Abstract: Air filtration assemblies configured to provide instant detection of particles and/or improve particle filtration are disclosed. The assemblies may include an air inlet duct in fluid communication with a compressor of a gas turbine system. The air inlet duct may include an inlet for receiving intake air including intake air particles, and an outlet positioned opposite the inlet. The assembly may also include a plurality of vane filters at the inlet, an array of fabric filters positioned in the air inlet duct, downstream of the vane filters, and a silencer assembly positioned in the air inlet duct, downstream of the fabric filters. Additionally, the assembly may include an electrostatic component positioned in the air inlet duct, downstream of the fabric filters. The electrostatic component may be configured to charge the intake air particles that pass through the vane filters and the fabric filters.

Abstract: This invention is directed to an air purification method capable of removing small aerosols and a wide size range of aerosols, with minimum aerosol radius smaller than 0.01 micron. The method humidifies the air in an enclosed space and produces supersaturation at a level of at least 12 percent in at least a portion of the enclosed space so that water vapor condenses on aerosols to form water droplets. The method also coalesces the water droplets formed by supersaturation using coalescence devices that can coalesce droplets with minimum radius smaller than 0.01 micron, thereby lowering the equilibrium supersaturation, enabling water droplets to grow faster, be more stable and easier to be removed compared to when coalescence is absent. The method dehumidifies the air so that the water droplets with captured aerosols are removed. Coalescence enables droplets to grow under a lower ambient supersaturation level, thus saving a considerable amount of energy.

Abstract: Provided is a dust collection method using a dust collection device. The dust collection method includes: a step of forming a rotating airflow by means of suction with a suction device, the rotating airflow progressing while spiraling along an inner wall surface of a main body; a step of supplying liquid from a supply nozzle; a step of spreading out the liquid with the rotating airflow on the inner wall surface thereby to continuously form a liquid catcher, the liquid catcher rotating as a film of the liquid; and a step of separating smoke and/or dust to outside by centrifugal force due to the rotating airflow and capturing the smoke and/or dust with the liquid catcher, the smoke and/or dust being contained in air introduced to the inside of the main body.

Abstract: A subsea fluid processing system which receives a wellstream flow. The subsea fluid processing system includes a pressure control device which regulates a pressure of the wellstream flow, a gas-liquid separator unit which receives the wellstream flow downstream of the pressure control device and which provides a liquid stream and a gas stream, a first membrane separator which receives the gas stream and which provides a retentate stream and a permeate stream, a compressor which receives the permeate stream and which provides a compressed permeate stream, and a discharge cooler which receives the compressed permeate stream and which provides a cooled compressed permeate stream for injection into a subsurface reservoir. A density of the cooled compressed permeate stream is higher than a density of the compressed permeate stream.

Abstract: A filter insert is useful for the separation of liquid droplets from a gas flow, particularly a gas flow from an internal combustion engine. The filter insert includes a media packet with layered portions of filter media. The media packet includes at least one layer of filter media with capillary effect to close the media packet to gas passage.

Abstract: A displacement ventilation system includes a vertical duct located inside an enclosed space and extending between a floor and a ceiling of the enclosed space, an air inlet coupled with the vertical duct for drawing air into the displacement ventilation system, and an elongated diffuser extending adjacent the floor for diffusing at least some of the outside air over the floor of the enclosed spaced. The displacement ventilation system desirably includes a return air duct extending adjacent the ceiling and being coupled with the vertical duct for removing return air from the enclosed space and advancing the return air toward the vertical duct, a heat exchanger for transferring thermal energy between the return air and the outside air, and a heat pump for changing a temperature level of the outside air or the return air passing through the heat pump.

Abstract: The exhaust gas treatment apparatus has a sealed vessel which is vertically partitioned into two spaces by a partition. A portion of the sealed vessel lower than the partition is an absorbing liquid storage portion, and a portion of the sealed vessel upper than the partition is an exhaust gas introducing portion. The partition is provided with a large number of sparger pipes so that the sparger pipes reach inside an absorbing liquid stored in the absorbing liquid storage portion. The partition is provided with a single gas riser in communication with a space upper than the absorbing liquid in the absorbing liquid storage portion. An upper end of the gas riser passes through a top plate portion of the sealed vessel and protrudes upward.

