Noise Reduction Techniques in HVAC Compressors

Sealed compressor design to reduce vibration and noise by preventing gaps between the compressor container and base member during welding. The compressor has a cylindrical container with compressor and motor inside. The container bottom is welded to a base that supports it. The container bottom has an opening in the center that fits into an opening in the base. Welding spots are formed between the base and container at intervals around the opening. The welding spots extend a predetermined length in the circumferential direction and are positioned between the outer edge of the base opening and the container opening rim. This prevents deformation between the spots that could form gaps between the container and base during welding.

Source

A linear compressor with improved muffler design to reduce noise and improve rigidity. The compressor has a piston that linearly reciprocates in a cylinder to compress a fluid. It uses mufflers to suppress noise. The first muffler is attached to the piston. The second muffler is attached to the back cover spaced from the piston. The second muffler has a rib protruding from its inner or outer surface. This rib improves rigidity of the second muffler without affecting the refrigerant flow. The rib guides the muffler cover position relative to the muffler body. It also guides the muffler body position relative to the back cover. The ribbed muffler improves rigidity compared to a plain muffler. The ribbed muffler, in combination with the elastically supported back cover, reduces noise by amplifying the piston's

Source

Compressor device that improves energy efficiency and reduces vibrations compared to conventional compressors. The device has a compressor element to compress fluid. An adapter with expansion chambers at the outlet modifies the acoustic impedance to compensate for pressure pulsations. The adapter inlet has a smaller diameter than the outlet to create a step change. This causes the outgoing pressure pulsation to compensate the incoming pulsation, smoothing the fluid flow. The larger outlet area also improves evacuation and reduces pulsations.

Source

Rotary compressor and refrigeration cycle apparatus that reliably reduces pressure pulsation and vibration in the intermediate pipe connecting the low-stage and high-stage compressors, while downsizing the compressor overall. The compressor has a muffler connected to the intermediate pipe between the low-stage and high-stage compressors. The muffler outlet area is within a specific range relative to the flow path area. This optimized muffler size provides sufficient pulsation reduction without excessive muffler size. The compressor also has a fixation mechanism to secure the muffler. The muffler can be tangent or inside an imaginary circle centered on the compressor's axis, encompassing the accumulator, to minimize overall compressor size.

Source

Piston compressor with multiple gas discharge paths to reduce noise and vibration during operation compared to a single discharge path. The compressor has a cylinder head with a high-pressure chamber and a discharge hole. The crankcase has a high-pressure chamber, discharge channel, and discharge hole. The compressor has additional gas guide holes in components like the head gasket, valve plate, valve, and gasket. These paths allow gas to discharge via the crankcase channels instead of just the head hole, spreading out the discharge and reducing impact. This can significantly reduce vibration and noise compared to a single discharge path.

Source

Co-rotating scroll compressor for improved quietness. The scroll compressor has a driving scroll and a driven scroll that rotate around eccentric axes. To improve quietness, the scrolls have reduced thickness portions near the opposing scroll ends. These protrusions align the center of gravity of each scroll's spiral portion closer to its axis. This reduces dynamic imbalance during rotation compared to having thick scroll ends.

Source

Window-type air conditioner design to reduce noise transfer between the indoor and outdoor units. The air conditioner separates the compressor and outdoor heat exchanger from the indoor unit. It connects the two modules with a support that has soundproofing around the refrigerant pipe. This prevents noise from the compressor reaching the indoor space. The support also has features to improve connection strength considering the external forces applied to the window-mounted air conditioner.

Source

Reciprocating compressor design with reduced vibration transmission to the enclosure and improved discharge gas flow at high speeds. The compressor has multiple flexible discharge hoses connecting the discharge muffler and discharge pipe. This allows vibrations from the compressor body to be isolated from the enclosure since the flexible hoses can move independently. It also prevents clogging of the discharge gas during high-speed operation since the flexible hoses can accommodate any expansion/contraction of the discharge gas.

Source

Reducing noise in devices like compressors and ducted air movers by using a noise-damping resonator. It involves adding an acoustic resistive screen over an aperture between the air flow duct and a gas-filled cavity. The screen resists airflow between the duct and cavity, forming a resonator that attenuates noise in a target frequency band. The screen characteristics are optimized based on duct, cavity, and aperture geometry to maximize noise reduction.

