Should I Hire a Contractor or Keep it In-House? | Part 2: Research Methodology


Eli Macha presented a technical paper at the 2021 RETA National Conference titled IIAR 6: Should I Hire a Contractor or Keep it In-House? This blog series includes excerpts from his technical paper.

Rather than simply stating the author’s opinion of in-house vs contracted work, the intent of this [blog series] is to provide accurate and actionable information for facilities with ammonia refrigeration systems, and potentially, for refrigeration contractors. In order to achieve this end, a four-pronged approach was taken. 

Contractor Involvement Survey

First, a formal survey was taken of facilities with ammonia refrigeration systems. A Google Forms quiz was sent to all clients of Resource Compliance, Inc. who have ammonia refrigeration systems. The end result was 28 viable submissions. 

After the submissions were recorded, some additional information was attached to each facility. Given that these facilities are clients of Resource Compliance, Inc., the information was readily at hand. To better assess the data, it was necessary to quantify the size and complexity of the systems. Unfortunately, the maximum intended inventory of ammonia is not necessarily the best indicator. Consider, for example, that one facility with 4 compressors had an inventory of 1,000 lbs while another facility with 4 compressors had an inventory of 57,000 lbs. Instead, the following method was used to form rough categories for the 28 facilities.

  • The following major components were tallied:
    • Compressors
    • Condensers
    • Evaporators
    • Other Heat Exchangers (Excluding Oil Coolers)
    • Pressure Vessels (Excluding Oil Separators)
  • The combined total was used as a rough indicator regarding the system’s size and complexity. The smallest number was 6 and the largest was 219. 
  • The following categories were assigned based on the total number of components. The gaps in ranges are due to no facilities having a total number of components within the range not listed (e.g. no facilities had a total number of components between 17-32).
    • Small | Range: 6-16. Number of facilities: 6.
    • Medium | Range: 33-53. Number of facilities: 9.
    • Large | Range: 61-95. Number of facilities: 9.
    • Extra-Large | Range: 102-219. Number of facilities: 4.
  • These terms (Small, Medium, Large, and Extra-Large) will be used throughout this [blog series]. 


The second approach to the research was formal interviews with individuals in the industry. Subjectively speaking, these individuals are very experienced and understand how to manage both employees and contractors. The following individuals were interviewed:

  • Craig Nielsen | Craig is the Director of Engineering for Producers Dairy. He oversees several ammonia refrigeration facilities and has been in the industry for 40 years.
  • Rene Soto | Rene is the Maintenance Manager for Bronco Wine Company. He oversees two large production wineries in the Central Valley of California.

IIAR Literature

The third resource used in the development of this [blog series] is the IIAR literature. ANSI/IIAR 6-2019 is a tremendous resource for ammonia refrigeration facilities. Until this standard was published, there was no consolidated list of necessary inspection, testing, and maintenance items required to keep an ammonia refrigeration system safe and functional. Throughout this [blog series], numerous citations from this standard will be used to aid facilities in understanding the minimum requirements and best practices.

Consulting Experience

Finally, the last element of information to contribute to this [blog series’] findings is the author’s own anecdotal experience. The author is a Process Safety Consultant with over 40 clients having ammonia refrigeration systems. Meeting with these facilities every quarter has allowed the author to field numerous questions related to in-house vs contracted work. Suggestions for implementing mechanical integrity programs have gone through the crucible of reality. Some recommendations are great in theory but are impractical in reality. The author also has a wide range of experience with different types of facilities. Consultation is provided to small family-owned businesses as well as to some of the largest businesses in the world. Additionally, this experience has been gained across multiple industries which include the following: cold storage, freezing, dairy processing, winery, meat processing, juice and beverage processing, and logistics.

This four-pronged approach of surveys, interviews, IIAR literature, and personal experience should enable this [blog series] to provide effective and simple recommendations for implementing a mechanical integrity program according to IIAR 6.

The previous blogs in this series are available in the following links:

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