Ventilation without the icy blast

[Sea Dog]

My high and low level ventilation meets BSS recommended levels, but the present double digit minus temperatures have really highlighted an issue we've so far just lived with. The rear end vent comes into the trad back end engine/control space through 2 gunwale level vents, one to port under the boards into the engine 'ole (where the Eberspacher is sited, with a snorkel on its air intake direct to the vent) and one to starboard into the stairwell, although the two spaces are really one and the same with boxing in but also an access gap. There's also a fair bit of vent provided by unsealed doors out to the steerer's step. The vent from there into the bedroom is facilitated by purpose built gaps over and under the bedroom rear door. The top gap is fine but there is a cutting draught under the door. Whilst I don't wish to simply block it off and potentially cause a safety issue, it would be nicer if it wasn't quite so much like a tube leading directly to the Russian steppes!

The stove, incidentally, is at the very opposite end of the 57' boat and has plenty of high and low level vent around it.  So, with air breathing engine and appliances being supplied with air well outside of the aft bedroom, do the panel think I need to continue to haemorrhage brownie points by telling the missus to man up, or is possible to safely improve the icy blast issue?  

Thanks.

[Machpoint005]

I'd suggest working out what the total open area you need is, and blocking up the icy blast bit if you can get away with it. Bear in mind that the BSS-recommended ventilation is calculated taking into account the rating of the solid fuel stove, all 4 hob burners, and the grill, and the oven, so you only need the full whack if you are in the habit of using the whole shooting match at once.

We bought a new gas cooker a couple of years ago, and lo and behold, the ventilation requirement went down, so we can now meet BSS without fixing a hopper window in the open position.

As with most safety issues, a little thought with the guidance borne in mind (but not followed blindly) is not a bad thing.

I assume you have CO detectors though!

Edited December 12, 2017 by Machpoint005
sp.

[mrsmelly]

I would block it up, sounds like you have far too much. Have at least two co alarms at two strategic points in the boat they go off way before any high levels of gas can accumulate.

[rusty69]

Some kind of sausage dog,curtain, or closeable vent springs to mind.

[mross]

On my boat, the low-level vents, near the stove, are connected to a bow locker that itself is vented from outside.  Inside the locker is a small radiator.  Quite a clever idea, I thought.  (not my idea, I hasten to add).  But it only works when I run the Alde has the stove has no back boiler.

I've always left all the hopper windows open so would be quite happy to seal off the low-level vents.  I had a mains-powered gas leak alarm on the floor, near the cooker to eliminate that risk 

Edited December 12, 2017 by mross

[carlt]

Turn your Ecofan to face the vent and it will blow the cold air back out of the boat.

 

[mrsmelly]

4 minutes ago, carlt said:

Turn your Ecofan to face the vent and it will blow the cold air back out of the boat.

 

Bloody good thinking!! that's the engineer in you

[rusty69]

.......Or consume vast quantities of Carlt's Cauliflower and sprout curry and point your bum at the vent. Don't wotever you do feed any to the three legged Dalmation though.

Edited December 12, 2017 by rusty69

[mross]

Does everyone have a gas-leak detector OR switch off the gas at night?  Or do some consider the flame-failure devices are enough?

[Sea Dog]

Thanks for the response fellas.

I do have CO detectors at sleeping/sitting head level in the bedroom and lounge respectively. The stove is on 24/7 (obviously!) but won't be breathing bedroom air and, as I'm alongside on shore supply this week, I'm using the immersion for hot water so the Eberspacher is having a rest (but wouldn't be using bedroom air either). We do have a couple of opening portholes in the bedroom too. With this in mind, I am tempted to shut that particular air flow down as it does seem excessive - it's certainly excessively cold! 

Good to have a sanity check here before I make that decision though, and I thank you for the above and any future comments.

[cereal tiller]

30 minutes ago, carlt said:

Turn your Ecofan to face the vent and it will blow the cold air back out of the boat.

 

Yeabut ,the Thrust created by the Freco Fan could alter the Boat's Water line,Check your Weed Hatch is secure before taking the Safety Chocks out of the Fan!

[mrsmelly]

5 minutes ago, Sea Dog said:

Thanks for the response fellas.