Source

Heat pumps represent an essential component of the energy transition. While they are effective in generating heat, also generate sound, which has potential to cause annoyance. Therefore, it is enhance transparency sound behavior. Analyses were performed identify factors influencing levels at both and system levels. A total three refrigerant compressors examined with objective determining most acoustically efficient components currently available key acoustics. Two low-noise axial fans used illustrate differing characteristics when a heat pump application. Based on tests measurements level, speeds compressor fan confirmed as significant emissions air-to-water pumps. In addition, flow temperature operating point identified influencing. The results employed develop improved demonstrator. model could be developed that capable describing behavior for wide range conditions. This methodology allows increased Different behaviors can demonstrated basis model, discussions definition maximum specifications held data. Sound should not only linked output, this increases uncertainty comparability.... Read More

Source

Air-cooled compressor installation with improved fan housing for radial fans to reduce pressure drop, noise, and improve airflow. The fan housing has the fan inlet and outlet parallel planes. The fan axis at an angle between 0-45° to the inlet plane. The outlet edge doesn't intersect the fan axis extension to avoid bending airflow. This eliminates the need for the fan to bend airflow through a 90° turn at the outlet, reducing pressure drop and noise.

Source

A rotary compressor design for reducing noise, vibration and improving efficiency in air conditioners, refrigerators, and heaters using natural refrigerants like CO2. The compressor has a discharge space with 3-10 times the cylinder volume to mitigate pulsation when the gas exits the compression chamber. This reduces pressure fluctuations and noise compared to conventional compressors. The discharge space is formed by recessing one end plate and covering it with a separate plate.

Source

A piston rod mechanism for an air compressor that reduces noise during operation. The mechanism has an intake valve secured to the piston with pivot pins. It also has a receiving portion in the piston to house the closed intake valve. This allows the intake valve to oscillate relative to the piston as it moves. The receiving portion prevents the valve from contacting the piston and generating noise when the valve is closed. This improves the overall noise level of the air compressor. The valve can be made of silicone, the rod of plastic, the bearing of metal, and the piston ring of rubber to further reduce noise.

Source

Apparatus for damping pressure pulsation in a refrigerant compressor that reduces noise without significant pressure loss. It has a piston in a housing that can move to control flow area. The piston has seals to create chambers that expand the fluid as it flows. This dampens pressure pulsations when the compressor has low flow. The piston moves between closed and fully open positions. The chambers allow flow when the piston is not at the ends. The piston seals contact the housing seals. This simple, compact design with minimal components and materials reduces costs and space requirements compared to complex valves or silencers.

Source

A linear compressor for compressing a refrigerant using a piston that linearly reciprocates in a cylinder. The compressor has two muffler units to improve noise filtering, intake efficiency, and space efficiency. The first muffler is between the piston and back cover. The second muffler surrounds the first muffler and has a communication hole between the inner and outer mufflers. This allows fluid flow between the mufflers. The outer muffler also surrounds the cylinder opening. This dual muffler setup filters noise, improves intake efficiency by capturing and compressing more fluid, and saves space compared to a single muffler.

Source

Abstract In this paper, a systematic experimental study is carried out on the overclocking operation of chillers. Based platform under nominal refrigeration conditions, evolution key performance parameters such as evaporation pressure, condensation capacity, power, and noise different driving frequencies was tested. The results show that with increase frequency, capacity increases linearly, while coefficient chiller decreases significantly, sound pressure level shows nonlinear acceleration upward trend. This achievement can provide theoretical basis engineering decision support for selection design chillers, frequency conversion optimization, energy efficiency-noise collaborative control in industrial field.

Source

Motor-driven compressor with improved heat dissipation and noise reduction. The compressor has an inverter to convert DC power to AC for the motor. A noise reducing unit at the inverter input reduces common mode and normal mode noise in the DC power. The inverter case is thermally coupled to the compressor housing. A damping unit forms a magnetic path for the choke coil leakage flux and increases choke inductance. This damping unit covers part of the choke coil side surface and is thermally coupled to the inverter case and compressor housing for heat dissipation.

