Patent Application
20120018123
Heat exchangers per se are not new to the art. The function of the fresh air heat exchanger of the instant invention is to provide ventilation, heating and treatment or purification of the air from a building. This is accomplished through several sequential phases within one complete unit. The uniqueness of the fresh air heat exchanger is that it automatically switches operating modes while the building is occupied or unoccupied. The fresh air heat exchanger of this invention is controlled by the existing temperature control system in the building. It can be self controlled or a combination of both. Standard fresh air heat exchangers will only cycle when the building is unoccupied. This unit removes stale air, uses the heat from the stale air to warm incoming cool fresh air, then the stale air is exhausted while the preheated fresh air is heated by a hot water coil and optionally purified by a UV cell then released into the room. U.S. Pat. No. 5,632,334 issued to Grinbergs on May 27, 1997 is incorporated herein by reference for what it teaches concerning heat recovery ventilators or heat exchangers.
The instant invention is a mode switching fresh air heat exchanger that has simultaneous movement of the hot air and cold air within the system. The device consists of a housing having a front, a back, a top, a bottom, a near end, and a distal end.
There is an opening located in the interior back of the housing that is a fresh air exterior opening louver panel. There is also a first duct to carry the fresh air from the louver panel to a first heat recovery ventilator.
The device contains an open grill located in the interior front, near the bottom that is a stale air open grill and located interiorly to the housing and adjacent to and aligned with the grill is a filter for the stale air. There is a second duct to carry the filtered air to a second heat recovery ventilator connected in air carrying tandem to the first heat recovery ventilator and a third duct to carry the heat recovered air to the outside through the louver panel. There is a fourth duct to carry the fresh air to a heating zone and through an air vent into a room. This air vent is located in the top of the housing. The air is conveyed through the heating zone by a variable speed electrical fan.
The fresh air and stale air are simultaneously moved by electrical blowers and electrical components for electrifying the blowers and fans.
The advantages of the devices of the instant invention include, but are not limited to, exhausting at the ground floor level, intake above the ground, eliminating the pick up of debris and the like by the device, eliminates ductwork in the ceiling of the buildings in which they are used, eliminates a majority of dampers and damper controls, use of an air cleaner system in the flowing air to clean up bacteria and the like.
When the air is drawn in from the bottom 10, it flows into room air duct 24 into the heat exchangers 72 in the housing 18 where it is passed by the incoming fresh air to preheat the fresh air, then the room air is exhausted through exhaust port 78. The room air duct 24 is connected to the housing 18 via a collar 28 and a draw band 26. The circulation of the air into and throughout the fresh air heat exchanger 2 is provided by the blower 30. The blower 30 pulls air from the base front 14, through the filter 50, through the room air duct 24 into the heat exchangers 72 in the housing 18 and then exhausted.
The fresh air is drawn in and passes by the room air preheating the fresh air. From that point the air is forced through the coil supply duct 22, through the hot water coil 34, through the UV cell 62 and then the air that is now heated and cleansed arrives at the room. The room air is passed by a heat exchanger 72 which captures heat and then transfers that heat to the fresh incoming outside air.
The solid line with dashes indicates the circulation cycle where room air is filtered at filter 50, then on to the blower 30 where it is moved to the coil supply duct 22. The air is then heated in the hot water coil 34, passed through the UV cell 62 and returned to the room heated and purified. This is the unoccupied cycle.
The other cycle that is indicated by the solid line with asterisk is the exhaust. This cycle is simultaneous to the first cycle in that the room air, before it is exhausted, is passed by the heat exchangers 72 to warm the fresh incoming outside air. Then the room air is exhausted.
In the building occupied mode there are three phases of operation and one phase for the unoccupied building mode. In the first phase the outside air passes through the exterior louver panel 54 and enters the fresh air heat exchanger 2 through an elbow 44. The fresh air is then drawn into a heat recovery ventilator. Simultaneously, stale warm air from inside the building is pulled into the bottom front 14 of the fresh air heat exchanger 2 through a grill 82 where it is first filtered for particles. The filtered air enters the room's air duct 24 within the fresh air heat exchanger 2 and then passes through the heat recovery ventilator 4 where it is discharged outside through the exterior louver panel 54. Stale warm air is constantly being replaced by an equal quantity of outside fresh air. The heat recovery ventilator 4 can meet fresh air requirements of the building and is capable of at least 250 cubic feet per minute.
As the two air streams pass through the heat recovery ventilator 4, they do not mix. They pass through air filters 50 on either side of an aluminum heat exchange core in housing 18 which transfers heat from the outgoing air to the incoming air. This allows the heat from the building to be saved and from being lost to the outside.
Condensate drains are located at the bottom of the heat recovery ventilator 4 below the aluminum heat exchange core. The drains then pass through the fresh air heat exchanger 2 where a sump pump is located. The pump then discharges to the buildings existing drain system.
The second phase begins once the air has been warmed during phase one by the heat recovery ventilator 4 and a supplemental heating of the air is accomplished by a hot water coil 34 located within the fresh air heat exchanger 2 above the heat recovery ventilator 4. The hot water coil 32 is connected to the building's hot water system and can meet up to 20,000 BTU off heat loss from the room. A variable speed controlled fan or blower 30 continuously pulls the conditioned heat recovery ventilator 4 air across the hot water coil 34 and into the room.
The third phase begins prior to the heated air entering the room from the heat recovery ventilator 4 after phase two, it passes across a cell 62 located downstream of the hot water coil 34. The cell 62 utilizes oxidation technology that consists of a high intensity broad spectrum UV tube (100-300 nm) in a hydrated catalytic matrix cell. Low level ozone is produced in the cell, the majority of which is converted into airborne hydro peroxides, super oxide ions, ozonide ions and hydroxides. The UV bulb is encased in a poly tube to prevent any glass or mercury leakage. Also, the entire assembly is encased in a protective metal cell. This cell eliminates sick building syndrome risks by reducing odors, air pollutants, chemical odors, smoke, mold bacteria, and viruses.
The fresh air heat exchanger 2 also has an unoccupied building phase where the heat recovery ventilator is bypassed. The room air enters the fresh air heat exchanger 2 through the bottom passing through a grill 82 where it is filtered, heated by the hot water coil and recirculated back into the room by the variable speed fan. Another unique feature of the device 2 is the intake and exhaust is well above ground level. Prior art units have their exhaust and intake at ground level making them receptacles for lawn debris and snow causing all kinds of internal problems with the units.
