Manuchehr Mehdizadeh

Manuchehr Mehdizadeh , MD of Roxara Engineering , Houston , Tx (USA)

Benefits of Anhydrous Ammonia in Refrigeration Systems

BY MANUCHEHR MEHDIZADEH, BSME LIFE TIME MEMBER ASHRAE, COMMITTEE OFFICER @ IIR, REFRIGERATION CHAIR @ ASHRAE HOUSTON CHAPTER Ammonia Refrigeration Basics Refrigeration systems use basic physics to transfer heat energy out of one area and into another, leaving the first area cooler than it was before as in the cold store systems. Various ice production […]

Basics on Air Conditioning VRS Refrigeration

BY MANUCHEHR MEHDIZADEH, BSME LIFE TIME MEMBER ASHRAE, COMMITTEE OFFICER @ IIR, REFRIGERATION CHAIR @ ASHRAE HOUSTON CHAPTER Before I discuss the impact of refrigeration (or cold chain) industries in our daily lives, it is imperative that we briefly discuss the status of air conditioning industries in our daily lives too.  It is ironic that […]

A Brief on Food Safety

According to Food and Agriculture Organization (FAO) report of 2013, the global food wastage is estimated at 1.6 billion tons of “Primary” product which is equivalent to edible food wastage of  1.3 billion tons. 

Manuchehr Mehdizadeh,
MD, Roxara Engineering LLC , Houston-Tx

In an era where we are still faced with famine in certain countries, population growth, depleting natural resources, and consumer demand for non-preservative and organic agricultural products food preservation and safety has become even more critical.

The primary step is to comply with updated version of Food Safety Modernization Act (FSMA) which aims to ensure the U.S. food supply is safe, by shifting the focus from responding to contamination to preventing it.

This was accomplished by establishing new safety standards for Agricultural and Dairy producing farms and holding importers accountable for the safety of their products thru design of standards which minimizes risk of illness from food borne pathogens.

Furthermore NASA’s  Hazard Analysis Critical Control Point (HACCP) are applied as a systematic approach to food safety in all stages of food chain, from food production and preparation processes to packaging and distribution.

Despite the prevailing food industry’s regulatory standards,  it has unfortunately been observed that agricultural, dairy and food products can and has been deliberately contaminated.

For instance in 1984 at Dalles-Oregon, the Rajneeshee religious sect contaminated salad bars at local restaurants to disrupt the local elections. 

Another incident  in 2002 at Nanjing, China deliberate food poisoning is attributed to more than 28 fatalities. To combat these treats and mitigate such occurrences, the Threat Assessment Central Control Point (TACCP) is extensively applied.  This is also covered in British Standard Institution documents PAS 96:2014 (Guide to protecting & defending food and drink from intentional attack). 

In short TACCP or food defense  is a risk management methodology that aligns with HACCP but has a different focus that  requires direct input from employees of different disciplines. 

Therefore through Food Safety Supply Chain System, the food fraud occurrence can be prevented by advent of following standards and guides:

  • Food Safety – HACCP hazards
  • Food Defense – TACCP threats
  • Food Fraud – VACCP vulnerabilities

As we all agree that food quality is a measure of how well a product meets a set of manufacturers’ specifications.  This simply begins with quality ingredients which are derived from quality vendors. 

Through RFID and AI concept even the quality control & sanitization feedback provided to the vendors achieves best results.  In this manner vendors can also be rated on quality of their products in addition to their prompt delivery and shipping schedule. 

While food supply chain has become increasingly global, and with increasing demand on requirements of extra add-on to manufacturing, use of paper work is now been replaced by cloud & software tools to provide more accurate tracking, tracing and elimination of contamination. 

While abiding the concept of proper documentation, the food quality and safety solution need be maintained thru process of Audits & Compliance, Traceability & Recall  Management  and Corrective/Preventive Action (CAPA).

Key to this point is redundancy where solutions are able to talk to each other, share & exchange data between different applications and deliver the data in a meaningful way for FSQA (Food Safety Quality Assurance) team to act upon efficiently. 

Also manufacturers of food processing facilities must focus on IIOT networking and ensure that the purchased food processors are capable to implement USGBC’s Green Technologies to achieve sustainability targets.

