct, turbulators and central rod are made of corrosion resistant metals such as aluminum or stainless steel.

Abstract: An air to air heat exchanger for ventilating buildings has the air streams maintained in direct contact with little mixing by tangentially introducing the air streams along cylindrical surfaces in opposite directions to form spiral, counterflows. Valves are provided to switch the flows for winter and summer operation.

Abstract: A heat exchanger for reclaiming energy from an exhaust airstream. The exchanger includes a porous metal element suitable for absorbing heat from the exhaust airstream, means for reciprocally moving the porous element back and forth transversely to the exhaust airstream, an inlet duct for receiving the exhaust airstream and directing it through the porous element to an outlet duct, and reclaiming air blower means for delivering two heat-reclaiming airstreams through the porous metal element, one on either side of the exhaust airstream, and an air exhaust fan in the path of said exhaust airstream for drawing said airstream through said porous element.

Abstract: A valve assembly for use with air treatment apparatus is disclosed. The assembly includes shutter valves disposed in the air flow channels and actuatable by the flow of air therethrough.

Abstract: There is provided a method and apparatus which produces a particularly high-quality fresh air atmosphere in large industrial plant buildings, the high-quality atmosphere being provided to the lower two meters of height with simultaneous heat recovery from the exhaust air and exhaust air purification. The apparatus includes a feed air tower which, as a component built in series, eliminates many of the costly ventilation ducts, reduces fuel costs to a low level, and prevents remixing with poor air from the upper layers of the air in the plant.

Abstract: The specification discloses an air-to-air, polymeric heat exchanger having a housing and a core removably mounted within the housing. The housing includes four generally identical duct units, which are secured to one another, and a top and a bottom, which are secured to the duct units. The core includes a pair of end walls and a plurality of tubes extending between, and opening through, the end walls. Each end wall includes a plurality of tubular projections or pockets extending from the end wall in a common direction. Opposite ends of the tubes are secured within the tubular pockets in the opposite end walls. A method of constructing the core includes the step of severing the tubular projections after the tubes are positioned therein to expose the tube interiors through the end walls. Preferably, the tubular projections are severed using a hot wire to also fuse the tubes within the end walls.

Abstract: A refrigeration apparatus includes a cooling chamber having a given useful space therein, and a cold generator having a cold air loop connected to the cooling chamber for cooling the given useful space, the cold air loop including a compressing device, a heat exchanger disposed downstream of the compressing device and exposed to the ambient air for cooling air drawn from the useful space with a relatively high temperature level almost to the temperature of the ambient air after compression, cooling device downstream of the heat exchanger, an expansion device downstream of the cooling device, the air being returned to the useful space after subsequent expansion and corresponding cooling below the lowest temperature level, and an additional heat exchanger for dehumidifying the circulated air current in the loop, the additional heat exchanger including heat exchanger surfaces, air drawn from the cooling chamber being dried from the upper temperature level with the aid of expanded cold air by the of condensation

Abstract: An interdome enclosure system takes advantage of the latent heat of condensation for energy efficiency. The system includes, in combination with a humid environment, such as a heated pool and an outer enclosure housing the pool, an inner enclosure disposed within the outer enclosure and over the pool and a differntial fan operated heat exchanger for creating an atmospheric pressure within the space between the inner and outer enclosures which is positive relative to the atmospheric pressure within the inner enclosure. The heat exchanger includes a pair of conduits disposed in heat exchange relationship to one another. Assisted by an inlet fan, one conduit communicates dry, fresh cool air from the exterior of the outer enclosure into the space between the enclosures, while the other conduit, assisted by an exhaust fan, communicates moisture-laden, warm air from the inner enclosure directly to the exterior of the outer enclosure.

Abstract: A ventilator of the heat exchange type includes an air passageway communicating between an interior of a room to be ventilated and the outdoors, a first centrifugal fan for introducing outdoor air to the interior of the room, a second centrifugal fan for discharging indoor air outdoors, both centrifugal fans being disposed within the air passageway so that outlet areas communicates to each other, and two electric motors for alternately driving the centrifugal fans respectively. At least any one of the centrifugal fans is formed of a heat-accumulative material so that heat contained in the indoor air is accumulated in the centrifugal fan formed of the heat-accumulative material and that the heat accumulated in the centrifugal fan is dissipated to the suction air. Heat exchange is thus performed by accumulating the heat in one of the centrifugal fans during indoor air discharge operation and by dissipating the heat to the outdoor air during outdoor air suction operation.

