SE543165C2 - Ventilation system including ventilation device for regulating supplied outdoor air during simultaneous purification - Google Patents

Abstract

The present invention relates to a ventilation system (S) for supplying purified and conditioned air to a building comprising a ventilation device (V). The ventilation device (V) comprises a first inlet (1) for recirculated indoor air, a second inlet (2) for outdoor air which is heat exchanged with outgoing indoor air, an outlet (5) for mixed air (23), a mixing chamber (3) and a recirculation fan ( 41). The first inlet (1) and the second inlet (2) are arranged in the mixing chamber (3) and the ventilation device (V) further comprises a second chamber (4) which is flow-connected to said mixing chamber (3). At least one pre-filter (11) is arranged in the first inlet (1) and at least one first filter (30) is arranged between the mixing chamber (3) and the second chamber (4). The outlet (5) is arranged in the second chamber (4) and the ventilation system (S) comprises an FTX unit (20) which is connected to the second inlet (2) for incoming outdoor air of the ventilation device (V).

Description

The present invention relates to a ventilation device comprising a first inlet for recirculated indoor air, a second inlet for outdoor air, an outlet for mixed air, a mixing chamber and a recirculation fan. The invention also relates to a ventilation system comprising such a ventilation device and a method for pre-regulating supplied outdoor air to a building while simultaneously purifying the supplied outdoor air and purifying recirculated indoor air.

BACKGROUND People in the Western world spend an average of 90 percent of their time indoors. Indoor air is therefore of great importance to our health. A poor indoor environment can lead to ill health and reduced work and performance enjoyment. Indoor air is often worse than outdoor air because there is a lot of pollution from materials, equipment and substances inside the building. Bad air means many disadvantages, not least for asthmatics and allergy sufferers, such as poor sleep, headaches, irritated mucous membranes, etc. Particularly sensitive individuals such as asthmatics and allergy sufferers have problems finding solutions that effectively and comprehensively satisfy their need for good air quality in the entire indoor environment . Increasing problems with emissions from building materials, more aggressive bacterial outbreaks and "too tight" building constructions, with consequent mold and spores, are also problem areas for which there are no good solutions.

A deteriorated outdoor environment with increased pollution and above all the presence of ever smaller particle sizes, so-called nanoparticles are being recognized as a growing problem.

Air purification is a much neglected area in ventilation systems. There is also a lack of flexibility in filter adaptation if there are special needs.

The interest in energy efficiency/savings, control and management also requires an increasingly elaborate ventilation solution. Today, it is less common, in smaller installations, with ventilation solutions that include sensor technology and control mechanisms. The possibilities for customizing a ventilation system are therefore limited.

Installation of an air cooler pump is in most cases a point solution, which means that the cooler/cooling is unevenly distributed in the property. The uneven distribution is also affected by the fact that measuring points cannot therefore provide effective control of the pump.

The need to make ventilation more energy efficient has led to the FTX systems (exhaust and supply air ventilation with heat exchanger). In an FTX system, the exhaust air is collected together with the supply air in an FTX unit that contains a rotating exchanger and filter. For example, up to 80% of the heat in the indoor air can be returned and heat cold supply air.

The Swedish construction code gives instructions primarily regarding circulation and oxygenation of the indoor air. For different environments, requirements are set for air turnover in litres/person/sec and a minimum requirement for air turnover of 0.35 l/s per m2. Furthermore, air currents are regulated with instructions on overpressure/underpressure in different spaces. Simple filters, fans, supply and exhaust air devices with different locations are part of the installation. Particularly sensitive environments, especially for allergy sufferers and asthmatics, are supplemented with point solutions in the form of portable air purifiers, extra filters, air locks, etc. which is ineffective as they rarely affect the entire indoor environment but mostly only benefit individual rooms. The supply of new oxygenated air also means that the energy issue must be taken into account. The installation is completed with heat exchangers, heating and cooling units, etc. On top of all this, a control system is introduced to make the plant more energy efficient, i.e. demand-adapted ventilation. With many point solutions, special adaptations and maintenance points, many facilities become sensitive to change, difficult to maintain and expensive to install, upgrade and develop. Efficiency also becomes difficult to overview.

There are a lot of particles in the air, ranging from a few millimeters long to as small as a millionth of a millimeter (nm). The size of the particles is very important for how far down in the airways the particles stay when inhaled. Larger particles stay up in the nose and throat without causing health problems. Particles smaller than 5 µm can reach the alveoli, the human blood vessels, which can be harmful to health. Large particles fall down quickly, while small particles can float freely for weeks and become persistent carriers of viruses, bacteria, etc. while many small particles in the air give the impression that the air is "dry".

