forced ventilation

[[2574]]

I'm thinking of fitting an in-line 12v fan in a pre-existing passive fresh air duct with the intention of increasing air circulation in the boat. However I'm wondering now whether this is wise as it'll upset the original boat builders thinking on the ventilation necessary. It's when the fan is off that I'm concerned as the effective capacity of the ducting will be reduced because of the fan motor and propellor in the 65mm ducting. Does anybody have an thoughts/experience of the subject?

TIA


Rob

 

[Twister_Ken]

I opted for 'proper' fans where the airflow can be directed. See pix...

Saloon

Forecabin

Aftcabin

 

[pvb]

Shame you didn't have a bit of a tidy-up before taking the pics, Ken!

 

[Twister_Ken]

Shame you didn't have a bit of a tidy-up before taking the pics, Ken!

I did - I took the big metal stick out the saloon - you know the one that holds up the sails.

(actually, not my pix, but from the www of the people that did the electrickery)

 

[BERT T]

I have looked at doing something similar in the compartment which houses the generator. It already has two mushroom type vents and I am going to mount an 80 or a 100mm 12v computer fan underneath one of the vents to increase the airflow.

 

[NormanS]

Twister Ken, I can see how your fans will stir the air around, but I don't see how they will contribute at all to ventilation.

 

[Twister_Ken]

Perhaps they don't but the moving air does have a distinct cooling effect. They're three speed and 'gimballed' so that they can aimed in any direction. Combined with a forward-facing opening of the forehatch and aft-facing on the main saloon, and a couple of mini-dorades, it seems to work.

 

[pcatterall]

I have also been considering ventillation, partly because Coral Wind is off to warmer climes. I have spent many years in hot climes and (without A/Cs!)in basic accomodation including houseboats.
I did find that when( at last) evening came and the outside cooled down the interior took a long time to follow suit!
We did find that large extraction fans were very useful in encouraging cooler air to flow in and the air flow generated had its own cooling ( evaporating ) effect.

 

[William_H]

Fans

I think you will find the modern computer cooling type fans work inn a duct really well on little current. I can however see your concern that the fan will restrict natural flow if power is off. I can only suggest you try a fan hopefully in a way that you can reverse if you don't like it. good luck olewill

 

[Deleted member 36384]

..... Does anybody have an thoughts/experience of the subject? ....

Rob,

I have experience of mushroom vents with and without fans, both the same size, on the same yacht. The ones with the built in fans appear to flow less air on a windy day when in natural air flow mode (of course) compared to the ones with no fans built in. However, the air flow is still high. I also have dorade type vents and these offer superior natural air flow compared to the mushrooms both in venting and extracting positions.

On a day with low wind velocity both are poor ventilators so can't really comment on this aspect.

 

[GAJ]

We have a fan mounted alongside the Eberpacher heater, it is connected to the main heating ducting by a Y branch.
This fan can be switched independently of the Eber and provides forced air circulation without wearing out the fan on the heater. There is a flap valve that directs the air flow into the system from whichever unit is running and at positive pressure. It works and moves a lot of air and in our case drawing the air from outside the boat from the cockpit area.

We also have the Hella type fans for some waft inside these are quiet and use only a little juice.