In conclusion staying on the forefront of economic growth in food safety industry requires cutting-edge information from authoritative international agencies where food safety, regulatory challenges, sustainability, operational efficiencies and digital measures matters. It is anticipated that with new wave of automated digital & robotic manufacturing, demands of feeding growing global population will be embraced, strictly adhering to food safety regulations.

For queries on Food Safety, Kindly contact here-

Integrated Safety Management Thru RMP/PSM Regulations on Ammonia Refrigeration Installations

Mr Mehdizadeh , MD of Roxara Engineering , Houston , Tx (USA)

These new comers need to get familiar with regulatory bodies concerned with worker & public safety such as OSHA (Occupational Safety and Health
Administration) and the EPA (Environmental Protection Agency).This will ensure that risks are mitigated at proven knowledge levels as employed to industry practitioners. Thus safe work
practices should be clearly communicated and become part of the corporate culture where the focus should continue to be on recognition of safety and health hazards in their workplace.

In recent years, OSHA has stepped up adherence to this standard via rigorous inspections enforced by its National Emphasis Program (NEP) on Process Safety Management regulated
industries which include the eco-friendly ammonia refrigeration facilities. This means that owners and operators of large ammonia systems in excess of 10,000 pounds now have the added
responsibility and expense of continuous record keeping in preparation for NEP inspections. Additionally OSHA requires that employers keep records on employee training so that when
employers conduct mandatory audits of the program, any inconsistencies can be detected and corrected. In this manner the facility under inspection ensures the protection of workers
from work-related injuries, illness and deaths.

To partially reduce the regulatory burden, the following safety services are also recommended for implementation:
• Modern cold storage applications call for bigger systems to support increasing low temperature requirements. Many are opting to prevent bumping up against the 10,000lbs ammonia threshold and are evaluating cascade system by combining R717 with CO2 (R744) in system architectures by removing the ammonia circuit of the system from occupied spaces.

• Recommended practices for proper ventilation of plant rooms to manage ammonia leaks , is of crucial importance in the design & safety standards set forth in the IIAR-2-2014 standards.

• Instead of traditional stick-built ammonia systems, a low charge ammonia package (modular) skid-mounted units be incorporated. These provide energy efficiency and are internally piped, insulated & factory wired thus reducing in house labor and eliminating construction of big machinery rooms.

• Installation of ammonia detection system ( to activate emergency exhaust fans for continuous ventilation) with properly installed , maintained and strategically located sensors which are the essential element in preserving the safety of employees and products in any cold store facility.

• Installing of remote monitoring systems can be a valuable safety tool, as it would cover from detection of leaks and high liquid levels to a change in system pressure and can be
analyzed 24/7/365 by an expert in-house technician.

• The use of analytics technology (sensors and software) to identify trends and patterns is another practice that can be implemented. Therefore, facilities that want to operate safely and wish to comply with internationally recognized codes and standards should rely on what is called RAGAGEP or (Recognized and Generally Accepted Good Engineering Practices) applicable to ammonia refrigeration systems. These lists, though not representative or inclusive for each country and state, are a good basis for understanding what programs a facility should have to operate safely and yet comply with outside agencies or local chapters with jurisdictions over their facility.

The following are list of OSHA/EPA programs that need to be implemented regardless of the amount of ammonia in the facility:
– Bloodborne Pathogens (29 CFR 1910.1030)
– Compressed Gases (29 CFR 1910.101)
– Confined Space (29 CFR 1910.146)
– Electrical Safety (29 CFR 1910.333)
– Emergency Action Plan (29 CFR 1910.38)
– Ergonomics (29 CFR 1900.900-945)

Emergency Eyewash and Safety Shower (29 CFR 1910.151, ANSI Z358.1) Exit Routes (1910.34, 1910.35, 1910.36, 1910.37)
-Fall Protection (29 CFR 1910.22)
-Fire Prevention Plan (29 CFR 1910.39)
– Powered Industrial Trucks (29 CFR 1910.178)
– Hazard Communication (29 CFR 1910.1200)
– HAZWOPER (29 CFR 1910.120)
– Hearing Conservation Program (29 CFR 1910.95)
– Housekeeping Program (29 CFR 1910.38)
– Laboratory Standard (29 CFR 1910.1450)
– Lockout/Tagout (29 CFR 1910.147)
– Machine Equipment Safety and Guarding (29 CFR 1910.212)
– Medical Surveillance Program (29 CFR 1910.95, 1910.120)
– Personal Protective Equipment (29 CFR 1910.132, 1910.133)
– Record Keeping (29 CFR 1910.1904)
– Respiratory Protection (29 CFR 1910.134)
– Spill Prevention, Control and Countermeasures (40 CFR Part
112) Storm Water Pollution Prevention Plan (40 CFR Part
– Superfund Amendments Reauthorization Act (SARA) (40CFR
Part 355.30) Used Oil Management Program
– Welding and Cutting Safety Program (29 CFR 1910.251 -255)
Workplace Security Plan