Abstract: An air to air heat exchanger particularly for contaminated air from an animal barn or the like includes a core formed by a plurality of thin-walled flexible plastics tubes supported at respective ends in tube sheets. The tubes are held under tension and arranged vertically in parallel rows and columns so that cold fresh air enters parallel to the rows horizontally beneath the upper tube sheet and then moved downwardly along the outside of the tubes to escape horizontally parallel to the rows above the lower tube sheet. The contaminated warm air passes from a plenum beneath the lower tube sheet upwardly along the inside of the tubes to an outlet at the top of the tubes. This direction of movement of the air causes a self-cleaning effect by condensate at the top of the tubes running down and cleaning the interior of the tubes of any collected contaminants. The design also enables the use of convenient inexpensive flexible tubes without allowing air movement to cause unacceptable flexing.

Abstract: Disclosed is a ventilator including a heat exchanger having a fresh air channel and a stale air channel. The respective channels are pneumatically isolated, but, are arranged in contiguous and interwoven fashion such that incoming fresh air may pass in countercurrent heat exchange relation to the outgoing stale air twice. The fresh air channel has an inlet in communication with air external to the ventilated space and an outlet in communication with the ventilated space. The stale air channel has an inlet in communication with the ventilated space and an outlet in communication with the external space. The heat exchanger features heat transfer means in communication with the fresh and stale air channels which is formed by a septum having a first surface in heat exchange relation with the fresh air channel and a second surface in heat exchange relation with the stale air channel. The septum is wrapped in successive spaced turns to form alternating sections of the fresh air and stale air channels.

Abstract: A ventilator unit (1) intended for installation in the outside wall of a room such that used air (A) from the room is vented to the outside atmosphere through the outside wall while fresh air (B) is introduced from the outside and supplied to the unit (1) where it is suitably air conditioned, before being blown into the room, the unit comprising an exhaust fan (12) and an inlet fan (13), and also including for purposes of heat recovery a heat exchanger (15', 15") for transferring heat from the outflowing air (A) to the inflowing fresh air (B), wherein the two streams of air (A, B), as known per se, alternate periodically through two equal regenerator masses.

Abstract: Ventilation and heat exchanging system for premises housing animals, especially poultry, the system having one or more fans, one or more ducts for outgoing air which extends through an inner ceiling to a general collecting air flue, on the sides of which connect two vertically spaced sheets the space between which are connected to the collecting air flue, and behind the outer sheet which functions as a heat exchange sheet there opens one or more ducts for air intake (7) through an inner ceiling. Of the mentioned sheets the lower surface of the inner sheet is equipped by a heat insulating layer (4), the heat insulating ability of which at least in the vicinity of the ducts for incoming and outgoing air (1 and 7) in essence corresponds with the heat insulating ability normally required by an inner ceiling.

Abstract: Apparatus for recovering heat or cooling from a room space and ventilating it, consisting of heat accumulators in which the outgoing air releases its heat and from which the incoming air picks up heat or vice versa and which are alternatively connected by one end with the exhaust duct and intake duct of the room space, the direction of flow in these ducts being the same all the time under control by two flaps, and the opposite ends of the heat accumulators being connected to the fresh air intake duct and the outgoing exhaust duct, the direction of flow being the same in these latter ducts all the time under control by the two flaps. The heat accumulators consist of elements which may be added or taken off two and two, in accordance with the required capacity of the apparatus, and that the intake and exhaust ducts carried to the room spaces can correspondingly in a manner known in itself be lengthened or shortened by means of branch pieces.

Abstract: A heat exchanger for ventilating insulated dwellings with minimum internal heat loss, is disclosed. The heat exchanger is characterized by its very low manufacturing cost, its excellent efficiency and its minimum and easy maintenance. The heat exchanger consists of an elongated box-like casing forming two opposite end chambers interconnected by a plurality of longitudinally-extending, thin walled glass tubes. Warm stale and humid air is expelled through the glass tubes from one to the other chamber, while cool outdoor drier air is circulated within the casing along a generally sinusoidal path about the glass tubes, so that a heat transfer occurs through the walls of the glass tubes. The casing is made of molded foam plastic for good heat insulation and in two half-parts having inner edges releasably and sealingly joined by a tongue-and-groove arrangement. Each half-part has a tongue and a groove, each extending along half the periphery of its inner edge, so that the half-parts can be made in the same mold.

Abstract: A heat exchanger (10) for transferring heat between intake air and exhaust air is disclosed. The heat exchanger (10) includes a plurality of ducts (11) having open first and second ends (11c and 11d). The ducts (11) are connected in a vertical space relationship to one another defining therewith two sets of channels. A first set of channels (11a) being inside the ducts (11) and a second set of channels (11b) being between the ducts (11). Intake air passes through the first set of channels (11a) and exhaust air passes through the second set of channels (11b). The air flow in the second set of channels (11b) is confined. The heat exchanger has a releasably attached bottom (24), whereby when the bottom (24) is released, there is ready access to clean said second set of channels (11b) between the ducts (11). Also, the intake air and exhaust air enter and an exit through their respective sets of channels without mixing.