Hello,
I have an electric pool pump and am trying to figure out how many BTU's are given off during normal operation (let's say 1 hour). The specs are as follows:
1hp RPM 3450 230v @ 7.5 amps 0.75kw/hrI was told that there should be some formula to find this out; however I cannot seem to find it. Any help would be great.
Thanks, Doug
Based on normal motor efficiency around 75 to 80%, you can probably estimate that the motor will produce a waste heat of about 1/4 of its rated mechanical output. A horsepower is 770 watts, so the waste heat is about 770/4 about 200 watts goes into the air cooling the motor. Of course all the mechanical output also gets converted to heat in the pool water as friction, so about 770 watts goes into the water.
-- Regards, John Popelish
-- 1 kilowatt-hour = 3413 BTU
You need to be careful as to what you refer .........
BTU = Board Of Trade Unit = Kilowatt Hour
BThU = British Thermal Unit, which ISTR is energy needed to raise 1 lb of water by 1 degree F.
The usual conversion factor that I have seen is ! hp = 746 watts. I did a check in wikipedia and they give 745.699 871 582 270 22 watts. They also give different types of horsepower, (imperial, metric) with slightly different conversion factors (746 vs 736 watts).
-- Hmm... BTU as an acronym for "British Thermal Unit" is hardly deprecated, as indicated by Wikipedia at: http://www.wisegeek.com/what-is-a-btu.htm and Webster\'s at: http://www.websters-online-dictionary.org/definition/BTU Moreover, from the context of the article it should have been abundantly clear that the OP was asking for a conversion from watt-hours to British Thermal Units, so what\'s your point?
Answering this question per the above info.
1) 230 x 7.5 =3D 1725 watts. 2) But one horespower is 746 watts. 3) So item one maybe the starting current? Using that it IS a 'one' horsepower motor which at 230 volts will have a 'running' current of 746/230 =3D 3.2 amps. 4) If the motor has typical efficiency of 75%; 25% of the (one horsepower) wattage is dissipated as electrical heat. 5) 746 x 0.25 =3D 186.5 watts. 6) 1000 watts =3D 3413 BTU (British Thermal Units). 7) Therefore 186.5/1000 x 3413 =3D 636.5 BTU, dissipated as electrical heat by the motor itself.
By the time i realized that I had remembered the factor wrong, others had already given the correct value.
The point to make is that just entering BTU or HP into Google gives the conversion factors at the top.
But thanks for the help.
Correction: you have to enter [horsepower] to get the conversion factor.
Just FYI, that should be 1000 Watt-hours = 3413 BTU
... per hour.
Mark
Yup. Just revisited this thread. Your right man. 1000 watt hours it is. i.e. One kilowatt hour or one 'unit' in some jurisdictions.
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