When a facility has less than 10,000 pounds of ammonia charge in its refrigerating system, both OSHA’s PSM and EPA’s RMP use their respective General Duty Clause (GDC) and RAGAGEP gets
involved to inspect and generate citations . These clauses describe responsibilities owners and operators have to be diligent in preventing chemical releases. This includes both an employer’s recognition of hazards and most importantly the industry’s recognition of hazards! The prominent ammonia refrigeration consensus standards are issued by IIAR and ANSI/ASHRAE-15 Standard.

The General Duty Clause (GDC) compliance basically involves the following:
• Identification and assessment of process hazards.
• Maintaining a safe process system
• Minimizing consequences of any ammonia release
• MOST IMPORTANT! – adhering to industry codes and standards.
(NOTE: This is commonly referred to as “Recognized and Generally Accepted Good Engineering Practice” – RAGAGEP.)

Compiling and updating the following information are essential to GDC compliance:
• Process Safety Information (PSI) including current P&ID’s
(NOTE: A crucial standard to be considered is in IIAR Bulletin 110 -Section 4: Records)

• Process Hazard Analysis (PHA) with a discussion of potential release scenarios and their impacts.

  • Operating Procedures
    • Training
    • Pre-Start up Procedures
    • Mechanical Integrity and Preventive Maintenance
    • Hot Work Permit
    • Incident Investigation
    • Emergency actions, planning, and response
    NOTE: Under OSHA and EPAs General Duty Clauses, if one has multiple facilities and the majority of the facilities are under RMP, then RMP can be applied to the ones whose
    ammonia charge are under the 10,000 pounds. Once the facility goes over 10,000 lbs – PSM goes into effect The following two programs need to be developed and implemented when the amount of ammonia charge in any facility is greater than 10,000 pounds:
    • OSHA’s PSM program has 14 elements that must be addressed by Employers:
    • Employee Participation
    • Process Safety Information (PSI)
    • Process Hazard Analysis (PHA)
    • Operating Procedures
    • Training
    • Contractor Management
    • Pre-Startup Safety Review
    • Mechanical Integrity (B109’s)
    • Hot Work Permit
    • Management of Change
    • Incident Investigation
    • Emergency Planning and Response
    • Compliance Audits
    • Trade Secrets
    EPA – Risk Management Program ( in compliance with 40 CFR Part
    • EPA’s RMP supports the Management System & defines following major components:
    • Hazard Assessment – This assessment has specific requirements. It includes such items as a “worst-case release scenario”, dispersion modeling, potentially affected population and environmental impact, etc.
    • Prevention Program – This component is essentially identical to OSHA’s PSM elements. (Note exception: Trade Secrets are not included, and Emergency Response is handled as a
    separate component.)
    • Emergency Preparedness & Response Program – Although EPA’s program follows OSHA’s requirements for HAZWOPER (1910.120(q) and /or Emergency Action Plans (1910.38) – it also requires this component to be integrated with the community response plan. NOTE: CFR denote Code of Federal Regulations ; for instance OSHA1910 are used to designate the health safety regulations in the Federal CFR. For further guidance OSHA and EPAuse following standards to qualify citations:
  • ANSI/IIAR-2 “Equipment, Design and Installation of Ammonia Mechanical Refrigeration Systems” IIAR Bulletin 109 “IIAR Minimum Safety Criteria for a Safe Ammonia Refrigeration System”
  • IIAR Bulletin 110 “Start-Up, Inspection and Maintenance of
  • Ammonia Mechanical Refrigeration Systems”
  • IIAR Bulletin 114 “Identification of Ammonia Refrigeration
  • Piping and System Components”
  • ANSI/ASHRAE -15 “Safety Standards for Refrigeration Systems”
  • `Implementing above integrated safety solutions provides
  • following advantages:
  • Protect Employees, Investments and the Environment
  • Increase Productivity & Quality
  • Reduce Likelihood & Severity of Adverse Consequences
  • Comply with Good Industry Practices
  • Achieve Community Social Goals

