Fans...which is/are the best please?

[Pinetops]

We have a 747 in each sleeping cabin. Air flow and low current attractive but all efforts to minimise resonance/vibration have still left them relatively noisy. No reply from Caframo. Good compared with some alternatives but would only give them 7/10. The 747 looks the same as the 757. Is the 757 definitely quieter - not sure what difference "direct wire only" makes.

We later installed a Scirocco 807 in the saloon and are delighted with it. It is on a similar thickness bulkhead to the 747's but there is no resonance/vibration. It does not reciprocate but is adjustable up/down; side to side; and pivots out so do not understand the comment comparing it with the 757. The timer is a boon - if sleeping on the saloon bunk it's great to have it turn off automatically after ,say, 2 hours. If we were re-equiping we would use a Scirocco in all cabins, despite the cost.

 

[Frankie-H]

We have always used the much cheaper automotive fans. 2 speed, if you run a 24v fan at 12v!. About €12-15 a time.

 

[oldvarnish]

We have four 757s, including one on coil-cooling duties in the refrigerator compartment (thank you Viv Cox for the tip).

I missed that. Presumably in hot places you save energy overall by running a fan in addition to the fridge's fan. Correct?

 

[vyv_cox]

I missed that. Presumably in hot places you save energy overall by running a fan in addition to the fridge's fan. Correct?

On many boats, including mine, the air flow from the cool bilge to the warm outdoors is tortuous, or perhaps non-existent. Air flow over the heat exchanger is therefore reduced to low levels, making fridge operation in hot weather expensive in battery power. Directing a fan onto the exchanger, preferably after rearranging the flow route, makes a big difference. Even a small computer fan is worthwhile.

 

[ITH]

I missed that. Presumably in hot places you save energy overall by running a fan in addition to the fridge's fan. Correct?

Yes as Viv says there is quite an advantage in energy saving. More importantly (in my case) the fridge/compressor unit is some 20 years old, convection-cooled, and was just not up to the job in the high ambient temperatures in the Med. Before fitting the fan the compressor ran more or less continuously, even at night, and still didn't keep the internal fridge temperature low enough.

 

[oldvarnish]

On many boats, including mine, the air flow from the cool bilge to the warm outdoors is tortuous, or perhaps non-existent. Air flow over the heat exchanger is therefore reduced to low levels, making fridge operation in hot weather expensive in battery power. Directing a fan onto the exchanger, preferably after rearranging the flow route, makes a big difference. Even a small computer fan is worthwhile.

Top tip. Thanks. I've got the equator to cross again at some stage. I'll give it a go.

 

[Pinetops]

Now realise our fans must be 757's since they are wired into the circuit and the only difference to a 747 is that the latter plugs in. The only thing we have not tried to quieten them is to change the blades. However, listening to a friend's 757's which he was happy with obviously we all have different tolerance levels.

Caframo do not give air volumes. I would judge that our Scirocco airflow is somewhat more than the 757 because the fan is a bit bigger. It also has the advantage of 3 speeds.

Fan comparisons would make a good topic for a sailing magazine.

Pinetops

 

[Salty John]

The 757 does 144 cubic feet per minute on slow speed, 210 cfm on high. I don't have a figure for the Scirocco. It's a pity they've seen fit not to publish volumes anymore - I wonder why.