My ship finally came in!

[z1ppy]

Lovely looking boat that! Me and Mrs Zippy have commented on them a few times, If Mr Nautical is watching, how about swapping trip on Aviator for same on one of your lovely craft!

Seriously, it looks like a ship! even for me, a out and out speed freak i can see the attraction and we have spoken about something like that for our later years!

one very lucky owner and hope he has many happy hours on her!

 

[aquapower]

The whole trip was 519.99 nms - I planned it at 520! Made me smile when I turned by trusty Garmin 76, which I always take as my personal log and in case the $000's of nav kit goes down, off!

I have a Garmin 76 for that same reason, got nearly 5000nm on it now, I havnt yet found another handheld that goes all day on two aa batterys.

 

[MapisM]

Mine and Mr ORY are totally dfferent approaches even though we both avoid running gensets all night and all evening. I have to run genset in afternoon (but i do anyway, for cooking and airco)...

J, actually the two approaches are not as different as they might appear.
I can't remember exactly the recharging power, but it's quite substantial, possibly even more than the 250A you mention, though I can't tell for sure by heart. And on top of that, both engines have upgraded alternators (220A each).
The point is, Mr.ORY dislikes not only gensets, but also A/C, which he plans to use as little as possible. For that reason, the air handlers can run alone, with no compressors, so that they can be used out of inverters, without turning on a genset, go figure!

I think that the major difference is that such massive batteries weight is much less of a concern in a D or SD boat, than in a P boat.
I would have certainly advised Mr.ORY (or anyone else, for that matter) against almost 2T worth of batteries on a P boat, and I fully understand your choice of not upgrading them.

 

[jfm]

J, actually the two approaches are not as different as they might appear.
I can't remember exactly the recharging power, but it's quite substantial, possibly even more than the 250A you mention, though I can't tell for sure by heart. And on top of that, both engines have upgraded alternators (220A each).
The point is, Mr.ORY dislikes not only gensets, but also A/C, which he plans to use as little as possible. For that reason, the air handlers can run alone, with no compressors, so that they can be used out of inverters, without turning on a genset, go figure!

I think that the major difference is that such massive batteries weight is much less of a concern in a D or SD boat, than in a P boat.
I would have certainly advised Mr.ORY (or anyone else, for that matter) against almost 2T worth of batteries on a P boat, and I fully understand your choice of not upgrading them.

Thanks for the info. He wants to run the air handlers but not the chillers? Mostly that is just moving air around, without changing its temperature. And making noise. Is the idea that the blast of wind from the air handlers provides a fan-cooling feel to a person? If so, that's a questionable way to do it. The frictional losses of blasting air along all that a/c lagged piping, around corners, etc is high. You'd be much better off having simple fans close to the bed running off the inverter (that's what I do at night: I use 230v simple fans like on an office desk, one for each bed). With the great headroom in OR70 I think I would have specced a 230v inverter powered big/slow ceiling fan above the master bed. There isn't enough headroom in my boat for this

Yes I see your point that moving 1.5tonnes extra of battery is less in D than P. You will be able to test in a while by comparing burn rate AOTBE +/- 1500litres of fuel. FWIW in my boat at 22kts adding 6 tonnes of fuel costs 2 litres/nm. Adding 1.5 tonnes at D speed is therefore perhaps in the order of 0.1 litre per mile, which I agree isn't much in the grand scheme.

Interesting stuff. As I said, it is a beautiful boat. I look forward to seeing her with all the cardboard removed sometime, maybe Cannes 2012. And you should consider a tennis court option for that flybridge

 

[MapisM]

With the great headroom in OR70 I think I would have specced a 230v inverter powered big/slow ceiling fan above the master bed.

LOL, would you believe that also this one was specced?!
Though to be honest this specific idea came from another boat which was already built like that.

Yep, the F/B is indeed impressive.
Maybe not big enough for a tennis court, but it would comfortably accomodate a billiard or a ping-pong table!
Or, more aptly, a huge tender of course.

Oh, and I suppose you've not had the opportunity to climb above the hard top. I did on a similar boat at Ft.Lauderdale, that alone is larger than most F/Bs! Not to mention the view from up there, standing at no less than 21' above the w/l...

PS: I forgot to mention: if you saw the cabins, you didn't actually see any fans above the beds because the space was enough to hide them inside some dropped ceilings.

