Units moderator. There should be a units moderator assigned.

[Warpspeed]

The latent heat of ice to water transition is 144 btus/ pound. A ton is 2000 lbs
To melt a ton of ice it would have to absorb 288000 btus.
Maybe tons were smaller back then.

I really do not know, but historically the "ton" with regard to refrigeration plants was and is definitely tied to how much ice was involved, and that is a fact.

I suppose its like one horsepower.
Comparing a genuine hairy horse to a 1Hp motor directly is difficult.
But James Watt did that, and the horsepower has since become the recognized unit.

 

[Starex]

I really do not know, but historically the "ton" with regard to refrigeration plants was and is definitely tied to how much ice was involved, and that is a fact.

I suppose its like one horsepower.
Comparing a genuine hairy horse to a 1Hp motor directly is difficult.
But James Watt did that, and the horsepower has since become the recognized unit.

I just looked it up.
melting a ton of ice in 24 hours requires 11,917 Btu/hr.

 

[Starex]

Question for a quiz;
How many horses does it take to air condition a 2000 square foot home?

 

[RV8R]

Question for a quiz;
How many horses does it take to air condition a 2000 square foot home?

African or European ?

 

[MattiFin]

The "ton" came about in the refrigeration industry, because back in the days of horses, your domestic cool box used a block of ice to keep your food cool. So the amount of cooling you got from a certain weight of ice was a useful measure of cooling capacity.
Its all about latent heat of water and ice.

When mechanical refrigeration and air conditioning came along, people still thought in terms of "tons" of cooling capacity.
And your nerdy refrigeration engineer knew that it takes 12,000 BTU to either freeze a ton of water, or melt same.

So indeed, a unit of cooling is definitely directly tied to a mass at standard earth gravity. Strange, but true.

Or more accurately WAS tied directly to mass. Modern version of 12,000 BTU = 1 TR is probably selected for simplicity.
To begin with there is half a dozen slightly different BTU's in use.
ASHRAE BTU is 1055.056 Joules.
Freezing water is 333.4J/g and short ton(US) is 907 184.74 grams = 302455392.316J/ ton ...
1 ton of freezing capacity is 11945 BTU

 

[Starex]

African or European ?

Do you mean houses or horses?

1 ton of freezing capacity is 11945 BTU

You mean 11945 BTU/ hr for 24 hours.

 

[RV8R]

Or more accurately WAS tied directly to mass. Modern version of 12,000 BTU = 1 TR is probably selected for simplicity.
To begin with there is half a dozen slightly different BTU's in use.
ASHRAE BTU is 1055.056 Joules.
Freezing water is 333.4J/g and short ton(US) is 907 184.74 grams = 302455392.316J/ ton ...
1 ton of freezing capacity is 11945 BTU

Here is the SI “Metric”




Based Upon Water


Where in The World is The Mayo Clinic ?

 

[SparkyJJO]

Units suck and just confuse things.
BAN ALL UNITS.

 

[HighDesertOffgrid]

Or more accurately WAS tied directly to mass. Modern version of 12,000 BTU = 1 TR is probably selected for simplicity.
To begin with there is half a dozen slightly different BTU's in use.
ASHRAE BTU is 1055.056 Joules.
Freezing water is 333.4J/g and short ton(US) is 907 184.74 grams = 302455392.316J/ ton ...
1 ton of freezing capacity is 11945 BTU

How many calories is that? Thinking of ditching my LFPs for the thousand year shelf life of Hostess Twinkies.

 

[MattiFin]

Here is the SI “Metric”

Joule has been the SI unit for last 76 years, I believe calorie is used with food energy content in US despite being half-metric?
(also by grandmas in here)

US should express the chocolate bar energy content in BTU's or foot-pounds-force

 

[Hedges]

Don't get me started on tyres (=tires for those that claim to have visited the moon). Not sure about in the USA, but in the UK tyres are sized in a format like 255/35 R18 where 255 is the width in mm, 35 is the % of the sidewall depth compared to the width, and the 18 is the diameter of the wheel... in inches!

