Air filtration system

Abstract

System (10) for supplying filtered air to an enclosed space (12), comprising: a first air supply pump (14) configured to draw air from an external environment (16) and drive compressed air through the system (10) to the enclosed space (12); a power source (22) configured to supply electrical power to the first air supply pump (14); first filter media (24) positioned between the first air supply pump (14) and the enclosed space (12) downstream of the first air supply pump (14), the first filter media (24) being adapted to provide coarse filtration of the compressed air pumped by the first air supply pump (14) through the first filter media (24); and second filter media (28) positioned between the first filter media (24) and the enclosed space (12) downstream of the first filter media (24), the second filter media (28) being configured to provide fine filtration of the compressed air pumped by the first filter media (24) through the second filter media (28); characterized in that the system (10) further comprises: a first control valve (50) positioned between the first air supply pump (14) and the first filter media (24) downstream of the first air supply pump (14), the first control valve (50) being configured to control the flow of pressurized air from the first air supply pump (14); a first reversing control valve (74) positioned between the second filter media (28) and the enclosed space (12); a reverse air flow path (76) extending between and connecting the first control valve (50) and the first reversing control valve (74); and a second reversing control valve (78) positioned between the first control valve and the first filter media (24); wherein: the first control valve (50) is selectively operable to redirect a flow of compressed air from the first air supply pump (14) to the reverse air flow path (76); the first reversing control valve (74) is selectively operable to stop the air flow to the enclosed space (12) and to redirect the air flow from the reversing air flow path (76) through the second filter media (28) and the first filter media (24); and the second reversing control valve (78) is selectively operable to redirect the flow of compressed air passing through the first filter media (24) to the environment (16); wherein, when compressed air flows through the first and second filter media (28) from the reverse air flow path (76), the compressed air displaces particles captured by the first and second filter media (28) and expels the particles displaced by the first and second filter media (28) from the system (10) to the outside environment (16) through the second reversing control valve (78).

Description

INTRODUCTION

[0001] The present invention relates to a system according to the preamble of claim 1 for filtering air for human respiration, as is essentially known from US 6 979 359 B2.

[0002] Current filtration systems only filter particles larger than 300 nanometers. Viruses are smaller than this and are not filtered by current respiratory filters.

[0003] High-efficiency particulate air filters (HEPA filters) and KN95 masks only capture particles 300 nanometers or larger in size, and KN95 masks are only 95% effective. Ultra-low particulate air filters (ULFA filters) only capture particles 120 nanometers or larger. Pollutants and viruses are much smaller than this, so they can pass through HEPA and ULFA filters.

[0004] Consequently, while current filtration systems and methods for filtering air achieve their intended purpose, there is a need for a new and improved system and method for filtering air that captures particles no larger than 1 nanometer. SUMMARY

[0005] According to the invention, a system for supplying filtered air to a closed space is presented, which is characterized by the features of claim 1.

[0006] The system includes a first air supply pump configured to draw air from an external environment and drive compressed air through the system to the enclosed space, a power source configured to supply electrical power to the first air supply pump, first filter media positioned between the first air supply pump and the enclosed space downstream of the first air supply pump, the first filter media configured to provide coarse filtration of the compressed air pumped by the first air supply pump through the first filter media, and second filter media positioned between the first filter media and the enclosed space downstream of the first filter media, the second filter media configured to provide fine filtration of the compressed air pumped by the first filter media through the second filter media. The system further includes a first control valve,positioned between the first air supply pump and the first filter media downstream of the first air supply pump, wherein the first control valve is configured to control the flow of compressed air from the first air supply pump. The system further comprises a first reversing control valve positioned between the second filter media and the enclosed space, a reversing air flow path extending between and connecting the first control valve and the first reversing control valve, and a second reversing control valve positioned between the first control valve and the first filter media, wherein the first control valve is selectively operable to redirect the flow of compressed air from the first air supply pump to the reversing air flow path, the first reversing control valve being selectively operable,to stop the air flow to the enclosed space and to redirect the air flow from the reverse air flow path through the second filter media and the first filter media, and the second reversing control valve is selectively operable to redirect the compressed air flow passing through the first filter media to the environment, wherein, as the compressed air flows through the first and second filter media from the reverse air flow path, the compressed air displaces particles captured by the first and second filter media and expels the particles displaced from the first and second filter media from the system to the outside environment through the second reversing control valve.

[0007] In another aspect, the first filter media is configured to remove particles larger than approximately 5 micrometers from the compressed air flowing through the first filter media.