Particles are formed indoors or come in via the ventilation from the outside and consist of, for example, textile fibers, paper dust, soot, minerals, skin flakes, plant parts, secretions from office machines and other electronics and microorganisms. The size of the particles affects how far down into the air waves they can reach and what they consist of affects the effect they have on the body.

Document WO 09157847 describes a ventilation system for a multi-room building. The system is based on a conventional heat exchanger system, but also includes the possibility of connecting at least one of the rooms to a separate ventilation chamber. In the chamber, air from at least one of the rooms is mixed with outside air. The mixed air then passes through a filter and is then led further into at least one of the rooms.

Document WO 2010104427 describes an air purification and heating system for a building with several rooms. The system includes an air cleaner, means for directing air through said air cleaner, ducts for conducting rising air from the air cleaner to the rooms in the building, a mixing chamber for mixing air from inside the building and air from outside the building, which chamber is connected to the duct leading mixed air through said air conditioners, a duct leading the exhaust air intake from the outside of the building and having an outlet in the mixing chamber, and ducts leading exhaust air out of the building.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a ventilation device and a ventilation system which overcomes or at least minimizes the problems described above. This can be achieved through a ventilation system according to patent claim 1.

Thanks to the invention, a ventilation device and a ventilation system are offered which constitute an integrated solution for oxygenation, air purification and tempering of the air to ß rooms in a building. At the same time, there is a local point for control and regulation when both recirculated indoor air and supplied outdoor air are mixed in the device.

According to one aspect of the invention, the ventilation device includes at least one pre-filter arranged in the first inlet, which gives the advantage that coarse particles and dust are captured from the recirculated air so that it does not follow you into the ventilation system.

According to another aspect of the invention, filtered recirculated indoor air and filtered outdoor air are mixed in the mixing chamber before the mixed air passes through a microfilter so that the air that flows out to all rooms in the building has been particle reduced by more than 85%. Furthermore, a continuous recirculation and purification of the indoor air is achieved.

According to yet another aspect of the invention, the ventilation device includes a first valve inside the pre-filter, which valve is closed if the recirculation fan were to stop for some reason. This gives the advantage that air cannot then go backwards through the pre-filter and thus carry dirt and particles back into the building.

According to another aspect of the invention, the ventilation device includes silencers which dampen the sound in the device. This is an advantage as the device should be centrally located in the building, adjacent to the rooms where moon people stay on a daily basis.

According to one aspect of the invention, the device comprises a first and a second pressure sensor arranged on either side of said at least one pre-filter. Furthermore, the device includes a third, a seventh and a fourth pressure sensor arranged on opposite sides of the first and the second filter. Named sensors measure the differential pressure across the respective filters and communicate these values to the local steering and control panel for possible forwarding to an app in a mobile device when a set final pressure drop has been reached and also to fetch information about current pressure for status reporting. The application also provides a qualified assessment of whether the filters need to be cleaned or replaced. Furthermore, the device includes a pressure sensor which keeps a set air flow constant on the supply air from the FTX unit and if the overpressure becomes too low, the system can fail so that measures can be taken. The same applies to a pressure sensor that is arranged after the second chamber as ways and constantly maintains a set air flow on the recirculation fan via the control and control panel. The invention also includes space for and is prepared for the installation of a setup selectable sensors of various types that communicate with the same control and control panel. Givama can be intended to measure particles, ozone, radon, VOC, C02, N02, relative humidity, etc.

The ventilation system according to the invention offers a step-by-step purification of indoor air as the indoor air first passes a coarse filter and possibly a medium filter before the indoor air is mixed with filtered outdoor air and the mixed air is then carefully filtered in at least one microfilter. The ventilation system can be equipped with combinations of filters according to needs and wishes.

According to one aspect of the invention, the ventilation system according to the invention supplies all rooms with purified, ventilated air, which gives the advantage that all rooms become accessible with the same high air quality.

According to yet another aspect of the invention, the ventilation system includes some form of drainage pump, which means that the building can be provided with a stable indoor temperature all year round.

According to a further aspect of the invention, the system includes a bypass line around the spring pump so that the purified air can be led through the bypass line, for example when the spring pump is defrosted in order to avoid cooling of the air that is carried out into the building.

The invention also addresses the problem of lack of maintenance in ventilation applications. In order to create ease of maintenance, the invention centralizes the essential filters in the ventilation system, makes them easily accessible, monitors them and reports the status and need for measures. At the same time, the problem of soiling of supply air ducts is solved by eliminating the possibility of particles spreading beyond the microfilter.

