Use Case & Customer Feedback – Micro DC Aircon

• Project: Power Distribution Box / Cabinet
• Cooling Approach: Active Air Cooling
• Demand: A company that specializes in outdoor distribution boxes in Saudi Arabia is looking for a battery-powered, variable-frequency direct current (DC) portable air conditioning unit. This micro DC aircon unit is intended to cool down the distribution box and maintain a temperature of around 20℃ degrees Celsius, even in high ambient temperatures reaching up to 60℃ degrees Celsius.
• Recommended product: 2.8cc Twin Cylinder Micro DC Aircon

Customer Feedback (DV2820E-AC):

The portable air conditioning unit provides powerful cooling performance, fully meeting the customer’s requirements and achieving temperature reduction in the distribution box. Additionally, this unit, equipped with a dual-cylinder compressor, is highly resistant to high temperatures. It can operate reliably and steadily even in outdoor environments with high ambient temperatures.

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Test Result From The Saudi Arabia Client

Q&A of Twin Cylinder Micro DC Aircon

1. The Saudi Arabia customer is inquiring whether this portable air conditioning unit comes with a ducted hose for air ventilation. The answer is YES. The RIGID company also provides the inlet and outlet hoses of portable aircon units.

Following are the hose diameters:

*Inlet

• Internal diameter: 38mm
• External diameter: 42mm

*Outlet

• Internal diameter: 35mm
• External diameter: 38mm

2. The customer wants to know if it is acceptable to use a single-turn 50kohm potentiometer for compressor control by fitting a remote control with a potentiometer. The answer is, that it is not suitable, but we suggests alternatives such as PWM Speed Control, 0-5V Speed Control, or TTL communication port. The RIGID company recommends four options for speed control in an attached document.

3. The customer mentions that the potentiometer was set to approximately 8 Amps, and when they adjusted it, the maximum DC current reached 16 Amps. They expected it to reach 25 Amps or 300W. RIGID company advises using a multimeter to measure the resistance of the potentiometer within the range of 5kΩ to 30kΩ, with the factory default setting being 23kΩ.

The reason is that the compressor stops working when the resistance is 50kΩ and provide a speed test formula based on resistance. The running the compressor above 5500rpm is possible but may result in increased noise and higher working current, without causing harm to the compressor.

Compressor speed = 6000-134 x R (kΩ) ( 1901/1902)

4. The customer experiences noisy vibration from the compressor when the power exceeds 10 amps. They inquire if this is normal and ask for suggestions to reduce the noise. The answer is, that it is normal to have noisy vibration above 10A power and advises keeping the compressor speed between 3000 and 3500rpm to minimize the noise.

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Working Principle – Micro DC Aircon

RIGID company DC (Direct Current) air conditioner used to cool an electronics enclosure on a robot operates on the same principles as a traditional air conditioner but is designed to run on DC power sources commonly found in mobile and remote applications.

Cooling Cycle:

The DC air conditioner utilizes a cooling cycle, similar to a typical air conditioning system. The cycle involves the circulation of a refrigerant through a closed loop.

Components:

Compressor: The compressor is responsible for pressurizing the refrigerant gas. In a DC air conditioner, the compressor is designed to run on DC power, usually supplied by the robot’s battery or power source.

1. Condenser: After being compressed, the refrigerant gas becomes hot and is then circulated to the condenser. The condenser is a heat exchanger that dissipates the heat from the gas, causing it to condense into a high-pressure liquid.
2. Evaporator: The high-pressure liquid refrigerant is then sent to the evaporator, which is located inside the electronics enclosure on the robot. As the refrigerant flows through the evaporator, it evaporates, absorbing heat from the surrounding air inside the enclosure. This process cools down the air inside the enclosure.
3. Expansion Component (capillary): The high-pressure liquid refrigerant is throttled through an expansion valve just before entering the evaporator. This reduces its pressure and allows it to evaporate at a lower temperature.
4. Heat Transfer: As the refrigerant evaporates inside the evaporator, it draws heat from the electronics and the air inside the enclosure. This heat transfer process effectively cools the electronics.
5. Fans&Blower: A fan or blower inside the enclosure helps circulate the cooled air over the electronics, ensuring even cooling and efficient heat exchange.
6. Thermostat and Control: To maintain a consistent temperature inside the enclosure, the DC air conditioner typically includes a thermostat and control system. The thermostat monitors the temperature and activates or deactivates the cooling process as needed to maintain the desired temperature.
7. Power Supply: Since the air conditioner is designed to run on DC power, it can be directly connected to the battery or solar power source. This makes it suitable for mobile applications where AC power sources may not be readily available.