Source

Heat pump water heater with mufflers to reduce noise transmission from the compressor. The heat pump water heater has mufflers, an inlet muffler between the compressor and air inlet, and an outlet muffler between the compressor and air outlet. These mufflers prevent sound waves generated by the compressor from traveling through the air inlet and outlet and escaping the water heater, reducing exterior noise levels.

Source

Electric compressor for refrigeration applications that has reduced noise, vibration, and pulsation compared to prior art scroll-type electric compressors. The compressor has features like a modified fixed scroll floor, an isolation/constraint system, and a reed mechanism in the head. These reduce oscillations and pulsations during operation that can transmit to the housing and cause noise, vibration, and durability issues. The modified scroll floor reduces articulation and oscillations of the scroll. The isolation/constraint system isolates the housing from compressor oscillations. The reed mechanism in the head releases compressed refrigerant earlier from side ports before the central port to prevent strong pulsations in the refrigerant flow.

Source

Electric compressor for refrigeration systems that compresses refrigerant using a scroll compression device. The compressor has features to improve efficiency, reduce noise, and extend durability compared to prior scroll compressors. These include: 1. Swing-link mechanism with integrated limit pin to replace separate drive and eccentric pins. This simplifies and strengthens the connection between the drive shaft and swing-link. 2. Discharge head with an integrated oil separator to separate oil from refrigerant before exiting. 3. Scroll bearing with oil injection orifice to ensure adequate oil lubrication. 4. Bearing oil communication hole in the drive shaft to improve oil flow to bearings. 5. Dome-shaped inverter cover to reduce vibrations and noise.

Source

Motor-driven compressor with a noise reduction circuit to mitigate EMC issues. The noise reduction circuit is integrated into the inverter device which converts DC power to AC power. It uses a common mode choke coil with a divided annular conductor. One section of the conductor is thermally connected to the housing and the other section is thermally connected to the main body. This allows induced current to flow around the coil in a circumferential direction, reducing leakage flux. The divided conductor section with lower resistance and thermal conductivity helps dissipate heat generated by the induced current to the housing.

Source

Motor-driven compressor for vehicle air conditioners with improved noise reduction. The compressor has a housing containing the compression unit, motor, and inverter. The inverter has a noise reducing unit with a common mode choke coil, smoothing capacitor, and two damping portions. One damping portion is nonmagnetic and surrounds the coil windings to reduce normal mode noise by generating magnetic flux to resist leakage flux. The other damping portion is magnetic and reduces normal mode noise on the opposite side of the coil. This configuration helps damp common mode and normal mode noise in the compressor inverter.

Source

A noise reduction refrigeration system for household appliances that achieves a lower noise level than conventional low-temperature systems. The system employs a unique configuration where the high-pressure side of the low-temperature refrigeration cycle loop operates within a narrower pressure range compared to conventional systems. This configuration enables the low-pressure side of the refrigeration cycle loop to operate within a broader pressure range, allowing the low-pressure compressor to achieve a lower suction pressure and exhaust pressure. The system achieves this by configuring the high-pressure side to operate at a lower absolute pressure range (2-11 bar) and the low-pressure side to operate at a higher absolute pressure range (0.2-1.1 bar), thereby reducing the overall system pressure drop and resulting noise.

Source

A heat pump compressor noise reduction device for household air source heat pumps that effectively reduces compressor noise while maintaining system performance. The device comprises a compressor body, a vibration-damping pad fixed to the bottom of the compressor body, a top cover that covers the compressor body, and a surrounding plate that encloses the compressor body between the top cover and the bottom plate. This design provides optimal damping of the compressor's vibration through the vibration-damping pad, while the top cover and surrounding plate work together to provide effective noise reduction around the compressor.

Source

A compressor design to reduce compressor noise in air conditioning systems. The design incorporates a unique muffler configuration that optimizes airflow management through the exhaust port. By strategically positioning the muffler's mounting structure, the system achieves a specific axial depth ratio (H) that balances airflow velocity and pressure drop. This configuration enables the compressor to operate within a narrower range of axial depths, thereby reducing the noise generated by the exhaust port. The design ensures structural integrity while maintaining optimal airflow characteristics, resulting in a quieter compressor operation.

