Boat refrigeration insulation gotcha for Australians (and maybe some others)

[David B]

Originally Posted by StuM

There's always someone who completely fails to grasp the fundamental principle of number bases.


2.54 centimeters is NOT a base unit. Apart from conversion to/from archaic imperial units, that figure is irrelevant.

Why divide by 8 in a decimal based system?

Why use a system which has different number bases for different uses?

Yes, I am so glad we - along with most of the rest of the world - use the logical metric system. Whenever I see measurements like 63/64" (of an inch), I just give thanks we are not involved in that rubbish anymore. 25mm is so much more sensible .

[RaymondR]

Originally Posted by David B

Yes, I am so glad we - along with most of the rest of the world - use the logical metric system. Whenever I see measurements like 63/64" (of an inch), I just give thanks we are not involved in that rubbish anymore. 25mm is so much more sensible .

In a digital world a positional value base 10 system such as the metric system is obsolete. If one is working on say DA conversion, say an 8 bit unit which will allow 256 increments. having to work in 10 base with all the fractional values the conversions require is a pain in the butt.

[Steven UK]

Apologies if I missed something here... but I work for an American manufacturing company and we are 100% metric in all corespondents and test reports etc. people still discuss in miles, Fahrenheit etc. my son is in school and they teach in metric. This is all in the outback of Minnesota....

[RaymondR]

Originally Posted by Steven UK

Apologies if I missed something here... but I work for an American manufacturing company and we are 100% metric in all corespondents and test reports etc. people still discuss in miles, Fahrenheit etc. my son is in school and they teach in metric. This is all in the outback of Minnesota....

I agree.

As an oil driller who worked in many parts of the world where different measurement regimes apply I know from experience that with the odd exceptions (Mars spacecraft software designers for instance) Americans can be taught the metric system.

[StuM]

Originally Posted by RaymondR

In a digital world a positional value base 10 system such as the metric system is obsolete. If one is working on say DA conversion, say an 8 bit unit which will allow 256 increments. having to work in 10 base with all the fractional values the conversions require is a pain in the butt.

Depends on what you mean by "digital world"


Joe User doesn't care about number base as long as he can see easily recognisable characters on his screen. It's us poor mugs at the coal face that have to worry about converting 0 - 255 into 0 - 11




or for that matter converting radians to degrees or nautical miles



There would advantages to living in an octal or hexadecimal world, but since humanity has almost universally adopted a decimal system (probably because of the number of digits we possess), I see little possibility of change there.



In fact you can make arguments in favour of just about any number base, but that is not the same as discussing units of measure with consistent versus inconsistent multipliers. Whichever number base you choose, consistency of multipliers is the key.

[StuM]

Originally Posted by Steven UK

Apologies if I missed something here... but I work for an American manufacturing company and we are 100% metric in all corespondents and test reports etc. people still discuss in miles, Fahrenheit etc. my son is in school and they teach in metric. This is all in the outback of Minnesota....

Is your anchor and chain denominated in kgs and mms or inches and pounds?

[Mauruuru]

well almost all science and engineering education uses MKS system and most engineers in the US then convert it all back to English to communicate with customers etc.....

[Mr B]

Why build your own fridge freezer unit,
RV Award stores, Bunnings, Tentworld, 4 x 4 shops, Etc Etc, all have huge Freezer, Fridge units for sale off the shelf,

12 Volt, 12 and 240 volt, 12, 240 volt and LPG, units, Some are 24 volts as well,
All Plug and play,
If you can get one thru your door, A lot of boats are putting in Domestic Fridge Freezer units, Upright and chest freezers,

It must be a Victorian thing, We can get them here,

[FlyingScot]

Originally Posted by nautilee

I used Aerogel/Cryogel - very thin layers but extremely effective insulator interspersed with aluminium foil layers and inserted on the inside of my freezer compartment - couldn't access the outside without dismantling the galley which was not acceptable. Best to use - 3 layers on outside wall to hull which in mine is curved, 1 or 2 layers on base, 2 or 3 layers on back wall to aft lazaretto, and 1 to 2 layers on front to galley. Then had thin fibreglass interior panels made and glued and sealed in situ. Couldn't get into the top hinged lid, so attached a thick removable section of yoga mat. Also added additional seal strips all way around top of box and lid. Made a HUGE difference. Bought the Aerogel/Cryogel as a rolled sheet on line from the U.S. [I was in West Indies at the time & had it shipped]. Much more efficient and thinner insulation than any other.
Good luck.

I recently bought a roll of Cryogel 10mm thickness. I haven't used it yet, but man is it dusty.
Supposed to be twice as good as anything except vacuum panels. But I'm not sure I would put vacuum panels in a moving boat.

[LargeMarge]

Oops.
I wanted to post a witty reply about Americans joining the metrical crowd with playing that foreigner game called 'soccer', so I looked-up the size of a soccer-ball to make an informed comparison.
What sizing system do they use, American or metrics? Hmmm?

Apparently, 'Size 5' soccer-balls are for 'U12 and up'.
'Size 4' soccer-balls are for 'U8 to U12'.
Soccer may use other size balls for other 'U' sizes, but about then, my eyes glazed-over and I noticed it was time for my nap.

I'm glad I could contribute worthily.

[barcoo]

Stu dont you just love a weather update in the news when total snowfall for the day is 4.2 mm. Just how do they measure the .2 mm. Must use an awful accurate ruler

[RaymondR]

Originally Posted by barcoo

Stu dont you just love a weather update in the news when total snowfall for the day is 4.2 mm. Just how do they measure the .2 mm. Must use an awful accurate ruler

That's actually quiet an interesting question.

Snow flakes vary in size and consequently must have a variable packing density. Does a thick fluffy snowfall pack down less than one of small flakes and is there a standard size they are compared to or do they just measure the thickness of the fall no matter the actual water content and if so what point on the surface do they take the measurement to?

[barcoo]

Thats why as an Aussie living in Canada I always drive my tractor to town. Solves the argument of which side the steering whel is on.

[GILow]

Originally Posted by RaymondR

That's actually quiet an interesting question.



Snow flakes vary in size and consequently must have a variable packing density. Does a thick fluffy snowfall pack down less than one of small flakes and is there a standard size they are compared to or do they just measure the thickness of the fall no matter the actual water content and if so what point on the surface do they take the measurement to?

That piqued my curiosity too, so I checked with Wikipedia which told me more than I really wanted to know.

But to save you looking, it seems they melt the snow to measure it, which kinda makes sense.

https://en.wikipedia.org/wiki/Snow_gauge

[StuM]

Originally Posted by barcoo

Stu dont you just love a weather update in the news when total snowfall for the day is 4.2 mm. Just how do they measure the .2 mm. Must use an awful accurate ruler

Probably an artifact of converting measurements in inches ( the standard being to the nearest 10th) to millimeters and using the result with excess precision.


(In which case, you won't actually see 4.2. You will see 2.5 and 5.1 for 1/10 and 2/10 of an inch )


Metric stations measure snow in centimeters.