BRIEF DESCRIPTION OF THE FIGURES The invention will hereinafter be described in more detail with reference to the attached figures, in which: Fig. 1 schematically shows a side view of a ventilation device according to the invention, and Fig. 2 schematically shows a flow chart for a ventilation system according to the invention.

DETAILED DESCRIPTION OF THE FIGURES The following detailed description and the examples contained therein are intended only to describe and illustrate certain embodiments of the invention and are not intended to limit the scope of the invention in any way.

Figure 1 schematically shows a side view of a ventilation device V according to the invention in a preferred embodiment. The ventilation device V comprises a first inlet 1 for room air 10 and a second inlet 2 for an outside air flow 21 from preferably a conventional FTX unit. These two inlets 1, 2 open into a mixing chamber 3 where the room air 10 and the outdoor air 2l are mixed before it flows through a filter 30 to a second chamber 4. In the second chamber 4, silencers 40 are preferably arranged. A recirculation fan 4l is also arranged in the second chamber 4. From the second chamber 4, the air flows through an outlet 5 into the building's system of supply air ducts and further out to all rooms in the building. If desired, an air/air heat pump 6 is arranged after the outlet 5 for tempering the mixed 23 air.

In the preferred embodiment, the ventilation device V has the shape of a square box, and the device is preferably placed centrally in the building to be able to collect air from the entire house as evenly as possible. The device normally takes up no more floor space than a normal-sized refrigerator for a normal-sized villa of up to 200 m2. In the described example, the ventilation device V is arranged in a wardrobe where the wardrobe is centrally located in the house. The first inlet 1 is preferably arranged at a low height near the floor. This results in a better re-mixing of the air and thus better spread of the weather. Furthermore, a more efficient cleaning is obtained as larger particles sink downwards and accumulate near floor level. Said first inlet l is flush with the wardrobe wall so that it is easy to clean the filter. Ventilation ducts preferably connect at the top of the device V. The casing can be given an attractive design so that the ventilation device/casing can be exposed to the room and that it must also be understood that holes in walls may be required so that the inlet l is centrally located in the building while the ventilation device can be located on the other side the wall in a smaller, more defined space such as a laundry room or a storage room. The housing also preferably includes a tight-fitting service hatch or door so that the components inside the ventilation device are easily accessible for replacement etc.

The first inlet 1 for the room air 10 comprises at least one pre-filter 11 which removes dust and other coarse particles, the pre-filter 11 is preferably a coarse filter and can for example consist of PPI mat or the like. Inside the pre-filter 11, a medium filter 12 is arranged, in the described example, which medium filter 12 screens out particles in the order of size down to about 0.4 µm. The medium filter 12 is preferably of M5 class and is accessible via the first inlet 1. The room air 10 also passes through a first damper S1 before it enters the mixing chamber 3. In the mixing chamber 3, the room air 10 is mixed with the outside air 21 which enters the mixing chamber 3 via the second inlet 2. The room air 10 and the outside air 21 is mixed and flows further through at least a first filter 30, which first filter 30 is preferably a microfilter such as an H10 HEPA filter. It is also possible, as shown in Figure 1, to arrange another filter, a second filter 31 in front of the first filter 30. The second filter 31 can for example be a carbon filter alternatively a chemical filter which effectively removes odors and more. The mixed air 23 flows into the second chamber 4, which second chamber 4 has preferably been arranged with silencers 40 so that the ventilation device is quiet. In connection with the second chamber 4, the recirculation fan 41 is arranged, which fan 41 keeps the air flow constant. The recirculation fan 41 is regulated for a greater air flow than the inflow of outside air 21 and thus creates an inflow of room air 10 into the mixing chamber 3. The air further flows out of the second chamber 4 via an outlet 5 which is preferably arranged at the top of the ventilation device V.

The ventilation device described above is V in itself, but depending on where in the world the device is to be installed, it can be advantageously combined with some form of dehumidifier and/or cooling unit when the indoor air needs to be tempered. The air gets the desired temperature and is then carried on to the rooms in the building through air ducts and supply air devices in different rooms, according to known technology. Thanks to recirculating the already tempered indoor air and mixing it with added outside air from, for example, an FTX unit, the need to cool/heat in the heater and/or cooling unit is reduced, which provides energy savings and the heating and/or cooling unit can be dimensioned with lower power.

By recirculated air is meant the air found in the home where the majority of the air is air that has passed the ventilation device V. The mixed air 23 that comes out via the supply air devices in the rooms consists of about 1/3 room air and about 2/3 outdoor air. Part of the air that comes out of the supply air devices leaves the house via exhaust air ducts, while part of the mixed air flows into the ventilation device V. The expert realizes that the recirculated air can also contain air that has entered through temporarily open windows and/or doors, but that this air in such cases constitutes a relatively small part.