Abstract: A highly alkalized humic and fulvic filter reagent for the removal of multiple contaminants from a gas is provided. The contaminants removed from the gas stream may include, but are not limited to, Carbon Dioxide, Sulfur Oxide, Nitrogen Oxides, Hydrogen Sulfides, radionuclides, mercaptans, ammonia, toxic metals, particulates, volatile vapors, and organics. The present invention further includes the disposal of the filter reagent by way of using the highly alkalized humic and fulvic filter for soil fertility, releasing the carbon dioxide from the filter reagent, converting the liquid filter reagent into a solid for disposal or for use as a contaminant removal filter for waters, wastes, and chemicals.

Abstract: A humidifier for treating humidified air with germicidal light is provided. The humidifier includes a water reservoir, an atomizer to atomize a supply of water, and an ultraviolet light source to expose the atomized water to germicidal light. The ultraviolet light source extends vertically within a cylindrical channel to irradiate the atomized water dissipating upwardly from the atomizer. The water reservoir can include a carbon filter and a hardness-removing module for removing containments and metal oxides from the water supply. A control panel indicates the remaining useful life of the ultraviolet light source, the carbon filter and the hardness-removing module based on historical humidifier usage and water quality levels.

Abstract: The present invention relates to a glass laboratory apparatus that includes a pre filter and a main filter to scrub solids from a gas using water filtration. A preferred embodiment of the present invention includes a main vessel adapted to hold a volume of a liquid such as water and an inlet conduit with an opening above the liquid level in the main vessel and an outlet below the surface of the liquid level in the main vessel. A pre filter arranges in the inlet conduit at a level above the liquid level in the main vessel. A main filter is located below the water level in the main vessel. A negative pressure is supplied to draw a gas through the first, pre-filter, through the water and second main filter.

Abstract: Horizontal duct scrubbing systems for removing particulate matter from a gas are disclosed. The horizontal scrubbing systems may receive a particulate-containing gas stream (e.g., containing PM10 and/or PM2.5 particulate matter), and remove at least some of such particulates by spraying liquid droplets co-current to the flow of the gas stream, where the liquid droplets have a volume median droplet diameter (DV0.5) of from 240 microns to 600 microns. The scrubbing system may be substantially free of flow deflection members between a liquid inlet manifold and a demister. The system may be remove at least 50 wt. % PM10 and/or PM2.5 particulate matter from the gas stream.

Abstract: A system and method of cleaning and scrubbing contaminants, including sulfides, from an unclean or raw gas includes one or more containers, each of which include a gas permeable receptacle or bag containing an appropriate gas scrubbing medium for removing the contaminants from the gas stream. A gas extraction device is adapted via inserted into the gas scrubbing medium with the gas permeable receptacle wherein the gas extraction device is connected to at least one gas outlet port in the container. A series of containers can be used wherein the containers are connected sequentially to remove the gas. A system for bypassing one of the plurality of containers in order to clean out the container while the gas cleaning mechanism is still in operation is also described.

Abstract: A system and method of cleaning and scrubbing contaminants, including sulfides, from an unclean or raw gas includes one or more containers, each of which include a gas permeable receptacle or bag containing an appropriate gas scrubbing medium for removing the contaminants from the gas stream. A gas extraction device is adapted via inserted into the gas scrubbing medium with the gas permeable receptacle wherein the gas extraction device is connected to at least one gas outlet port in the container. A series of containers can be used wherein the containers are connected sequentially to remove the gas. A system for bypassing one of the plurality of containers in order to clean out the container while the gas cleaning mechanism is still in operation is also described.

Abstract: Method and apparatus for separating a target substance from a fluid or mixture. Capsules having a coating and stripping solvents encapsulated in the capsules are provided. The coating is permeable to the target substance. The capsules having a coating and stripping solvents encapsulated in the capsules are exposed to the fluid or mixture. The target substance migrates through the coating and is taken up by the stripping solvents. The target substance is separated from the fluid or mixture by driving off the target substance from the capsules.

Abstract: An apparatus for removing unwanted contaminates from gases, wherein the apparatus can include a housing that has at least one removable portion. The apparatus can also include a reaction chamber formed within the housing. A cartridge can be disposed in the reaction chamber. The cartridge can be connected to the removable portion of the housing.

Abstract: A system adapted to separate a natural gas feed stream into a sweetened gas stream, at least one liquid waste stream and at least one gaseous waste stream, and to discharge, recover or destroy the at least one liquid waste stream and the at least one gaseous waste stream.