[0008] In another aspect, the second filter media is configured to remove particles between about 1 nanometer and about 20 nanometers in size from the compressed air flowing through the second filter media.

[0009] According to another aspect, the enclosed space is a face mask configured to deliver air that has passed through the first filter media and the second filter media to an individual user. Such face masks exist and are used, for example, in the healthcare industry.

[0010] In another aspect, the power source is configured to supply between about 20 and about 32 watts of power to the first air supply pump, and the first air supply pump is configured to supply air pressurized to between about 6,894 kPa (1 psi) and about 20,684 kPa (3 psi) to the face mask at a flow rate of between about 30 liters per minute and about 60 liters per minute.

[0011] According to another aspect, the enclosed space is a vehicle cabin.

[0012] According to another aspect, the system further comprises a second air supply pump configured to draw air from the enclosed space and drive pressurized air through the system to the outside environment, and third filter media positioned between the second air supply pump and the outside environment downstream of the second air supply pump, the third filter media configured to provide fine filtration of the pressurized air pumped by the second air supply pump through the third filter media.

[0013] According to another aspect, the system further comprises a second control valve positioned between the second air supply pump and the third filter media downstream of the second air supply pump, the second control valve being configured to control the flow of pressurized air from the second air supply pump.

[0014] In another aspect, the third filter media is configured to remove particles between about 1 nanometer and about 20 nanometers in size from the compressed air flowing through the third filter media.

[0015] According to another aspect, the system further comprises fourth filter media positioned between the second air supply pump and the third filter media downstream of the second air supply pump, the fourth filter media being configured to provide coarse filtration of the compressed air pumped by the second air supply pump through the fourth filter media before the compressed air passes through the third filter media.

[0016] According to a further aspect, the fourth filter media are configured to remove particles larger than 5 micrometers from the compressed air flowing through the fourth filter media.

[0017] Furthermore, a method for supplying filtered air to an enclosed space is described. The method comprises supplying electrical power to a first air supply pump having a power source, drawing in air from an outside environment with the first air supply pump and driving compressed air to the enclosed space with the first air supply pump, with first filter media positioned between the first air supply pump and the enclosed space downstream of the first air supply pump, providing coarse filtration of the compressed air pumped by the first air supply pump through the first filter media and removing particles larger than approximately 5 micrometers from the compressed air with the first filter media, and providing fine filtration of the compressed air with second filter media positioned between the first filter media and the enclosed space downstream of the first filter media,which is pumped from the first filter media through the second filter media, and removing particles that are between approximately 1 nanometer and approximately 20 nanometers in size from the compressed air with the second filter media.

[0018] In another aspect, supplying electrical power to the first air supply pump with the power source further comprises supplying between about 20 and about 32 watts of power to the first air supply pump with the power source, and driving pressurized air to the enclosed space with the first air supply pump further comprises driving air pressurized to between about 6,894 kPa (1 psi) and about 20,684 kPa (3 psi) with the first air supply pump to the enclosed space at a flow rate between about 30 liters per minute and about 60 liters per minute.

[0019] According to another aspect, the method further comprises drawing air from the enclosed space with a second air supply pump and driving pressurized air to the outside environment with the second air supply pump, and with third filter media positioned between the second air supply pump and the outside environment downstream of the second air supply pump, providing fine filtration of the pressurized air pumped by the second air supply pump through the third filter media, and removing particles between about 1 nanometer and about 20 nanometers in size from the pressurized air with the third filter media.

[0020] According to another aspect, the method further comprises, with fourth filter media positioned between the second air supply pump and the third filter media downstream of the second air supply pump, providing coarse filtration of the compressed air pumped by the second air supply pump through the fourth filter media, and removing particles larger than 5 micrometers from the compressed air with the fourth filter media before the compressed air passes through the third filter media.

[0021] According to the invention, the system further comprises a first reversing control valve positioned between the second filter media and the enclosed space, a reversing air flow path extending between and connecting the first control valve and the first reversing control valve, and a second reversing control valve positioned between the first control valve and the first filter media. The method further comprises diverting a compressed air flow from the first air supply pump to the reversing air flow path with the first control valve, stopping the air flow to the enclosed space with the first reversing control valve, and diverting the air flow from the reversing air flow path through the second filter media and the first filter media, and displacing particles trapped by the first and second filter media, and diverting a compressed air flow passing through the first filter media.to the environment with the second reversing control valve and expelling particles displaced by the first and second filter media from the system to the outside environment.

