An air exchanger for continuously exchanging indoor air with outdoor air to provide a constant supply of fresh air into a structure which includes a heat exchanger having a continuous structure which defines adjacent first and second sets of channels which open toward opposite sides of the air exchanger. The air exchanger draws outdoor air through the first set of channels in a first direction and indoor air through the second set of channels in a second, counter-direction. Heat is transferred between the indoor and outdoor air streams such that when the outdoor air enters the room, its temperature approaches the indoor temperature and indoor heating or cooling effects are minimized.

A compact air-ventilator with high efficiency thermal exchanger and air filter in which the thermal exchanger utilise a light-weight assembly of parallelly stacked thin metallic plates with pre-formed spaces. The high efficiency air filter includes a combination of filter elements including a mesh grid, an activated carbon layer and a HEPA filter. This air-ventilator can be built-in as part of an air-conditioner or as a stand alone unit to provide additional air circulating to conventional air-conditioners to improve indoor air quality. The thermal exchanger as well as the filters can be made with modular design to allow for easy periodic maintenance and replacement.

A heat exchanging system of a ventilating device includes: a heat exchanging housing communicating with an outdoor air passage and an indoor air passage; a rotational shaft rotatably supported at one side of the case of a ventilating device; and a heat exchanging elements mounted at an outer circumferential surface of the rotational shaft at regular intervals, and performing a heat-exchanging operation of outdoor air and indoor air while being rotated by a wind force of outdoor air passing the outdoor air passage and a blow force of indoor air passing the indoor air passage. Thus, any additional driving unit is not necessary to rotate the heat exchanging system, so that a fabrication cost can be reduced, the overall size of the ventilating device can be reduced, and a noise and vibration can be reduced.

A humidity moisture exchanger (HME) for trapping heat and/or moisture normally lost during mechanical ventilation and the like. This HME includes a housing having a first chamber and a second chamber. The second chamber includes a pair of fluid ports connectable, in series, to a fluid flow tube extending from the patient. Inside the housing is a filter or an absorbent heat and moisture collecting material. To permit the uninhibited passage of fluid through the housing, the absorbent material is removed from the second chamber area and temporarily stored within the first chamber area.

Described is a method of conditioning a gas stream comprising passing the gas stream into a vessel 10 which contains a rotating enclosure 12 and which contains an apparatus 18 to rotate the enclosure, which enclosure is pressure sealed from the surrounding atmosphere and which is divided into a plurality of modulating zones 14, 16; treating the gas to modify its properties within the enclosures due to the presence of modulating materials 68 within the zones in the enclosure; and passing the modified gas to an outlet 24, 25 of the vessel. Also described is an apparatus for conditioning a plurality of gas streams.