Abstract: There is provided an exemplary dust trap and a system and method for filtering air. An exemplary dust trap comprises a housing with an air intake. The exemplary dust trap also comprises a plurality of screens disposed within the housing downstream of the air intake and configured to pass air and capture airborne contaminants, wherein the screens are configured to provide an unscreened air passage between the screens.

Abstract: Methods for removing sulfur from a gas stream prior to sending the gas stream to a gas separation membrane system are provided. Two schemes are available. When the sulfur content is high or flow is relatively high, a scheme including two columns where one tower is regenerated if the sulfur concentration exceeds a preset value can be used. When the sulfur content is low or flow is relatively low, a scheme including one column and an absorption bed.

Abstract: A rotating packed bed RPB that includes a first and second packed bed both arranged on the same rotatable shaft. A gas is directed via a gas inlet through the first packed bed in co-current flow with a liquid in a radially outward direction towards the outer radius of the packed bed. The liquid enters the first packed bed via a first liquid inlet. The gas exiting the first packed bed is directed to the second packed bed and forced through it in a radially inward direction in counter-current flow with a liquid, which enters through a second liquid inlet. The arrangement allows an operation of the rotating packed bed with less energy compared to RPBs of the prior art operating in counter-current flow only. The apparatus allows low-cost design and high design flexibility.

Abstract: A method and arrangement for removing solid particles and tar component from carbon monoxide gas. In the method, carbon monoxide gas is conducted from a ferroalloy smelting furnace (1) to a gas scrubber (2), the carbon monoxide gas is scrubbed in the gas scrubber (2) by a liquid medium for removing part of the solid particles, the carbon monoxide gas is conducted from the gas scrubber to a blower (3), the flow rate of the carbon monoxide gas is increased by the blower (3), and the carbon monoxide gas is conducted to a particulate filter (5) and the remaining solid particles are essentially filtered in the particulate filter (5) from the carbon monoxide gas.

Abstract: An apparatus is provided for drying a gas by gradually releasing and condensing the moisture in various chambers of a column, different pressures and different temperatures thus being present in the chambers of the column. The gas to be dried is first fed into the bottom chamber, where the largest amount of the water contained in the gas is condensed, and the gas is then discharged from the bottom chamber via a nozzle. Subsequently the gas is cooled and fed into at least one more chamber located above the first chamber, where further moisture is condensed before the resulting condensate is fed via a pipe—preferably shaped like a siphon—into the bottom reservoir to prevent the gas from flowing from the chamber below into the chamber above. A process which enables a gas to be dried is also described.

Abstract: This invention relates to a method and apparatus for treating a raw product stream (raw synthesis gas/raw syngas) generated by underground coal gasification (UCG). In one aspect, the invention concerns a method and apparatus for cooling and initial cleaning of raw syngas gas, so that the treated UCG product stream is suitable for downstream applications such as for energy or chemical production. In another aspect, the invention concerns a method and apparatus for isolating, treating and handling a raw UCG product stream that is generated either when igniting or decommissioning an underground coal gasifier and, due to its consistency, is generally unsuitable for energy or chemical production.

Abstract: Methods for removing sulfur from a gas stream prior to sending the gas stream to a gas separation membrane system are provided. Two schemes are available. When the sulfur content is high or flow is relatively high, a scheme including two columns where one tower is regenerated if the sulfur concentration exceeds a preset value can be used. When the sulfur content is low or flow is relatively low, a scheme including one column and an absorption bed.

Abstract: A modular amine plant having a front-end module and a back-end module in fluid communication with each other. The front-end module having pre-fabricated connections for the association of various equipment including: a filter, an absorption tower, and a flash tank. The back-end module having pre-fabricated connections for the association of other various equipment including: a heat exchanger, a distillation tower, and a reboiler. The modular amine plant capable of being installed at a site in less than about 5 days. The modular amine plant further having moment forces sufficient to withstand wind speeds of about 100 miles per hour.

Abstract: Disclosed is a device for purifying a process gas in a reflow soldering system. Said device comprises a receptacle that contains at least one packing bed. The process gas is fed to the receptacle via a gas inlet while being discharged from the receptacle after penetrating the packing bed. The inventive device further comprises an apparatus for delivering a liquid fluid to the receptacle. Secondary materials of the soldering process in the reflow soldering system can be absorbed by the liquid fluid and thus be eliminated from the process gas. Secondary materials and/or droplets and vapors of the fluid can additionally be absorbed and adsorbed on the surface of the packing.