[0022] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for illustrative purposes only. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described here are for illustrative purposes only; they show: Fig. 1 is a schematic view of a system for supplying filtered air to an enclosed space, wherein the enclosed space is a face mask, according to an exemplary embodiment; Fig. 2 is a schematic view of a system for supplying filtered air to an enclosed space, wherein the enclosed space is a vehicle cabin, according to an exemplary embodiment; Fig. 3 a schematic view of the system of Fig. 1, wherein the compressed air flow through the first and second filter media is reversed; Fig. 4 a schematic view of the Fig. 1, whereby air is filtered before being expelled from the enclosed space to the environment; and Fig. 5 is a flowchart illustrating a method for supplying filtered air to an enclosed space according to an exemplary embodiment. DETAILED DESCRIPTION

[0024] The following description is merely exemplary in nature.

[0025] With reference to Fig. 1, a system 10 for supplying filtered air to an enclosed space 12 includes a first air supply pump 14 configured to draw air from an outside environment 16, as indicated by arrow 18, and drive pressurized air through the system 10 to the enclosed space 12, as indicated by arrow 20. A power source 22 is configured to supply electrical power to the first air supply pump 14. First filter media 24 is positioned between the first air supply pump 14 and the enclosed space 12 downstream of the first air supply pump 14. The first filter media 24 is configured to provide coarse filtration of the pressurized air pumped by the first air supply pump 14 through the first filter media 24, as indicated by arrow 26. Second filter media 28 is positioned between the first filter media 24 and the enclosed space 12 downstream of the first filter media 24.The second filter media 28 are designed to provide fine filtration of the compressed air pumped by the first filter media 24 through the second filter media 28, as indicated by arrow 30. The filtered air is driven from the second filter media 28 to the enclosed space 12, as indicated by arrow 32.

[0026] As in Fig. 1, in an exemplary embodiment, the enclosed space 12 is a face mask 34 configured to deliver air that has passed through the first filter media 24 and the second filter media 28 to an individual user 36. To deliver breathable air to a face mask 34 for an individual user 36, the power source 22 is configured to supply between approximately 20 and approximately 32 watts of power to the first air supply pump 14, and the first air supply pump 14 is configured to deliver air pressurized to between approximately 6.894 kPa (1 psi) and approximately 20.684 kPa (3 psi) to the face mask 34. Air expelled by the individual 36 into the face mask 34 is directed out of the system 10, as indicated by arrow 38.To support breathing for a person 36, the first air supply pump 14 must supply air to the face mask 34 at a flow rate between approximately 30 liters per minute and approximately 60 liters per minute. Since the power consumption of the power source 22 is relatively low, between approximately 20 and 32 watts of power, the power source 22 could be a rechargeable battery pack, thus allowing the system 10 to be portable.

[0027] With reference to Fig. 2, in another exemplary embodiment, the enclosed space 12 is a vehicle cabin 40. The first supply pump 14 of the system 10 draws air from outside a vehicle 42 through inlets 44, as indicated by arrows 46, and forces filtered air from the system 10 to the interior vehicle cabin 40 through vents 48 within the vehicle 42. The system 10 may include a first supply pump 14 capable of providing an increased flow rate such that the system 10 can supply filtered air to the entire interior vehicle cabin 40, thus supplying filtered air to all passengers in the vehicle 42 with an HVAC system operating in recirculation mode. Likewise, the system 10 may be adopted to supply filtered air directly to the face mask 34 of the passenger 36 in the vehicle 42, making it independent of HVAC system operation and therefore reducing its capacity requirements.Likewise, the system 10 may be designed to provide personal protection for seated airplane passengers, as well as for healthcare workers and patients. Likewise, the system 10 could be designed to supply filtered air to a larger enclosed space 12, such as a room or an entire building. If the system 10 is designed for a relatively large enclosed space, such as a large room or an entire building, such as a house, the system 10 may be designed with larger second filter media 28 or multiple second filter media 28 positioned in parallel to provide adequate airflow with a moderately sized first air supply pump 14.

[0028] With further reference to Fig. 1, in another exemplary embodiment, a first control valve 50 is positioned between the first air supply pump 14 and the first filter media 24 downstream of the first air supply pump 14. The first control valve 50 is configured to control the flow of pressurized air from the first air supply pump 14.