Source

Noise reduction device for heat pump air conditioners that utilizes a novel sound-absorbing mechanism integrated into the compressor housing. The device comprises a compressor, a sound-absorbing mechanism connected to the output end of the compressor through a pipeline, and a sound-absorbing cavity with multiple sound-absorbing channels. The sound-absorbing mechanism is arranged in a sealed, end-to-end configuration within the cavity, with both ends connected to the end cover. The input and output pipes are arranged away from the cover, communicating with the cavity through separate channels. This configuration enables effective sound absorption while maintaining the compressor's operational integrity.

Source

A compression refrigeration system and refrigeration device that eliminates compressor noise through a novel muffler design. The system incorporates a muffler with a specially configured chamber between the compressor and condenser, where exhaust and intake pipes are inserted. This chamber creates a buffer zone that significantly reduces the compressor-pulsation noise and vibration. The system also incorporates a comprehensive cleaning system to prevent impurities from entering the system.

Source

A heat pump unit with integrated noise reduction system that achieves both efficient heating and cooling while minimizing noise. The unit features a sound-absorbing plate integrated into the finned heat exchanger design, which optimally positions airflow paths for optimal sound absorption. The plate is strategically positioned to maximize sound absorption while maintaining airflow efficiency. An electric control box is positioned in front of the compressor to block noise propagation. The system is integrated into the unit's design, eliminating the need for separate noise-reducing barriers or enclosures.

Source

A noise reduction device for air conditioners that effectively absorbs low-frequency and intermediate-frequency noise. The device comprises a muffler frame with a perforated plate that encloses the muffler cavity. A sound-absorbing layer is attached to the perforated plate, filling the cavity. The perforated plate has through holes that allow the noise to pass through, while the sound-absorbing layer absorbs the noise. The sound-absorbing layer fills the cavity, with the perforated plate providing the initial path for noise entry.

Source

Compressor assembly and air conditioner with reduced noise and vibration by using resonant sound absorption structures around the compressor. The compressor body has a cover with resonance structures inside that fall between the cover and compressor body. The structures have shapes like helmholtz resonators. The resonant frequencies of the structures in each group match compressor frequency bands. This converts vibration energy to heat through friction. The structures absorb compressor noise by resonance. It provides effective noise/vibration reduction compared to traditional damping.

Source

A compressor and air conditioning system that reduces compressor noise through advanced liquid separator design. The system employs a unique liquid separator configuration that eliminates the traditional liquid separator's high-frequency resonant peaks while maintaining optimal low-frequency performance. The separator's design incorporates a specially engineered separator wall that effectively suppresses the 1500 Hz resonant frequency, while maintaining the separator's high flow rates and pressure characteristics. This innovative design approach enables the compressor to operate at high speeds while significantly reducing noise levels, particularly at frequencies above 1500 Hz.

Source

A low-noise compressor that reduces vibration and noise generated during gas transportation through a novel combination of sound-absorbing and damping materials integrated into the compressor casing. The compressor comprises a casing, a compression mechanism arranged in the casing, and a compression drive mechanism for driving the compression mechanism to work. The compression mechanism includes a first compression structure and a second compression structure, where the first compression structure is located on one side of the casing, the second compression structure is located on the other side of the casing, the casing is in contact with the first compression structure and the second compression structure, compression chambers are provided at corresponding positions of, wherein there are two compression chambers, a first compression chamber and a second compression chamber respectively, the first compression structure is provided in the first compression chamber, the second compression chamber is arranged in the second compression chamber, the air outlet of the first compression chamber communicates with the air inlet of the second compression chamber through a connecting pipe, the connecting pipe is provided with a sound-absorbing and shock-absorbing material made of sound-absorbing material.

Source

Electrochemical device that reduces airborne noise in air shafts of the heat pump. The device includes a refrigerant circuit, a interference silencer, and a pipeline.