Advantages – Micro DC Aircon

RIGID DC air conditioner units offer several advantages for cooling electronics enclosures, especially in mobile and remote applications:

1. Efficient Cooling: The DC aircon effectively cools electronics enclosures, preventing overheating of sensitive components. They maintain a stable and controlled temperature within the enclosure.
2. Compact and Space-Saving: These DC A/C units are typically compact and designed to fit into tight spaces. This is essential for robots and other devices with limited enclosure space.
3. DC Power Compatibility: They can run on DC power sources commonly found in mobile applications, such as batteries or solar power, making them suitable for use in remote locations where AC power may not be available.
4. Portability: They can be easily moved or mounted on mobile equipment, vehicles, or robots. This flexibility allows for cooling in various locations.
5. Quick Installation: RIGID DC A/C units are often designed for easy setup, reducing downtime when incorporating them into a new or existing system.
6. Customizable Cooling: RIGID provides custom products with adjustable settings, allowing users to tailor the cooling to their specific needs.
7. Quiet Operation: The twin-cylinder units (DV28 & DV38 series) are often engineered for quiet operation, making them suitable for applications where noise levels need to be minimized, such as in robotics or surveillance equipment.
8. Energy Efficiency: DC air conditioners are designed to be energy-efficient, helping to conserve power in battery-operated systems or in situations where power supply is limited.
9. Remote Monitoring and Control: The DC systems all come with drive boards, which enable users’ remote monitoring and control capabilities, allowing users to adjust settings or achieve complicated functions regarding the enclosure’s temperature and operation.
10. Reliability: The tropical series DC air conditioner units are typically built to withstand harsh environmental conditions (60℃/140℉), ensuring the reliable operation of electronics even in challenging settings.
11. Extended Component Life: By maintaining a stable and lower operating temperature, these air conditioners can extend the lifespan of electronic components, reducing the frequency of replacements and repairs.

Recommend Models:

1. DV1920E-AC-T (Tropical, 450W)
2. DV2820E-AC (Tropical, 700W)

Micro DC Aircon for telecom outdoor cabinet-RIGID

To put it simply, RIGID company Micro DC aircons are a useful and effective way to keep electronics safe and cool in mobile and remote setups. They’re flexible, save energy, and prevent electronics from getting too hot or affected by the environment.

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In Summary

RIGID company DC air conditioner units, in this case, are used for cooling electronics parts on a Power Distribution Box operated by circulating a refrigerant through a closed loop. The Micro DC Aircon includes components like a compressor, condenser, evaporator, fans and blower, expansion part, and refrigerant. The refrigerant absorbs heat from the electronics inside the enclosure, and a fan helps distribute the cooled air. The DC Aircon is controlled by its drive board which can be integrated into the user’s software to gain complicated functions, and it runs on DC power from the battery, making it suitable for mobile applications. Overall, the RIGID micro DC aircon is an ideal air cooler to prevent electronics from overheating and ensures reliable operation in different conditions.

About RIGID

Back in 2010, we introduced the RIGID miniature DC compressor to the Chinese market. Our goal was to bring a new refrigeration solution that combined performance with a small size.

In 2016, we established the RIGID brand and started working on our first DC compressor. Our team of experts dedicated years to developing innovative solutions, resulting in the world’s smallest cooling systems. Today, you have a range of options to choose from, and we’re ready to customize a compact cooling system for any application you need.

Here’s what you can expect from us:

1. We work closely with you right from the start. We carefully listen to your requirements and suggest the most suitable small cooling systems for your specific needs.
2. We offer worldwide delivery. Our experts have a quick turnaround time for designing cooling systems, and we’re prepared to send our devices to any location around the globe, ensuring they arrive promptly.
3. We prioritize exceptional quality at competitive prices. At RIGID, we use top-quality components in our products, guaranteeing value for your money and impressive durability. Moreover, we strive to offer competitive prices that fit your budget.