[0029] The first filter media 24 provides coarse "microfiltration" and is designed to remove particles larger than approximately 5 micrometers from the compressed air flowing through the first filter media 24. The first filter media 24 captures larger contaminant particles such as dust and dirt. As shown, the first filter media 24 is positioned downstream of the first air supply pump 14. It should be understood that the first filter media 24 may also be positioned upstream of the first air supply pump 14, such as at an inlet to the first air supply pump 14, without departing from the spirit of the present invention. Such filter materials exist and are used, for example, in air and water purification processes.

[0030] The second filter media 28 is a membrane that provides fine "ultrafiltration" and is designed to remove particles between approximately 1 nanometer and approximately 20 nanometers in size from the compressed air flowing through the second filter media 28. Such membrane materials exist and are used, for example, in water purification processes. Such membrane materials have not been used for air filtration due to the resistance they impart to the air flowing through them. A human would be unable to draw air through a membrane made of such a material, thus the first supply pump 14 is required to force the air through the second filter media 28 to the enclosed space 12.

[0031] The power requirements of the first air supply pump 14 are directly related to the resistance of the air flowing through the second filter media 28. Thus, if filtration requirements are less stringent, a smaller or less powerful first air supply pump 14 that uses less power may be used. For example, if the system 10 is only required to filter particles that are 30 nanometers or larger in size, the system may be designed with a membrane of second filter media 28 that creates less resistance to air flow than a membrane of second filter media 28 that would trap particles that are 1 nanometer or larger in size, thus requiring less air pressure to drive the air through the second filter media and a smaller, less power-consuming first air supply pump.This allows the system to be tailored to specific filtration needs to optimize power consumption.

[0032] With reference to Fig. 3, in an exemplary embodiment, the system 10 further includes a first reversing control valve 74 positioned between the second filter media 28 and the enclosed space 12, a reversing air flow path 76 extending between and interconnecting the first control valve 50 and the first reversing control valve 74, and a second reversing control valve 78 positioned between the first control valve 50 and the first filter media 24. The first control valve 50 is selectively operable to redirect a flow of pressurized air from the first air supply pump 14 to the reversing air flow path 76, as indicated by arrows 80.The first reversing control valve 74 is selectively operable to stop air flow to the enclosed space 12 and to redirect air flow from the reversing air flow path 76, as indicated by arrow 82, through the second filter media 28, as indicated by arrow 54, and through the first filter media 24, as indicated by arrow 52. The second reversing control valve 78 is selectively operable to redirect the flow of pressurized air passing through the first filter media 24 to the atmosphere, as indicated by arrow 56. As pressurized air flows through the second and first filter media 28, 24 from the reversing air flow path 76, the pressurized air displaces particles trapped by the first and second filter media 24, 28 and expels the displaced particles from the system 10 to the outside atmosphere through the second reversing control valve 78.Alternatively, when pressurized air flows through the second and first filter media 28, 24 from the reverse air flow path 76, the pressurized air displaces particles captured by the first and second filter media 24, 28, and the system 10 agitates and ejects the displaced particles within a chamber surrounding the first and second filter media 24, 28.

[0033] With reference to Fig. 4, in another exemplary embodiment, the system 10 further includes a second air supply pump 58 configured to draw air from the enclosed space 12 and drive pressurized air through the system 10 to the outside environment 16, as indicated by arrow 60. Third filter media 62 is positioned between the second air supply pump 58 and the outside environment 16 downstream of the second air supply pump 58. The third filter media 62 is a membrane similar to the second filter media 28, configured to provide fine filtration and remove particles between approximately 1 nanometer and approximately 20 nanometers in size from the pressurized air flowing through the third filter media 62, as indicated by arrow 64. A human would be unable to drive air through a membrane of such a material, thus the second air supply pump 58 is required to drive the air through the third filter media 62 to the outside environment 16.

[0034] According to another exemplary embodiment, the system 10 may include a second control valve 66 positioned between the second air supply pump 58 and the third filter media 62 downstream of the second air supply pump 58. The second control valve 66 is configured to control the flow of pressurized air from the second air supply pump 58.

[0035] In yet another exemplary embodiment, the system 10 includes fourth filter media 68 positioned between the second air supply pump 58 and the third filter media 62 downstream of the second air supply pump 58. The fourth filter media 68, like the first filter media 24, is configured to remove particles larger than approximately 5 micrometers from the compressed air passing through the fourth filter media 68, as indicated by arrow 70. The fourth filter media 68 provides coarse filtration of the air, capturing larger contaminant particles before the air reaches the third filter media 62. The third and fourth filter media 62, 68 ensure that small particles, such asViruses can be removed from the air expelled by a person 36 using the system 10 before such air is released back into the environment 16, as indicated by arrow 72, which helps prevent the spread of such viruses.