Recirculation, however, means that the completely purified air via doors and other openings is quickly purified.

In the embodiment described here, it is described how the ventilation device V is combined with an air-air cooler pump 6. The mixed air 23 leaves the ventilation device V via the outlet 5, passes a third damper S3 to the air-air cooler pump 6. Connecting an air-air cooler pump 6 with the ventilation device V gives advantages such as that the distribution of cold to all rooms takes place with the same efficiency as the distribution of heat and you can easily maintain a constant temperature all year round.

Figure 2 schematically shows a flow chart for a ventilation system S according to the invention. In the system shown, there is a heat recovery unit of FTX type 20 where incoming outdoor air is heat exchanged with outgoing indoor air in a manner known to the person skilled in the art. Incoming outside air 2l preferably passes an outside air filter 200 before the outside air 2l reaches a heat exchanger 20l where the outside air 2l is heat exchanged with exhaust air 22 from the building. These flows are regulated by controlling a supply air fan 202 and an exhaust air fan 204 and are balanced against each other to maintain good air pressure in the building according to conventional technology, they are preferably balanced so that a slight negative pressure of a few percent is obtained in the building. This is to avoid possible overpressure in the building if the exhaust air filters in the FTX unit become too dirty. The outdoor air filter 200 is, for example, a filter in the F7 fine filter class, which during normal operation removes up to 51% of particles of size 0.4 um, 86% of size 1.0 um and 99.1% of 5 um before the incoming outside air 2l reaches the heat exchanger 20l. The exhaust air 22 from the building preferably passes an exhaust air filter 203 of, for example, M5 class, which protects the fans and the heat exchanger from contamination before the exhaust air 22 is heat exchanged in the heat exchanger 20l. The FTX system maintains a constant supply air and exhaust air flow in the entire house and has a heat recovery from the exhaust air of approx. 80%. In a conventional FTX unit 20 there is an electric afterheater 205 which is preferably switched off when the FTX unit cooperates with a ventilation device V according to the invention as it is more efficient to let the heater pump 6 heat the air.

The incoming outdoor air 2l from the FTX unit 20 flows further to the ventilation device V and into the mixing chamber 3 where it is mixed with room air l0 which flows into the mixing chamber 3 via the first inlet l. In the demixing chamber 3 the mixed air 23 passes a microfilter 30, preferably an Hl0 HEPA filter , and preferably also a carbon filter 3 l , when the air flows into the second chamber 4. From the second chamber 4, the air flows on to the air-air heater pump 6, where the purified air is given the desired temperature, and is carried further into the building through supply air devices in different rooms. In other words, indoor air recirculates in the building and the proportion of recirculated air is in the range 30 - 60%, preferably 35 - 50% and even more preferably around 40% of the total air flow that passes through the ventilation device V. Thanks to the already tempered indoor air l0recirculating and mixing with the incoming outside air 2l, the need to cool/warm in the air-to-air heating pump 6 is reduced, which leads to energy savings. Additional advantages of the indoor air l0 recirculating is that the turnover of the room air l0 increases, which means that odors, spores etc. disappear faster than in pure FTX systems.

The ventilation system according to the invention also includes a number of sensors that measure pressure and temperatures.

The ventilation system includes a first temperature sensor Tl as a constant meter blowing temperature into the rooms in the building. Furthermore, the system includes a second temperature sensor T2 which pours a constant set room temperature via a control and control panel 9. The control and control panel 9 is preferably arranged in connection with the ventilation device V so that everything is in one and the same place. It is then easy to get an overview of set values, adjust if necessary, all control preferably takes place from here. Of course, it is understood that the second temperature sensor T2 can be placed in another location according to conventional technology.

At the inlet 1 for indoor air, a first pressure sensor P1 is arranged and inside the pre-filter 11 and the medium filter 12, in the mixing chamber 3, a second pressure sensor P2 is arranged. The first Pl and the second P2 pressure sensor measure the differential pressure over the filter 11 and the medium filter l2 in order to, when the set final pressure drop is reached, emit some kind of signal so that the filters can be cleaned/replaced. Preferably, it larrns to a mobile app when the set final pressure drop is reached, as in the app you also have the option to directly order new filters.

The ventilation system also includes a third pressure sensor P3 arranged in the mixing chamber 3 flow-wise before the second filter 3l and a fourth pressure sensor P4 after the first filter 30. The third and fourth pressure sensors P3, P4 measure the differential pressure across the two filters 30, 3l and larrn, in the same way as described above, if the set final pressure drop is reached. In an advantageous embodiment, a seventh pressure sensor P7 is arranged between the first and the second filter which measures and reports the differential pressure across the respective filters 30, 31. In this way, it can be indicated which of the filters 30, 31 requires cleaning or replacement.

