A clothes dryer exhaust vent (dryer vent) and the method of installation in a residential or commercial building exterior foundation wall, during construction of a building, to save the expense and costs of a clothes dryer exhaust vent installation after a building has been constructed, to reduce repair and additional construction costs. The dryer vent has a rigid wall mounting plate (plastic or metal) that is mounted in the construction block array of an exterior building foundation wall while the wall is under construction. The clothes dryer exhaust vent includes a clothes dryer exhaust vent tube connected through the rigid, wall mounting plate (manually removable), an exterior (outdoors) hemispherical-shaped clothes dryer vent open end cover assembly, manually removable for cleaning and removing lint, said cover assembly including a clothes dryer exhaust vent flapper valve.

Disclosed is a method of operating an air purifier by executing an artificial intelligence (AI) algorithm and/or a machine learning algorithm in a fifth generation (5G) environment connected for the Internet of Things. A method for operating an air purifier comprises determining whether an indoor situation is a situation in which protection of a filter is necessary based on sensor information from at least one sensor, in response to a determination that the indoor situation is the situation in which protection of the filter is necessary, suspending an air purifying function, and operating one or more ventilation devices. According to the present disclosure, it is possible to protect the air purifier from a situation in which a life of the filter of the air purifier can be drastically shortened.

Disclosed is a method of operating an air purifier by executing an artificial intelligence (AI) algorithm and/or a machine learning algorithm in a fifth generation (5G) environment connected for the Internet of Things. A method for operating an air purifier comprises determining whether an indoor situation is a situation in which protection of a filter is necessary based on sensor information from at least one sensor, in response to a determination that the indoor situation is the situation in which protection of the filter is necessary, suspending an air purifying function, and operating one or more ventilation devices. According to the present disclosure, it is possible to protect the air purifier from a situation in which a life of the filter of the air purifier can be drastically shortened.

An environmental control system of a vehicle including a first inlet for providing a first medium, a second inlet for providing a second medium, a compression device arranged in fluid communication with the first inlet, and an expansion device separate from the compression device. The expansion device is arranged in fluid communication with the second inlet. Energy extracted from the second medium within the expansion device is provided to one or more loads of the vehicle.

A ventilator (1) includes: an air supply fan (2) to supply outdoor air to a room; an air exhaust fan (3) to exhaust indoor air, out of the room; and a total heat exchanger (4) which is made with partition boards (41) being moisture-permeable flat parts and with spacer boards (42) being corrugated parts, the partition boards and the spacer boards being alternately stacked, the total heat exchanger exchanging heat between the outdoor air and the indoor air; and thereby suppresses ice formation. The ventilator (1) includes: an indoor temperature sensor (7); an indoor humidity sensor (8); an outdoor temperature sensor (6); and a control unit (5) to control operation of the air supply fan (2) and the air exhaust fan (3) on a basis of at least one state quantity estimated by substituting the indoor air temperature, the indoor air humidity, and the outdoor air temperature in a total heat exchanger model formula (51a) representing characteristics of the total heat exchanger (4).

Provided is a fan filter unit with which the performance of a HEPA filter can be measured at multiple points with ease and in a short time. The fan filter unit has a first HEPA filter, a second HEPA filter, and exhaust means installed between the first HEPA filter and the second HEPA filter. The first HEPA filter, the second HEPA filter, and the exhaust means are integrated by a housing.

A vent cover assembly to cover an opening in a crawl space vent includes a vent cover having upper and lower surfaces, an outer perimeter and a planar clip. The vent cover includes a slit positioned through the upper and lower surfaces of the vent cover to receive the clip. The clip has a ring portion and a first leg and a second leg extending therefrom. The first and second legs are configured to be slidably inserted through the slit of the vent cover. The first and second legs of the clip are positioned and configured to receive therebetween a portion of a vertically positioned central wall of the crawl space vent. The central wall is frictionally griped between the first and second legs of the clip, and the inner surface of the vent cover is simultaneously positioned over an outer perimeter of the vent to close the vent.

A vent cover assembly to cover an opening in a crawl space vent includes a vent cover having upper and lower surfaces, an outer perimeter and a planar clip. The vent cover includes a slit positioned through the upper and lower surfaces of the vent cover to receive the clip. The clip has a ring portion and a first leg and a second leg extending therefrom. The first and second legs are configured to be slidably inserted through the slit of the vent cover. The first and second legs of the clip are positioned and configured to receive therebetween a portion of a vertically positioned central wall of the crawl space vent. The central wall is frictionally griped between the first and second legs of the clip, and the inner surface of the vent cover is simultaneously positioned over an outer perimeter of the vent to close the vent.

A ventilation system includes an inside air passage having inflow and outflow ends communicating with an indoor space to be ventilated, at least one permeable film unit including a permeable film, and an air supply passage having an inflow end communicating with an outdoor space and an outflow end connected to a downstream side of the permeable film in the inside air passage. The permeable film allows a target gas to pass and allows the target gas that has passed through the permeable film to be discharged into outdoor air. The target gas contains at least one of carbon dioxide and a volatile organic compound in indoor air that flows in the inside air passage. Alternatively or in addition, the ventilation system can include an outside air passage and a discharge passage in place of or in addition to the inside air passage and the air supply passage, respectively.

The invention relates to a method for controlling a passive-ventilation system of a building, comprising: determining an outdoor air temperature of air in an environment of the building; determining an indoor air temperature of at least one zone inside the building; calculating a temperature difference by subtracting the determined outside air temperature from the determined indoor air temperature; and, if the calculated temperature difference is greater than zero, controlling a state of at least one passive-ventilation device of the passive-ventilation system to be in any of a closed state, an open state, and one of one or more intermediate states between closed and open state. Each of the states corresponds to one value of an opening fraction value of the at least one zone inside the building varying between 0 and 1.