LG launches 5th generation VRF

UK: LG has continued the European roll-out of its fifth generation VRF air conditioning system with its official launch in the UK.

The Multi V 5 is said to boast a host of new features. These include a ‘Dual Sensing Control’ system, an advanced design of inverter compressor, large capacity condensing unit, improved seasonal capacities and anti-corrosion coating.

The technologies are said to guarantee heating performance at -25°C and maintain 100% heating capacity at -7°C. Heating operation is extended by 11% per day with what is claimed to be a 7% reduction in power input when compared to conventional VRF systems.

Dual sensing control

Incorporating dual sensing controls, the Multi V 5 reacts to load requirements by monitoring both temperature and humidity levels, reacting to both sensible and latent heat loads.

Using Smart Load Control (SLC), the system operating conditions are regulated in reaction to both latent and sensible heat loads rather than a traditional sensible load only, increasing energy efficiency by up to 31% compared to none SLC models.

A typical VRF system operation would fluctuate considerably in order to maintain the required room conditions, normally operating on a thermostat on, thermostat off cycle. The Multi V 5 Dual Sensing Control offers each user a selectable Comfort Cooling option. This is said to maintain supply air temperatures around the desired room set point, reducing on/off cycling, eliminating draughts and delivering maximum user comfort. 

Inverter compressor

LG’s own 5^th generation compressor offers a host of developments, including a high-sided shell (HSS), high pressure oil return (HIPOR), and a new polyetheretheketone (PEEK) bearing allows an all inverter. These developments are said to enable the compressor to operate between 10-165Hz, increasing partial efficiencies, extending capacity, and increasing reliability.

Polyetheretheketone is a thermoplastic polymer commonly used in aeroplane engines. Its use in the scroll bearings of the LG compressor is said to provide high reliability due to low frictional wear at high temperatures, caused normally by periods of oil-less operation.

LG’s HiPOR high pressure oil return is designed to reduce compressor energy wastage by returning oil directly into the sump of the compressor, instead of via a traditional method of suction line return. Oil viscosities are said to be kept low, volumetric efficiencies high and this adds to increased compressor efficiencies by up to 10%, says LG.

LG’s concept of real time oil monitoring is included in each compressor.  The so-called Smart Oil Management utilises a sensor placed in each compressor to monitor oil levels in real time, allowing corrective action when required, improving life cycle expectancies and extending heating periods by eliminating unnecessary oil return, coupled with the added ability to balance oil levels between compressors.

Large capacity outdoor

The design of the high efficiency fan incorporated within the Multi V 5 condensing unit’s four-sided heat exchanger is said to have been inspired by Humpback whale flippers. The fan’s resulting increased airflow has contributed to an enhanced efficiency and capacity to a position where the Multi V 5 is able to provide 26hp (72.8kW) from a single outdoor unit.

Ocean Black Fin

The four-sided heat exchanger employs LG’s Ocean Black Fin anti-corrosion coating to reduce the effects of corrosion normally found in coastal and industrial environments. The two-part coating consists of a black epoxy resin providing the resistance and a hydrophilic coating to minimise the accumulation of moisture, which would accelerate any chemical reaction. 

Improved heating performance

A split heat exchanger, humidity sensor regulation and real time oil level monitoring all work together to give Multi V 5 improved heating performance through delayed defrosting.  Dual Sensing Control regulates the evaporator temperature to latent heat loads, therefore maximising its exchange efficiency for longer periods.  Alongside Dual Sensing Control, vapour injection technologies, guarantee heating performance at -25°C, maintaining 100% heating capacity at -7°C.

Multi V 5 system technologies help to increase heating operation time by 11% per day and lead to a 7% reduction in power input when compared to conventional VRF systems.

Claiming its new new flagship VRF system will offer the industry unparalleled design and efficiency opportunities, Andrew Slater, LG Air Conditioning’s technical and research manager, said: “Multi V 5 carries the factors considered at design stage through to real life system regulation, through humidity monitoring – part of our Dual Sensing Control. We believe that extending our development to consider all areas of system application, will allow customers to benefit from the comfort levels and operational savings that are expected from an industry leading solution.”