Furthermore, there is a fifth pressure sensor P5 arranged in the supply air line before the inlet to the mixing chamber 3, which fifth pressure sensor P5 measures and keeps constant a set air flow on the supply air from the FTX unit 20 via a speed-regulated fan 202 that controls via said control and control panel. This ensures that supplied outdoor air to the extension meets the minimum requirements according to the building code. In the event of, for example, too low a pressure here, due to, for example, a blockage in the outside air intake grille, a warning can be sent to said app and measures can be taken.

A sixth pressure sensor P6 is arranged in the supply air duct after the second chamber 4 and after the recirculation fan 41. This sensor measures and maintains a set air flow on the speed-regulated recirculation fan 41 via the steering and control panel9. This air flow must be greater than the supply air flow from the FTX unit, for example twice as large, in order for a recirculation flow of indoor air characteristic of the invention to be achieved. Here, too, an alert can be advantageously sent to said app in the event of low pressure.

There are preferably three dampers arranged in the ventilation system. A first damper S1 is arranged inside the medium filter 12, a third damper S3 is arranged in the supply air duct between the second chamber 4 and the air-air heater pump 6 and in a bypass line 7 above the third damper S3 and the air-air heater pump 6 a second damper S2 is arranged. In normal operation, the first damper S1 and the third damper S3 are open and the second damper S2 is closed.

If the recirculation fan 41 were to stop for some reason, the first damper S1 is closed so that air cannot go backwards towards the pre-filter 11 and thus carry dirt and particles from the pre-filter 11 out into the building again and that the pressure drop through the air-air cooler pump 6 is minimized.

The bypass line 7 is preferably used in cases where an air-to-air heater pump 6 is used which periodically runs a defrost. The third damper S3 is closed and the second damper S2 is opened and during the time that the defrosting is in progress the air is led from the ventilation device V via the bypass line 7 and thus it is avoided that the air coming from the ventilation device V is cooled down. The recirculation fan 41 keeps the air flow constant. 11 With an inventive ventilation device and a ventilation system comprising such a ventilation device, an advantageous method for regulating supplied outdoor air to a building has been developed where it is possible to supply outdoor air to the building in a very energy-efficient manner while simultaneously purifying the supplied outdoor air and purifying recirculated indoor air. The method according to the invention includes the steps of: a) supplying outdoor air and indoor air to a mixing chamber (3) in a ventilation device for forming a mixed air (23), b) filtering the mixed air (23), c) distributing the mixed air (23) in the building via supply air ducts, d) clean the indoor air in a pre-filter (ll) before it is introduced into the mixing chamber (3), e) regulate the inflow of indoor air to the mixing chamber (3) by controlling a recirculation fan (4l), which is arranged to supply the supply air ducts with mixed air (23), so that the proportion of supplied indoor air in the mixed air (23) in the range 30 - 60%, preferably 35 - 50% and even more preferably around 40% is achieved.

Additional advantages can be achieved if the method also includes one of the steps to: f) regulate the flow rate over the filter included in the ventilation device (V) (11, 12, 30, 3 l) to a maximum of 50%, more preferably 35%, more preferably a maximum of 20 % of filtered flow, g) heat exchange the exhaust air (22) with incoming outdoor air (2l), and h) regulate the exhaust air flow (22) in relation to the flow of incoming outdoor air (2l) so that a negative pressure is created in the building.

In order to be able to carry out tests of various kinds, the applicant has installed a ventilation device V and a ventilation system according to the invention in a house. The ventilation device V has, in accordance with the preferred design, been arranged centrally in the building in order to be able to collect the indoor air that is to be recirculated as evenly as possible from different parts of the building.

In this case, the ventilation device V has been arranged in a wardrobe centrally located in the house. The inlet for the indoor air is arranged at the bottom of the wardrobe and goes through one wall of the wardrobe into one of the rooms in the house. In the attic above the wardrobe, the conventional FTX unit 20 is arranged and the incoming outdoor air 2l passes the FTX unit 20 on its way to the mixing chamber 3. The mixed air 23 flows through the ventilation device V according to the invention and on to the air pump 6. From there all rooms are supplied in the building with air that has passed the ventilation device V, via conventional supply air ducts.

