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Anonymous Poster

What's the Power of 1-Ton AC?

03/23/2010 9:07 AM

what is the power of 1 ton unit in kw?any one can help me
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#1

Re: what is the power of 1 ton ac

03/23/2010 9:10 AM

http://en.wikipedia.org/wiki/UNIT_OF_REFRIGERATION
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Tornado
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#2

Re: what is the power of 1 ton ac

03/23/2010 9:34 AM

This question can be interpreted in two ways.

First, in terms of refrigeration effect, 1 ton = 12,000 Btu/h, and 1 kW = 3412 Btu/h (or maybe 3415; I'm spacing.) Thus 1 ton = 12,000/3412 ≈ 3.52 kW.

Second, in terms of how much power it takes to produce 1 ton of refrigeration, this depends on the temperatures involved and the efficiency of the system. For air conditioning temperature ranges, 1 ton of refrigeration requires about 1 hp = 0.746 kW.

This rate of moving energy (3.52 kW) versus consuming energy (0.746 kW) gives a COP (coefficient of performance) of 3.52/0.746 ≈ 4.72.

(By the way, there is nothing "over unity" about this; it just means that the majority of heat energy being transferred comes from the air being cooled; the additional "heat of compression" comes from the mechanical input.)

Further BTW, the OP correctly identifies this as power, which is a rate per time of energy usage or transfer.)

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lyn
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#3
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Re: what is the power of 1 ton ac

03/23/2010 9:52 AM

Nicely done!
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msamad
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#5
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Re: what is the power of 1 ton ac

03/23/2010 11:47 AM

For additional help, see the previous thread http://cr4.globalspec.com/thread/44316 which is also informative.

- MS

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wareagle
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Re: what is the power of 1 ton ac

03/23/2010 11:43 AM

You need to get on the Internet and do some of this research yourself.

A electric nickel chrome heater element produces 3.4 BTU/Hour
The very efficient mechanical refrigeration compressor produces 8.533 BTU/Hour+/-
I had a 4 ton unit 10 SEER that pulled 28 amps. That's 28x240 = 6720 kva /4ton = 1.7 kva per ton
One ton of frig.=12000 BTU/hour
1 watt=8.533 BTU/hour compressor

4 tons x 12,000=48,000 BTU/hour

48,000/8.533=5,625 watts 1.4 kw per ton 1.75 kva per ton

5,625/240 volts=23 amps more efficient machine

If you include the SEER, then you can do it another way. SEER is defined as the heat transferred per unit of energy, that is in BTU/watthour.

P = AC load/SEER

For your 4 ton unit and SEER = 10,

P = (48,000 BTU/hour)/(10 BTU/watthour) = 4,800 watts,

then throwing in PF,

I = P/(VxPF) = 4800W/(240V x 0.8) = 25A 1.2 kw per ton or 1.5 kva per ton

This is comparable to the other result.
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