The reason why VRFs are becoming popular in the Middle East

Utpal Joshi, head – VRV Dx consulting sales, Daikin Middle East, explains how VRFs are becoming popular in the Middle East

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VRV systems once installed correctly requires very little maintenance.
Igor NobiloDoputeno koritenje za potrebe dokumentacije i promocije od strane tvrtke Daikin Izuzetak su jumb
VRV systems once installed correctly requires very little maintenance.

VRV (variable refrigerant volume) systems were invented in Japan in the early 80s by Daikin they are also known as VRF (variable refrigerant flow). These systems are the first choice of many developers and consultants in the Middle East in the last five years. So, what are the reasons behind the popularity of VRV systems?
The main features of VRV systems are:
1.Central System – One Outdoor Multiple indoors with thermostats
2.Lowest energy consumption
3.Long Piping Runs
4.Quite operation
5.Smart features with easy integration to home automation 
Conventionally, DX systems were used in residential villa, midrise commercial & residential buildings. DX systems usually consumes 1.6-1.8 kW/TR and today’s tech savvy and aware customers are asking for smart and energy-efficient systems like VRV. VRV has the lowest 1.18 kw/TR at peak load conditions and the yearly average is 0.7 kw/ TR. There are many cases where replacing with VRV has cut the energy bill to half! Also, many new developments in the region at infrastructure planning and design phase has reduced their power intake from grid by 30% using VRV systems.
The large scale villa developments in YAS Island, Saadiyaat, MBR District One, Ruwais Housing are some of the examples of leading designers taking VRV as technology of the future and saving big power grid loads. The main attraction in residential sector is due to low noise, flexibility and space saving design. Do you know that the VRV foot print is just 1 m2 for 10 TR systems?
First-time designers can use diversity on a DX systems, meaning that the indoor unit total of up to 130 TR can be connected to outdoor of 100 TR (up to 30% less diversified outdoor unit capacity) if the design permits. Usually, diversity was only possible in a central system like chilled water but now it is possible with DX as well. Another important point is the Design Time. A VRV system with software tools can generate piping schematics in 10% of the time than conventional systems with proper schematic diagram including pipe sizing. This is further aided by CAD plugin like VRVCAD for both 2D and 3D Revit. A large variety of BIM objects are made available by all manufacturers.
Although VRV started with the residential sector, it has grown rapidly in commercial and residential buildings. Buildings typically are more energy wasters since the central system was generally not charged for energy use. With the introduction of district cooling and BTU metres, the industry has moved towards reducing the wastage. However, the challenge remains, and on the other hand, DX system for a building would usually make the roof full of outdoor units, around hundreds in numbers.
VRV offers a unique advantage to buildings. It has got the smallest footprint and less number of outdoor units as compared to a DX system, and at the same time, it is allowing the designer to consider diversity. The long piping run allowed in a VRV system (90-metre vertical + 100-metre horizontal = Total 190 metres) makes it possible to use VRV in buildings.
For high-rise buildings, developers and designers now have choices like side discharge mini VRV, same floor outdoor unit installation, or water-cooled VRV. Designers increasingly are taking these opportunities with the choice to plan the space for efficiency.  Developers can offer alternative systems than chilled water where tenant billing and self-maintenance is possible. In high-rise buildings VRFs can provide a good solution as a result of long piping capabilities, and the ability to separate electric consumption for multi billing. Outdoor units can be installed on the roof, service floors, ground or the side of building behind louvers.
Water-cooled VRF systems can be used in buildings where there is no place for outdoor units such as glassed high-rise buildings as they are usually connected with a cooling tower or a geothermal system. Solar-operated VRF systems are not very practical in the GCC as power consumption, long running hours, large capacity requirements and the need to store power for night operation make it difficult to manage.
VRF is an inverter (or VFD) system meaning the speed of compressor is varied to meet the exact load demand with additional advantages such as the ability to account for diversity and running time of indoor units, hence reducing the outdoor unit size compared to indoor reducing tonnage and footprint. Consultants need to account for FCU /AHU when calculating total power consumption on chillers and comparing to VRF as normally FCUS/AHUs is not accounted in the chillers pricing or EER values.
VRF units are now being considered for retrofit applications due to their flexibility and ease of installation.  Generally, in retrofit application, sometime cooling load increases but there is no additional electrical power available. With energy-efficient systems like VRV, these problems are easily solved. Also, the ROI of 3-4 years makes VRV a popular choice to be considered for retrofit
applications.
Solar air-conditioning is being mooted for a long time. However, there are great solar manufacturers and AC manufacturers, and so the best way to get maximum advantage is by collaborations and picking the best of both worlds and using solar power to generate free electricity. The industry is looking more towards Net Zero Energy Building using solar and VRV as components. This is due to the fact that night cooling remains an issue.
This is also fuelled by a higher reliability of operations of VRV as compared to DX systems. VRV systems once installed correctly requires very little maintenance and in today’s world of IOT and big data, companies like Daikin are offering services that collects daily data of operation for each individual VRV system on 123 parameters through a national server in Japan. These data are processed and trended against the ideal operation curves. With these data, for the first time in the industry failure of components can be predicted in advance! The system is constantly monitored and measured on different components and if they start deviating from the normal operation it predicts that they may break down if the deviation continues and it sends a message to the owner or service team to go and check the possible issue and correct the problem.
VRV systems are smarter in taking advantage of ambient temperature changes. As ambient temperature drops by 5 degrees (from 46 degree C to 41 degree C on a hot summer day at night), the load on the system decreases and SMART VRV increases the evaporation temperature so that we get cooling at the same time but with less refrigerants. This latest innovation simply saves more than 28% of energy than normal VRV.
VRF systems can be connected to cloud systems for most brands for control, monitoring and energy management. BMS or home automation interfaces are available, and integration is very easy. In many cases, 70% of the cost of BMS is AC related and with VRV all the components are usually inbuilt. BMS costs can be reduced by up to 50%. Manufacturers are offering mini BMS systems; VRV central control systems able to communicate and control other systems like pumps, fans, CCTV, elevators, lighting circuits, etc. Home automation system based on KNX, MODBUS, BACnet or any other has been successfully working in many large projects and traditional thermostats have become a story of yesterday being replaced by home automation touchscreens. So, are you ready to ride the future with VRV technology?

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