Abstract: A gas filtration apparatus and method comprises a housing with an inlet for gas to enter and an outlet for the gas to exit. The housing contains a filter comprised of sintered metal fibers having an active filtration area through which the gas flows to remove suspended particles from the gas. The filter is substantially uniform in thickness and porosity through the active filtration area. The filter media being sealed to a metal structure in the housing with the metal structure having an opening to permit gas to flow through. A method of making a vapor/gas mixture includes the steps of producing a vapor in a gas to form the vapor/gas mixture passing the vapor/gas mixture through an opening in a housing containing a filter comprised of sintered metal fibers through which the vapor/gas mixture flows.

Abstract: The present invention relates to a glass laboratory apparatus that includes a pre filter and a main filter to scrub solids from a gas using water filtration. A preferred embodiment of the present invention includes a main vessel adapted to hold a volume of a liquid such as water and an inlet conduit with an opening above the liquid level in the main vessel and an outlet below the surface of the liquid level in the main vessel. A pre filter arranges in the inlet conduit at a level above the liquid level in the main vessel. A main filter is located below the water level in the main vessel. A negative pressure is supplied to draw a gas through the first, pre-filter, through the water and second main filter.

Abstract: A process for the extraction of an unwanted material from a gas comprising the steps of introducing an extraction liquid into a fluid having an unwanted liquid therein to form a physical aerosol comprising a plurality of extraction liquid droplets and the fluid, allowing the plurality of extraction liquid droplets to interact with the unwanted liquid in the gas to cause the extraction liquid droplets to be “wetted out” and captured on a porous medium, where the liquid is further contacted by the gas and simultaneously formed into a plurality of coalesceable droplets, coalescing the coalesceable droplets into larger droplets containing the unwanted liquid, and separating the larger droplets containing the unwanted liquid from the fluid.

Abstract: A method, apparatus and system for minimizing a quantity of particulate matter entrained within a gas stream is provided. A coarse filter removes at least a portion of particulate matter having a relatively-large particle size from the gas stream. An agglomerator agglomerates particulate matter having a relatively-small particle size remaining in the gas stream into particulate clusters after the portion of the particulate matter having the relatively-large particle size has been removed by the coarse filter. An injector introduces an agglomerating material into the gas stream before the gas stream enters the agglomerator. The agglomerating material promotes agglomeration of the particulate matter having the relatively-small particle size into the particulate clusters. And a second filter receives the gas stream and removes at least a portion of the particulate clusters entrained within the gas stream exiting the agglomerator.

Abstract: A system includes a direct contact absorber configured to circulate a flow of a liquid desiccant solution for absorbing moisture from a gas stream flowing through the direct contact absorber.

Abstract: A humidifier for treating humidified air with germicidal light is provided. The humidifier includes a water reservoir, an atomizer to atomize a supply of water, and an ultraviolet light source to expose the atomized water to germicidal light. The ultraviolet light source extends vertically within a cylindrical channel to irradiate the atomized water dissipating upwardly from the atomizer. The water reservoir can include a carbon filter and a hardness-removing module for removing containments and metal oxides from the water supply. A control panel indicates the remaining useful life of the ultraviolet light source, the carbon filter and the hardness-removing module based on historical humidifier usage and water quality levels.

Abstract: A system and method of reducing ammonia emissions. The system and method include a facility having a waste storage compartment below a floor comprised of slats with openings therebetween. A plurality of injection pipes are attached to a bottom surface of the slats. Each of the plurality of injection pipes includes a plurality of precipitation nozzles.

Abstract: An aerosol separator is arranged before a CO2 compressor to prevent wear and damage in CO2 recovery systems for the recovery of CO2 arising during fermentation using a compressor.

Abstract: A method and systems for collecting particulates suspended in a fluid flowing through a duct are provided. The system includes a duct including an inlet opening configured to admit a flow of gas into the duct, during operation the gas including particulate contaminants and moisture and a source of hydrophobizing agent coupled in flow communication with the duct. The system also includes a nozzle configured to channel a flow of the hydrophobizing agent into the flow of gas such that during operation a flow of gas including hydrophobized particulate contaminants and moisture is formed and a filter medium for separating the hydrophobized particles from the flow of gas.

