# Thread: Heat pumps, over there and back

1. Originally Posted by jpsmith1cm
1 ton = 12,000 btu. You can surely convert from there.
That's per hour.

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Ton is a term left over from the ice house days. Imagine the early days of refrigeration when cold storage was converted from ice to mechanical systems. An operator knew how many tons of ice they needed. A mechanical system would have to provide the same cooling power as however many tons of ice. The term has stuck with us ever since. Maybe because its handy like shoe sizes. Supposedly a one ton block of ice would provide 288,000 Btu over 24 hours or 12,000Btu/h. Not sure how valid that is.

3. Nice explanations. Very interesting!
Originally Posted by csealer
Ton is a term left over from the ice house days. Imagine the early days of refrigeration when cold storage was converted from ice to mechanical systems. An operator knew how many tons of ice they needed. A mechanical system would have to provide the same cooling power as however many tons of ice. The term has stuck with us ever since. Maybe because its handy like shoe sizes. Supposedly a one ton block of ice would provide 288,000 Btu over 24 hours or 12,000Btu/h. Not sure how valid that is.
Originally Posted by csealer
I think one of the biggest differences between the European and US heat pumps is that the US units are reversible providing heating and cooling with one unit. Our heat pumps could be sized to cover 100% of the heating load but would be grossly over sized for cooling. So we're forced to compromise. Size for cooling and make up the difference in heating with auxiliary heat. There is also a matter of economics. It's much more expensive to install a 2-speed 5-ton that will cover heating and cooling demand than it is to install a 2-ton with auxiliary heat.

4. ## BTU's and Kilowatts do not really convert

Because BTUs and kilowatts measure different types of quantities.

A BTU is a measure of heat energy.
A kilowatt measures power (energy per unit time).

1 BTU equals 0.0002928 kilowatt-hour

1 BTU/minute equals 0.01757 kilowatt.

To convert a watt to BTUs, the factor is:

1 kilowatt of power = 3412.1416 BTU/hr
3.412 BTUs equal a watt.

1 kW = 3412.1416 BTU/hour

PHM
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Originally Posted by jpsmith1cm
1 ton = 12,000 btu. You can surely convert from there.

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Lol, this is the greatest forum! I'm overwhelmed with answers and explanations!
(not to forget the occasional history lesson )

Thank you all for your great answers! They are helping me as we speak

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With the facts from this thread I calculated that:
1 kWh = 0,2842313 ton
1 ton = 3,5182613 kWh
Is this correct?
Last edited by Recessor; 09-14-2009 at 06:04 AM.

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