The current regulatory environment and energy efficiency continue to influence the commercial air conditioning market especially when it comes to investing in new technologies. Marketing communication manager for Danfoss Cooling, Laure Durrbach, presents research from the company's 2017 HVAC trends in Asian markets report.
The phaseout of ozone-depleting substances under the Montreal Protocol has led to the introduction of a broad variety of replacements, including HFCs such as R-134a, R-410A and R-404A. The recently agreed Kigali amendment on a global phasedown of HFCs will trigger further changes in the market.
Energy consumption, energy cost and grid reliability can also be decisive parameters for building owners in fast growing markets when it comes to air conditioning.
Depending on the building size, type and use, as well as the surrounding climate, end users and OEMs are looking for solutions that are suitable for every context.
From mid-size office buildings that are in operation 10 hours per day, five days a week to data centres and large hospitals that operate 24 hours per day, all year long, this range of environments requires new design options.
Triggered by refrigerant and energy efficiency constraints, scroll compressors continue to extend their operating envelope.
They have continuously extended their operating envelope over the past years, replacing screw technology in capacity ranges which were previously reserved to the latter.
There are many reasons for the growing success of scroll compressors in the market.
One major element is the possibility of combining multiple scrolls in so-called manifold configurations. The development of the manifold design has been sparked among others by energy efficiency requirements which are often expressed as part load efficiencies. In this case, the combination of multiple scrolls allows a higher flexibility than one single circuit with a single alternative compressor.
Manifold scroll configurations provide very flexible modulated cooling capacity.
This means extending capacity and performance while maintaining design and applied costs at competitive levels. The specific characteristics of HFC R-410A, which has been used widely to replace R-22 in stationary air conditioning applications has also contributed to the growth of scroll compressors.
Due to its high volumetric capacity, it allows reducing the size of the compressor and the heat exchanger and improves the heat exchange behaviour. All of these elements lead to reduced applied costs.
In addition to these inherent advantages, manufacturers like Danfoss are working hard to further optimise the technology.
Specific organ pipes maintain safe oil levels at part-load conditions in manifold configurations and Intermediate Discharge Valve (IDVs) mechanically reduce excessive compression of refrigerant under part-load conditions while maintaining the same cooling capacity.
Up to 12 steps of capacity modulation allow for precise load-matching capabilities, which results in further enhanced energy performance – on average by 15 per cent in W/W chillers and by six per cent in rooftops and A/W chillers.
While fixed speed scroll compressors cover a wide range of applications, there are cases where even higher energy efficiency is needed. For example, in buildings with high energy consumption combined with load fluctuations such as in data centres, manufacturing plants, hotels or hospitals.
In these cases, variable speed technology including inverter scrolls and/or the Turbocor oil-free centrifugal technology deliver outstanding energy efficiency in full and part load operation with energy savings of up to 40 per cent compared to traditional compressors. The capacity of Inverter Scrolls now ranges from 13 to 83 kW (up to 180 kW in hybrid manifold).
Oil-free centrifugal chillers can range from around 200kW to 2MW cooling capacity.
Offering the advantage of friction-free magnetic bearing technology, which eliminates the cost of oil-related equipment and management hardware as well as the maintenance cost associated with oil service, centrifugal oil-free chillers have started to be the preferred technology whenever highest energy efficiency is needed.
What’s more, variable speed technology allows for an extremely low starting current (2 amps) compared to that of screw compressors (100 amps) which is particularly relevant for applications with a backup power supply such as data centres, where the power backup needs to consider starting current requirements of large equipment like chillers.
The HVACR industry has been undergoing major changes over the past decade and continues to evolve rapidly.
Global changes in refrigerant policies, triggered by international treaties such as the Montreal Protocol and the environmental pressure to reduce CO2 emissions, are all playing a decisive role.
At the same time, population growth, combined with higher standards of living and an increased demand for more comfort, health and technologies places a lot of pressure on electricity demand making energy efficiency even more important.
In this challenging environment, it is more important than ever to work with reliable partners such as Danfoss.
Details at chillers.danfoss.com or refrigerants.danfoss.com.