Project: Horizontal DC Compressors for Transport Refrigeration
Cooling Approach: Air-cooled
Cooling Approach: The United States client, a BABA-certified HVAC maker, is developing a roof-mounted, battery-driven AC system for electric vehicles. They seek RIGID’s horizontal DC compressor for its space-saving, efficient, and high-performance design. Ideal for buses, delivery vans, and EV fleets, the system ensures durable, energy-efficient cooling with minimal cabin space use.
Recommended products: Horizontal BLDC Compressor

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Project Background –

Rooftop Air Conditioning System for Electric Vehicles

The client, a Build America, Buy America (BABA) certified HVAC systems manufacturer, specializes in designing, manufacturing, and installing customized air conditioning and heating systems for commercial, specialty, and heavy-duty vehicles. Their latest project focuses on developing a roof-mounted, battery-driven air conditioning solution for electric vehicles, where space-saving design, high efficiency, and superior performance are top priorities.

Recognizing the critical importance of climate control in vehicle comfort and safety, the client aims to integrate RIGID’s horizontal DC compressor technology into their rooftop systems. The horizontal design ensures compact installation, maximizing cabin space while maintaining a low profile. Powered directly by the vehicle’s DC battery, it enables energy-efficient cooling without compromising driving range.

Roof-mounted condensers are ideal for buses, delivery vans, and electric transport fleets, offering key benefits such as improved cooling efficiency (since heat rises), reduced energy consumption, and enhanced durability — protected from road debris and harsh conditions.

By combining RIGID’s high-performance DC compressors with the client’s HVAC expertise, this collaboration aims to deliver next-generation electric vehicle climate systems that are compact, efficient, and built for long-lasting performance

Introduction: Cooling in Motion

In the modern world of global logistics, transport refrigeration plays a crucial role in ensuring food safety, pharmaceutical efficacy, and product integrity. From fresh seafood to vaccines, millions of temperature-sensitive goods are on the move daily — and every kilometer counts. Behind this silent revolution lies a critical component: the compressor.

At the heart of mobile cooling systems, RIGID’s Horizontal DC Compressors are redefining performance standards for transport refrigeration units (TRUs). Compact, durable, and energy-efficient, these compressors are trusted by global leaders in the cold chain industry. Whether installed in vans, trailers, food trucks, or mobile medical units, RIGID compressors ensure dependable cooling anywhere, anytime.

RIGID Horizontal DC Variable-Speed Compressor

The client developed a customized mobile refrigeration system based on its 48V DC variable-speed compressor. The system ensured stable cooling with minimal vibration and noise, making it ideal for transport vehicles.

 

Solution

Horizontal DC Compressor

The Challenges of Transport Refrigeration

Unlike stationary systems, Transport Refrigeration Units (TRUs) operate under constantly changing conditions. They face vibration from uneven terrain, frequent power fluctuations, and extreme ambient temperatures. Maintaining consistent cooling from 10°C to -30°C requires equipment that’s not only efficient but exceptionally durable.

Every industry relying on TRUs — from food logistics to pharmaceuticals — demands uninterrupted performance. A minor compressor failure could mean spoiled cargo, financial loss, or even health risks. That’s why the compressor design must balance efficiency, reliability, and compactness — and this is where RIGID stands out.

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RIGID: The Trusted Partner for Transport Refrigeration

RIGID’s compressors are used by world-leading transport refrigeration companies for a reason. Built for mobile environments, RIGID Horizontal DC Compressors deliver unmatched reliability, low vibration, and exceptional energy efficiency.

Each unit is engineered for 24/7 continuous operation in challenging transport conditions. The compact horizontal design allows integration into tight vehicle compartments, while low noise and minimal vibration make it ideal for refrigerated trucks, mobile kitchens, and delivery vans operating in urban environments.

RIGID’s compressor portfolio supports AC and DC power inputs, R290 refrigerants, and variable-speed operation, ensuring flexibility for diverse global applications.

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How Transport Refrigeration Units Work

Transport refrigeration systems rely on heat transfer principles to maintain desired cargo temperatures. They remove heat from the insulated cargo area and dissipate it outside, continuously cycling refrigerant through evaporation and condensation.

Depending on the cargo type, TRUs maintain:

• 10°C to 4°C for dairy, beverages, and fruits.

• 0°C to -18°C for meat, seafood, and frozen products.

• 2°C to 8°C for pharmaceutical goods like vaccines or biologics.