Source

A compressor vibration and noise reduction structure that significantly reduces vibration transmission and noise generation in air conditioner compressors. The structure includes a noise reduction shell around the compressor, flexible vibration damping rings between the shell and compressor, outlet and intake pipe damping parts, and vibration reduction seats. The damping rings, seats, and parts isolate and absorb vibrations between the compressor and shell, pipes, and housing. The intake pipe damping part connects the pipes and seals to prevent air leakage. The shell and compressor vibration damping reduces transmission to the shell and housing. This simple, low-cost structure significantly reduces compressor vibration and noise compared to improving accuracy and balance.

Source

A noise-reducing enclosure for HVAC systems that minimizes compressor noise transmission through the housing. The enclosure encloses the compressor within a rigid metal shell, with an outer insulating structure that includes a rigid plastic sheet and a foam layer. The enclosure is designed to provide structural mass to absorb compressor vibrations, while maintaining a tight seal to prevent air leaks. The enclosure is mounted to the housing first end, creating a hermetically sealed structure that significantly reduces compressor noise transmission through the duct system.

Source

A compressor assembly and refrigeration system that reduces compressor noise by incorporating a wavelength tube muffler. The muffler is strategically positioned to intercept and dissipate the high-frequency pressure wave generated during compressor operation, thereby significantly reducing the sound intensity transmitted to the outside environment. The muffler is integrated into both the compressor and the accumulator, with its chamber communicating through a circulation port. This design enables the muffler to effectively suppress the high-frequency noise characteristic of compressor operation.

Source

A compressor assembly and refrigeration system design that reduces compressor noise through a novel resonance chamber muffler configuration. The design incorporates a muffler that houses a resonant chamber with a unique cavity configuration where the cross-sectional area of the chamber's end is larger than the adjacent cavity's end. This design creates a resonant cavity that amplifies and dissipates sound energy, effectively reducing compressor noise levels. The muffler is strategically positioned outside the compressor's inner cavity, allowing direct sound entry from the compressor's exhaust port. This design enables the muffler to capture and dissipate sound energy while maintaining optimal airflow and pressure conditions.

Source

A noise-reducing silencer for compressors that integrates directly into the compressor's air inlet while maintaining operational efficiency. The silencer comprises a housing, a silencer core comprising two spiral chambers stacked on each other, and sound-absorbing material within the spiral chambers. The core design enables effective noise reduction without compromising airflow or compressor performance. The silencer can be integrated into the compressor's air filter or attached as a separate element to achieve optimal noise reduction while minimizing installation complexity.

Source

A low-noise heat pump system that minimizes noise generation through optimized compressor placement and system design. The system employs a novel compressor mounting configuration where the compressor is integrated into the heat pump unit casing, rather than being mounted on the chassis. This eliminates the direct motor-axial interaction with the chassis and eliminates the resonant pipe connections, significantly reducing noise levels. The system also features a specially designed fan configuration that reduces fan noise through optimized airflow paths. The integrated compressor and fan design provides a low-noise operation characteristic, making it suitable for residential applications where noise sensitivity is a concern.

Source

A scroll compressor for heat pump systems that achieves superior noise reduction through a novel silencing assembly. The compressor incorporates a sound-absorbing material in its exhaust port, with an additional elastic member positioned between the exhaust port and the scroll. This dual-path silencing approach effectively absorbs both the high-frequency noise generated by the compressor discharge and the lower-frequency noise radiated through the exhaust port. The elastic member absorbs the gas discharge noise, while the sound-absorbing material in the exhaust port absorbs the port noise. The system's design enables both port and exhaust noise reduction, significantly improving overall system noise performance compared to conventional muffler-based solutions.

Source

Cryogenic refrigeration condensing unit with anti-noise device that addresses the challenge of meeting both indoor and outdoor noise standards for commercial refrigeration equipment. The device integrates a low-temperature refrigeration compressor, condenser fan, and vapor-liquid separator into a single unit. The compressor outlet is connected to a condenser, while the condenser outlet connects to a reservoir. The reservoir inlet is connected to a vapor-liquid separator, which then connects to a cold-air pipe. An anti-noise device comprises a cover with integrated sound-absorbing material and ventilation channels that direct noise away from the compressor. This innovative design enables the condensing unit to achieve both indoor noise standards (60 dB) and outdoor noise requirements (61-73 dB) while minimizing noise transmission through the condenser fan and compressor.