Abstract: The present invention provides a humidifier assembly for humidifying a gas stream. The humidifier assembly including a heating element structured to be disposed in the gas stream for directly heating the gas stream as the gas stream passes therethrough and a supply of fluid provided at or near the heating element.

Abstract: In an air filtering apparatus for generating electrolytic water, infiltrating the electrolytic water into a gas-liquid contact member, and blowing air to the gas-liquid contact member by an air blowing fan, thereby filtering air, including a drain pipe for discharging the electrolytic water and a drain tank for receiving and stocking the electrolytic water discharged from the drain pipe which are mounted in a housing, the drain tank has a vertical tank body and disposed so as to be taken in and out through the front surface of the housing.

Abstract: A method and apparatus are provided for improving the efficiency of an aqueous froth filter. An array of saturated mesh assemblies interacts with an incoming contaminated air stream. As the air stream flows through the saturated mesh assemblies, an aqueous froth is generated immediately downstream of each mesh assembly. As the bubbles of the froth move downstream towards the next saturated mesh assembly, the velocity of the air stream causes at least some of the bubbles to burst. The bursting bubbles rupture into hundreds or thousands of micro-droplets. The micro-droplets are used together with the aqueous froth to coalesce with or otherwise bind with contaminants in the air stream. An optional feature is that massive particles greater than three microns in diameter are removed by inertial impaction, whereby those heavy particles collide with the walls of serpentine shaped vanes of a mist eliminator. The method and apparatus are capable of filtering chemical and biological warfare agents out of an air stream.

Abstract: Generally, the present invention provides a method and apparatus for removing a vapor phase contaminant from a gas stream, thereby reducing the concentration of the vapor phase contaminant in the gas stream. In one embodiment, the present invention provides a method for removing a vapor phase contaminant from a gas stream, comprising contacting a gas stream comprising a vapor phase contaminant with a first side of a membrane; sorbing the vapor phase contaminant using the membrane; reacting the vapor phase contaminant into an reacted form of the vapor phase contaminant; transporting the reacted form of the vapor phase contaminant through the membrane to a second side of the membrane; contacting the second side of the membrane with a liquid; and dissolving the reacted form of the vapor phase contaminant into the liquid. Methods for making a membrane comprising a metal for use in the present invention is also described.

Abstract: The present invention is a mobile air contaminant control system that includes a filter assembly enclosed by a mobile outer chamber. The filter assembly is tapered to create a large volume air way downstream from the filter assembly that enables more even air flow and filter loading. One or more exhaust fans pull the air through the filter assembly and exhaust it to the exterior of the chamber. The system is functionally attached to an exterior structure having at least one air intake and housing a work piece. As airborne contaminants are generated from the work piece(s), the control system exhausts them from the exterior structure through the filter assembly and into the external environment.

Abstract: A method of removing contaminants from a contaminated gas or vapor stream, which method includes passing a contaminated gas or vapor stream through a bed of curled separating media linearly in an upward direction at a linear velocity of up to 6 m/s; allowing a contaminant in the contaminated gas or vapor stream to collect on the separating media as the gas or vapor stream passes through the bed of separating media, thereby removing the contaminant from the gas or vapor stream and thus purifying the gas or vapor stream; allowing the contaminant that has collected on the separating media to pass from the separating media into a collection zone; removing the contaminant from the collection zone; and withdrawing a purified gas or vapor stream from the bed of separating media.

Abstract: The invention provides methods and apparatuses for removing additional aerosols and in some cases additional particulate matter from a gas stream, wherein a certain portion of such aerosols and particulate matter has already been removed using a primary aerosol and particulate collection device. In some embodiments, the invention includes a method for removing additional aerosols from a gas stream, including passing a gas stream having a plurality of aerosols through a gas duct; removing a first portion of the plurality of the aerosols using a primary aerosol collector; passing the gas steam through a screen; collecting at least a second portion of the plurality of aerosols on the screen; and cleaning a portion of the screen outside of the gas duct. The invention also provides various apparatuses for use in performing the method of the invention.

Abstract: A process for removing carbon dioxide from a gas stream by scrubbing the carbon dioxide from the gas stream with a mixture of ammonium and alkali carbonates such as sodium carbonate and/or potassium carbonate. Using the mixed alkali carbonate solution as the CO2 scrubbing solution offers the opportunity for both low regeneration energy and low ammonia volatility while still maintaining a high rate of CO2 hydration.

