17 February 2020 Monday

Current Technical Developments and Environmental Relationship in Hvac&R Sector

Hüseyin Onbasioglu,
 R&D Manager, Friterm Corp. 

Especially in the last 20 years, the energy efficiency targets set out in the scope of fighting against the problem of global warming and the F-Gas regulations published in 2006 also shaped the technical studies on the conditioning and cooling systems and equipment. Another problem that is indirectly caused by global warming is the reducing amount of rainfall in some regions of the world or rainfalls occurring as disasters like storms and floods without being beneficial to feed the underground resources.  Herewith, various technologies are being researched in order to prevent the waste of service water, which is defined as “fresh water” in recent years, and to reduce its use especially in industrial processes.

Energy Efficiency

In the course of the 2020 strategy published by the EU in 2009 and the associated targets, the importance of energy recovery systems providing energy saving is increasing day by day in order to reduce energy demand from fossil sources and to reduce CO2 emissions as well as to meet energy demand with renewable energy increasingly. In this context, the minimum efficiency limits required for the supply of heat recovery systems (HRS-Heat Recovery System) to be used in HVAC&R systems have been gradually increased by the EU ECO-DESIGN Directive. Therefore, technological development efforts have been intensified so that these systems can meet the specified efficiency criteria and provide values above those limits. In addition, EUROVENT initiated the HRS (Heat Recovery Systems) certification program in 2016 to protect the end users and provide a healthy competitive environment. One of the most important developments to be mentioned about energy efficiency is undoubtedly EC (Electronically controlled) fan technology. In this way, unnecessary fan power consumption is prevented because of seasonal and daytime temperature changes or demand changes.

The Global Warming

Another important aspect of the environmental issues is “Global Warming” and the climate change that emerges as a result, the effect of which is being perceived especially in recent years. The most important relation of the HVAC&R sector in this regard is that, fluorinated gases currently used in “Vapor Compressed” cycles are known to have high  GWP (Global Warming Potential) values. Fluorinated gases, which are currently used widely in the sector as refrigerant gases, have an average GWP value of around 2500 units. Given that the GWP value of CO2, accepted as a reference value, is only 1 on this scale. Thus, contribution of fluorine gases to Global Warming can be estimated. In this context, the F-Gas Directive has been issued by the EU Commission in order to gradually reduce the use of fluorinated gases to the level that will not affect the environment. The EU F-Gas regulation, which was published in 2006 for the first time, was revised in 2014 and republished with the code of EU 517/2014. As a result of the F-Gas Directive, which aims to reduce the use of fluorinated gases to the lowest levels until 2030, studies on new refrigerant mixtures with a very low GWP value is intensified in the sector. In addition, various scientific-technical studies are being carried out on systems and equipment in order to spread the use of refrigerants with GWP values of 0 or 1, called “Natural Fluids” such as R744 (CO2), R717 (Ammonia), R290 (Propane).

Studies on R744 fluid-based systems are focused on expanding the areas of use and increasing system efficiency, especially in the northern countries. Another focus of work is the introduction of some innovative equipment integration and system developments in order to increase the efficiency and availability of Transcritical R744 systems in the middle-climate countries. Ammonia, one of the oldest fluids defined as environment friendly, is known as the indispensable fluid of industrial cooling from past to present. Due to its thermophysical properties and low cost, ammonia maintains its prevalence as a refrigerant in industrial applications where pumped cooling systems are preferred. Due to the F-gas regulation, basic scientific and technical studies are another important agenda in the search for natural fluids to replace fluorinated-gases in small systems in order to improve the thermal characteristics of Ammonia in the two phases of Direct Expansion (Dx) systems. 

Protection of Fresh Water Resources

As a result of the climate change, the amount of fresh water per capita is decreasing day by day due to the consumption increasing in parallel with the increasing world population and the decrease of rainfall in some regions. Based on these and similar problems, considerable developments are concluded on the adiabatic precooling systems (Fogging, cool pad, etc.) in the HVAC&R and energy production sectors. In this respect, both the amount of fresh water consumed for this purpose and the total energy consumed by the fans are reduced by providing adiabatic pre-cooling in hot climates.

As a result, it will not be a mistake to say that in the coming years technical studies and developments in the HVAC&R sector will be driven by environmental policies and strategies.