The present invention discloses a refrigerator controlling method and system with a linear compressor. The method comprises: monitoring an environment temperature T of the refrigerator located in the environment comparing the environment temperature T with a preset environment temperature threshold T0; if T is larger than T0, controlling a refrigerating unit and/or a heating unit in the refrigerator such that the refrigerator runs under a first operation condition; and if T is smaller than or equal to T0, controlling the refrigerating unit and/or the heating unit in the refrigerator such that the refrigerator runs under a second operation condition. When the linear compressor runs within predetermined time, a refrigeration amount of the linear compressor under the second operation condition is controlled to be larger than a refrigeration amount of the linear compressor under the first operation condition, such that a compartment of the refrigerator reaches a target temperature.

Provided are a control method and apparatus for increasing the amount of a circulating refrigerant, and an air conditioner. The control method includes: when a refrigerating capacity need is equivalent to a heating capacity need in the operation of an air-conditioning system, determining whether the discharge temperature of a compressor is greater than a preset safety alert value; if the discharge temperature of the compressor is greater than the safety alert value, adjusting the frequency of a fan of an outdoor heat exchanger; and when the discharge temperature of the compressor is not greater than the safety alert value, controlling to stop the adjustment of the frequency of the fan, and maintaining the air-conditioning system to operate at the adjusted current frequency of the fan.

A system includes an electronic power converter and a controller. The electronic power converter supplies power to one or more motor drives of an HVAC system. The controller obtains a plurality of pulse width modulation (PWM) algorithms. Each PWM algorithm has an associated spectrum of frequencies. The controller further determines one or more resonance frequencies associated with the HVAC system. The controller also selects a first PWM algorithm from the plurality of PWM algorithms wherein the spectrum of frequencies of the first PWM algorithm lacks frequency peaks that overlap with the one or more resonance frequencies associated with the HVAC system. The controller further operates the electronic power converter according to the first PWM algorithm.

Disclosed are a carbon dioxide overlapping type heating system and a control method therefor. The heating system comprises a low-temperature stage loop, a high-temperature stage loop and a heat supply loop, wherein a low-temperature stage compressor (3) and a high-temperature stage compressor (7) are both variable-frequency compressors; and a water pump (10) is a variable-frequency water pump.

Methods and related systems for controlling superheat in a climate control system are disclosed. In an embodiment, the method includes (a) determining a superheat of a refrigerant downstream of a coil of a heat exchanger of the climate control system. In addition, the method includes (b) determining that an expansion valve upstream of the heat exchanger is fully open. Further, the method includes (c) adjusting a speed of air flowing across the coil or a speed of a compressor of the climate control system after (b) based on the determination in (a) to control the superheat of the refrigerant.

A refrigerant measurement adjustment system includes: a refrigerant sensor for a building and configured to measure an amount of refrigerant present in air outside of a refrigeration system of the building; and an adjustment module configured to: adjust the amount of refrigerant measured based on an adjustment to produce an adjusted amount; and determine the adjustment based on at least one of: an air temperature; an air pressure; a relative humidity of air; a mode of operation of the refrigeration system; a change in the measurements of the refrigerant sensor over time; and whether a blower that blows air across a heat exchanger of the refrigeration system located within the building is on.

In a split system heat pump cooling and heating system, an auxiliary hot water storage tank is provided as an energy storage bank. Two sets of coils run through this storage tank, a first set carrying hot refrigerant from the heat pump to deposit energy and a second set carrying hot potable water to remove energy. Valve and switch matrixes are operated at the heat pump to provide hot potable water from the energy storage bank during both normal space heating and cooling operations of the heat pump.

Various embodiments of the teachings herein include a device for controlling a HVAC system of a room. The device may include: a memory storing a metamodel for a distribution of physical quantities of air in the room, the metamodel based on reduced order modeling of a plurality of executed simulations of the physical quantities for a first configuration of the room; and a processor programmed to determine a value of a first subset of the physical quantities at a certain location in the room using the metamodel and a set of measured values of each physical quantity being measured by a number of physical sensors.

An air conditioner unit includes a refrigeration loop, a variable speed compressor coupled to the refrigeration loop, an indoor temperature sensor, an electric heater, and a controller operably coupled to the variable speed compressor, the indoor temperature sensor, and the electric heater. The controller is configured to operate the variable speed compressor at a target speed, identify an auxiliary heating trigger of the air conditioner unit, and operate the electric heater according to the auxiliary heating trigger.

An outdoor unit includes at least one heat exchanger, a first motor including a first fan, a second motor including a second fan, an inverter that applies voltage to the first motor and the second for respectively, a connection switching unit that switches the voltage applied to the second motor between on and off, and a control unit that controls the inverter and the connection switching unit. The inverter is disposed closer to the first motor than to the second motor.