For pure gas refrigerants (like R134a) the bubble point temperature is equal to dew point temperature. However, for some refrigerant mixtures (like R407C or R407F) the bubble point temperature is not the same as dew point temperature. For these refrigerants the difference between the saturated vapour temperature (dew point temperature) and saturated liquid temperature (bubble point temperature) at constant pressure is referred to as the “temperature glide” of the refrigerant mixture.
This year Mike Ladell has been a part of the HVAC&R industry for 60 years. Beginning with a 4-year apprenticeship at JH Stranack. Mike then went on to work at both Marshall’s and Brown’s Refrigeration before starting his own business, Ladell’s Services, which he ran for 16-years. Mikes next ran Yucon Coils’ Natal branch, before leaving to launch a new company Afcon.
Afcon’s initial focus was on selling Yucon shell and tube condensers, that were at the time manufactured in South Africa, as well as split units. Mike’s specialty soon presented itself when he designed, manufactured and sold Industrial Units to Telkom, Richard Bay Minerals and Richard Bay Coal Terminal. In the 90s, Mike was also one of the first in the industry to develop, in conjunction with Recoil, V shaped coils for a client.
Mike has thoroughly enjoyed his time in the industry, stating that he particularly enjoys the new and ever different challenges each job poses, and we are sure he’ll be around for some time to come. As someone once said “If you don’t know Mike Ladell, you aren’t in refrigeration”.
Mike advocates for a refocus on training in the HVAC&R industry and the introduction of a levels system through which standardisation across the industry can be ensured.
How simple is it to install refrigeration equipment for a cold room?
Remember installing Window wall units? Basically make a hole, slide in unit and connect to power!
We now offer the same convenience with our Cubimax units. It’s even simpler as the hole can easily be cut into the Cold Room Panelling. Your installation time is reduced and you have the knowledge that the unit is pre-charged and factory tested. Note the Cubimax units are suitable for Freezer rooms and Cold Rooms.
Click on the following link to download more information.
Afcon is well known in the industry for stocking ONDA Braised Plate Heat Exchangers for all your immediate needs.
We have now introduced a range of ONDA Gasketed Plate Heat Exchangers. Manufactured in Italy, ONDA Plate Heat Exchangers are designed for small to large applications. Materials available 304 s/s, 316 s/s and Titanium. Our advantage is our highly competitive pricing and fast delivery times. Units can leave the factory in 2 weeks prior to airfreight or sea-freight depending on your requirements.
We select and price enquiries within 1 hour and ensure you have quick turnaround in all aspects, from ordering to supply.
How the Bitzer IQ Module works in refrigeration systems with Bitzer reciprocating compressors
This video explains how the Bitzer IQ Module in refrigeration systems works with Bitzer reciprocating compressors.
The new, intelligent operating concept with Bitzer IQ Modules was developed to take full advantage of the potential of new technologies in terms of energy efficiency and straightforward integration into refrigeration systems, whilst ensuring simple service.
Afcon addresses where the industry in going in terms of gas use?
Currently in Europe there are many discussions regarding the phasing out of the staple refrigerants previously used in Refrigeration applications namely R404a and R507a. Both these refrigerants have a high Global Warming Potential of over 4000. The current guidelines recommend using refrigerants with a GWP of 2500 or below. So the options being advocated in Europe are divided into following groups.
a. HFO/HFCs these being R448a, R449A, R452A - these are non-flammable synthetic refrigerants
b. Hydrocarbon’s these being Natural gas refrigerants – R290 Propane ( flammable refrigerants)
c. Ammonia
d. CO2
Several case studies have shown that the use of Hydrocarbon’s provide efficiencies with less refrigerant required and low power consumption on the plant. Also certain Refrigerant companies are manufacturing Hydrocarbon blends to be a direct replacement for R22 systems. However stringent guidelines must be observed because of the flammability.
Ammonia and CO2 are still only used by contractors who are specialists in these Natural gases so it is clearly not a solution to all requirements.
Since South Africa generally follows Europe – I think the large importers of refrigerants in South Africa will eventually govern the changeover via price and availability, indirectly influencing which refrigerants become the industry standard in the future. Watch out for the increasing prices on R404a/R507a eventually pushing contractors and suppliers to look at alternatives.
Bitzer recently advised in their Distributor’s meeting in Leipzig that new plants must be capable of longevity, so they must be designed with the long term ability of working on several refrigerants without the main components requiring change. This seems the best advice for the present.
Over the last 20 years Stuart has cultivated his knowledge at Cool Power, Barlows, Samsung, SANBS, and now at Carel. Currently Stuart’s focus is on expanding Carel’s brand name and sales in the KZN and Eastern Region.
Much like our last Customer Profile feature, Craig Scott, (click to view this article), Stuart enjoys the challenges that the industry and his job offers, namely providing high efficiency controls for each unique customer's need and project, at a competitive rate. Once this has been achieved Stuart enjoys site visits, where he can view the controls in action, and ultimately the successful job.
Carel Control’s products have been successfully used across many industries, including pharmaceutical, diary and retail. Over the last three years Stuart has been involved in many successful projects. One of these being the new Dairy Day dairy in Howick, as well as another with Cipla. Stuart was also involved in the installation of Carel’s first HEOS, water loop refrigeration system, in Durban.
Stuart’s impact at Carel can be seen by the considerable increase in Carel sales that have been achieved over the last three years, with Afcon being one of the its most successful wholesalers.