• Enhance Overall Business Performance

As stated TRAINING becomes an essential practice for recognition, avoidance, and prevention where a number of methods are recommended and must be available on-site & ondemand.
These include classroom, online and self-taught social media based training which has the benefit of access anywhere in the world and can includevariety of areas thus :
• Ammonia Safety
• Auditing
• Effective Operating Procedures
• Incident Investigation/RCA
• Process Hazards Analysis
• Management of Change/PSSR
• Mechanical Integrity
• Safe Work Practices
• OSHA General Safety & Compliance

In order to arrange for training classes in any country, it is advisable that a “train-the-trainer” approach is followed where employers arrange for training of their senior staff to coordinate
with relevant inspection companies in the US. In addition it is important that the trainers continue to keep their certifications up to date by taking relevant training courses on a periodic or yearly basis.

“This article published in AAR Newsletter of June 2017 is being reproduced herein with permission of Mr Mehdizadeh , MD of Roxara Engineering , Houston , Tx (USA)”



Commentary -Impact of temperature control for pharmaceutical & Biomedical Products

By Manuchehr Mehdizadeh, Design/Build Engineers, Houston, Tx (USA).

Mission Critical : Solving temperature control for pharmaceutical applications requires techniques perhaps more complex than those used for data centers and food storage facilities.

Given the case of pharmaceutical , where India is the world’s third largest pharmaceutical producers , the impact is critical as even a slight drift of  0.5C temperature change can effect quality of transported drug. 

It is estimated that almost 20% of temp sensitive health- care products arrive damaged or degraded which is due to broken cold chain, including 25% of vaccines. 

Whether for data servers or pharma warehouses , maintaining a controlled temp is equally critical, but these environments must be maintained in vastly different manner .  In other words mission-critical temperature control is not one size fits all. 

Unlike modern data servers which could shut down if it gets too hot, pharmaceutical compounds have no such built-in safeties.  They could simply lose their ability to be effective , causing patients cholesterol levels  climb , blood pressure  spike , and infections  spread  thus impacting the quality of life for all.

Quality Safety : Medicinal products require controlled storage and transit conditions in order to ensure that their quality is not compromised.

This applies to low-risk products as well as high-risk products such as vaccines, insulin and blood products , which normally require storage temp between 2°C and 8°C.

Distributors of drug products are required to record storage and transportation temperatures, as well as being licensed by appropriate authorities. Temperature monitoring devices should be used to demonstrate compliance with the records that are kept.  This trend calls for a new paradigm to achieve regulatory compliance.  

At every point in the pharmaceutical distribution chain , precautions are required to minimize the effect of external conditions on quality and stability of product. 

It is mandatory that records should provide reliable up-to-date evidence of compliance, in case of audits and investigations from MHRA (Medicines & Healthcare Regulatory Agency ) and other stakeholders.    

It is advisable that distribution centers carry out an in-house compliance audit before deciding on a storage facility , transport system or taking on a new range of products. 

Chain of Custody :  During the storage and transit of pharmaceutical product,  the chain of custody and environmental constraints needs to be strictly documented. 

This includes R&D to manufacturing (production facility) , logistics & distribution , warehousing and clean room spaces (distribution centers) with its validation and finally the consumer (patients) that represent the ‘last mile’ in the logistics chain for pharmaceutical products . 

However what happens between that ‘extra mile’ and the ‘final mile’ the temp sensitive products may sit on a shelf for an extended period thus causing  this warehouse to become critical. 

As such industry inspectors must conduct regular audits of environmental  monitoring systems combining temperature, humidity, with automated alarm functions, real-time sensors where information is stored in cloud based servers for conducting analytics and identify problems.  

Market ; Of all the statistics emerging around the global pharmaceutical industry this year, two big numbers attract the attention of both manufacturers and their logistics partners: An over $260 billion, the amount the “BRIC” nations (Brazil, Russia, India and China) are poised to account for in pharmaceutical sales for by 2019. 

