afcon answers

Which fouling factors are suggested for the selection of shell and tube heat exchangers?

The fouling factor is important for the selection of an evaporator. The values suggested to input in selection software are:

For evaporators:
- Normal water in closed circuit: 0,000043 m2K/W;
- Water in open circuit: 0,000086 m2K/W;
- Solutions with glycol <40%: 0,000086 m2K/W;
- Solutions with glycol >40%: 0,000172 m2K/W.

For condensers:
- Normal city water: 0,000043 m2K/W;
- Treated tower water: 0,000043 m2K/W;
- River water: 0,000086 m2K/W;
- Solutions with glycol <40%: 0,000086 m2K/W;
- Solutions with glycol >40%: 0,000172 m2K/W.

To read more blog posts click here



Eberle AC Controls

Eberle is a leading European brand that manufactures energy efficient residential and commercial heating and air-conditioning controls. Eberle has over 80 years of experience and prides itself on reliability, quality, technical excellence and sustainable production.

Afcon holds a wide range of, reasonably priced, Eberle controls. This range includes controls with dual heating and cooling options as well as single function controls. We also offer the choice of LED indicators and models with proportional outputs for heating and cooling.

For more information on Eberle AC Controls, and controls technical specifications, click here . . .





To read more blog posts click here . . .





In 2014 F-Gas regulations, in Europe, were amended in order to prompt a phasedown of the use of HFCs. This regulation change was undergone with the hope that HFCs would be reduced to only 21% of its current usage by 2030. This goal is on track to being achieved as a 63% decrease is expected by 2018.

This phase down is being achieved through the introduction of quota allocations and sectorial bans on high-GWP HFCs as well as multiple governments taking further steps to reduce the use of refrigerants with a substantial impact on the environment.

Bitzer has expanded their range of compressors to meet this need for environmentally sustainable refrigeration. The Bitzer Ammonia Compressor Pack (ACP) does just that. Bitzer’s ACP is designed for a wide range of operations in high, mid and low temperature applications in industrial refrigeration and process cooling.

Bitzer Ammonia Compressor


Technical specifications

- Available with a capacity range of 100 to 450 TR

- Modular compressors units comprise up to 3 compressors

- Compressor packs can be connected (up to 9 compressors) and connected to a single controller

- Equipped with frequency inverter

- Common oil separator



- Optimal part load performance

- High efficiency: individual compressors can be turned on and off depending on requirements

- Maximum redundancy for high operating reliability: system has multiple ammonia screw compressors which increases its reliability over single industrial compressors

- Bitzer advanced oil management system

- Reduced installation costs

- Durability

- Fast availability for all replacement parts

For more infoamtion . . . 

bt download pdf


To read more blog posts click here . . .



customer profile no lines


Cyril Maurel

Cyril Muarel, managing owner at Shosholoza Airconditioning & Refrigeration cc, has been working in the HVAC&R industry for 20 years. Cyril is a second generation in the industry, following in his fathers footsteps. His 20 years of experience have allowed him to specialise in hospital’s, data centre applications, as well as Refrigeration and compressor overhauls. Cyril is extremly passionate about his work and passing on the knowlege he has gained through training. We sat down with him to discuss how he got to where he is today. . .


What is your general background? Why did you go into this industry originally?

I have an Airconditioning and Refrigeration background. I got into the industry because my Father was already involved in it. After my first year, I loved the industry, and my passion grew from there.

Where did you study or do your apprenticeship?

I studied at Technical College, completing my N6. Achieved my Refrigeration Trade Test and Electrical Trade test. And went on to work full time at Shosholoza after leaving school, and studied part time.

Where have you worked over the years?

I have always worked at Shosholoza airconditioning, since 1998, 20 years.

Do you have a specialty or specific focus?

My specialty is hospitals, data centre applications, Refrigeration and compressor overhauls. My special focus currently is getting registered with the ECSA as a professional Engineering Technician, growing within the design and engineering side of the industry.

Where did you gain your experience?

I gained my experience through my Dad, as well as having the opportunity to work within the various fields of HVAC&R. I built a lot of relationships and always asked experienced technicians, Engineers and suppliers questions. I read a lot of HVAC books, which keeps me up to date on current trends. I am a member of SAIRAC and ASHRAE. I have enrolled in all the SAIRAC short courses, as well as the ASHRAE courses.

What do you enjoy about your work?

Being able to provide employment, interacting with my staff, customers and suppliers. Solving problems on site, and most importantly, I love learning something new everyday within the industry.

What projects have you worked at in the past, or do so currently, that you think are of interest?