 

[John100156]

Fans do not cool the space, they actually add heat to it, due to the heat output from the motor.

They simply increase the velocity of air passing over the skin, making the human body feel cooler, enabling it to evaporate more moisture, but this increases the heat rejected and humidity in the space. So in essence, they both heat and raise the RH in a room!

However, 'fan only' is much cheaper to run than A/C......!

As has been said, overcoming flexible duct resistance does absorb energy, to give you some idea how much, a duct run with a resistance of say 125 pascals is the same amount of energy it takes you to suck water up a straw about half an inch...! One benefit of flexible ducting is that it absorbs noise, so not all bad....

 

[MapisM]

Fans do not cool the space, they actually add heat to it, due to the heat output from the motor.
...
However, 'fan only' is much cheaper to run than A/C......!

Well, of course the rationale behind the fans is rather that they can run on inverters, hence with no genset, than cost saving per se.
In fact, no matter how silent and vibration-free gensets are, in the total silence at night they can obviously be perceived.
The idea is that sometimes, when anchored in a nice bay with no wind whatsoever, even with the portholes open there is little to no air flow inside, and fans can be enough to grant some air circulation, cooling the cabins a bit without turning genset+a/c on.
I guess that in very hot Jul/Aug Med nights, a/c will be necessary anyway, but it's an additional possibility, probably good enough in many other nights. If given the choice, I'd rather have it than not, anyway!

 

[John100156]

No, that's my point, fans will only cool down the person and only when higher air velocity passes over the skin. In the scenario suggested, air circulation in a cabin cannot on its own cool a cabin, it actually heats it slightly!

If you want the cabin cooler, it's A/C and Genny on I'm afraid. Now at night, it may be different, only if the outside air is cooler than the inside, it could be used to circulate and cool the cabin a bit.

Environmental temperature is a function of air and mean radiant surfaces temperature, roughly 50/50. So what you can do as a compromise is to use the AC and Genny to cool down the cabin lower than normal to pre-cool the cabin surfaces then switch to fans!

In the Med where we are, it's AC-on almost all the time in summer......! My last boat did not have AC, we had many fans, but it was almost unbearable.......

Isolate the vibrations as best you can, cry about how much it costs to run, invest in ear plugs if you have to, but its AC and Genny on for me in summer.......

 

[MapisM]

Now at night, it may be different, only if the outside air is cooler than the inside, it could be used to circulate and cool the cabin a bit.

Yep, that's exactly the idea of Mr.ORY, in fact.

I'm surprised to hear that you need A/C throughout the whole summer, anyway.
Where are you located? I live aboard in southern Sardinia during summertime, and I don't need two digits to count the number of days when I really NEED to turn A/C on.
Not to mention when overnighting at anchor: I can't remember to have ever kept the genset+A/C on for the whole night.
Then again, in my cruising area a total absence of wind is as rare as hen's teeth, and surely the thick wooden build of my boat also helps keeping the inside cool...

 

[John100156]

I'm in Sant Carles De La Rapita, Spain, same marina as Hurricane.

OK, I do have to admit, I have never spent a whole night on the hook, I have always managed to secure a berth in a marina, there could be a mutiny (SWMBO) otherwise. I have though used the AC and Genny a lot this year when at anchor, during long days in the lagoon.

We are hoping to spend some time cruising over to and around Mallorca next year, I expect to be staying overnight on the hook then and may very well need to eat my words. Elec is inclusive in our marina, we had the AC 'on' 24/7 this summer!

Sorry to OP for thread drift.

Sardinia is I am told often more breezy, so what you're doing with your AC/boat makes total sense to me!

Roll on next summer......

 

[Solitaire]

I have a Garmin 76 for that same reason, got nearly 5000nm on it now, I havnt yet found another handheld that goes all day on two aa batterys.

I have nearly 3 times that amount, but you are right about the battery life. I just left it running on the fly bridge and the batteries lasted for about 10 hours.

 

[MapisM]

I'm in Sant Carles De La Rapita, Spain

Interesting. I quickly checked on Google Earth, and I'm actually a tad further South: 39°09'N vs. 40°37'N of Sant Carles...
The difference in air circulation and the coastal (as opposed to island) local climate must be indeed relevant.
Running the A/C 24/7 for the whole summer, hence keeping doors and portholes closed, would drive me nuts.
Not that I spend so much time inside, anyway!
[/off topic]