These numbers are noteworthy because they demonstrate that R&D follows logistics. As products evolve to meet demands for more targeted therapies, demand for more targeted logistics solutions grows as well. And that means a need for customization for everything from clinical trial material (ctm) samples to finished products.

Transport :  While in transit thru refrigerated truck carriers , GPS monitoring must track location and temperature ranges. In addition RFID (Radio Frequency Identification) based systems also used for tracking and reporting. 

Even airports have started to provide suitable cold storage facilities for pharmaceuticals.  In addition 24-hour fool-proof security and security monitoring systems need to be provided to ensure safety of pharmaceutical products.   

Packaging: However manufacturers still cannot rely on the supply chain alone. As such, the ability to pack for varying temperature ranges is evolving to meet diverse product needs.

Almost all packaging manufacturers are developing vacuum insulated panels (VIP) and phase change material (PCM) solutions that allow for easier handling and storage of temperature-controlled products and samples.

The new host of offerings and solutions means a multitude of choices when it comes to choosing the right packaging for a particular product. 

Compliance & Audits :  The impact of Good Distribution Practice (GDP) on temperature-controlled transport continues to grow.

In short, GDP including GMP emphasizes temperature control during the whole supply chain—no transport without temperature monitoring.

As it relates to pharmaceuticals specifically, GDP addresses Quality Management Systems (QMS) and documentation, personnel and training, risk management (including Standard Operating Procedures – SOPs), facilities/storage, transport and much more.

Due to increasing regulatory burden, quality departments within manufacturers’ supply chain operations are gaining more and more authority.

This, coupled with the complexity of regulatory compliance, means that various stakeholders on the manufacturing end must ensure that suppliers and transport partners comply with applicable regulations, taking a risk-based approach and enforcing audits and quality agreement. 

Submitted by: : Design/Build Engineers, Houston, Tx (USA).

CASE STUDY: An Innovative Upgrade for Odisha Ice Cream Making Facility

“This report was formulated & edited by Mr. M. Mehdizadeh [of Houston ,Tx (USA)] for Mr. Anand Joshi , Senior Partner ‘Manik Engineers’ who are the leading world class manufacturers (from Pune, India) of Valves, Controls & Monitoring Devices for the Industrial/Commercial Refrigeration & HVAC Industries. Mr Joshi is also the editorial chairman to India’s AAR Newsletter (Association of Ammonia Refrigeration) published monthly from Pune”

This is a case study on improving plant efficiency and safety of Ammonia Refrigeration System at a modern technology Ice Cream manufacturing unit. The plant is located at Cuttack near Bhubaneshwar, Odisha. The production capacity of the facility is designed for 10 MT of ice-cream per day for meeting the market requirements of Odisha and the neighboring states. We understood that walking around the plant can identify many small improvements that can enhance profitability. Also that an improperly operating unit required considerable field work. In walking between the control room and the main equipment, lot of discrepancies were noticed between the piping and its controls. Often these could signal heat gains from the environment which adds load to the existing refrigerating system.

The team from ‘Manik Engineers’ were called upon for troubleshooting of this plant and the directive from the owner was to upgrade in phases the existing refrigeration plant for higher efficiency and safety,fixing the heat gain problem while involving reasonable investment . Many a times plant upgrade /modernization leads to complete change of plant, whereby heavy investment and payback period of 3 to 4 years are estimated. Hence it was decided that plant improvement be based on saving energy while increasing capacity thru green design, aiming to achieve highest efficiency and safety management plan.

The objective further was to keep ROI period less than a year while achieving minimum 15% in energy savings. The refrigerant used in the plant is natural refrigerant, that is, pure(anhydrous) Ammonia , which earns a high environmental marks with ODP & GWP being Zero and in case of leaks, breaks down to its natural components of nitrogen & hydrogen in a relatively short time. This facilities’ refrigerating system operated thru natural (gravity) flooded feed.


Although today many people turn to IOT to quickly load up information, we decided to follow a systematic study to accordingly implement the above. The primary step was to prepare a HAZOP report and investigate operational plant problems on day to day basis. We proceeded by recording plant operation parameters and operating hours. Finally after careful study, the following problems were observed in the existing refrigerating system:

1. The chiller rooms and freezer rooms were not able to achieve desired temperature in spite of long running hours of compressors.

2. All unit compressors including standby units were required to remain in operation in order to meet the required refrigeration capacity.