Highway House – Supply and installed 2 Trane chillers, Cooling towers, Cooling Coils and BMS system. We have completed 5 Telkom sites for Data Centre installations. Currently we have been appointed a Refrigeration Project for a new Government Hospital.

Any other information you think is of interest, or would like noted?

I have a great passion for what I do. I have a great interest in training as I feel there is a lack of skills in our industry. I have been to Italy for training on Controls, Surgical Room Airconditioners from TECNAIR LV, as well as to Dubai for training through ASHRAE for HVAC Design.


To read more blog posts click here

Afcon AnswersScreen_Shot_2017-01-27_at_12.06.45_PM.png

What does “Approach” mean in heat exchangers?

This term refers to the difference between the leaving process fluid temperature and the change of state temperature of the refrigerant. For evaporators, if water is cooled from 12°C to 6°C and evaporating temperature is 1°C, the approach is 5K. For condensers, if water is warmed from 30°C to 35°C and condensing temperature is 40°C, the approach is 5K.

bitter logo

Bitzer Compressors and Ammonia Seminar

Following the success of last year’s Roadshow Bitzer South Africa offered another Road Show event in Durban yesterday, covering Bitzer compressors and Ammonia applications.

The event was held at the Durban Country Club. And was a great success. Thank you to all who attended, and to Bitzer South Africa for hosting.

If you are interested in the information discussed at this seminar . . .

bt download pdf





Afcon AnswersScreen_Shot_2017-01-27_at_12.06.45_PM.png

What is “Bubble Point”?

The bubble point is the temperature at which a liquid forms bubbles (usually the lowest boiling point of one of the constituents of a mixture like R407C).





All the Best for 2017 from Afcon Industrial Equipment. We would like to wish our staff and customers very Happy New Year and a prosperous 2017.

coming soonHappy 2017Africa

Afcon have supplied equipment into Africa for many years and we continue to supply products and equipment to many African countries. With the range of products and agencies that we are able to supply, Afcon have raised their presence in Africa during 2016.  As a refrigeration wholesaler with everything from copper piping, Refrigeration Gas, Parts and equipment, this includes modular refrigeration equipment that is ready to install and built to custom specifications. We have the pleasure and privilege of supplying some of the world best refrigeration products. Afcon are well situated to supply you with world class products and equipment from our many suppliers that we have acquired agencies for.

So from Cape town to Cairo, Afcon are able to supply you with your refrigeration requirements.



Open iTunes to buy and download apps.


The BITZER REFRIGERANT RULER Work out refrigerant data – quickly and easily – with the free BITZER REFRIGERANT RULER from BITZER. The BITZER REFRIGERANT RULER, developed for iOS, covers all of the common refrigerants and contains data on their relevant physical properties. It offers an intuitive user interface with which it is quite simple to work out temperature and pressure for various refrigerants. The tool is one of the few applications which enables the use of imperial and metric units at the same time. It is available in both English and German. The main functions On the start screen, the user is shown all of the relevant information about the selected refrigerant, such as its dew and bubble point depending upon the pressure, as well as information about the best type of oil to use, the refrigerant’s global warming potential (GWP value) and its safety group. A ‘Refrigerants’ menu at the top-left edge of the screen gives you an overview of all available refrigerants as a list. When you select a refrigerant from the list, you are then shown its details page which contains more valuable information. By swiping to the right or left on the start screen, you can also switch directly to another refrigerant. Settings and filter functions can be found at the top right. The filter functions make it possible to restrict the refrigerants shown by their GWP values or to just show natural refrigerants. The settings allow you to switch between metric and imperial units. Additional advantages of the BITZER REFRIGERANT RULER The extra functions to select for natural refrigerants and for GWP values are two new and convenient options. Moreover, you can also access BITZER’s latest refrigerant report directly from the app!


screen696x696 screen696x696 1

10′s of thousands of LPA® pumps have been installed as a simple retrofit means of getting liquid refrigerant to the expansion valves when minimum head pressure controls are set to reduced head pressures, thereby saving energy and increasing capacity at mild to cold outdoor temperatures.
The LPA® pump eliminates the usual problems of capacity loss and poor oil return due to operating with low head pressure.
Improved performance and efficiency of a system that has flash vapor in the liquid line. This is especially apparent if flash vapor is a serious problem, as in systems with excessive liquid line pressure drop, elevation gain in the liquid line, or if the air surrounding the liquid line is warmer than the outdoor temperature.
Reduced scaling problems on water-cooled systems when a small amount of high pressure liquid from the pump outlet is injected into the discharge line, reducing the vapour temperature.860 SS 050 EA

The LPA works by boosting liquid refrigerant through the system…

The LPA works by boosting liquid refrigerant through the refrigeration system. By increasing the liquid’s pressure, the associated saturation temperature is raised, while the liquid temperature remains the same. The liquid becomes sub-cooled; reducing the potential for flashing prior to the expansion valve. With LPA, your business will enjoy higher efficiency, lower power draws and substantial cost savings.

reciprocating compressor cylinder head cooling LPA pump 


Taken from:



Nicknamed the work dog, now available with a high strength stainless steel housing to meet with pressures on demand. Built to stand up under heavy loads, LPA (Liquid Pressure Amplification) pumps, are equipped with built-in overload protection. Under adverse conditions, the magnetic drive acts as a clutch to eliminate overloading and motor burnouts.

