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AHI Carrier related components such as boilers , compressors with magnetic bearings , and so on , these sorts of developments are not feasible to adopt in VRF systems owing to scale . On the other hand , VRF systems with smaller capacity components are enabled to more easily develop and implement technological changes and therefore after being trialled and tested – the technology that can make chillers better can be transferred .
Currently , components-wise each system contains similar technology such as compressors that can step up and down as demand requires , but when you get to screw type chillers on the largest scale , there is not much of a comparison in technology . The same applies for centrifugal compressors and oil free compressors for chillers .
VRF systems are something which are better suited to applications where you have several smaller applications , many hotel rooms and the like where engineers need to accommodate many people with different demands , and which gives the occupant the ideal setting for their individual requirement . Chilled water systems are better suited to larger space cooling where individual control is not of critical importance to comfort .
CURRENT STATUS IN SA BETWEEN SYSTEMS For certain sectors of the market there is definitely big competition between selecting chillers and VRF systems . What has been noted is that based on historical factors of what works for companies that have been in the industry for much longer and have great knowledge of chillers , their function , and design - this is their preferred system no matter what the application is because it ’ s simple to replicate . Here there is also a great show of support for this type of system because of the known fact that a chilled water system also comes with a longer lifespan than a VRF system . This attraction to chiller solutions further involves the fact that even though chiller technology may change , they are easy to work on and replaceability of individual components is seamless compared to the technology involved in VRF systems where if a PC board fails an entire section of a facility may be offline or communication between components can be broken . VRF technology when it changes can also mean an outcome of replacement of an entire system while a chiller can be replaced totally from where it stands , and the system can continue ( perhaps with a few modifications at most ). Chillers can also operate on manual controls where this is not possible for VRF
© RACA Journal | Benjamin Brits systems , and chillers can also utilise free cooling options .
Selection of a VRF system then for the other parties is preferred because it provides exceptional energy consumption values and offers the ability to bill clients individually . It incorporates the latest exceptional technology , installation is easy and doesn ’ t require any special additional electricity supply points . VRF systems also have the great benefit of being modular and can thus be added on as demand changes and central plant rooms are not required . Their footprint is far lower so saving space is a plus and then from a sensitive environmental aspect the use of a precious resource , water , is limited . VRF systems are also supported from suppliers with the benefit of “ included calculations and drawings ” making it a simple choice for clients to make use of . Selecting VRF systems is also known to just be easier from a holistic design point of view .
From an environmental perspective , both systems do have arguments for them related to resources and also refrigerants .
LOOKING AT BUILDING AND GLOBAL TRENDS From an ownership point of view , system selection has also seen influence of late depending on who has the buying power . Is this the building owner or the developer ? If the owners of the building , a great deal of importance falls around how long they plan to own the building before offloading it , this may be a five-year period and therefore they will have concerns over investment returns but
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Many facilities today make use of both chillers and VRF systems to meet various demands ( including air handling units and cooling towers ).
Some chillers can use free cooling with seasonal conditions – such as during winter times when ambient temperatures are naturally lower .
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