The contamination of exhaust and supply air ducts is significantly reduced in a system according to the invention thanks to the fact that the indoor air is filtered directly at the first 1 inlet, the outdoor air 21 is filtered before it reaches the FTX unit 20 and the mixed air in the mixing chamber 3 is filtered in a microfilter 30. Furthermore, the risk of mold, bacterial growth, etc. significantly as the mixed air 23 that goes into the building is effectively cleaned. Additional advantages of the air being recirculated are that the distribution of the springs is very efficient and the need for radiators can be reduced because the springs from, for example, wood burning stoves, are pumped out to all spaces. Additional advantages of a ventilation device V and a ventilation system according to the invention are that when particles in air store the springs, cleaner air means that the air carries less particle-borne springs into the exhaust air.

During his studies, the applicant has made measurements of particles in the sizes 0.3 µm, 1 µm and 5 µm on four different occasions and at three different locations. Table A shows the number of particles measured in the respective sizes in a building with conventional supply/exhaust air ventilation. Measurements have been made on outdoor air outside the building, on room air in the building and on the air entering the rooms from the supply air devices (TF devices).

TABLE A0.3 um 1 um 5 umRoom air 4661100 678000 74000TF-don 3088000 600000 212000Outdoor 4049000 302000 10000 Table B shows the number of particles measured in the respective sizes in another building device with a conventional supply/exhaust air ventilation. Measurements have been made on outdoor air outside the building, on room air in the building and on the air entering the rooms from the TF device. 13 TABLE B0.3 pm 1 pm 5 pmRoom air 4509000 530000 78000TF device 3332000 345000 69000Outside 5069000 163000 6000 Table C shows the number of particles measured in the respective sizes in the building equipped with a Ventilation device V and a Ventilation system according to the finding. Measurements have been made on outdoor air outside the building, on room air in the building and on the air entering the rooms from the TF device.

TABLE C0.3 pm 1 pm 5 pmRoom air 773000 47000 0TF-don 226000 0 0Outside 6636000 132000 5000 In table D, the number of particles measured in the respective sizes in the building arranged with a Ventilation device V and a Ventilation system according to the invention is shown. Measurements have been made on outdoor air outside the building, on room air inside the building and on the air entering the rooms from the TF device. Measurements years made On a different occasion than the measurements seen in table C.

TABLE D0.3 pm 1 pm 5 pmRoom air 1173000 42000 0TF-don 530000 0 0Outside 30604000 1298000 40000 14 The tables show how much particles of the different sizes are in the outdoor air at the various measurement times. Tables A and B show that there are more particles in the air from the TF devices and in the room air than in the outdoor air, which indicates that the ventilation ducts contain a lot of dirt and particles that are brought into the buildings. Furthermore, it can be seen in tables C and D that the air coming from the supply air devices contains a significantly lower proportion of particles in all three measured sizes. Particles in the size of 1 µm and 5 µm were measured to be zero, while particles in the size of 0.3 µm are significantly lower in the building with the ventilation device and the system according to the invention. It can also be deduced that there is a marked difference in the particle content in the indoor air in the different buildings. In table D it can be seen that in the building arranged with the ventilation device V and the system according to the invention there are 0 particles in the size 5 um, about 500,000-600,000 fewer particles in the size 1 um and about 3,000,000 fewer particles in the size 0.3 um. It is worth noting from Tables C and D that the measurements were made outside and in the house arranged with a device and a system according to the invention fixed at different times. In table D it can be read that there is a much higher load of particles in the outdoor air than at the time of measurement as measured in table C. Despite the large difference, the system has a high degree of separation of particles and in the air that exits via the TF devices there are zero particles of size l um and 5 um. An advantage of the invention is that the smallest particles that nevertheless get through the filters are kept suspended in the air currents and are therefore not deposited in the ducts, with the result that minimal or no particles get stuck there and thus the need for cleaning the ducts is minimized or avoided.

The following data is from the house where the ventilation device V and the ventilation system according to the invention have been installed and run and where all measurement data has been taken. The expert realizes that dimensions, flows etc. are adapted to where the device/system is to be installed.

