When the world-famous yacht designer Germán Frers designed our boat, he incorporated the need for good ventilation of the interior. However, cruising in the tropics the interior will ge HOT. We have chosen to install a number of fans.


By Kaare   |   2022-11-14


When going South into the tropics we need extra ventilation below deck. Our Hallberg Rassy is blessed with a number of dorado’s which helps a lot. Furthermore the hull has been insulated with 25mm cellular insulation above the waterline. However when we get closer to the equator extra measures are needed.


To help with the airflow we have installed a number of ventilator throughout the boat. We have put 2 in the aft cabin to cover each of the beds. In the central part of the boat we have installed one in the galley, and one to cover the sofa and dining table,and finally we have installed one in the forward bunk area.


The ventilators are all Caframo, model Bora. They can be bought from the Hallberg Rassy store, however they can also be found cheaper on different websites. The beauty of the Caframo ventilator is the very low energy usage. They have 3 speed, and at the highest speed they use only 0.27A corresponding to 3.2W. Energy-usage is always paramount in a boat, where we have to make our own energy.


Furthermore we have to consider which circuits to supply the power to the ventilators. On IRIS we have 6 circuits for all the different lights. Each circuit has a 10A automatic circuit breaker which means we can safely connect 100W to each circuit (25% safety reserve). Having converted all the lights to LED, and by including the new LED-strips, we are down to less than 25W for the worst loaded circuit. Adding a maximum of two ventilators is then well within the safety margin.


The other aspect is the cable dimension. For the circuits we have the same safety margin as with the circuit breaker, because the system is designed for a much higher load. For the individual ventilator only a thin cable is needed because of the low energy requirement.


On IRIS there are a number of connection boxes 5*5cm creamy white plastic. The main feeder cables for the different circuits are lead to these boxes, and it is therefore optimum to connect the ventilators to these boxes. Only in one instance was it impossible to lead the ventilator cable hidden to a connection box, instead we connected the ventilator in parallel with one of the light fittings. The safety margin is still observed with respect to the cable dimension because of the previous switch to LED.


All in all we are very pleased with the appearance of the white Caframo ventilators, and can’t wait to get to the tropics to try them out.