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The state of the art of marine conditioning


fig2This was the subject of an interesting convention held by the Lombardy section of atena and hosted, as were the earlier appointments, at the Milan headquarters of the Lega Navale Italiana.

Silvia Chiarito

During the convention, the working characteristics of various HVAC systems designed for vessels of differing dimensions were presented by technicians of some of the most renowned manufacturing companies.

Comfort and low impact
The subject of innovation in new conditioning plants designed for energy efficiency, quality of service, ease of installation and reliability was introduced by Bernardo Cerrai of Frigomar.
The new generation, variable speed Frigomar compressors, based on continuous current synchronous motors, compared with the old on-off compressors, can create a high level of comfort on board, minimising deviation from the set values of temperature and humidity for the environments to 0.5°.
The new compressors permit remarkable energy savings, of the order of 40 to 50%, thanks to the complete elimination of peaks of current at start-up, typical of older models, at the same time guaranteeing greater quietness, a reduction in bulk and so easier installation.
This is a very important aspect, as conditioning systems account for the highest energy demand on yachts. Frigomar systems are designed mainly for yachts and work boats of about 15 m. A fundamental aspect is the possibility of installing them also on sailing yachts, if the batteries are adequate.
In addition greater reliability has been achieved, both with the elimination of brushes and the broadening of the working range, which is now between 5° and 40° of seawater temperature, with an increase of more than 10° compared with earlier systems.
Finally, we must underline the respect of EMC regulations on electromagnetic compatibility, which minimises disturbances on other systems on board.

Technical characteristics
The systems offered by Frigomar are heat pumps (suitable also for heating with an inverse cycle) that work with seawater temperatures from 5° to 40°C. They are extremely compact with a structure in AISI 304 stainless steel.
Energy efficiency, quietness and long life are guaranteed by a compressor coupled with a synchronous electric motor and permanent brushless magnets, with low frequency (20 Hz) start-up without peaks thanks to a power booster and continuous speed regulation by an inverter with active harmonic abatement filters.
Alternating current powering depends on the generator on board, with power absorption noticeably lower than that of traditional systems. A converter makes it possible to use batteries of sufficient power.
The system uses radial fans with reverse blades that permit multiple non-linear channelling of the flow with speed regulation.
The strong points include extreme silence, an increase in energy efficiency (of the order of 40 to 50%), faster reaching of the set temperature and more efficient temperature maintenance with adjustments of the order of 0.5°C.

Customised conditioning
Christian Caspani presented Condaria products, based on know-how gained in more than 30 years of experience in medium power air-conditioning for yachts and special vessels. Condaria conditioning systems are suitable for the needs of medium-sized yachts, with a growth trend in megayachts.
In addition to compact dimensions, safe operation, high quality materials and quietness, the undoubted strong point of Condaria products is the possibility of custom design, also turnkey, in complete collaboration with the yacht builder. Among the innovations presented were the Microchiller, a powerful but compact unit that can be used both the conditioning and heating and suitable both for new yachts and retrofits, and the Chiller that uses R410 refrigerating fluid. Of particular interest to is the possibility of controlling fan coils and chillers with domotics that can control the conditioning levels of a full 16 environments simultaneously permitting customisation of conditioning for each environment. Finally, it is also possible to provide conditioning for vessels operating in extreme conditions by installing boilers with Eberspacher diesel generators that allow heating of interiors even with sea temperatures below 8°C (thanks to collaboration between the two companies).

Energy efficiency

Water based conditioning systems using chillers on three production lines from 18,000 to 310,000 BTU. A new line of chillers with motor is controlled by an inverter with power from 24,000 to 60,000. Machines generally built with stainless steel structures, seawater pipes in CuNi and IP 55 electrical systems. Refrigeration using R 40. Compressor start-up on on/off conditioners with smart start system that can reduce peaks of current by 65%. Shutdown system for excessively low seawater temperature. Possibility of heating using a connected Eberspacher diesel generator heated boiler. Conditioning normally using fan coils that can also be channelled and/or have electrical heating resistances (excluding water circulation). Advanced control domotics through local switch panels that can also be interfaced with other systems on board.

Satisfying different needs
Francesco Ficara presented the technical characteristics of systems made by Heinen&Hopman Italia, founded in 2009 with headquarters in La Spezia, solutions that are highly innovative in technical terms perfected in close collaboration with the headquarters in the Netherlands and with design offices of shipyard customers.
Starting from the premise that in the yachting sector comfort on board depends on climate, on contained dimensions and low levels of vibration and noise, Francesco Ficara illustrated the motivation behind Heinen&Hopman’s search for solutions that can guarantee custom systems suitable for any environment and for varying needs.
In particular, to guarantee reduction of vibration and noise levels, a detailed analysis was conducted of requirements on board, starting from requests for extremely quiet environments, to seek solutions that could respect levels as low as 40 dB.
Among the most interesting innovations we should certainly mention the magnetic levitation compressor, recently patented, which requires no oil or maintenance.

Reducing system power

Principally channelled air type systems with UTA with humidity abatement systems and active filters against the spread of bacteria and viruses.
Rotating compressors for noise reduction and availability of patented magnetic levitation compressors for larger systems.
Differential setting system valves.
Generally chiller type systems also available with heat pump systems.
Maximum noise reduction using UTA, plenum conduits and silenced air distribution and recycling accessories that permit system noise reduction up to 40 dB. Also available are special proportional flow electronically controlled fan coils.
Generally custom systems with the possibility of outlet recovery systems, heating by water, motor circulation et cetera.
Advanced system control domotics.
The company, on request of the yacht owner, can present verification of maximum temperatures and relative humidity, which permits a considerable reduction of plant power.


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The Mini Controller designed by the Swedish Zipwake and distributed in Italy