The test house has a living area of 183.9 m2. Outside air flow (supply air) = 72.5 l/s Exhaust air flow (exhaust air) = 75 l/s Recirculation flow (basic flow) = 70 l/s (the air flow can be increased if necessary) The following dimensions have been used in the duct system. From the FTX unit 20 down to the ventilation device V, a channel with a diameter of 160 mm is arranged. From the ventilation device V to the air-air heater pump 6, two channels with a diameter of 200 mm are arranged, in this example two channels have been used to reduce the speed, but the person skilled in the art realizes that it can also be a larger channel and that the channel/channel maker has other dimensions than just a circular cross-section . For example, the channel could have a square cross-section. From the air-air heater pump 6 out to the TF device in all rooms, the duct is from 160 mm in diameter down to 125 mm diameter at the TF device. Furthermore, the pre-filter 11 in the test housing consists of 1 plate Bulpren S28280, black gap 20 mm with dimensions 610x610 mm. The medium filter 12 is an M5 filter with the dimensions 592x592x150 mm. The incoming outside air 21 passes an F7 filter with the dimensions 470x207x260 mm before the incoming outside air 21 reaches the FTX unit 20. The exhaust air 22 from the building also passes an exhaust air filter which is an F7 filter with the dimensions 470x207x260 mm. Furthermore, the first filter 30 is an H10 HEPA filter with the dimensions 592x592x292 mm and the second filter 31 is a carbon filter of the DinCarb CNP type with the dimensions 610x610x96 mm. Thanks to the dimensioning of the various parts in the system, a large flow is obtained with a lower flow rate than conventional systems . In the system according to the invention, the flow rate over the filters 11, 12, 30, 31 included in the ventilation device V is regulated to a maximum of 50%, more preferably a maximum of 35% and even more preferably a maximum of 20% of the filtered flow. In the building where the ventilation device V and the ventilation system according to the invention have been installed and run, the first filter 30 is an H10 HEPA filter and the total flow used over the filter 30 is about 140 l/s, while the nominal flow of this filter is 833 l/s, which gives a low pressure drop over the filter. Over the pre-filter 11 and the medium filter 12, a flow of approx. 70 l/s has been used, while the nominal flow on these filters is usually approx. 400 l/s.

In Graph 1 below, it is illustrated how the amount of particles with a size of 0.3 um increases markedly at the time when a window is opened in one of the bedrooms in the test house. Before the window is opened, the concentration of particles with a size of 0.3 um is around 1,000,000. When the window is opened, the concentration rises, in the minutes that the window is open, by approximately 39,000,000 particles. When the window is closed, the level drops to about 10,000,000 particles in about 30 minutes and then it decreases a little more slowly towards the level that was before the window was opened. Denintema recirculation contributes to purifying the unfiltered air that enters the house through temporarily opened doors or windows. 16 GRAPH l šêßgxfæ: .âmrrasëë In the ventilation device V according to the invention, a larger air flow is used overall, the flow rate is lower, significantly lower than what the filters normally work with, which gives a better separation of particles. By designing the system with a lower flow rate, which is achieved with relatively large ventilation ducts and a large filter surface, a lower pressure drop across the filters is obtained, which increases their service life. In accordance with the inventive concept, the flow rate must amount to a maximum of 75% of the normal flow rate for the corresponding conventional dimensioning, preferably a maximum of 60% and even more preferably a maximum of 50%. Thanks to the large proportion of recirculated indoor air in the system according to the invention, the mixed air has a higher temperature when it reaches the air-air heater pump, which makes it work more efficiently and it becomes more economical. A lower flow rate also gives the advantage that it produces less noise.

Thanks to the invention, all rooms in the building get the same high air quality where the particle content is greatly reduced by more than 85%. The recirculation means continuous purification of all air, both indoor air and outdoor air, while the energy in the already tempered indoor air is utilized. The air that enters through temporarily opened doors and the odors, emissions and particles that are generated, also indoors, indoors are effectively taken care of.

The person skilled in the art realizes of course that the filters mentioned above can be replaced as desired, for example the microfilter 30 can be of a different type or class, for example a HEPA filter type H13 or another HEPA/ULPA class if needed. It is also understood that the other 17 filters can be varied according to needs and wishes, for example, the medium filter M5 could be replaced with a fine filter F7, etc. In addition to the sensors/meters discussed above, there are of course also other sensors/sensors to further increase maintenance accuracy, control options and air quality level reporting, for example sensors/meters/sensors regarding 0 VOC volatile organic substances 0 COz 0 Particles 0 Relative humidity %0 Radon 0 N02 0 Ozone It is further understood that the ventilation device and the ventilation system according to the invention can be installed in all types of buildings such as residences, schools, official buildings, etc. In cases where it is installed in larger buildings, such as in a kindergarten, it is advantageous to install a ventilation device per department instead of drawing the indoor air along long ducts to a single device, as this gives a greater risk of the accumulation of indoor-generated particles in the ducts. In the description above, reference is made to an air-to-air heating pump, but the person skilled in the art realizes that there may still be other alternatives that transfer heating/cooling to the air passing through, for example via a rock heating pump, ground heating pump. The ventilation system according to the invention has a fast heat and cooling transfer to the rooms in case of rapid weather changes thanks to air to air transfer. The ventilation device according to the invention can be connected to an existing ventilation system in a building, but because a higher flow is used in the device, problems with noise can arise. You can then add additional channels to remove the noise, but if sound is not a problem, it can be connected to the existing system without additional measures. In new constructions, it is advantageous to dimension the upper ducts, or alternatively draw more ducts to prevent noise.