 

Good to have a sanity check here before I make that decision though, .

Sanity check on here!!  That's got to be the best ever yet!!

[Sea Dog]

35 minutes ago, carlt said:

Turn your Ecofan to face the vent and it will blow the cold air back out of the boat.

 

 

2 minutes ago, cereal tiller said:

Yeabut ,the Thrust created by the Freco Fan could alter the Boat's Water line,Check your Weed Hatch is secure before taking the Safety Chocks out of the Fan!

Isn't MrSmelly's mega-thread enough for you guys?! 

[Dr Bob]

48 minutes ago, Sea Dog said:

 

Isn't MrSmelly's mega-thread enough for you guys?! 

Its just insecurity on their behalf – knowing they haven't got a leg to stand on – even a wooden one – when it comes to scientific facts. If you run your Ecofan more you could buy a good draft excluder with the 15% you save on fuel.

[Sea Dog]

12 minutes ago, Dr Bob said:

Its just insecurity on their behalf – knowing they haven't got a leg to stand on – even a wooden one – when it comes to scientific facts. If you run your Ecofan more you could buy a good draft excluder with the 15% you save on fuel.

I can't run it more - it's on 24/7 as it is!   Plus, as anyone reading the Eco Fan thread properly will know, I also have 2 fictitious ones - one on my fridge and one on my galley worktop. Actually, they're the best ones.

Now, back on topic....

[David Mack]

3 hours ago, Machpoint005 said:

Bear in mind that the BSS-recommended ventilation is calculated taking into account the rating of the solid fuel stove, all 4 hob burners, and the grill, and the oven

Plus so much per occupant for the maximum occupancy. So if you declare your boat as having 6 berths the ventilation requirement will be more than the same boat declared as a 2 berth.

[mross]

Does everyone have a gas-leak detector OR switch off the gas at night?  Or do some consider the flame-failure devices are enough?

BSS actually says,

CALCULATION OF FIXEDVENTILATIONREQUIREMENTS
The formula used to calculate the fixed ventilation requirement is derived from BS 5482‐3 Annex B
(Code of practice for domestic butane and propane gas‐burning installations — Part 3: Installations
in boats, yachts and other vessels), but as extended by BS8511AnnexA (Code of practice for the
installation of solid fuel heating and cooking appliances in small craft)to address solid fuel stoves and
other appliances.
The formula for calculating the fixed ventilation requirement( inmm2 )is asfollows:
=    [2200 xU] +  [650 x P] +  [550 x H] + [440 x F],  where:
U= inputrating for all unflued appliances(inc. cookers)(in kW)
P = number of personsfor which the accommodation space is designed
H = nominal outputrating of all open‐flued solid fuel appliances(in kW)
F = inputrating for all open‐flued appliances(in kW)

[ditchcrawler]

3 hours ago, mross said:

Does everyone have a gas-leak detector OR switch off the gas at night?  Or do some consider the flame-failure devices are enough?

Having worked on gas detection seeing the cost of the units and the amount of maintenance they required to keep them working I wouldn't rely on one to protect me.

[mross]

4 minutes ago, ditchcrawler said:

Having worked on gas detection seeing the cost of the units and the amount of maintenance they required to keep them working I wouldn't rely on one to protect me.

So, do you turn the gas off at night??

[rusty69]

20 minutes ago, mross said:

So, do you turn the gas off at night??

Nah.If you did, you wouldn't be able to enjoy "Fanny By Gaslight"

 

[Sea Dog]

Good points on the BSS vent calculations, thanks.

Tonight, there's a rolled up towel keeping Siberia at bay and the back end is a much nicer place to be!

[mross]

5 minutes ago, rusty69 said:

Nah.If you did, you wouldn't be able to enjoy "Fanny By Gaslight"

Who needs gaslight?  

[rusty69]

1 minute ago, mross said:

Who needs gaslight?  

Don't get too excited, you might get more gas than you bargained for. 

[cereal tiller]

5 minutes ago, mross said:

Who needs gaslight?  

The Sprout Curry Gastro Terrorists.

[ditchcrawler]

31 minutes ago, mross said:

So, do you turn the gas off at night??

I don't have gas, but if I did I wouldn't switch it off, But I would ensure that I had first class sound gas system.