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Re: The chilling truth about cold horsepower -- more about chiller ratings

Jerry Smith:

> Can't say that I can shed much light on the subject,
> maybe only more 
> confusion. There is also a unit called a boiler
> horsepower which converts to 
> 33,520 btu/hr. or 9.803 kilowatts. A standard horsepower
> converts to 0.7457 
> kilowatts. I copied these values out of a conversion
> factor booklet I 
> received at a Trade show years ago. . .

Yes, that's what all the sources I can find say, too.  One
HP, in any engineering conversion table will tell you 1 hp
= 12,000 tons refrigeration = 745.7 watts = 2240 BTU/hr. 
Somehow, the aquarium chiller industry has taken to
equating that Tons Refrigeration to BTU/hr.

Consider, for example, I asked the folks that make ViaAqua
chillers why the same model is reported sometimes as 1/5 hp
and 1/4 hp.  They said the 1/4 hp rating is Mitsubishi's
rating for its motor, which drive the chiller and the 1/5
hp rating is The 1/5 HP rating is based on general
comparison with the aquarium industry (i.e., 1 hp=12,000
aquatic chiller BTu/hr.)  

I'm still searching for a reference from any standards
source that supports this last equation.  I wonder if maybe
one of the chiller makers made up the eqution a long time
ago, perhpas mistaking Tons Refrigeration for BTU/hr.  In
the aquatic hobbies, once something get said, it's often
repeated as gospel for decades. 

Anyhow, it's unclear just what the ratings mean.  The
useful info, if reproted according to standards is input
energy requirement (watts should be used since the units
run on electricity) and output capacity (Tons refrigeration
or BTU/hr.)  From this you can also assess energy
efficiency.  But these things are only informative if
they're based on standards.

Scott H.,  still looking for "Wendel IV" Java fern ;-)
Welcome back KR

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