Claims (4)

Ventilation system (S) for supplying purified and conditioned air to a single building comprising a ventilation device (V), wherein the ventilation device (V) comprises a first inlet (1) for recirculated indoor air, a second inlet (2) for outdoor air which is heat exchanged with outgoing indoor air , an outlet (5) for mixed air (23), a mixing chamber (3) and a recirculation shaft (41), characterized in that said first inlet (1) and said second inlet (2) are arranged in said mixing chamber (3), that the ventilation device ( V) further comprises a second chamber (4) which is expediently connected to said mixing chamber (3), at least one pre-filter (1 1) is arranged in said first inlet (1) and at least one first filter (30) is arranged between said mixing chamber (3). 3) and said second chamber (4) and that the outlet (5) is arranged in said second chamber (4) and in that the ventilation system (S) comprises an FTX unit (20) which is connected to the second inlet ppet (2) for incoming outdoor air of the ventilation device (V). Ventilation system (S) for supplying purified and conditioned air to a single building according to claim 1, characterized in that said at least one pre-filter (1 1) is a coarse filter, preferably a PPI mat. Ventilation system (S) for supplying purified and conditioned air to a single building according to claim 1 or 2, characterized in that said first inlet (1) comprises a second pre-filter (12), which second pre-filter is preferably an M5 class medium filter. Ventilation system (S) for supplying purified and conditioned air to a single building according to claim 1, characterized in that the ventilation device further comprises a first damper (S1) fl suitably arranged after said first prefilter (ii), Ventilation system (S) for supplying purified and conditioned air for a single building according to any one of claims 1-4, characterized in that a second filter (31) is arranged between said mixing chamber (3) and said second chamber (4). Ventilation system (S) for supplying purified and conditioned air to a building according to claim 5, characterized in that said first filter (30) and / or said second filter (31) consists of a carbon filter and / or a chemical filter and / or a microfilter. Ventilation system (S) for supplying purified and conditioned air to a single building according to any one of claims 1-6, characterized in that the device further comprises a first pressure sensor (P1) and a second pressure sensor (P2) fl suitably arranged on either side of said at least one pre-filter ( 11). Ventilation system (S) for supplying purified and conditioned air to a single building according to claim 5, characterized in that the device further comprises a third (P3) and a fourth (P4) pressure sensor arranged to measure the differential pressure across the first (30) and second (31) the filter, wherein the third pressure sensor (P3) is arranged in the mixing chamber (3) des fatefully before the first (30) and the second (31) filter and the fourth pressure sensor (P4) is arranged in the second chamber (4) fl fatefully after the first (30) ) and the second filter (31). Ventilation system (S) for supplying purified and conditioned air to a single building according to claim 8, characterized in that the device further comprises a fifth pressure sensor (P5) fl suitably arranged before the mixing chamber (3) and a sixth pressure sensor (P6) fl suitably arranged (4) after the second chamber ). Ventilation system (S) for supplying purified and conditioned air to a single building according to any one of claims 1-9, characterized in that the ventilation device comprises a housing which preferably has the shape of a ladder, said housing accommodating the mixing chamber (3) and the second chamber (4 ), that the first inlet (1) is arranged in one side wall of the housing and designed so that the first pre-filter (11) is accessible from the outside and that replacement of the pre-filter (11) can be performed from the outside of the housing, that another side wall comprises a tight-fitting service door the mixing chamber (3), the second chamber (4) and the components arranged therein become accessible and replaceable. Ventilation system (S) according to claim 1, characterized in that the system further comprises a heating and / or cooling unit (6), where mixed air (23) from the ventilation device (V) is tempered before it is discharged into the building via a supply air device. Ventilation system (S) according to claim 11, characterized in that said heating and / or cooling unit (6) is an air-air heat pump (6), that the system comprises supply air duct between the second chamber (4) and the air-air heat pump (6) which supply air duct comprises a third damper (S3), further characterized by a bypass line (7) over the third damper (S3) and air-to-air heat pump (6) which bypass line (7) comprises a second damper (S2) and that the ventilation system is interlocked in such a way that the third damper (S3) is closed and the second damper (S2) is opened when defrosting the air-air heat pump (6) so that the mixed air (23) flows through the bypass line (7). Ventilation system (S) according to claim 1, characterized in that the recirculation shaft (41) is arranged to keep the air flow constant.