[0036] With reference to Fig. 5, a method 100 for supplying filtered air to an enclosed space 12 with a system 10 according to the present invention is schematically shown. Beginning at block 102, the method includes supplying electrical power to the first air supply pump 14 with the power source 22. Shifting to block 104, the method 100 includes drawing air from the outside environment with the first air supply pump 14 and driving pressurized air to the enclosed space 12 with the first air supply pump 14, as indicated by arrows 18 and 20 in Fig. 1 shown.

[0037] Shifting to block 106, the method includes, with the first filter media 24 positioned between the first air supply pump 14 and the enclosed space 12 downstream of the first air supply pump 14, providing coarse filtration of the compressed air pumped by the first air supply pump 14 through the first filter media 24, as indicated by the arrow 26 in Fig. 1, and removing particles larger than approximately 5 micrometers from the compressed air with the first filter media 24.

[0038] Shifting to block 108, the method 100 includes, with the second filter media 28 positioned between the first filter media 24 and the enclosed space 12 downstream of the first filter media 24, providing fine filtration of the compressed air pumped from the first filter media 24 through the second filter media 28, as indicated by the arrow 30 in Fig. 1, and removing particles that are between about 1 nanometer and about 20 nanometers in size from the compressed air with the second filter media 28.

[0039] In an exemplary embodiment, supplying electrical power to the first air supply pump 14 with the power source 22 further comprises supplying between about 20 and about 32 watts of power to the first air supply pump 14 with the power source 22. In addition, driving compressed air to the enclosed space 12 with the first air supply pump 14 further comprises driving air pressurized between about 6.894 kPa (1 psi) and about 20.684 kPa (3 psi) with the first air supply pump 22 to the enclosed space 12 at a flow rate between about 30 liters per minute and about 60 liters per minute.

[0040] Shifting to block 110, in an exemplary embodiment, the method 100 further comprises drawing air from the enclosed space 12 with the second air supply pump 58 and driving pressurized air to the outside environment 16 with the second air supply pump 58, as indicated by arrow 60 in Fig. 4 is specified.

[0041] Shifting to block 112, the method 100 includes, with the third filter media 62 positioned between the second air supply pump 58 and the external environment 16 downstream of the second air supply pump 58, providing fine filtration of the compressed air pumped by the second air supply pump 58 through the third filter media 62, as indicated by the arrow 64 in Fig. 4, and removing particles between about 1 nanometer and about 20 nanometers in size from the compressed air with the third filter media 62.

[0042] Shifting to block 114, in an exemplary embodiment, the method 100 further comprises, with the fourth filter media 68 positioned between the second air supply pump 58 and the third filter media 62 downstream of the second air supply pump 58, providing coarse filtration of the pressurized air pumped by the second air supply pump 58 through the fourth filter media 68, as indicated by arrow 70 in Fig. 4, and removing particles larger than 5 micrometers from the compressed air with the fourth filter media 68 before the compressed air passes through the third filter media 62.

[0043] Moving from block 102 to block 116, in another exemplary embodiment, the method 100 includes redirecting a flow of pressurized air from the first air supply pump 14 to the reverse air flow path 76 with the first control valve 50, as indicated by arrows 80 in Fig. 3. Moving to block 118, the method 100 includes stopping the air flow to the enclosed space 12 with the first reversing control valve 74 and diverting the air flow from the reversing air flow path 76, as indicated by arrow 82 in Fig. 3, through the second filter media 28, as indicated by the arrow 54 in Fig. 3, and the first filter media 24, as indicated by the arrow 52 in Fig. 3, and displacing particles captured by the first and second filter media 24, 28. Shifting to block 120, the method 100 includes redirecting a flow of pressurized air passing through the first filter media 52 to the outside environment with the second reversing control valve 78 and expelling particles displaced by the first and second filter media 24, 28 from the system 10 to the outside environment, as indicated by arrow 56 in Fig.3. Shifting to block 122, in an alternative exemplary embodiment, the method 100 includes redirecting a flow of pressurized air passing through the first filter media 52 to ambient with the second reversing control valve 78, and the system 10 agitates and ejects the displaced particles within a chamber surrounding the first and second filter media 24 and 28.

