Swedish manufacturer Dometic has launched a larger version of its VARC48 variable capacity chiller, opening up options for larger yachts to take advantage of the innovative technology. The new VARC72 model (below), rated at 72,000 BTU, features the same variable speed system as its smaller sibling and aims to deliver the same efficient, more cost effective and quieter aircon handling for a wider market. The new unit was unveiled at the recent SeaWork exhibition, with orders now being taken.
“Trying to keep new products and new innovations coming in is the key for us,” Steve Morris, director EMEA for Dometic, tells SuperyachtNews.com. “Variable speed chillers are something where we’ve invested a huge amount of our time and effort – this is where we see the industry going in the next five years.”
The variable speed element means that there is no start-up current, due to it being effectively a DC inverter-driven system. “The aircon system on any boat was always the largest single inductive load so it needed loads of power to start it and then over the time you would get huge peak surges as the compressor cycled on and off,” says Morris. “That’s gone now with variable speed. It’s dual frequency so it doesn’t matter where in the world you are, and the voltage runs from 40Hz to 120Hz as its operational range.” The variable mode also means that the chiller demand – using the return water temperature as its gauge – adjusts automatically according the to ambient conditions. For example, overnight the units may run at low load to maintain the temperature, and as solar gain increases during the day the chillers gradually ramp up to the peak load required. “It’s a finely tuned system,” Morris enthuses. “It’s not about starting or stopping, it’s about slowing itself down or speeding itself up and only drawing the power it needs to react to the return water temperature. If there’s such a thing as a green product in the marine world, this is it.”
The VARC units feature several different modes, including a boost mode which can be used to drop the temperature quickly, and an econo-mode where you can set the maximum power draw for the aircon system and it will keep within those limits – ideal if you are somewhere with limited facilities and want to avoid spikes that would trip the shorepower. The units are also offered with extensive, intuitive touchscreens that can pull up any system information the engineer might need to monitor, but which also offer a far simpler interface for easy control by the owner or guests.
The units can be stacked to cover larger boats – the original VARC48 units offer 14kW of cooling of which you might install two on a 75-footer or four on a 90-footer. “We’re looking right now at the next level,” Morris explains, “and we had such demand for the VARC48 that bigger boats wanted the system straight away so we came up with the VARC72.” While this would mean that you could use two 72s in place of four 48s, the scope for larger superyachts would still mean multiple units, although again that is something that Dometic is looking to address – a larger 10-ton unit is also in development and is likely to be launched to market next year. Dometic is also considering porting the variable speed tech to its smaller units which, although more expensive that the current range of standalones, would mean an easy option for boats that don’t have an AC system on board. With a potential target size of around 10m, it could prove an interesting development for superyacht tenders.
It also quickly becomes clear that the whole subject of variable speed tech gets Morris quite animated. “I know I sound stupidly enthusiastic,” he concludes, “but this is what I do and this technology for me is exciting.” It would seem redundant to tell him to chill…
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