The 875-SS-050-VSD (Variable Speed Drive) is now available with a high frequency drive compatible motor designed for continuous use up to 75hz if required.

PS 725 psi / 50 bar
PT 1,036 psi / 72 bar
TS Min -22°F / -30°C
TS Max 160°F / +72°C
Inlet ODF Copper 1-5/8″
Outlet ODF Copper 1-1/8″
Motor Power .75 hp
Voltage 208-230 /460
Ampere 2.4-2.2 / 1.1
Phase 3PH
Frequency 50 / 60Hz
Thermal Overload

REFRIGERANTS: (Fluid Type /GAS GROUP 1&2 /UL Classified)

Co2 R-290 R-134a R-401a R-401b R-401c R-402a R-402b R-404A R-407A R407b R-407c R-408a R-409a R-410A R-500 R-507

OUTDOOR PROTECTION IP54 | Altitude 2000M | Corrosive & Polluting Substance Class 4C2 | Vibration & Shock Class 4S2 | Presence of Dust Class 4S2 | Corrosion Protection Level ClassIP43B

MAINTENANCE: Maintenance free, no service required.

Manufactured to: DIR 97/23/EC “CE” CAT A1 / UL Recognized \ Shipping Weight 46 lb’s | Dimensions L 25″ x W 16″ x H 16″ \ Component Weight 42 lb | Dimensions L 17″ x W 14″ x H 10″

Mechanical Life Wet End Assembly +20 years | Mechanical life Impeller +100,000 continuous hrs | Mechanical Endurance +300,000 cycleshanical Endurance +300,000 cycles860 SS 050 EA



Taken from:



customer profile no lines

Alvin Brown

Alvin, owner and manager director of Thermal Dynamics & Engineering and JNC Thermal Systems, has been working in the HVAC&R for 20 years. He has gained much experience allowing him to specialise in chillers, so we sat down with him to discuss how he began his career, where it has taken him and what he feels helped him get where he is today.

What is your general background?
Why did you go into this industry originally? My father was the Refrigeration & Air-Conditioning Engineer at Beacon Sweets for 23 years, this naturally drew my interest to the trade from my young high school days. He started teaching me to repair small scale refrigeration equipment in our garage from the time I was in grade 10. After matriculating, I did my apprenticeship at York International, qualified, then slowly moved my way up in the Industry, ultimately to opening Thermal Dynamics & Engineering in 2009.

Where did you study or do your apprenticeship?
I studied at UNISA, did my apprenticeship, and many plant specific training courses, at York International.

Where have you worked over the years?
Started off at Million Air Services(about 2 years), spent 4 years at York International, spent a short 7 months at Combined Air Services, spent 6 years as a service manager and share holder at DJ Thermal Engineering, opened Thermal Dynamics & Engineering beginning of 2009 until present.

Where did you gain your chiller experience?
Fortunately, I was well trained on chillers from York International days, grew and gained experience throughout my career, actually still learning now, you never stop learning.

How long have you been working in the industry and how long specifically with chillers?
Been in the industry for 20 years and have been exposed to chillers since the beginning.

What do you enjoy about working with chillers, which led to your specialisation in them?
I like to specialize in a field, you tend to always be needed in the industry.

What plants have you worked at in the past? Or do so currently?
Eskom Power Station in Drakensburg, Boxmore Plastics (Harrismith, CPT, Bloemfontein & Mauritius, Zambia), Coca Cola (PE, Mozambique & Mauritius), St Augustines Hospital, Sasko Bakery, Boxer Meats Factory in Ballito, just to name a few. All the plants at the above sites are chillers for production purposes. We also work on several cold storage facility plants which run on screw compressors (low temperature and medium temperature), a few ammonia screw sets used for food production blast freezers and many air-conditioning systems from chilled water to standard DX split systems.

Which fouling factors does Onda suggest for the selection of shell and tube heat exchangers?

