A system and method of retrofitting a heating, ventilation, air conditioning, and refrigeration system (HVACR) including one or more brazed, soldered, or mechanical connections between refrigerant lines is disclosed. The method includes removing a refrigerant from the HVACR system. The refrigerant that is removed is a non-flammable refrigerant. An enclosure is installed over the one or more brazed, soldered, or mechanical connections between refrigerant lines. A refrigerant is added to the HVACR system. The refrigerant being added has a global warming potential (GWP) that is relatively lower than the refrigerant removed from the HVACR system. The refrigerant being added has a relatively higher flammability than the refrigerant removed from the HVACR system.

The present disclosure relates to a digital control device based on artificial intelligence, belonging to the technical field of intelligent control. The digital control device based on artificial intelligence used by the present disclosure can comprehensively monitor the environmental data including temperature, humidity, smoke concentration, oxygen content, infrared temperature signals, etc. in real time by providing a control system, an environmental monitoring system and an actuating system, and generate control instructions through the monitored environmental data so that the actuating system can make corresponding actions accordingly, thus solving the problems existing problems in the prior art that the monitoring comprehensiveness is low, misjudgments or missed judgments are easy to occur, sensors cannot collect external environmental information in a time-sharing manner, and the practicability and service life are short.

Device for treating air and/or surfaces with treatment substance for disinfecting, can include a blower for sucking and blowing air, at least one conveying device for conveying the treatment substance, and at least one feed nozzle for feeding the treatment substance, wherein the feed nozzle is connectable to the conveying device via a connection line. The at least one feed nozzle can be arranged in the air flow of the blower, wherein the at least an end of a feed nozzle is removable and can also be arranged at a distance from the device, and can be connected to a ventilation duct of a ventilation and/or air-conditioning system of an environment. Additionally or alternatively, at least one further feed nozzle, which is connected or connectable to the conveying device via a connecting line, can be connected to a ventilation duct of a ventilation and/or air-conditioning system of the environment.

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.

A portable air cleaning apparatus includes a housing, an actuating and sensing device and an air cleaning unit. The housing includes an inlet through hole and an outlet through hole. The actuating and sensing module and the air cleaning unit are disposed inside the housing. The actuating and sensing module includes an actuating device and a sensor. The actuating device drives an external air to flow into an interior of the housing via the inlet through hole and discharge the air via the outlet through hole, so as to form an internal air flow. The sensor detects the internal air flow to generate an air-sensing result, such that the actuating and sensing module can accordingly control the air cleaning unit to turn on, turn off, or adjust cleaning intensity. Thus, the portable air cleaning apparatus can monitor and automatically clean the ambient air at the same time.

A method of controlling an air conditioner system, the method including transmitting, by a first unit among a plurality of units belonging to a particular group, a wireless tuning command to a second unit; measuring, by the second unit, reception sensitivity and a transmission and reception success rate by wirelessly communicating with units belonging to the particular group while reducing a signal strength from a default signal strength; when the reception sensitivity and the transmission and reception success rate satisfy the predetermined standard, determining, by the second unit, that the signal strength corresponding to a level right before a level satisfying a predetermined standard is the signal strength to be used; and transmitting, by the second unit, information related to the determined signal strength to the first unit. Accordingly, an optimal signal strength at which mutual interference is prevented may be set.

An air conditioning system using a fuel cell system can reduce energy consumption for air conditioning and can use the electricity produced by operating the fuel cells, where a fuel cell blower that is used to operate fuel cells is also used for air conditioning. The air conditioning system includes an air intake line connected between an interior and an exterior of a building; an air blower disposed in the air intake line to supply external air to the interior; a first intake shut-off valve for opening or closing the air intake line; a fuel cell system receiving air in the interior by operation of the fuel cell blower and producing electrical energy; and a controller controlling operation of the first intake shut-off valve to open the air intake line when the fuel cell system is operated.

A controller for controlling an environmental condition of a building space includes a proxy sensor configured to measure a proxy value indicating whether an occupant is within the building space and an occupancy sensor configured to measure an occupancy value. The controller includes a processing circuit configured to determine whether the occupant is within the building space based on the occupancy value of the occupancy sensor, generate a proxy parameter based on a first proxy value measured via the proxy sensor in response to a determination that the occupant is not within the building space based on the occupancy value of the occupancy sensor, determine whether the occupant is within the building based on a second proxy value measured via the proxy sensor and the generated proxy parameter, and control one or more pieces of building equipment to control the environmental condition of the building space.

A method is provided for operating a controlled atmosphere (CA) system to regulate the atmosphere in a cargo storage space. The CA system comprises a gas exchange module operable to vary the level of a component gas in the cargo storage space, a control module to control operation of the gas exchange module, and at least one of an oxygen sensor and a carbon dioxide sensor, each being operable to measure a parameter indicative of a level of oxygen or carbon dioxide respectively in the cargo storage space. The method comprises: the control module determining a respiration parameter value indicative of the rate of change of oxygen level and/or the rate of change of carbon dioxide level in the cargo storage space due to respiration of goods in the cargo storage space; and the control module controlling operation of the gas exchange module based on the determined respiration parameter value to target an oxygen level setpoint and/or a carbon dioxide level setpoint.

A room 100 in a building has a living etc. space 101 of volume V that is an enclosed space. Ventilation of an air flow F is performed from the outside to the living etc. space 101. Entering/exiting of air as an air current between the inside of the living etc. space 101 and the outside is eliminated, and at least a part of the boundary between the living etc. space 101 and the outside is configured from a gas exchange membrane 310 having a diffusion constant D, a thickness L, and an area A for gas molecules of interest. When air inside the living etc. space 101 is sufficiently agitated and the concentration of gas molecules constituting the air is made spatially uniform, (t) is controlled so as to vary according to

[00001]$\begin{array}{cc}\left(t\right)={}_o-\frac{\mathrm{BL}}{\mathrm{AD}}.Math.\left(1-\exp \left(-\left[\mathrm{AD}.Math.\text{/}.Math.L\right].Math.t.Math.\text{/}.Math.V\right)\right)& \left(9\right)\end{array}$

B(m.sup.3/s) is the gas consumption amount inside the living etc. space 101, .sub.1(t) is the gas concentration inside the living etc. space 101 at time t, and 0 is the gas concentration of the outside.