Using a "stack effect" ventilator overwinter

[sarabande]

Using a \"stack effect\" ventilator overwinter

A colleague came back from India and linked me to this photo
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showing how "stack effect" and low speed wind can be used to ventilate large buildings.

I wonder if there is any potential for fitting one instead of a hatch to make sure that the boat is well ventilated when left. Apparently they are available in all sizes.

Any engineers around ?

 

[pvb]

Re: Using a \"stack effect\" ventilator overwinter

Doesn't "stack effect" ventilation rely on convection, ie the air inside is warmer than the air outside? Probably wouldn't work in a boat in winter. Wind-powered ventilation is likely to be fine.

 

[Gothik29]

Re: Using a \"stack effect\" ventilator overwinter

The stack effect works better when you've got warmer air inside the building, however air moving over the roof increases in velocity therefore reduces pressure. This will 'suck' air from the building, in the same way that a self bailer on a sailing dinghy 'sucks' water out the boat when it's moving with sufficient velocity.

There's some scope to fit a system like this onto a boat, but the best method I've seen so far would be the solar powered vents with built in fans. They're not cheap, but should provide mechanical ventilation even in winter.

 

[wanderlust]

Re: Using a \"stack effect\" ventilator overwinter

for stack effect to work efficiently you need a chimney effect with a low level inlet and a high level exhaust. Boats are the wrong shape for this to work unless you stand it on its transom maybe! I ventilate my boat successfully during the winter with 3 large dorade type ventilators. The mouth on the vents is about 100mm diameter each. They pass serious air flow and ensure no condensation or mildew. Cross ventilation of this type is far more effective than stack effect in this application.