What Does the "M" in Mbtu Stand For?

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SUMMARY

The "M" in Mbtu stands for "1,000," indicating that Mbtu represents 1,000 British Thermal Units (BTUs). However, there is some confusion in the industry, as "mBTU" is often used to denote "Million BTUs" (10^6 BTUs), while "mmBTU" is used for the same purpose. The discussion highlights the inconsistency in terminology, particularly in the United States, where BTUs are sometimes treated as a unit of power (BTU/hr) rather than energy. Ultimately, the consensus is that "M" is derived from the Roman numeral for 1,000, and MBH (1,000 BTU/hr) is a common measurement in heating systems.

PREREQUISITES
  • Understanding of British Thermal Units (BTUs)
  • Familiarity with heating system terminology, specifically MBH
  • Knowledge of energy measurement units and conversions
  • Basic grasp of the differences between energy and power units
NEXT STEPS
  • Research the differences between BTU and BTU/hr in heating applications
  • Learn about energy conversion factors, specifically between BTUs and kilowatt-hours (kWh)
  • Explore the implications of using customary units versus SI units in engineering
  • Investigate the historical context of energy measurement terminology in the United States
USEFUL FOR

Engineers, HVAC professionals, and anyone involved in energy management or heating system design will benefit from this discussion, particularly those needing clarity on BTU measurements and their applications.

Artman
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What is "Mbh" really?

Okay, this might sound stupid, but what does the "M" in Mbtu stand for? I know what it means, 1,000 x btu, but how would you say it? "_ British Thermal Units" Someone asked me and I really don't know.
 
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Hmm.. how about many British Thermal Units? :wink:

I don't really know.

- Warren
 
I'm not sure if this has been settled one way or the other.

Sometimes mBTU is used for Million BTUs or 10^6 BTUs. However, others use the notation mmBTU for this and mBTU (consequently) gets used for 1000 BTUs.
 
Why does your title say "Mbh" ?
 
Gokul43201 said:
I'm not sure if this has been settled one way or the other.

Sometimes mBTU is used for Million BTUs or 10^6 BTUs. However, others use the notation mmBTU for this and mBTU (consequently) gets used for 1000 BTUs.
Abbreviated form of the same thing (I think). One of the guys I work with thinks it is just the roman numeral for 1000. Could this be?
 
chroot said:
Hmm.. how about many British Thermal Units? :wink:

I don't really know.

- Warren
:smile: It surprises me you didn't know.
 
Why doesn't the world just stick with SI ? Sometimes, I really can't stand this BTU - KWHr (and foot-pounds to Newton-meters and psi to pascals and all the rest of it) conversion b@!$#!t :mad:

Could 'm' be from 'millenius' for 1000 ? Perhaps, but I doubt it.

I think it's more likely that the Brits first used the 'mBTU' for a million BTUs (for energy consumption in iron and steel plants and such)...long before they could conceive of a need for a symbol representing 1000BTUs ! Then one day someone came along and demanded a symbol for 1000 BTUs. If they had gone with the standard M=10^6, K=10^3, they would have simply suggested kBTUs. But instead they decided to use 'mm' for million, and use the 'm' for 1000 instead.

That's my theory and I'm sticking to it.
 
M is the Roman numeral prefix for 1000 and an MBH is 1000 Btu/hr.
 
Damn, there goes my beautiful theory !

Now what was it that Evo's signature said ??
 
  • #10


Artman said:
Abbreviated form of the same thing (I think). One of the guys I work with thinks it is just the roman numeral for 1000. Could this be?

It absolutely is simply the same as the roman numeral used as (1,000 times (x))
 
  • #11


Then remember that in English speaking countries it's a unit of energy, but in the USA it's a unit of power.
 
  • #12


Thanks for the responses on this guys. I hadn't checked back for awhile.
 
  • #13


Gokul43201 said:
Why doesn't the world just stick with SI ? Sometimes, I really can't stand this BTU - KWHr (and foot-pounds to Newton-meters and psi to pascals and all the rest of it) conversion b@!$#!t

maybe you should ask why didn't the world stick with Btus and pounds...I'm pretty sure they were here first ;)

by the way, it took me a long time to get to the bottom of the BTU per kWhr - 3412, 3413, 3415... etc. There are different conversion values because there are different BTUs - the heat needed to raise a pound of water one degree depends on the temperature you start at: 50F or 68F or 38 F or...

Now maybe that's a good answer to the question, maybe that's why the world didn't stick with Btus and pounds.

Oh, and I've been at this for a long time and MBtu is *always* a million (10^6) Btus. At least around here, anyway...
 
  • #14


gmax137 said:
maybe you should ask why didn't the world stick with Btus and pounds...I'm pretty sure they were here first ;)
Customary units make perfect sense in the areas they were invented in, it's much easier to estimate how many BTU needed for a certain size water boiler starting at a certain temperature than to work in kg and lookup the heat capacity and density. But it doesn't follow that it makes sense to use BTU to calcuate the energy of a battery.

Similairly an acre (being the area one ox can plough in one day) is a perfect unit for working out how many ox you will need - but doesn't make sense in chip design.

Astronomers do the same thing now, working in astronomical units and solar masses rather than m and kg.
 
  • #15


Artman said:
Thanks for the responses on this guys. I hadn't checked back for awhile.
Four years is a long time to wait...
 
  • #16


mgb_phys said:
Then remember that in English speaking countries it's a unit of energy, but in the USA it's a unit of power.

Is it really considered a unit of power? I just thought people dropped the "per hour" out of laziness or something like that.
 
  • #17


Redbelly98 said:
Is it really considered a unit of power? I just thought people dropped the "per hour" out of laziness or something like that.
I have only come across it in the USA to mean BTU (per hour)
But what can expect form a country that doesn't play cricket and can't spell colour! :rolleyes:
 
Last edited:
  • #18


Redbelly98 said:
Is it really considered a unit of power? I just thought people dropped the "per hour" out of laziness or something like that.
Its both, and yes, it's pretty much a matter of laziness, simplification.
 
  • #19


I suppose it's the same as saying "I was driving 10 miles over the speed limit". The "per hour" is assumed, out of our consistent (in USA) use of mph for units of car speed. But I've never heard anyone actually say that a mile can be a unit of velocity.

mgb_phys said:
I have only come across it in the USA to mean BTU (per hour)
But what can expect form a country that doesn't play cricket and can't spell colour!

Sir, since you have abandoned this perfectly good measurement system for metric, you gave up all rights to dictate how it is used!
 
  • #20


I'd say your analogy is correct and that with BTUs, it just became somewhat formalized. Functionally, it is the same, though: the correct term is derived from the context.

Sorta like (spoken) two, to, too or (written) saw.
 
  • #21


Indeed this is not 2004. Indeed the price of fuel oil is four dollars per gallon in 2011.

Fortunately in physics the answer is still the same.
I arrived at this forum because I was deciding whether or not to convert from oil
heat to gas heat in Seattle, WA. I calculated the energy equivalents. The energy
cost of gas is equivalent to one dollar per gallon for gasoline. Yes, it is; believe it or not. Gas is the wave of the future.

My answer was that I needed 100,000 Btu/Hr.

An independent reliable source, a salesman, said, about three months
before my calculation, that his boss had been in the gas business for
thirty years, and his boss said that I needed their 100 MBH boiler. I
did not know what the boss said because my wife had decided that I did
not have a need to know. I quickly developed a need to know when
she developed a need to know if she could write a check for $10,000.

In Seattle:

M is 1000,
B is Btu,
H is /Hr.

There you have it, physics in the real world.

Enjoy.
 

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