3. The reciprocating compressors were running full load at all times

4. The compressor suction pressure and plant evaporating temperatures did not correlate. The suction pressure was much lower than the corresponding room temperature.

5. The compressor discharge pressure were high considering the ambient conditions.

6. Complete plant was being operated manually.

7. The air cooler coils for chiller rooms and freezer rooms would often frost.

8. Although the cold room and freezer rooms were designed at -25°C room temperature , however the best temperature achieved would be below -14°C.

9. The defrosting system was manual and was never able to defrost the coils completely.

10. Plenty of oil was getting accumulated in Freezer air cooler units’ coils.

11. With existing airborne contaminants, entrapped air or gasses, plant measurement techniques and/or measurement device accuracy were non-existent .

12. The level control system was bypassed and operators were manually throttling the valves on receiver supply line.

13. Freezer air cooler coils were starved for liquid supply , while operators feared possible liquid surge to compressor.

14. Operators were kept occupied by operating various valves applying extra efforts to check operation, temperature and liquid level.

15. Due to minor leakages through flange joints and some welded joints , strong ammonia odor was continuously felt in the machine room.

16. The chiller rooms and freezer rooms were located around the plant , and many times the operator would be trapped in temp controlled rooms, thus preventing the trapped person to freely communicate with plant operators.


Above conditions lead to high energy consumption and loss of production while overall plant was unable to perform at designated requirements. Also considering that the allocated budget to rectify the above was quite limited and in view of time constrain, we decided to concentrate on achieving desired roomtemperatures, increase plant efficiency and improve plant safety at shortest period of time . Another constraint faced was limited jobsite availability of highly skilled and certified man power to operate the plant. Hence it was required to provide an automatic operating system which can be easily handled by professional plant operators. The following functions were performed to update plant operations smoothly and trouble-free:

1. Installed ASME-approved dual Safety (relief) Valves on all pressure vessels with required pressure ratings.

2. Calibrated compressor safety cut outs , wherein these were also repaired and re-connected for safety.

3. Installed (on each compressor) easy to use Automatic Compressor control system with energy monitoring.

4. Installed fully automatic air purger on condenser and liquid receiver circuit.

5. Installed automatic hot gas defrosting system (replacing the existing manual defrost) on all air cooling units in chiller rooms and freezer rooms.

6. Installed temperature monitoring and control devices for all cold rooms and freezer rooms.

7. The automatic level control system was serviced and put into use.

8. Installed the reflex type level gauges and removed the glass tube one.

9. Installed an integrated automatic ammonia leak detection system.

10. All flanged type valves were replaced with 40 bar weld in-line valves. The valves were chosen with back seating facility.

11. The chiller room alarm system with built-in battery back-up was installed on machine room doors for trapped operator and generate alarm in plant room. This unit was incorporated within-built battery backup so that it can work independently in the event of power outage.

12. The overall above system improvement were anticipated to provide a Low Life Cycle Analysis (LLCA) and low carbon emissions where the refrigerating system gets greener and the energy savings add to the bottom line footprints.


Above performance was successfully implemented within 10 to 12 working days . This was done together with the valuable assistance of plant operators and one certified welder, without any downtime or disturbing status quo of plant operations. Once the required changes was in place and analysis performed within baseline and prevailing industry standards, a positive win-win results achieved were evaluated as follows:

1. The compressor discharge pressure reduced significantly to 160 PSI from 220 PSI .

2. The automatic operation of compressor units removed operator interference and resulted in automatic & smooth loading/unloading of each compressor. Additionally overall energy requirements on compressors were reduced significantly.

3. The safety valves and release system ensured increased safety at plant and no discharge of ammonia in plant in the event the safety valve pops up.

4. The automatic ammonia leak detection and alarm system increased plant safety meeting OSHA’s PSM safety requirements extending operator flexibility in working around the plant.

5. The automatic hot gas defrost system replaced manual defrost operation.

6. The defrosting period was reduced to 15 minutes instead of 45 minutes.

7. The increase in cold room / freezer room temperature during defrost reduced to 2°C from 10°C.

8. The cold room / freezer room design temperature of -25°C was successfully achieved.

9. The time required for freezer operation reduced by approx. 25% .

10. Numbers of operating compressors were reduced. The standby compressor remained as standby, and never required to operate , unless when called upon.