[0044] A system 10 and method 100 of the present invention offer several advantages. These include filtering air to remove particles much smaller than possible with existing systems, including viruses, to protect a person 36 breathing such air. The system 10 and method 100 include the use of a first supply pump 14 to force air through a filter membrane through which a human would be unable to draw air, allowing the use of a filter membrane material suitable for capturing particles sized between 1 and 20 nanometers. The reversibility of the airflow through the first and second filter media 24, 28 allows the first and second filter media 24, 28 to be cleaned of previously captured particles, allowing the system 10 to clean itself.The use of third and fourth filter media 62, 68 and a second air supply pump 58 downstream of the enclosed space 12 allows air expelled by a person 36 or group of people to be filtered before being expelled into the environment 16. A system 10 of the present invention stops virus particles sized between 1 and 20 nanometers from being inhaled by a user of the system 10 and stops a user of the system from expelling virus particles sized between 1 and 20 nanometers into the environment 16.

Claims

[1] A system (10) for supplying filtered air to an enclosed space (12), comprising: a first air supply pump (14) configured to draw air from an external environment (16) and drive compressed air through the system (10) to the enclosed space (12); a power source (22) configured to supply electrical power to the first air supply pump (14); first filter media (24) positioned between the first air supply pump (14) and the enclosed space (12) downstream of the first air supply pump (14), the first filter media (24) being adapted to provide coarse filtration of the compressed air pumped by the first air supply pump (14) through the first filter media (24); and second filter media (28) positioned between the first filter media (24) and the enclosed space (12) downstream of the first filter media (24), the second filter media (28) being configured to provide fine filtration of the compressed air pumped by the first filter media (24) through the second filter media (28); characterized by , that the system (10) further comprises: a first control valve (50) positioned between the first air supply pump (14) and the first filter media (24) downstream of the first air supply pump (14), the first control valve (50) being configured to control the flow of pressurized air from the first air supply pump (14); a first reversing control valve (74) positioned between the second filter media (28) and the enclosed space (12); a reverse air flow path (76) extending between and connecting the first control valve (50) and the first reversing control valve (74); and a second reversing control valve (78) positioned between the first control valve and the first filter media (24); wherein: the first control valve (50) is selectively operable to redirect a flow of compressed air from the first air supply pump (14) to the reverse air flow path (76); the first reversing control valve (74) is selectively operable to stop the air flow to the enclosed space (12) and to redirect the air flow from the reversing air flow path (76) through the second filter media (28) and the first filter media (24); and the second reversing control valve (78) is selectively operable to redirect the flow of compressed air passing through the first filter media (24) to the environment (16); wherein, when compressed air flows through the first and second filter media (28) from the reverse air flow path (76), the compressed air displaces particles captured by the first and second filter media (28) and expels the particles displaced by the first and second filter media (28) from the system (10) to the outside environment (16) through the second reversing control valve (78). [2] The system (10) of claim 1, wherein the first filter media (24) is configured to remove particles larger than 5 micrometers from the compressed air flowing through the first filter media (24). [3] The system (10) of claim 2, wherein the second filter media (28) is configured to remove particles between 1 nanometer and 20 nanometers in size from the compressed air flowing through the second filter media (28). [4] The system (10) of claim 3, wherein the enclosed space (12) is a face mask (34) configured to deliver air that has passed through the first filter media (24) and the second filter media (28) to an individual user (36). [5] The system (10) of claim 4, wherein the power source (22) is configured to supply between 20 and 32 watts of power to the first air supply pump (14), and the first air supply pump (14) is configured to supply air pressurized to between 1 psi and 3 psi to the face mask (34) at a flow rate of between 30 liters per minute and 60 liters per minute. [6] System (10) according to claim 4, wherein the enclosed space (12) is a vehicle cabin (40). [7] System (10) according to claim 6, further comprising: a second air supply pump (58) configured to draw air from the enclosed space (12) and drive compressed air through the system (10) to the outside environment (16); and third filter media (62) positioned between the second air supply pump (58) and the outside environment (16) downstream of the second air supply pump (58), the third filter media (62) being adapted to provide fine filtration of the compressed air pumped by the second air supply pump (58) through the third filter media (62). [8] The system (10) of claim 7, further comprising a second control valve (66) positioned between the second air supply pump (58) and the third filter media (62) downstream of the second air supply pump (58), the second control valve (66) being configured to control the flow of pressurized air from the second air supply pump (58).

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