Streamlined RHVAC Leak Detection for an OEM Maximized Sensitivity, Minimal Footprint

A prominent global OEM in the RHVAC systems industry, operating five production lines, faced significant hurdles with their existing leak detection methods. The company utilized pre-charge, hard vacuum chambers and R410a refrigerant as the tracer gas for leak testing, alongside separate machinery for refrigerant charging and recovery. Their primary objective was to enhance leak testing capabilities, boost efficiency, and optimize space across their A-coil residential HVAC condenser and evaporator production lines.

The existing system presented several critical challenges:

Limited Detectable Leak Size: R410a's larger molecular size restricted its ability to detect small leaks, even those within the HVAC manufacturer’s specified test pressure and leak rate.
Environmental Contamination and Reduced Signal-to-Noise Ratio: Leaks occurring early in the production process contaminated the surrounding environment, increasing the ambient refrigerant background. This elevated "noise" significantly degraded the signal-to-noise ratio, making accurate identification and quantification of small leaks extremely difficult. Variability in upstream processes further exacerbated this issue, leading to inconsistent test repeatability.
Significant Space Constraints: The reliance on separate machines for gross/burst testing, refrigerant charging, leak testing, and refrigerant recovery resulted in a large physical footprint. With a required TAKT time of 30-45 seconds per line, multiple units of each machine type were necessary. This inefficient use of space hindered future expansion and optimization efforts

The VES Solution: A Multi-Faceted Approach to Leak Detection Excellence

Leveraging extensive expertise in helium leak testing systems, VES partnered with the OEM to implement a comprehensive, multi-faceted solution designed to address these critical pain points.

1. Enhanced Leak Detection Sensitivity with Helium:

To overcome the limitations of R410a, VES engineers proposed a transition to helium as the tracer gas. Helium’s significantly smaller molecular size allows for a much greater flow rate through leaks of a given virtual diameter. Furthermore, helium’s naturally low ambient concentration (approximately 5-6 ppm) provides a virtually noise-free background, making it an ideal tracer gas.

The implemented “charge-in-chamber” process further minimized background interference by evacuating the chamber and zeroing out any residual helium readings before introducing the tracer gas. This ensured that only helium leaking from the part was measured by the highly sensitive leak detector, enabling the detection of leaks orders of magnitude smaller than the customer’s original specifications.

2. Space Optimization through Integrated Systems:

VES provided three integrated “charge-in-chamber” machines for each production line. These innovative units consolidated the functions of refrigerant pre-charge, hard vacuum leak testing, refrigerant charging, and refrigerant recovery into a single machine. This groundbreaking design reduced the required footprint for each line to approximately one-third of the original size, all while maintaining the existing TAKT time.

3. Advanced Helium Management Infrastructure:

Beyond the integrated test machines, VES supplied a complete helium management infrastructure, including helium recovery systems and gas mixers. This comprehensive solution encompassed the necessary pipework and infrastructure to connect each production line to the helium supply and recovery systems. The pipework network was designed with multiple layers of redundancy, ensuring operational reliability. A key benefit of the gas mixers was the significant reduction in overall costs due to lower helium consumption.

Collaborative Process for Success:

Initial Technical Discussions: Focusing on the component itself (usage, industry, dimensions, types) and its technical application (environment, working pressures, limitations).
Governing Specifications and Risk Assessment: Understanding legal and industry standards, the strictness of adherence required, and the consequences of non-compliance.
Manufacturing Process Integration: Considering burst testing, electrical circuit verification, flow measurement requirements, and data recording needs.
Upstream and Downstream Process Analysis: Identifying opportunities to integrate processes within the leak test system to reclaim floor space and manufacturing time.
Determining Required Leak Tightness: Collaborating with customers to define precise leak tightness specifications. For HVAC, this often involves converting ASHRAE environmental standards for refrigerant loss (mass flow rate) into applicable helium leak rates. For instance, HVAC customers typically require leak rates in the low 10 −5 or high 10 −6 mbar*L/s range. VES can also help customers visualize leak rates in terms of virtual hole diameters, making the specifications more tangible
Cost Savings Estimation: Providing detailed estimates of annual helium requirements, factoring in recovery rates and the potential for reduced concentration with gas mixers, often leading to repayment periods well under a year. Gas mixing also serves as a hedge against future helium supply insecurity.−5 or high 10 −6 mbar*L/s range. VES can also help customers visualize leak rates in terms of virtual hole diameters, making the specifications more tangible.

Beyond the initial solution, VES provides comprehensive project management, installation planning, manuals, spare parts lists, commissioning resources, and ongoing production startup and training support. Our commitment to long-lasting relationships ensures continuous support and problem resolution.

Results: Unprecedented Savings and Enhanced Quality

The implementation of the new helium-based leak detection system yielded substantial benefits for the RHVAC OEM:

Significant Warranty Cost Savings:

By leveraging helium as a tracer gas and highly sensitive detectors, the OEM achieved an estimated 60% reduction in warranty claims. This dramatic decrease highlighted that their previous refrigerant-based method was failing to identify leaks within specification, leading to costly field failures.

Substantial Cost Savings Through Gas Management:

The integrated helium recovery systems achieved an impressive 92% recovery rate, significantly reducing helium consumption. Furthermore, the addition of gas mixing hardware allowed the OEM to decrease the tracer gas concentration from 100% to 30% without compromising test integrity. This simple adjustment resulted in approximately 70% annual savings in helium expenditures. The system’s high repeatability allowed for straightforward linear scaling of the acceptable leak rate based on the new gas concentration, requiring only a minor parameter change on the HMI. The integration of gas mixers a few years after the initial installation further amplified these cost savings.

Optimized Floor Space and Streamlined Operations:

The reduction of the overall system footprint to one-third of its original size directly addressed the OEM’s space constraints, paving the way for future expansion and optimization. The integrated “charge-in-chamber” machines streamlined operations, improving overall efficiency.

Conclusion: A Partnership for Long-Term Success

This case study demonstrates the transformative impact of advanced helium leak testing systems and a consultative approach to optimizing RHVAC manufacturing processes. By partnering with VES, the RHVAC OEM not only overcame critical leak detection challenges but also realized significant cost savings, improved product quality, and enhanced operational efficiency. VES’s commitment to rigorous quality management (ISO9001:2015, UKCA, CE standards, and third-party assessments by bodies like DEKRA or Bureau Veritas) ensures the highest levels of safety, functionality, and regulatory compliance. Our dedication to after-care, including pump rebuilds, spare parts, and sustaining engineering projects, solidifies a long-term partnership for continued success.