ventilate engine pods

[micky flinders]

I would like to ventilate using a solar driven fan. Lots of them available intergrated one piece style. I want the Solar mounted on the rear deck then feed the power below to a fan low down in the hull. The fan will be fixed into the bulkhead through to the pod.
The pods have inspection hatches but these are mostly closed as they are open to rain and the odd green wave. The vessel is an 11m power cat. Construction is ply and ply foam sandwich. Built in 2003.
Some wet rot appearing in the pods so ventilation is fairly urgent.
The pods are only <1 cubic meter. So a low volume continuious fan would be ideal. I will drill two exhaust holes for each pod up high through the bulkhead into the well ventilated hulls.
Solar with battery for night running ideal.
All comments welcome.
Cheers
Micky Flinders

[micky flinders]

To clarify. I am looking for a separate fan that will run from a separate small solar.
Pods are outboard pods. Twin yamaha 225s.

[Noelm]

Not too sure why you want to ventilate the pods, can you tell us why?

[Dignity]

Not too sure why you want to ventilate the pods, can you tell us why?

Noel, I think he is trying to dry out the pods internally, that's my take on it but if there is some "rot" happening. My suggestion Micky Flinders is to get the pods fixed as it is a disaster in the waiting room.

[Noelm]

Missed the bit about the rot, no fan is going to "fix" the pods, the rot has started and it will just spread, fan or no fan.

[micky flinders]

Its wet rot not dry rot. I have removed the rot and treated the pods with wood preserver.
My goal is to stop condensation forming inside the pods.
Otherwise the pods are bone dry.
To achieve that i need to circulate air through the pods.
I can do that by installing a blower low down in the bulkhead through to the pod. Then put two smaller exit holes up high, again through the bulkhead, to get air circulating.
So
1. I need to find a low energy fan or blower that can run more or less continuously.
2. I need to power the fan.
Options for power are house batteries or solar.
My preference is direct solar. Some solar vents have built in rechargeable batteries that run the fans at night. However, the ones i have seen on the internet are intergrated fans/solar.
I want a small solar with the rechargable batteries then run that power to a low volume continuously running fan. It will stop running only when the suns not out and built in battery is empty.
E.G. the fan in a computer runs continuously.
Can you help me find a small solar and fan as described?
Or do you have a better idea?





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[on-one]

I use something similar to this to power a PC fan to extract heat from the kid's cubby, no idea how it would survive in the marine environment

https://www.ebay.com.au/itm/Outdoor-...gAAOSw07BezzX6

[Fed]

The condensation premise is flawed, fixing the leaks will stop any water getting in.

[micky flinders]

Actually the condensation forms in droplets on the inside of the inspection hatches. It then drops into the pod. Nothing worse for timber boats than fresh water. Its sets up a hot house style of atmosphere inside. Perfect for growing mushrooms.
If i leave the inspection hatches off in fine weather the pods remain bone dry. This confirms condensation is the problem. Not leaks. Thanks for your comments.

The condensation premise is flawed, fixing the leaks will stop any water getting in.

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[micky flinders]

Sounds good. I have bought a computer fan from jaycar to experiment with. It moves about 1 cubic meter of air per min. Plenty. Unfortunatly the solar availabe at jaycar are not eoubust enough for a marine environment or are too big for the job. A solar about 100mm across would do.
Thanks for your help .

I use something similar to this to power a PC fan to extract heat from the kid's cubby, no idea how it would survive in the marine environment

https://www.ebay.com.au/itm/Outdoor-...gAAOSw07BezzX6

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[Fed]

A cubic Metre of air can only hold a couple of teaspoons of water, chuck a bag of desiccant in there.

Could the insp cover be leaking?

Trust me it's not condensation from the outside air.

The disturbing thing is fitting a fan may mask it but not really fix it.

[inveratta]

Interesting problem...


so many uncontrolled variables in this ..its hard to suggest much....its your boat and you see whats happening both in use ..storage, temperature and rainfall.. however also you have a natural advantage...2 pods....

I would try a few things which would cost nothing ..before starting to bore holes in bulkheads.......you've treated the rot and presumably dried the space as well in both pods...both pods are thought to be sealed by the inspection hatches...do they have an o ring or just turn lock in,,and there are no other openings.

Try differing regimes on each pod at the same time and try and induce sweating in one and not the other. If you can swap the tests over and see if it happens in the other pod..I would be seeing if the pods pressurised at all in day time heat.Anything that shows huffing and puffing through the day..I presume when you say condensation forms on the lids...youre saying not on the undersurface of the pod itself? You could check that by insulating the lid with some polystyrene.I would have a good look at the screw holes..silicon doesnt last forever...

anyway good luck...

[gazza2006au]

You really need to work out your required amp hours remembering the sun wont likely work untill the dun is up high enough lets say 10am? Sun will be gone by 3pm as u wont be there to turn the solar panel to optimise the output

Thats only 5 hours charge and thats only on a good solid sunny day

Factor in cloudy days, short seasons, dust on the solar panel etc..

Whats the fan pulling .5ah? Thats 12amps a day draining

Problem solved if u just fix the pods and seal them but anything with rot will just keep soaking thru the plywood untill all the plywood is broken down

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[micky flinders]

The pods dont seem to pressurize.
Not noticeably anyway.
The condenstion is most noticable on the inside of the plastic inspection hatches. It is also present on the internal roof. The hatches are new and seal with a soft rubber ring.
There is zero leaks when it rains or when i hose the top of the pods.
It has to be condensate.
The last thing i want to do is put holes in the bulkhead. However its the only practical way forward that i can see.
An expensive ducted solution would also be possible.
Anyways i am on the hunt for a small solar power generator that will work in a marine environment.
Unless someone has a better idea.

Interesting problem...


so many uncontrolled variables in this ..its hard to suggest much....its your boat and you see whats happening both in use ..storage, temperature and rainfall.. however also you have a natural advantage...2 pods....

I would try a few things which would cost nothing ..before starting to bore holes in bulkheads.......you've treated the rot and presumably dried the space as well in both pods...both pods are thought to be sealed by the inspection hatches...do they have an o ring or just turn lock in,,and there are no other openings.

Try differing regimes on each pod at the same time and try and induce sweating in one and not the other. If you can swap the tests over and see if it happens in the other pod..I would be seeing if the pods pressurised at all in day time heat.Anything that shows huffing and puffing through the day..I presume when you say condensation forms on the lids...youre saying not on the undersurface of the pod itself? You could check that by insulating the lid with some polystyrene.I would have a good look at the screw holes..silicon doesnt last forever...

anyway good luck...

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[micky flinders]

This is the fan. Just need a solar to run it. 20200910_195844.jpg

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