Key Takeaways
- Retrofitting vs Replacement: Retrofitting upgrades existing system components and piping, while replacement swaps parts like-for-like
- Planning is Critical: Successful retrofits require careful scheduling, site inspection, and pre-fabrication to minimize system downtime
- Five-Step Process: Follow a systematic approach: Planning, Preparation, Shutdown, Work Completion, and Testing/Restart
- Safety First: Always implement proper lockout procedures, pressure verification, and compliance with standards like TSSA
Understanding Retrofitting vs Replacement
HVAC/R System Retrofitting is one of the most diverse jobs you can perform in the industry. First, it’s important to understand that retrofitting is distinct from replacement. Replacement involves swapping components “like-for-like” or replacing piping along the same route with identical materials. Retrofitting, however, refers to upgrading an existing/operating system’s components, piping, or both to improve performance, efficiency, or adapt to new requirements.
Common Reasons for Retrofits
Several factors can necessitate a retrofit in commercial and industrial facilities:
- Component failure (where the root cause must be properly diagnosed and resolved to prevent recurrence)
- Piping issues including wear, cracks, or vibration damage
- Sub-optimal system performance requiring improved piping routes or upgraded components
- Changes in facility requirements or operational needs
In large commercial or industrial systems, the equipment’s purpose may change over time. For example, a freezer might need conversion to a cooler, or new process equipment may require integration with an existing header. Understanding how refrigerant properties work is crucial when modifying system configurations.
Step-by-Step Retrofit Process
Step 1 – Planning
Planning the shutdown requires careful consideration unless the equipment is seasonally offline. For our example valve tie-in on an ammonia system, the plant’s Operating Engineers coordinated with the Project Manager to schedule the outage when the affected evaporators could be taken offline with minimal impact to operations.
For complex jobs, the HVAC/R Mechanic/Foreman should inspect the site beforehand to:
- Identify potential barriers and access challenges
- Determine equipment and tool requirements
- Assess safety considerations
- Plan material staging areas
Step 2 – Prepare
Pre-fabrication of piping sections is standard practice for retrofits requiring significant piping work. This approach minimizes system downtime and ensures quality workmanship. In our tie-in example, the welder pre-welded black iron nipples into each valve side for immediate installation once the system was opened.
Preparation also includes:
- Gathering all necessary tools and materials
- Reviewing safety protocols
- Coordinating with other trades if needed
- Ensuring proper permits are in place
Step 3 – Shutdown and Begin
This critical phase involves:
- Turning off and isolating systems following facility procedures
- Implementing proper lock-out/tag-out procedures for safety
- Pumping out refrigerant if necessary to a safe storage vessel
- Verifying system pressure and safety before opening any connections
Step 4 – Complete Work
With the system prepared and secured, work execution can begin. Our tie-in example involved:
- Drilling two precise holes in the existing header
- Positioning access valves correctly for future service
- Completing welding work (at -20°F on a 120-foot high roof!)
Some retrofits may involve challenging conditions that require special consideration:
- Stuck components requiring specialized extraction techniques
- Confined space work necessitating additional safety measures
- Critical rigging operations for heavy equipment
- Working near live systems requiring extra precautions
When dealing with oil loss issues in screw compressors during retrofits, proper diagnostics can prevent future problems.
Step 5 – Test and Restart Equipment
Final steps include comprehensive testing and verification:
- Pressure testing to verify system integrity
- Oil addition as required for compressor protection
- System evacuation to remove moisture and non-condensables
- Refrigerant charging to proper levels
- Operational testing including superheat verification
For our tie-ins, we conducted a “Live Test” of the welds using refrigerant vapor through an isolation valve, a common practice with ammonia systems that’s recognized by TSSA. This method allows for immediate leak detection without the need for nitrogen testing in certain applications.
Business Growth Through Retrofit Expertise
Specializing in retrofit work can significantly expand your service offerings and customer base. Property.com’s ‘Know Before You Go‘ tool helps HVAC professionals identify commercial properties that may need retrofit services based on building age and system types. This valuable insight allows you to proactively approach potential clients with targeted retrofit proposals. Learn how Property.com helps HVAC pros grow their commercial service divisions.
Summary
If you enjoy both service and construction aspects of HVAC/R systems, retrofit work offers an exciting combination of both disciplines. It presents unique challenges but delivers the satisfaction of improving system functionality and efficiency. Successful retrofits require thorough planning, proper preparation, and systematic execution to minimize downtime while maximizing system improvements.
