Converting BTU to Electrical Watts 2

[noogfkho]

Hi,

Is there any rule of thumb on how can I convert the BTU to electrical watts (actual power consumption) and not converting it to heat load.

Hope that any Expert could assist me on this issue.

Regards,

Alex Foo

 

[GregLocock]

1 BTU / hr = 0.293 W

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[IRstuff]

If you're talking about A/C BTUs vs electrical consumption, the closest you can get is the actual datasheet for the A/C, which may or may not have the pertinent data.

If you know the SEER rating, you can use that to get the average consumption.

At the minimum, you know that the BTU/hr is the minimum power consumed.

TTFN

 

[yates]

See

http://en.wikipedia.org/wiki/British_thermal_unit.

Since there are EIGHT different values for the BTU. When are you English-speaking guys ever going to get around to using the metric system ??

 

[JStephen]

Do you mean the metric system? or the SI that we all learned in school? I notice some of those BTU definitions are based on calory definitions which are outdated, right?

 

[GregLocock]

That's right. I should have written that
1 BTU/hr =300000 kgf litre/hectare/s

cos that's metric innit? It makes so much more sense



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[rb1957]

is a kgf a metric unit ?

 

[katmar]

The "metric" system is only marginally more consistent than the English or Customary system. There was a metric system based on centimeters, grams and seconds (used by scientists) and another based on meters, kilograms and seconds (used by engineers). Plus many countries had their own metric specialities. There is even a metric horsepower (based on 10 legged horses?). The "kgf" falls into this marginal metric category. Force should be in newton, but kgf was very widely used.

The only way to go is SI. I know it is a big change for those used to feet and pounds and it takes a long time to get a "feel" for magnitudes in the new units. But I have yet to hear from anyone who has made the change and is keen to go back.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[JStephen]

I see stresses in kgf/cm^2 on foreign mill certs, so yes, it is still being used.

Ever wonder why they didn't make it so that one cubic meter was one liter, one liter of water was one gram, etc?

 

[insult2injury]

In my opinion, a competent engineer should be able to use english/cgs/mks/SI or any other custom unit system.

I2I

 

[GregLocock]

Did anyone check my maths?

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[IRstuff]

Pretty close 298,849

TTFN

 

[Fabrico]

This is a very handy downloadable free conversion chart.

http://joshmadison.net/software/convert/download.php

 

[CoryPad]

If we are checking maths, then Greg's original conversion is correct. 1 BTU/h {one significant digit} = 300 000 (kg_f l)/(ha s) {also one significant digit}.


Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[quark]

I got about 298547 kgf liter/hectare/s (at zero altitude, though I don't know how many digits I chopped off for g = 9.81 m/s²)

 

[handleman]

If we really care about significant digits, they don't apply to the 1 BTU/h since it was arbitrarily chosen by counting to be exactly 1 rather than being measured. The least significant conversion factor is the sig fig limiter in this case.