Feature
cooling , 40 % heating ). What becomes a challenge to negotiate in a system selection is when there is a requirement under these conditions to distribute full volumes throughout the system to have on-demand heating or cooling . If using a chiller system , in part load it may become energy-consuming with an example such as this to have the necessary availability in pipe loops , while a VRF system can supply hot or cold gas immediately as and when required . Essentially one would need to take into account what is happening with each system in “ standby-mode ”. For facilities that have high demands and operate long hours , the efficiency of each system type also features .
Capacity of either heating or cooling will also be a determining factor in system selection and if your proportion for cooling only or heating only is at 80 % 24hours a day , it would be probable that a chiller would be more suitable . On the converse , if you have an office block or 20 different tenants that will demand different temperatures for only a few hours a day , it makes sense to rather select a VRF system .
technology changes dramatically or there is a fundamental shift in sector labour demand and supply . This could be very relevant from a client ’ s perspective – as they will be the ones responsible for servicing and repairs . While a suitably certified plumber ( that generally comes with a lesser rate ) could perform certain system tasks on a chilled water system , other components or choices with VRF may require specialists ( that come at higher rates ).
Selection of each system type must therefore involve cognisance of different skill sets based on difficulty – pipework is far simpler than understanding a controller or the comprehension of error codes . The same applies for fault finding – the more complex a system becomes with pipe runs , no matter if chilled / hot water or refrigerant , the more time may need to be spent on site . Refrigerant leaks may prove to be more difficult to find while water leaks are easily visible . Here too the acknowledgement of various building and industry specific standards and legislation becomes important for technical teams . Standards require the limiting of refrigerant leaks into an occupied space and the use of detection alarms with VRF systems , however with chilled water loops this does not feature .
The same principle applies for servicing and repair ( or replacement ) of components , ease of access of the system and the amount of service points . This factor is extended the more pipes a system needs to include where pipe runs may reach kilometres in a single facility .
DEVELOPMENT OF EACH SYSTEM Today both chillers and VRF systems incorporate inverter technology which is what has shaped these systems over time . However , when you consider larger capacity chillers and
CAPACITY AND SYSTEM OPERATION Designs need to take into account intermediate months where you have varying proportion temperature requirements ( Eg 10 %
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