RACA Journal October 2026 | Page 49

SUPPORT

that reducing the negative impact from refrigerants released to the atmosphere would need to go hand in hand with a reduction in energy consumption. The move towards higher efficiency at the equipment or building level is a complementary concept to the avoidance of energy use and waste in absolute terms( increased eco-sufficiency). Reducing the use of mechanical equipment altogether by increased use of traditional cooling methods, the use of passive cooling or shading, or by influencing human behaviour for their operation are exemplary ways of following this concept for cooling applications.

EMISSIONS AND ENERGY EFFICIENCY In the context of refrigeration and air conditioning, greenhouse gas emissions caused by refrigerants when released to the atmosphere are called’ direct’, because they have a direct impact on global warming. ' Indirect’ emissions are caused by energy consumption during production, transport, operation and disposal of RACHP systems. Over the lifetime of RACHP equipment, both direct and indirect emissions lead to the total climate impact, often expressed with the Life Cycle Climate Performance( LCCP) or the Total Equivalent Warming Impact( TEWI).

Increased energy efficiency of cooling systems and reduced overall cooling needs do not only save the consumer or operator money, but they relieve the often-strained energy supplies and avoid black-outs, which can have a negative impact on the development of competitive industries and services. Energy efficiency also reduces the need for additional investments in energy infrastructure, which can be a huge financial burden to less developed countries.

Switching from ozone-depleting and climate-harming fluorinated substances to natural refrigerants in energy-efficient systems and applications is often referred to as‘ leapfrogging’. Finding opportunities to leapfrog could prevent countries and industries from having to phase new sets of fluorinated gases in and out again as international agreements become stricter over the coming years.

TOTAL EQUIVALENT WARMING IMPACT( TEWI) With regards to TEWI, a calculation method has been developed with which the effects on the greenhouse effect during the operation of refrigeration systems can be individually assessed( TEWI = Total Equivalent Warming Impact). The following shows a common formula for calculating the TEWI characteristic value, in which the respective areas of influence are subdivided accordingly.

The TEWI has three parts, which are added to calculate the total value.

TEWI = GWP × L × n + GWP × m × [ 1-arec ] + n × Eanno × b L leakage rate per year( kg / a) n system operating life in years( a) m charge of refrigerant( kg) arec recovery / recycling factor from 0 to 1

Eanno energy consumption per year( kW / a) b CO2 emission factor of power generation( kg / kWh)

As several of the assumptions and factors in this calculation method are usually specific to an application in a particular location, the TEWI allows only a comparison at one specific place such as France, Germany or elsewhere, and comparisons between different applications or different locations are not suitable. The TEWI calculation is important at the design stage or to support a retrofit decision( EN 378- 1, Annexure B).

Thanks for the question Prince, in the next issue I will give an overview of natural refrigerants. RACA

Supplied by HEAT GmbH

Leapfrogging to green cooling technologies.