Shopping centres, hotels, and numerous other places may need to be heated or cooled simultaneously.

Many buildings in the commercial & industrial sector, such as shopping centres, hotels, hospitals and manufacturing companies, need to be heated and cooled simultaneously throughout the year. Especially in mid-season. A necessity that depends on multiple factors, such as the type of building, the extent of crowded areas and the outdoor air temperature, and which is particularly characteristic of more complex architectural solutions.

So how can we fulfil this simultaneous requirement?

A very common solution is the independent production of thermal energy for heating and cooling energy for cooling and their transfer to different areas. The thermal energy produced by one or more boilers and the cooling energy produced by liquid chillers is the traditional solution. The low efficiency of this type of system is well-known. In fact, when cooling and heating are required at the same time, the production of cooling energy wastes a large amount of thermal energy, which with a chiller is expelled into the environment. This energy could instead by used to support other thermal energy systems or as a total replacement.

This does not occur with a Multifunction system. 

A multifunction unit is based on heat pump technology, capable of recovering energy that could be wasted by increasing the already efficient effect of the heat pump and thus increasing the efficiency of the whole system. With a single multifunction unit, such as Clivet’s SCREWLine4-i, which simultaneously, independently and efficiently produces heating and cooling, it is possible to replace both generators (boiler and chiller) working independently and save on system costs.

What are the advantages of Multifunction technology?
unparalleled efficiency
  • As we have seen above, Multifunction units ensure unparalleled efficiency. Thanks to heat pump technology, energy waste can be avoided by supplying hot and cold water simultaneously. 
  • Another advantage is how easy it is to adapt the system’s demands, even with variable heating and cooling loads, using the power modulation of multiscroll technology or inverter-controlled screw compressors. 
  • Then there is the added bonus of system simplification: With a single multifunction unit, less space is occupied than with a traditional system, the water circuit is simplified and installation and maintenance times are faster and cheaper. The boiler is no longer needed, costs for gas piping connection and periodic checks are eliminated, which saves time.
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How does the efficiency of multifunction systems change based on the building’s requirements?

When only chilled water needs to be produced for cooling, the multifunction unit provides the cooling capacity required by the cold side exchanger, while the hot side exchanger remains inactive. In this case, the excess heat produced is disposed of in the outdoor environment by the source exchanger. If, on the other hand, the building only requires hot water for heating, the hot side exchanger activates (exchanger optimised for heating), and the excess energy is still disposed of by the source exchanger. The best results in terms of efficiency are achieved when there is a simultaneous request for heating and cooling. A Multifunction unit can fulfil the system’s demands by simultaneously providing the required cooling and heating capacity on both cold side and hot side exchangers. No energy is wasted this way and the source exchanger is not used.

An example of a Multifunction unit: Clivet SCREWLine 4 -i

The SCREWLine4-1 unit is the perfect solution to fulfil the simultaneous demand for hot water and chilled water. 
Available in the Excellence version, with SEER up to 5.18 and SCOP up to 4.21, the Multifunction unit features screw compressors with inverter technology that improve operational flexibility, high efficiency EC fans and copper/aluminium hydrophilic condensing coils to facility water discharge from the fins and make defrosting cycles more efficient.
Thanks to the use of R-513A refrigerant, which has a low GWP = 631, Clivet’s Multifunction unit ensures a clear reduction in its environmental impact compared to solutions that use R-134A refrigerant (GWP = 1430). SCREWLine4-i also boasts a capacity modulation from 100% to 18% and very extensive operating limits that ensure it is fully operational with air temperatures between -10°C and +46°C, hot water production up to 60°C and chilled water production down to -8°C. 
The unit also offers a range of capacities from 450 to 990 kW and is available in three different acoustic versions, which ensure an even higher noise reduction of up to -12db(A) compared to the basic model.

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How much can you save with the Multifunction system?

To understand how much you can save with Clivet’s SCREWLine4-i Multifunction unit compared to a traditional solution (air-cooled liquid chiller and condensing boiler), an analysis of the annual consumption of a “typical office building” was carried out in several European countries (France, England, Italy, Turkey, Spain and Belgium). 
The building in question consisted of 6 floors and a total surface area of more than 1,000 square metres, the operating time was from 8am to 8pm, from Sunday to Saturday, with a set-point of 7°C in cooling mode and 45°C in heating mode. 
Based on the survey, Clivet’s Multifunction system made it possible to save between 25% (Adana – Turkey) and 37% (Paris – France) of the primary energy needed to heat and cool the environment, thereby confirming its high performance in terms of efficiency.