Afcon recently had the pleasure of attending Bitzer’s EMEA Distributor’s conference in Leipzig, Germany. The delegates come from the EMEA region – Europe, Middle East and Africa. This event occurs every two years and enables Bitzer distributors to stay informed of the latest innovations and future concepts.
One of the most impressive new options on the Bitzer compressors is their new IQ module, the CM-RC-01 device to replace standard SE-B1 motor protection module. This device has the following benefits:
It controls all the devices that are mounted on the compressor and comes from the factory pre-wired.
Oil heater
Oil protection
Motor Protection (PTC)
Discharge gas temperature protection
Pressure transducers (LP and HP)
Refrigeration Injection (RI)
Additional fan cooling Capacity Regulation (CRII)
Start Unloading (SU)
High Pressure switch
The device also allows for the control of CRII unloaders – meaning that you no longer require a sophisticated PLC controller only a device that has an external 0-10v signal.
The IQ device has a built in Data Logger and Bluetooth facility, plus as an added benefit compressors ordered with this device can have a 2 year extended warranty – since the compressor cannot run outside its envelope with this controller.
The main applications of Onda brazed plate heat exchangers is for the evaporation and condensation of refrigerant gas in air-conditioning and refrigeration plants, the hot water production in heat pumps and heat recovery. Onda's brazed plate heat exchangers are compatible with all modern refrigerants.
Only top quality materials are used in the manufacture the ONDA brazed plate heat exchangers. The Plate heat exchangers are made from Stainless steel thickness 0.0138” (316L type), the connections are also Stainless steel (304L type) and the brazing material is copper.
Afcon is the sole importer of Onda Brazed Plate Heat Exchangers in South Africa. Call us now for more information or browse our website http://www.afcon.co.za/onda
The SAIRAC Golf Day held on Friday 8th September, was the usual success and very well supported by the industry, with a record field of 38 four balls. Thank you to Tarryn Ching for her exceptional organisation. As always it is fantastic to meet our fellow HVAC&R colleagues in a relaxed atmosphere.
For the third year running Afcon sponsored the 11th hole. We thank all of you who visited our hole, and are certain the banter and cheer experienced cannot have been rivalled by any other. It was a glorious day out on the course in sunny Durban. Our congratulations to the winners of the day and to the Airconditioning Project's four ball who won the SAIRAC trophy.
To view the images bigger please click on each image. Our marketing team would love to hear your feedback on our new newsletter format.
This week we sat down with Craig Scott, of CS Air, to chat about where he started, where he is now, and everything in between.
Craig has been in the HVAC industry for 25 years, and first entered it at Republic Refrigeration and Airco, where his interest was sparked and he began his apprenticeship. Craig went on to work for Republic Refrigeration and Airco for two years thereafter, before moving to ACS, Air-conditioning and Pump Installations, where he worked for the next 10 years.
In 1999 Craig opened his own company and CS Air was born. Over the respective 18 years CS Air has worked on many exciting projects, and found it’s specialty in central plants particularly chilled water plants.
A current example of an exciting project that CS Air is working on, is the systems installation for the new Cornubia Virgin Active. Virgin Active has been a client of CS Air for nearly 25 years, and CS Air has been involved in the majority of Natal’s Virgin Active installations. Another project that CS Air has been able to “sink their teeth into” of late, is the new Sibaya Dunes development, which involves the installation of large Samsung VRV systems in the presidential apartments.
Craig is very passionate about what he does, and he states that his passion comes from his love of the challenge the HVAC industry provides. One of the major challenges of the industry is the technological advancements, which companies must keep abreast of. However Craig stated, that with the support of suppliers who bring in products that allow CS Air to provide the greatest efficiency and cost effectiveness to its clients, these challenges can be overcome.
What is the difference between Ethylene Glycol and Propylene Glycol?
What You Need To Know
Both ethylene glycol and propylene glycol solutions will effectively lower the freezing point of water allowing it to be freely pumped through a variety of heat exchangers, and can be used interchangeably for most applications. While there are many minor variations in the properties between ethylene glycol and propylene glycol solutions, however there are two key differences that dictate which of the glycols is chosen for a particular application, namely toxicity and viscosity.
Toxicity
Ethylene glycol is more toxic than propylene glycol. About 2 - 4 ounces of ethylene glycol can be fatal if ingested by an adult human. Whereas, propylene glycol is a food additive and is not harmful to humans if ingested in moderate amounts. Therefore, propylene glycol solutions are preferred for many applications, particularly when human exposure can occur.
Viscosity
While differences in viscosity between ethylene glycol solutions and propylene glycol solutions at elevated temperatures are minimal, at temperatures below -18C the viscosity differences become significant. If heat transfer at these low temperatures is required, ethylene glycol solutions should be used. In addition, ethylene glycol solutions will require less pumping horsepower under cold conditions. If these liquid characteristics are important, ethylene glycol is usually chosen for the application.
Major Tech test instruments have been designed and manufactured to operate under the harshest conditions, offering reliability and accuracy for Engineers, Electricians and Electronic Technicians. Major Tech’s instruments are all made to stringent specifications and offer top quality innovative product, as well as and reliability.Afcon carries a wide range of Major Tech products the most popular being the Multimeters, Clamp-on Meters, Thermo-Hygrometers, Thermometers etc. Afcon can advise and order any specialist equipment required. For a full llist of all the instrumentation both handhel and bench equipment that will assist you in carrying out your work, please contact us using the form button on home page and we will get back to you with the information.
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.
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 . . .
