Understanding the way in which a system is engineered, and the basis on which components are selected for each type of equipment, can be useful when deciding on the options for your application

Petra UK - Refrigerants


The refrigerants that are commonly used in refrigeration and air conditioning have changed over recent years, and are still changing, as the drive for greater efficiency and improved sustainability continues.

Selecting the most appropriate refrigerant is an important choice

Read more here...

Petra Screw Compressor


As with the refrigerant, compressor choice determines many of the characteristics of the unit in which they are installed.

What are the features of each type of compressor and what are factors to consider when deciding on the best solution for your cooling requirements?

Read more here...

Petra Condenser Coils


At Petra we manufacture our own copper/aluminium and copper /copper coils, and offer coating  options for protecting the coils against environmental damage.  

The type of condenser used is an important consideration when deciding on the best chiller for your application

Read more here...

Petra - Plate Heat Exchanger


The evaporator is one of the most important components of a chiller, and its  purpose of is to transfer the cooling energy from cold gas of the refrigerant to the water or other coolant media.

Two of the three commonly used types of evaporators are found within Petra's range of chillers

Read more here...

Petra - EC Fans vs Axial Fans

Condenser Fans

Fans are another significant  component of a chiller, as the efficiency of the fan motor is an important consideration.

Furthermore, fans can contribute to the noise level emitted by the unit and in certain applications this can be a deal breaker

Read more here...

Petra Thermostatic Expansion Device

Expansion Devices

In modern chillers and AC systems, we principally find that two of the four types of expansion device to be most frequently used are the thermostatic expansion valve and the electronic expansion valve.

Details of the function of the device, the differences between the types and the benefits of each can be found here...


The modern day drive for energy savings in buildings has resulted in buildings with small openings and little natural ventilation.  Consequently, energy saving goals and environmental comfort conditions can be in conflict, making an accurate and responsive controls system a vital componenent

Read more here...

Coming soon - 'The A-Z of Chillers'








We are working on a complete A-Z of Chillers (and all matters related) and are pleased to announce that this will be published soon.

Please check back again to see what we have for you, or sign up below to be notified as soon as this special feature is published.


World Refrigeration Day, 2021

The theme for World Refrigeration Day, 2021 is raising awareness of the people that work inside this hidden industry – the #coolingchampions and the #coolcareers that this industry offers

World Refrigeration Day

Petra is a proud sponsor of World Refrigeration Day which is an opportunity for all of us to come together to learn, share knowledge, build connections and find opportunities to collaborate to improve modern life

The ‘New’ Normal

As we begin to emerge from the lockdown, we think ahead to how we can work more closely with our clients and take the chance to re-confirm our intentions

Coronavirus – Update 4

Latest news from our Head Office in Amman regarding the status of operations at our manufacturing facilities

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


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

Petra UK - F-Gas Regulations Post Brexit

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.

Petra - EC Fans vs Axial Fans

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