11. Reduced the compressor running hours by approx. 25%.

12. The automatic level control system made sure that ACU/Freezer coils are flooded thus preventing liquid slop-over to the compressor.

13. The automatic level control system avoided operator’s interference by installing throttling valves on receiver supply line.

14. Oil accumulation in ACU and freezer units were eliminated.

15. Frosting on ACU & freezer units were eliminated.

16. The installed online data logging and remote monitoring system helped customer to monitor the plant on mobile phone, (using the concept of IOT), while travelling enjoying their holidays.

17. The temperature control system made sure that required temperatures are maintained continuously. No under shooting/overshooting observed. All temperature were maintained within ±2°C

18. The weld-in- lines valves eliminated the leakages through the previous flanged joints.

19. The back seating facility in the valve assured operators that now they don’t have to pursue in tightening valve glands.


Thus, over all plant performance were improved by:

1. Reducing the plant operation time, hence reducing the plant deficiency period.

2. Achieving plant temperature requirements .

3. Operating at optimum suction and discharge pressures.

4. The ammonia odor from plant room vanished.

5. Increased plant safety and performance requirements.

6. The automation of compressor, defrost system, liquid level control and plant monitoring allowed operators address other maintenance issues.

7. By recording, monitoring and following relevant industry standards, solutions on safety and visual communication management throughout the facilities were provided .

8. All components, parts, units and devices involved on this troubleshooting works are engineered, designed & manufactured as “Made in India” products.

After observing a trouble-free plant operation for a period of one year, an estimated 30% energy saving was derived with an overall payback period recovered within 4-5 months. Additionally it also improved product (ice cream) quality and production capacity as compared to (prior to above improvement) previous year. Thus a well-done job was accomplished.

Solutions for safety & Visual communication on ammonia refrigeration facilities

The risks involved with ammonia refrigeration are substantially reduced by EPA’s Risk Management program (RMP) and preventive maintenance. Part of that process is clear labeling of incorporated pipes and equipment. As the accepted industry experts in this field, the IIAR maintains a code of recommendations for refrigeration equipment labeling- Manuchehr Mehdizadeh, BSME Project Advisor-All aspect of Cold Chain Industries-USA

Ammonia Refrigeration Basics

The refrigeration systems use basic physics to transfer heat energy out of one area and into another, leaving the first area cooler than it was before. Indoor ice hockey rinks and grocery store freezer sections use the same process on a larger scale. Massive industrial facilities like petrochemical refineries and food processing plants rely on large-scale refrigeration systems for their day-to-day operations.

The most common type of industrial refrigerating system is a vapor-compression refrigeration. This approach uses a fluid called a refrigerant as the means of moving heat around. Most of the time, the refrigerant is a vapor. At one point in the system, it’s compressed to become a liquid; later, it’s allowed to expand and vaporize again. The process repeats on a cycle. Each time the refrigerant vaporizes, it absorbs heat energy from its surroundings, and each time it condenses, it releases that heat to its new location.

The physical properties of the refrigerant determine the pressure and temperature ranges of the system, along with the rate of cycling required for a given cooling effect. In turn, those details determine the efficiency of the refrigeration system as a whole. The choice of refrigerant is important, and many synthetic materials have been created for the purpose. In the past many kind of chlorofluorocarbons (CFCs) gases such as Freon R-12/R-22 etc were developed and widely used during the 20th century, until their destructive impact on the environment was discovered.

Why Ammonia Refrigeration?

Ammonia is a natural choice (with ODP=0 & GWP=0) of refrigerant on large cold chain industries. Following reasons areconsidered for choosing ammonia as a refrigerant:

  • Ammonia’s physical properties make it effective and efficient for large systems.
  • It breaks down quickly in the environment, minimizing potential environmental impact.
  • Any spill or accidental release can be quickly identified, because of ammonia’s strong odor.

According to the International Institute of Ammonia Refrigeration (IIAR), ammonia is 5 to 15% more thermodynamically efficient than competitive refrigerants. This allows an ammonia-based refrigeration system to achieve the same cooling effect while using less power. As a result, where ammonia refrigeration is incorporated, its overall system can provide a Low Life Cycle Cost Analysis (LLCA) , low carbon emission where the system gets greener and the energy savings add to the bottom line footprint.  This could also be a door opener in obtaining LEED certifications from the USGBC’s local chapter and an eventual recipient to OSHA’s PSM &EPA’s RMP certifications. 

