Air flow of a vent ?

[system 4-50]

Ventair = 3225mm2 or <5in2.  From my notes when I was doing it.  Don't know where I got it from. Will check when next on my boat.  Don't know wether its with or without bug mesh.

[Machpoint005]

1 hour ago, hider said:

You  can take  any measurable gap around hatches, slides, windows etc and include them as ventilation. It all counts.

Most boats are over ventilated if you work it all out.

Yes - just a 5mm by 400mm gap under the rear doors gives you 2000 mm^2 which is a fairly substantial amount.

 

 

 

 

[BilgePump]

Yes, the 'measurable gap' can be anything. BSS guy said I could have got away with the 2*950mm gap between the doors. Without gas prob able to be a bit more lenient but it had enough anyway with the Louvre.

 

[cuthound]

1 hour ago, hider said:

You  can take  any measurable gap around hatches, slides, windows etc and include them as ventilation. It all counts.

Most boats are over ventilated if you work it all out.

 

I had this very discussion with a BSC examiner on my last shareboat, before I knew of this forum's existance.

 

He told me it was "fortuitous ventilation" and couldn't be included in the calculations. When I asked him how the air knew it could go through a vent, but not through a gap he harrumped and marched off.

 

He wanted a large low level vent in the back door. I said as it was a privately owned shareboat and therefore the ventilation was advisory. He was sneaky and left me alone, and came back when the next co-owner was on board, who he persuaded to agree to the fitting of the additional ventilation in the back door. ?

[Keeping Up]

10 minutes ago, cuthound said:

 

I had this very discussion with a BSC examiner on my last shareboat, before I knew of this forum's existance.

 

He told me it was "fortuitous ventilation" and couldn't be included in the calculations. When I asked him how the air knew it could go through a vent, but not through a gap he harrumped and marched off.

 

He wanted a large low level vent in the back door. I said as it was a privately owned shareboat and therefore the ventilation was advisory. He was sneaky and left me alone, and came back when the next co-owner was on board, who he persuaded to agree to the fitting of the additional ventilation in the back door. ?

Sadly he was right, all the rules and definitions specifically exclude fortuitous ventilation. Our inspector (back when it applied to private boats) also even refused to allow ANY consideration of our roof vent which had a solar vent fan fitted, not even a 50% deduction and not even despite the fan running 24/7 thanks to solar and rechargeable battery. I had to get a new inspector!

[Momac]

2 hours ago, W+T said:

 

I have to say it did pass on a few items that it should of failed 

Never mind. They may be found next time.....or not.

 

May I suggest a fixed sign indicating 'ventilation to be provided when the stove is in use'.

 

[hider]

8 minutes ago, Keeping Up said:

Sadly he was right, all the rules and definitions specifically exclude fortuitous ventilation. Our inspector (back when it applied to private boats) also even refused to allow ANY consideration of our roof vent which had a solar vent fan fitted, not even a 50% deduction and not even despite the fan running 24/7 thanks to solar and rechargeable battery. I had to get a new inspector!

Thats not what my many examiners have said over the last 30 years!  How can a permanent gap in a door or hatch be fortuitous? Its not removable, its permanent.

[W+T]

11 minutes ago, MartynG said:

Never mind. They may be found next time.....or not.

 

May I suggest a fixed sign indicating 'ventilation to be provided when the stove is in use'.

 

I did fixed the points he missed anyway. And good point there i ma as we speak ordering a 'cooker shut off' plaque and will do the 'keep vents clear' aswel plaque now. 

[Alan de Enfield]

28 minutes ago, W+T said:

I did fixed the points he missed anyway. And good point there i ma as we speak ordering a 'cooker shut off' plaque and will do the 'keep vents clear' aswel plaque now. 

Just as an aside - that is only acceptable for boats that are known to be 'sea-going'.

 

 

Here is mine (can be seen at the rear of the hob behind the kettle)

 

 

 

Edited June 8, 2019 by Alan de Enfield

[WotEver]

3 hours ago, W+T said:

Afraid it is needed as mine has just failed on it.

Complain to the BSS office, Wayne.

 

Whether or not you decide to pay again with a different examiner the one who failed you on an advisory (and missed things which he should have failed you on) requires some re-education. 

[Ex Brummie]

If an appliance Manufacturers Instructions specify dedicated ventilation, in the absence of any provided, would this override the BSS by having such appliances not installed to manufacturers instructions?

Also, fortituous or adventitious ventilation such as gaps in doors can be rectified. If however the gap was marked as 'ventilator, do not block', this would then be dedicated ventilation. As far as identical vent covers on each side of a hole, then they still provide the stated ventilation of the unit.