Source

A scroll compressor for air conditioning systems that reduces exhaust noise through a novel sound-absorbing design. The compressor features a fixed scroll with a strategically positioned exhaust port, followed by a sound-absorbing component above the exhaust port. The sound-absorbing material is strategically positioned to effectively absorb the high-frequency noise generated by gas discharge from the exhaust port. This innovative design addresses the conventional limitations of traditional muffler solutions while maintaining the compact and lightweight characteristics of scroll compressors.

Source

Acoustic filter for compressors that achieves superior balance between noise reduction and thermodynamic performance. The filter comprises an inlet duct, an outlet duct, and a resonator chamber, with a main chamber that houses the filter components. The resonator chamber serves as a resonant cavity that enhances the filter's acoustic performance by creating a resonant frequency response. The filter's design enables efficient transfer of refrigerant fluid through multiple chambers, with the resonator chamber playing a critical role in achieving optimal acoustic performance. The filter's unique configuration enables both efficient noise reduction and high-temperature performance, making it particularly suitable for applications requiring both acoustic and thermodynamic performance.

Source

A refrigerant line muffler for HVAC systems that specifically attenuates low-frequency pressure pulses generated by variable speed compressors. The muffler employs a phase-shifting flow path between the inlet and outlet, creating destructive interference between the pressure waves from the inlet and outlet paths. This phase-shifting action effectively reduces the amplitude of low-frequency pressure pulses characteristic of variable speed compressors, particularly those operating below 100 Hz.

Source

A rotary compressor with improved noise reduction through resonance chamber design. The compressor incorporates a separator between the main and sub-bearings, with Helmholtz resonance chambers communicating through multiple gas flow passages. The separator enables direct communication between the resonance chambers, while the multiple flow passages enhance the resonance effect. This design eliminates the single silencer band typically found in conventional compressors, resulting in reduced noise levels.

Source

Air conditioner and heat exchange system that reduces vibration and noise in central partition areas. The system incorporates a sound-absorbing partition between the shell and the compressor, strategically positioned to minimize vibration transmission through the partition. This design enables the system to maintain efficient heat transfer while significantly reducing the noise generated by the compressor and its components.

Source

A compressor design that significantly reduces compressor noise through a novel mounting system. The compressor incorporates a noise-reducing member that surrounds the compressor body, with a separate mounting system for the noise-reducing element. The mounting system consists of two cylindrical members that fit into the compressor casing, with one end of the noise-reducing element inserted into the first member and the other end inserted into the second member. The mounting members are secured to the compressor casing using press-fitting or welding, while the noise-reducing element is mounted on the inner wall of the casing. This design provides a robust and precise mounting solution that effectively reduces compressor noise while maintaining structural integrity.

Source

A rotary compressor design with reduced noise and improved reliability compared to conventional rotary compressors. The compressor has a shell with a compression mechanism inside. The compression mechanism has main and auxiliary bearings that limit the compression chamber. A main silencer is mounted on the main bearing and an assistant silencer is mounted on the auxiliary bearing. This silencer setup reduces compressor noise. The compressor also has an air outlet connected to the shell and exhaust ports. The air outlet channel passes through the silencer structure. This channel redirects discharged refrigerant gas to the shell instead of directly exhausting it, preventing gas escaping the compressor and reducing noise. The compressor connects the air inlet, exhaust ports, and the channel in the silencer to reduce gas energy and noise compared to having separate external passages.

Source

A refrigeration device that significantly reduces noise levels through optimized acoustic design. The device comprises a box body with back cover board, a compressor positioned on the back cover board, and a sound-absorbing board situated between the compressor and the front surface. The sound-absorbing board is strategically positioned to create a defined sound-absorbing area between the compressor and the front surface, thereby minimizing sound transmission. This design enables the device to achieve significant noise reduction while maintaining effective refrigeration performance.

Source

Rotary compressor with reduced noise and vibration. The compressor has a shell, compression mechanism, and silencing device. The compression mechanism has an air cylinder with bearings. The silencing device is a muffler connected to the cylinder and bearings. The muffler has a volume and cross-sectional area to attenuate compressor noise. The muffler separates the compressor's noise-generating components from the rest of the compressor to reduce overall noise.

Source