The fouling factor is important for the selection of an evaporator. The value Onda suggest to input in selection software are:

For evaporators: -    Normal water in closed circuit: 0,000043 m2K/W; -   

Water in open circuit: 0,000086 m2K/W; -   

Solutions with glycol <40%: 0,000086 m2K/W; -   

Solutions with glycol >40%: 0,000172 m2K/W.

For condensers: -   

Normal city water: 0,000043 m2K/W; -   

Treated tower water: 0,000043 m2K/W; -   

River water: 0,000086 m2K/W; -   

Solutions with glycol <40%: 0,000086 m2K/W; -   

Solutions with glycol >40%: 0,000172 m2K/W.


THE South African market has seen an influx in the variety of available sources for the supply of disposable refrigerant cylinders. Quality and value for money should remain key considerations when purchasing refrigerant in disposable cylinders. The criteria below can be used as a guide to ensure peace of mind and ultimate satisfaction with product and cylinders purchased.

Refrigeration - Disposable Packaging:

Refrigerant Branding

Always purchase refrigerant that is in a branded disposable cylinder, because generic disposable cylinders are difficult to trace back to the source of manufacture. Branded disposables will carry either the manufacturer’s or the importer’s details.

Refrigeration Product Batch Number

Ensure the batch number of the product appears on the disposable; this batch number is specific to the batch of refrigerant in the disposable cylinder and is
used as a reference between the disposable cylinder and the Certificate of Analysis. This batch number also appears on our box.

Refrigeration - D.O.T. 39

This is the required specification that appears in SANS 10019 for disposable cylinders entering South Africa and should appear on all refrigerant disposable cylinders.

Refrigeration Manufacturing Codes and Disposable Batch Number

The code starts with an M and is followed by 4 digits, which is the disposable cylinder manufacturer’s code. This confirms full compliance with D.O.T. 39. The batch number printed on the shoulder of the disposable allows traceability of the disposable cylinder.

Refrigeration Safety Data Sheet (SDS)

It is a requirement that you have in your possession a Safety Data Sheet when using refrigerants. Ensure that the SDS coincides with the product being purchased and that the branding is the same. Should you change suppliers, or your supplier changes suppliers, you should request a new SDS as an SDS from one supplier cannot be used for product from another supplier.

Refrigeration - Certificate of Analysis (COA)

A COA should be requested for every purchase of refrigerants so as to check that the purity of the product conforms to AHRI 700 Standards. Make sure that the batch number on the COA is the same as the batch number on the disposable cylinder. We have come across a number of COAs being distributed in the market where the batch number on the COA does not match the batch number on the disposable cylinder. In some instances the results on the COA itself actually shows the product failing the requirements, yet the product and COA are still being distributed! For this reason we feel it is necessary to list the testing criteria of refrigerants according to AHRI 700 Standards which can be used for comparison.

Fundamental terms

On an international level, the use of the Systeme International d’Unités is used in refrigeration.  This is often referred to as the SI-system. For a number of countries the implementation of the SI-system is still an on-going process.  However, in many parts of the refrigeration community metric units or other alternative units are still used (the practically used alternative units will be shown in brackets). The table shows the SI-units and the other often used alternative units.


Temperature is a very important part of refrigeration. Almost all refrigeration systems are for the purpose of reducing the temperature of an object like the air in a room or the objects stored in that room. The SI-unit for temperature Kelvin [K] is an absolute temperature because its reference point [0 K] is the lowest temperature that it in theory would be able to obtain.

When working with refrigeration systems the temperature unit degree Celsius [°C] is a more practical unit to use. Celsius is not an absolute temperature scale because its reference point (0 °C) is defined by the freezing point of water (equal to 273.15 K).  The only difference between Kelvin and Celsius is the difference in reference point. This means that a temperature difference of 1 °C is exactly the same as a temperature difference of 1 K. In the scientific part of the refrigeration community temperature differences are often described using [K] instead of [°C]. This practice eliminates the possible mix-up of temperatures and temperature differences.

SI Table

Refrigeration - an introduction to the basics

Refrigeration is a process that removes heat. A refrigeration plant is used to cool down articles or substances, and maintain them at a temperature lower than the ambient temperature.

At the beginning of the last century, it was discovered that the growth of micro-organisms relies on temperature, growth declines as temperature falls, and after +10°C growth slows considerably.  This knowledge allowed the use of refrigeration to conserve foodstuffs using natural ice.  The first mechanical refrigerators for the production of ice appeared around the year 1860. In 1880 the first ammonia compressors and insulated cold stores were put into use in the USA.  Electricity was used from the beginning the 20th century and mechanical refrigeration plants came into being.  After the Second World War small hermetic refrigeration compressors were produced refrigerators and freezers began to be used in the home. Today, these appliances are regarded as normal household necessities.


SEO Consulting , Marketing