The challenge lies in maintaining these precise conditions while on the move. Vibrations, weather fluctuations, and intermittent power supply can impact performance. That’s why transport refrigeration demands compressors built specifically for mobile environments — compact, rugged, and vibration-resistant.

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RIGID Horizontal Rotary Compressors: Engineered for Performance

Efficiency Meets Durability

RIGID’s horizontal rotary compressors employ a roller-and-cylinder mechanism, which reduces mechanical wear by up to 20% and cuts operational noise in half compared to traditional piston compressors. This design ensures longer life, lower maintenance, and smoother operation under dynamic conditions.

The horizontal layout not only saves space but also provides superior balance, ideal for mobile installations. Its wide operating range (-40°C to +10°C) covers everything from frozen seafood to fresh produce and pharmaceuticals.

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Key Technological Innovations

1. Compression Liquid Injection Cooling Technology

Traditional compressors often face overheating at low evaporating temperatures. RIGID’s liquid injection technology introduces a pre-set capillary structure that injects refrigerant during the compression process, effectively lowering discharge temperatures.

Benefits:

• Prevents refrigeration oil deterioration

• Extends compressor lifespan

• Expands low-temperature performance range

• Reduces failure rates in harsh conditions

This ensures reliable operation even in deep-freeze applications, such as ice cream or vaccine transport.

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2. Internal Dual-Cylinder Compression Technology

RIGID’s dual-cylinder pump body and variable-frequency motor design work together to minimize starting impact and torque fluctuation. This innovation results in lower vibration, quieter operation, and longer service life.

The internal configuration also enables:

• Compact size with higher capacity output

• Enhanced efficiency under load variations

• Lower operating costs due to reduced mechanical stress

This makes RIGID compressors ideal for next-generation smart transport refrigeration systems.

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3. Built to Withstand Motion

RIGID’s compressors are equipped with vibration-dampening mounts and shock absorption technology, ensuring uninterrupted cooling even during off-road driving or sudden braking. These compressors maintain stable pressure and temperature control throughout long-haul routes, offering peace of mind to fleet operators.

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Applications of RIGID Horizontal DC Compressors

1. Food & Beverage Cold Chain

RIGID compressors keep the global food supply safe and fresh:

• 0–4°C: Dairy, meat, and produce transport — extending shelf life by up to 40%.

• -18°C: Frozen goods, ice cream, and seafood logistics.

From farm to table, RIGID’s reliable mobile refrigeration ensures consistent quality at every link in the chain.

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2. Pharmaceutical & Medical Logistics

In medical logistics, temperature control saves lives. RIGID compressors ensure stable temperatures for vaccines, blood plasma, and biologics — typically 2–8°C — during long-distance transportation.

Their compact DC-powered design enables integration into small medical delivery vehicles or portable cold boxes, ensuring pharmaceutical integrity from factory to patient.

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3. Mobile Catering and Food Trucks

For food trucks, mobile restaurants, and catering vehicles, RIGID compressors provide quiet and efficient cooling. Their compact form factor allows installation under counters or in tight spaces, supporting fridges, freezers, or ice machines — all powered by 12V, 24V, or 48V DC sources.

These units maintain freshness without engine idling, reducing noise and emissions — crucial for sustainable urban food operations.

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4. Marine and Fishing Transport

RIGID compressors are also revolutionizing marine cold chain logistics — ensuring freshly caught fish reach markets in optimal condition. Their corrosion-resistant design and energy efficiency make them suitable for boats and seafood transport vehicles.

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Case Study: 48V Mobile Cold Chain for Fresh Fish Transport

 

The client’s mobile cold chain system was designed to address the challenges of transporting fresh fish. Traditional methods using ice and fuel-based refrigeration often led to high mortality rates and environmental concerns.

Challenges

• Scarcity of 48V compressors: Few compact, low-noise, and energy-efficient options existed.

• Fish mortality rates: Traditional cooling methods caused up to 50% losses during transport.

• Sustainability concerns: Fuel-powered trucks and ice-based cooling waste energy and resources.

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RIGID R&D Team

RIGID’s R&D team is a dynamic group of engineers and innovators specializing in compact cooling technologies. With deep expertise in refrigeration, thermodynamics, and electronics, the team drives product innovation, customization, and performance optimization. Focused on precision, reliability, and energy efficiency, RIGID’s R&D team delivers cutting-edge thermal solutions tailored to demanding applications in telecom, medical, aerospace, and industrial sectors.