Abstract: The invention relates to a method for removing ammonia and dust from a waste gas that occurs during the production of fertilizers, preferably urea, in which method the waste gas is introduced into a first washer, and a cooling gas is introduced into the one washer and an aqueous solution is introduced into the other washer, whereby both the waste gas and the cooling gas pass through at least one mist collector before exiting from the washer, in each instance, is supposed to be developed further in such a manner that the waste gas pollution can be clearly reduced. This is accomplished in that the additional water is first introduced into a fine-washing area of the first washer, delimited by the mist collector on the top and by a liquid-impermeable partition bottom at the bottom, and sprayed onto the at least one mist collector, and the aqueous solution that forms in the fine-washing area is subsequently passed into the second washer.

Abstract: A dust collector (10) has a main body (12), the interior of which is divided by a tubular partition wall (26) into a central filtration chamber (30) and an outwardly-located annular cyclone chamber (32). At the upper part of the cyclone chamber (32), there is provided a water supply pipe (36) having radially directed nozzles (38) adapted to form a water film flowing down along the inner circumferential surface of the main body (12) and the-outer circumferential surface of the partition wall (26), respectively. Air to be treated is drawn under suction through an air intake (34) into the cyclone chamber (32) and swirling air is brought into contact with the water film whereby dust and particles are preliminarily collected while retaining an explosion-proof function. The cyclone chamber (32) and the filtration chamber (30) are communicated with each other at the lower portion thereof to permit the thus pretreated air to be drawn into the filtration chamber (30).

Abstract: A method of removing contaminants from a contaminated gas or vapour stream, which method includes passing a contaminated gas or vapour stream through a bed of curled separating media linearly in an upward direction at a linear velocity of up to 6 m/s; allowing a contaminant in the contaminated gas or vapour stream to collect on the separating media as the gas or vapour stream passes through the bed of separating media, thereby removing the contaminant from the gas or vapour stream and thus purifying the gas or vapour stream; allowing the contaminant that has collected on the separating media to pass from the separating media into a collection zone; removing the contaminant from the collection zone; and withdrawing a purified gas or vapour stream from the bed of separating media.

Abstract: A gasification system is disclosed having a combustion or reaction vessel, a scrubber housing, and a filter housing. A carbonaceous fuel is partially combusted in the reaction vessel to generate a combustible gas. An improved ash support and removal system reduces clogging and other problems in the reaction vessel. The combustible gas passes through the scrubber housing to remove matter such as tar and oil, and the scrubbed gas passes through a hybrid blower to the filter housing. Wood chips are used in the filter housing to provide a relatively clean, dry gas. Wastewater and other waste products from the scrubber housing and filter housing are captured and returned to the reaction vessel.

Abstract: The invention provides methods and apparatuses for removing additional aerosols and in some cases additional particulate matter from a gas stream, wherein a certain portion of such aerosols and particulate matter has already been removed using a primary aerosol and particulate collection device. In some embodiments, the invention comprises a method for removing additional aerosols from a gas stream that has aerosols previously removed by a primary aerosol collector, comprising passing a gas stream comprising a plurality of aerosols through a gas duct; removing a first portion of the plurality of said aerosols using a primary aerosol collector; passing the gas stream through a screen; and collecting at least a second portion of the plurality of aerosols on the screen. The invention also provides various apparatuses for use in performing the method of the invention.

Abstract: An inlet air chilling and filtration system for a turbine. The inlet air chilling and filtration system may include a first stage spray array with a first number of spray nozzle pairs, a second stage spray array with a second number of spray nozzles pairs, and a drift eliminator.

Abstract: An inlet air treatment system. The inlet air treatment system includes a housing with more than two symmetric sides. Each of the sides includes a number of air filters and a number of spray arrays. A central air deflector is positioned within the housing.

Abstract: An apparatus for reducing a relative humidity of air inside an enclosed space includes a portable outside air heat exchanger unit having a fan operative to create an air stream by drawing outside air from an intake and discharging the air stream through an outlet inside the enclosed space, and a temperature adjusting element located in the air stream. A heating source supplies heat energy to the temperature adjusting element in response to directions from a heat controller. A humidity sensor is operative to sense the relative humidity of the air in a sensing location and to send a humidity signal to the heat controller to change the amount of heat energy supplied to the temperature adjusting element in response to the humidity signal. HEPA filters and ultra-violet lights can shine on the air stream to kill mold spores and the like.