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Continuum Mechanics
Continuum mechanics deals with physical properties of e.g. fluids which are independent of any particular coordinate system in which they are observed. These physical properties are then represented by tensors, which are mathematical objects that have the required property of being independent of a specific coordinate system.
The History of Refrigeration
Dating back to prehistoric times, humankind has sought ways to maintain food and drink at lower than ambient temperatures, culminating the vibrant and dynamic HVAC&R industry that we see today. Learn more about the history in this brief summary
Water - Glycol Mixtures
Pure water freezes at 0 °C, that is, the polar water molecules arrange themselves into ice crystals. To be able to use the good heat transfer properties of water at lower temperatures, and to derive additional benefits that can be found with certain additives, we consider the properties of glycol
F-Gas & ODS Regs - Post Brexit
As a part of the EU, the UK was subject to the terms and conditions of legislation governing the emissions and supply of fluorinated greenhouse gases in Europe. With effect from 1st January 2021 however, these regulations will no longer apply in Great Britain and will be replaced.
EC Fans vs Axial Fans
In HVAC applications such as chillers or air conditioning systems, fans are second only to compressors in being consumers of power. There are a few different options available for fan motors and EC fans can have a big impact on the energy efficiency of the unit, as well as the levels of noise generated and maintenance required

Energy Efficiency of Chillers
Until relatively recently, the energy efficiency of chillers has mostly been indicated by manufacturers by stationary maps at full load operating points or the EER, the Energy Efficiency Ratio, which only represents a fraction of the real operating behaviour during the course of the year
How To Size A Chiller
Correctly sizing a chiller is of critical importance to ensure that it can meet the anticipated cooling load. One should also be careful not to oversize a chiller as this impacts not only the capital cost, but also incurs unnecessary whole-life costs. In this article we look at what information is required in order to properly select the right chiller for the job.

About Ozone Depletion
The ozone layer is one layer of the stratosphere and the stratosphere is the second layer of the Earth’s atmosphere. This is of importance to our industry as some chemicals that were historically used in the refrigeration process have been found to deplete the Earth’s protective ozone layer
Understanding AHUs
We find HVAC systems in buildings and industrial processes frequently these days. Such systems move air around a particular space and the technical term for this is air handling unit. In this feature we consider the construction of AHU’s, and the options available for the sections that it is most commonly consists of

Mitigating the Spread of Corona Viruses
In a departure from our usual message to the industry, in May’s edition of the ACR News we shared some researched information about how to mitigate the spread of viruses in buildings by use of mechanical measures. As an industry we believe that we have a responsibility to promote best practice in this regard

The Perception of Sound
Part 1
In order to understand the acoustics of any installation, it’s important to understand how sound is perceived and calculated. In Part 1 of a three part series, we look at the mathematics and physics of sound so that we can reach that understanding
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Continuum Mechanics
Continuum mechanics deals with physical properties of e.g. fluids which are independent of any particular coordinate system in which they are observed.
The History of Refrigeration
Our ‘History of Refrigeration’ timeline gives you a brief glimpse into the key milestones of the development of refrigeration and air conditioning
Water-Glycol Mixtures
Coolants are heat transfer media which are intended for use below 0°C. Due to its high specific heat capacity, water is often used even below 0 °C. However, pure water already freezes at 0 °C, i.e. the polar water molecules arrange themselves into ice crystals. Glycol as an additive is an effective solution for this
F-Gas Regulations
As a part of the EU, the UK was subject to the terms and conditions of legislation governing the emissions and supply of fluorinated greenhouse gases in Europe. With effect from 1st January 2021 however, these regulations will no longer apply in Great Britain and will be replaced.
EC Fans vs. Axial Fans
In HVAC applications, fans are second only to compressors in consuming power. Here we look at two types of fan motor that have a direct effect on the overall efficiency of a chiller or air handling unit
Annual energy efficiency of chillers – a comparison
The energy efficiency of chillers has in the past mainly been indicated by manufacturers by stationary maps at full load operating points or the EER …
Free-Cooling by ‘Thermosyphon’ method
Thermosyphon is one method that can be used to achieve free-cooling in a chiller and is discussed in this article
The Ozone Depletion Process
The ozone layer is one layer of the stratosphere and the stratosphere is the second layer of the Earth’s atmosphere. The stratosphere is the mass of protective gases that clings to our planet
Transmission and mitigation of the spread of corona viruses
In a departure from our usual message to the industry, in May’s edition of the ACR News we wanted to share some researched information about how to mitigate the spread of viruses in buildings by use of mechanical means
The Perception of Sound – Part 2
This is the second part of a small series on the topic of sound. In the first part we dealt with ‘The Perception of Sound’. Here we now try to clarify physical facts of sound propagation in gases. In particular, we derive the one-dimensional wave equation from a simple model.
Categories

Continuum Mechanics
Continuum mechanics deals with physical properties of e.g. fluids which are independent of any particular coordinate system in which they are observed.

The History of Refrigeration
Our ‘History of Refrigeration’ timeline gives you a brief glimpse into the key milestones of the development of refrigeration and air conditioning

Water-Glycol Mixtures
Coolants are heat transfer media which are intended for use below 0°C. Due to its high specific heat capacity, water is often used even below 0 °C. However, pure water already freezes at 0 °C, i.e. the polar water molecules arrange themselves into ice crystals. Glycol as an additive is an effective solution for this

F-Gas Regulations
As a part of the EU, the UK was subject to the terms and conditions of legislation governing the emissions and supply of fluorinated greenhouse gases in Europe. With effect from 1st January 2021 however, these regulations will no longer apply in Great Britain and will be replaced.

EC Fans vs. Axial Fans
In HVAC applications, fans are second only to compressors in consuming power. Here we look at two types of fan motor that have a direct effect on the overall efficiency of a chiller or air handling unit