Ammonia breaks down in the environment very quickly (lasting less than a week in the air). Unlike synthetic refrigerants like CFCs, it doesn’t damage the ozone layer. Most of ammonia’s potential for harm relies on there being too much of it in one place, not on its being leaked and scattered into the environment. Also, ammonia is mostlyused as a fertilizer and sprayed on fieldsfor industrial farming.

Also, in the event of any leak most people will notice the pungent smell of ammonia when it’s only about 20 parts per million (ppm) in the air. While some refrigerants have no noticeable smell, allowing small leaks to go unnoticed, that’s not the case with ammonia. Even a tiny amount in the air will be obvious. Importantly, the detectable concentration is much lower than the concentration that will cause immediate harm.

Limitations of Ammonia Facilities

The ammonia’s properties are best suited to large refrigeration systems, there is likely to be a large amount of ammonia in any system that uses it. Any water in the system would freeze and obstruct piping, so ammonia refrigeration systems uses anhydrous (dry) ammonia (without water or other impurities). The physics of vapor-compression refrigeration require the system to use enough pressure to compress the gas into liquid. Together, this means the refrigeration system uses required amount of pure ammonia under high pressure.

As a result, any ammonia-based refrigeration system may present a risk of accidental exposure to high concentrations of ammonia. That kind of accident could cause serious harm to worker health and safety.

OSHA considers anhydrous ammonia to be “immediately hazardous to life and health” at a concentration of 300 parts per million (ppm), or 0.03%. Ammonia is corrosive to the skin, eyes, and lungs, and even a brief exposure can result in severe chemical burns. Extreme cases can even prove fatal. Refer to ammonia safety and health information from OSHA.

Preventing an Ammonia Leak

OSHA recommends, among other steps, conducting a process hazard analysis (PHA) when ammonia refrigeration is present in a workplace. A PHA is a key component of broader Process Safety Management (PSM) efforts.  It consists of a careful review of potential problems—such as an ammonia leak—and steps to be taken to prevent such an outcome. Conducting this analysis may raise awareness among employees, promote a mindful attitude about safety, and engender a proactive approach to hazard and risk assessment.Requirements for PHAs can be found in compliance with 29 CFR §1910.119, OSHA’s standard for Process Safety Management (PSM) of Hazardous Chemicals.

Safety on Ammonia Refrigeration System

The risks involved with ammonia refrigeration are substantially reduced by EPA’sRisk Management Program (RMP) and preventive maintenance. Part of that process is clear labeling of incorporated pipes and equipment . As the accepted industry experts in this field, the IIAR maintains a code of recommendations for refrigeration equipment labeling.

Last updated in April 2014, IIAR Bulletin No. 114( a copy can be ordered from specifies sizes, colors, and arrangements for ammonia pipe and component labels. This coherent system simplifies maintenance and promotes safety, and is compatible with ANSI/ASME A13.1, the most widely-used industrial standard for general facility Pipe Marking.

There are five elements in a typical ammonia Pipe Marker:

  • Piping abbreviation, such as “LTRS” for Low Temperature Recirculated Liquid, to identify the part of the system that the pipe represents
  • Physical state of the pipe’s contents, indicated with the word ‘Ammonia’, shown with letters on a colored band: “LIQ” on yellow, for liquid; “VAP” on sky blue, for vapor; or both if the pipe could contain both phases
  • Pressure level, shown with letters on a colored band: “LOW” on green, for contents at 70 psig or less; or “HIGH” on red, for contents above 70 psig
  • Flow direction, indicated with an arrow pointing along the pipe in the correct direction

The piping abbreviation, pipe contents, and flow direction would be shown in black print on an orange background. Under the popular ANSI/ASME A13.1 pipe marking standard, that is the preferred presentation for pipes carrying toxic contents, such as ammonia. As a result, a pipe marker that matches IIAR Bulletin No. 114 also matches the broader standard.

Afree ammonia pipe marking reference chart describing the IIAR’s pipe marker system can be furnished by Graphic Products. Using this chart can help one’s facility maximize its safety and efficiency, simultaneously taking advantage on the proven power of ammonia refrigeration.