An HVAC system for a multi-unit building having a riser stack in flow communication with a single unit HVAC system. The single unit HVAC system has a first heat exchanger thermally connected to the riser stack, a second heat exchanger thermally connected to a fluid distribution system within the unit, and a closed loop fluid flow path extending between the first and second heat exchangers. The first heat exchanger exchanges heat between a riser stack fluid in the riser stack and the closed loop fluid in the closed loop fluid flow path and the second heat exchanger exchanges heat between the closed loop fluid and a distribution fluid of the fluid distribution system.

An air purifier includes a housing (1), an intake built into the housing (1) which is designed for the intake of air into the housing (1), an exhaust built into the housing (1) which is designed for the venting of air out of the housing (1), a blower (2) disposed in the housing for generating an air stream which flows from the intake to the exhaust, at least one filter (3) which is designed to purify the air flowing from the intake to the exhaust, and a bioreactor (4) which is disposed on and/or in the housing (1) such that the air stream flows through it, and which contains at least one life form (5) which is designed to at least partially convert CO.sub.2 contained in the air stream into O.sub.2 by means of photosynthesis.

An air purifier includes a housing (1), an intake built into the housing (1) which is designed for the intake of air into the housing (1), an exhaust built into the housing (1) which is designed for the venting of air out of the housing (1), a blower (2) disposed in the housing for generating an air stream which flows from the intake to the exhaust, at least one filter (3) which is designed to purify the air flowing from the intake to the exhaust, and a bioreactor (4) which is disposed on and/or in the housing (1) such that the air stream flows through it, and which contains at least one life form (5) which is designed to at least partially convert CO.sub.2 contained in the air stream into O.sub.2 by means of photosynthesis.

An HVAC decontamination system with regulated ozone output based on monitored ozone level in ambient air is disclosed. The HVAC decontamination system includes an ozone supply unit and an air analyzer. Based on one or more control signals from the air analyzer, the ozone supply unit is configured to: (i) generate ozone when an amount of ozone per unit volume of air is less than a predetermined threshold; and (ii) cease to generate ozone when the amount of ozone per unit volume of air exceeds the predetermined threshold.

An HVAC decontamination system with regulated ozone output based on monitored ozone level in ambient air is disclosed. The HVAC decontamination system includes an ozone supply unit and an air analyzer. Based on one or more control signals from the air analyzer, the ozone supply unit is configured to: (i) generate ozone when an amount of ozone per unit volume of air is less than a predetermined threshold; and (ii) cease to generate ozone when the amount of ozone per unit volume of air exceeds the predetermined threshold.

Systems and methods for circulating air in an enclosed environment are disclosed. In some embodiments, the system includes an inlet to receive air from outside of the enclosed environment and an air handling unit coupled to the inlet and also configured to receive circulated air from the enclosed environment. The air handling unit can be configured to affect a temperature of at least one of the received outside air and the received circulated air. Based on the received outside air and the received circulated air, the air handling unit can be further configured to generate air for supplying to the enclosed environment.

A system for controlling an environment to enhance circadian rhythm includes a control system associated with a building, and a plurality of sensors and environment enhancing devices placed within the building. Based on data transmitted by the sensors to the control system, the control system activates the environment enhancing devices to improve circadian rhythms of a resident.

The present disclosure relates to a diffuser module having an inlet and an outlet for use in connection with a) an air cleaning unit having an inlet and an outlet, wherein the inlet is adapted to receive ambient air and the outlet is adapted to disperse the cleaned air, and a housing containing the air cleaning unit, b) an air cooling unit having an inlet and an outlet, wherein the inlet is adapted to receive ambient air and the outlet is adapted to disperse the cooled air, and a housing containing the air cooling unit, or c) both a) and b), wherein the inlet of the diffuser module is connected to the outlet of the air cleaning unit and/or the air cooling unit and the outlet of the diffuser module is adapted to direct the cleaned air and/or the cooled air to a specified zone.

The present specification relates to a system for managing the condition of air in an enclosed environment comprising a flow path adapted to circulate a flow of air through the enclosed environment, the flow of air comprising at least one of a first portion comprising a gas comprising oxygen and a second portion comprising indoor air from the enclosed environment. The flow path selectively provides the portions. An air processing assembly is adapted to receive the flow of air. A first and a second air processing element is provided. A control system is adapted to determine the first portion of gas comprising oxygen and the second portion of indoor air from the enclosed environment and control the selectively coupling of the air processing elements to the flow path.

The invention relates to a method and to an apparatus for separating and utilizing carbon dioxide. According to the invention, carbon dioxide (3a, 3b) is separated from air (1a) being conducted to a building and/or from air (1c,1d) being circulated in the building to reduce the level of carbon dioxide in indoor air (1b) of the building (4), the carbon dioxide (3a, 3b) is recovered, and the carbon dioxide is conducted to a carbon dioxide treatment stage (5), where a chemical compound (6) is formed from the carbon dioxide. In addition, the invention relates to the use of the method.