Chiller horsepower and electrical usage

[solonavi]

*** Split from another thread, hence the discontinuity. ~Vinz ***

Wat abt adding a power to wattage conversion?

Saw on google that 1hp = 745.699872 watt. Is it true?

Thanks
JC

[vinz]

http://www.convert-me.com/en/convert/power lists several types of hp.

Anyway, a chiller might be rated at 1hp(metric), or 745.7W, but the actual electrical power needed to run it may be higher, because not all the electrical power drawn translates directly to chilling power. Some is used to operate the various prt of the chiller like the compressor and the fan, and some are lost from friction, etc.

For example, my 0.5hp chiller actually draws up to about 600+ W during full operation.

The engineers in the forum will be better at explaining this.

[solonavi]

Ya. There's actually what I will like to know, the exact power usage of a chiller. Can I assume that hp rating is only for the compressor?

Cheers
JC

[bclee]

The HP refers to the heat flow rate and does not refer to the electrical power. Both HP rating and the kW rating refer to different things.

BC

[bclee]

BTW, 1 HP is not = 746W for refrigeration calculation.

1 HP = 12,000 BTU/hr


BC

[solonavi]

Sorry for getting off topic but I need to get this cleared.

Mind me asking what it means by heat flow rate? Anyway to convert BTU to wattage?

Thanks
JC

[bclee]

Sorry for getting off topic but I need to get this cleared.

Mind me asking what it means by heat flow rate? Anyway to convert BTU to wattage?

Thanks
JC

Actually the unit HP is quite confusing. For chillers, it refers to the capacity to remove heat from a system. For power, it means something else. For boiler, it is different again.

1 HP refrigeration = 1 ton refrigeration = 12,000 BTU/hr = 3.5kW

BC

[bclee]

Ok... to give you the idea of HP...

0.5HP chiller is capable of removing 6300kJ of heat per hr.

If continously running for 1 hr, it will chill a 400L (~4-ft tank) by 3.8°C.

This will be totally wrong if you use 1HP = 746W.

BC

[vinz]

Ya. There's actually what I will like to know, the exact power usage of a chiller. Can I assume that hp rating is only for the compressor?

Cheers
JC

Nope. Dot not assume the HP of a chiller to mean anything about the electrical usage. What you need to know is the current it draws (amp) and its voltage. Using that you can calculate the actual power in W and hence the electrical usage and cost.

Check the specs of the chiller, some they will specify. JBJ Artica does. I assume Daeil is the same as the Artica ones as they are manufactered by the same people. Someone told me Daeil is the OEM, but I can't confirm it.

[solonavi]

Ok... to give you the idea of HP...

0.5HP chiller is capable of removing 6300kJ of heat per hr.

If continously running for 1 hr, it will chill a 400L (~4-ft tank) by 3.8°C.

This will be totally wrong if you use 1HP = 746W.

BC

Thanks for the explain. Always learning something new everyday.

Cheers
JC

[solonavi]

Nope. Dot not assume the HP of a chiller to mean anything about the electrical usage. What you need to know is the current it draws (amp) and its voltage. Using that you can calculate the actual power in W and hence the electrical usage and cost.

Seems like ohms law still the way to go, P=VI. http://www.mcsquared.com/watts3.htm
Actually, in this sense, will it means that all chiller (regardless of brand) that are rated with the same HP/BTU will draw almost the same amount of power? Note, I'm not talking abt its ability to cool a tank cause I understand that different design chiller have different capability to chill a tank faster or slower.

Check the specs of the chiller, some they will specify. JBJ Artica does. I assume Daeil is the same as the Artica ones as they are manufactered by the same people. Someone told me Daeil is the OEM, but I can't confirm it.

Yup. That's what I heard and from my research, it sure seems to be the case.
Check out the pix of the two brand chillers.
http://www.daeilcooler.com/en/goods/aquaruium.asp
http://www.jbjlighting.com/prod_chiller.html

Maybe we should split this discuss into a separate thread?

Cheers
JC

[bclee]

Seems like ohms law still the way to go, P=VI. http://www.mcsquared.com/watts3.htm
Actually, in this sense, will it means that all chiller (regardless of brand) that are rated with the same HP/BTU will draw almost the same amount of power? Note, I'm not talking abt its ability to cool a tank cause I understand that different design chiller have different capability to chill a tank faster or slower.

...

Cheers
JC

HP and BTU/hr is usually used to measure the cooling capacity of the chiller, not power consumption.

Check the electrical wattage for the power consumption. This is usually rated in W.

Check this out on JBJ chillers.

http://www.jbjlighting.com/prod_chiller_pg.html

BC

[xtrekker]

The most accurate way of measuring your electrical comsumpstion is using a True power meter. Or you can estimate it by using a current cramp to measure the current drawn by your chiller. The calculate the power use by this .....

True Power = I x V x P.f

I = Current
V = 240V AC
p.f = power factor of your device.

PUB only bills you the true power drawn.

cheers
xtrekker

*** Split from another thread, hence the discontinuity. ~Vinz ***

Wat abt adding a power to wattage conversion?

Saw on google that 1hp = 745.699872 watt. Is it true?

Thanks
JC

[solonavi]

Thank xtrekker. Ya, was aware of the current cramp. A fellow reefer in SRC did it b4.

But ur calculation has a p.f? Where do u get that figure from?

JC

[xtrekker]

Power factor ( P.f ) of the A.C machine i.e compressor motor should be some where on the compressor / chiller casing? together with the power ratings .

If you cannot find just use P = I x V this will give you the apparent power . True Power is usally lower then apparent power. So in fact you are paying for less then you what you calculated if you omit p.f.

cheers
xtrekker

Thank xtrekker. Ya, was aware of the current cramp. A fellow reefer in SRC did it b4.

But ur calculation has a p.f? Where do u get that figure from?

JC