Same here.

(Although I'm not sure about those vacuum-filled tires on the so-called "Lunar" rover.)

Where it absolutely, positively has to be correct for the tire to fit, use inches.
Width? Doesn't matter much. Notice how the bead can move around a lot to fit a "wide" range of rim widths?

Min/Max Tire Size For Rim Width

Tire width can have a dramatic affect by creating more traction on dry road surfaces when using the maximum tire width. Or maybe you're interested in fuel effic

tiregrades.com

 

[Tulex]

Question for a quiz;
How many horses does it take to air condition a 2000 square foot home?

You have to account for ventilation.

 

[Hedges]

Units suck and just confuse things.
BAN ALL UNITS.

How much do they suck? Or rather, what are the units of suck?

Understanding Vacuum Measurement Units

Vacuum gauges all measure the pressure readings in the range from atmospheric pressure down to some lower pressure approaching absolute zero pressure, which is not attainable. Some gauges read the complete range and others can only read a portion of the range, usually used for very low...

vacaero.com

How to Measure Vacuum: Methods, Units and Scales

Many considerations go into selecting the right type of vacuum system for a specific application. Many factors go into this.

www.tawi.com

• atm – standardized atmospheric pressure, 760 mmHg
• PSI – pounds per square inch, absolute (PSIA) or gauge pressure (PSIG)
• inHg – inches of mercury
• mmHg – millimeters of mercury
• Torr – almost but not exactly equal to millimeters of mercury
• micron (mTorr) – a millitorr is 1000th of a Torr
• kPa – kilopascals, newton-force per square meter
• mbar – millibars, bar (kPa x 100) x 1000

If nature abhors a vacuum, how can we root for the underdog?

Ion pump - Wikipedia

en.wikipedia.org

 

[RV8R]

Joule has been the SI unit for last 76 years, I believe calorie is used with food energy content in US despite being half-metric?
(also by grandmas in here)

US should express the chocolate bar energy content in BTU's or foot-pounds-force

The actual truth in Canada it is just like what @OffGridForGood wrote ,,, it is like we are Unit Bilingual here





Worked in the Construction Industry in Canada for 4 decades & didn’t really go to the lumber store for 38x89s or buy 18mm 1220x2440 sheets of plywood ,,, but we “wood” joke about it .

In another hobby of mine, aviation I have to “fathom” yet another unit system “Nautical”. I am just thankful the majority of my time is in hours .

Fathom - Wikipedia

en.wikipedia.org

 

[HighDesertOffgrid]

The actual truth in Canada it is just like what @OffGridForGood wrote ,,, it is like we are Unit Bilingual here

View attachment 195991



Worked in the Construction Industry in Canada for 4 decades & didn’t really go to the lumber store for 38x89s or buy 18mm 1220x2440 sheets of plywood ,,, but we “wood” joke about it .

Popping the hood on a North American car without both SAE and metric tools (extra 10mm sockets are requisite) is no fun.

 

[RV8R]

Popping the hood on a North American car without both SAE and metric tools (extra 10mm sockets are requisite) is no fun.

Funny how our World has become. Use to be NA vehicles were all SAE ,,, Not any longer

FWIW 1” = 25.4mm ( that gets you; length, area, volume, & socket size ) calculations.

 

[Starex]

Here is the SI “Metric”


View attachment 195986

Based Upon Water


Where in The World is The Mayo Clinic ?

View attachment 195988

 

[Starex]

Joule has been the SI unit for last 76 years, I believe calorie is used with food energy content in US despite being half-metric?
(also by grandmas in here)

US should express the chocolate bar energy content in BTU's or foot-pounds-force

 

[Starex]

Might be a scale that dieter take seriously. Who would want a fat foot.

 

[Starex]

Here is the SI “Metric”


View attachment 195986

Based Upon Water


Where in The World is The Mayo Clinic ?

View attachment 195988

That’s why I avoid doctors