On Thu, 02 Feb 2017 15:13:23 -0000, "James Wilkinson Sword"
wrote:

On Thu, 02 Feb 2017 05:12:05 -0000, wrote:

On Thu, 02 Feb 2017 00:06:15 -0000, "James Wilkinson Sword"
wrote:

On Wed, 01 Feb 2017 23:52:43 -0000, Mark Lloyd wrote:

On 02/01/2017 04:31 PM, James Wilkinson Sword wrote:

[snip]

BTU: https://en.wikipedia.org/wiki/British_thermal_unit
The metric unit is the calorie.

No, for power it's the kWh. We don't use BTUs in the UK anymore.

Calories are only for your body.

It's a unit of energy. Where the energy is is irrelevant.

They can measure the Calorie content of food by burning it and measuring
the heat produced. This isn't in anyone's body.

Nobody uses calories outside of the human body. We'd be better using watts everywhere though.

Watts tells you the cost of running but not the cooling capacity. I
supposed I could talk about the SEER but that might just confuse you
more.

Of course watts tells you the cooling capacity, it's a measure of power. In fact isn't the BTU energy, like a kWh? That cannot be used to tell how powerful a heater or air conditioner is. You need to know the rate of energy transfer, ie. power. My gas boiler is rated in kW. If I had an air conditioner, it could tell me how many kW can be moved.

It is just going to create a confusion factor. That is why when I
looked at a UK air conditioner calculator, it out putted BTU/hr along
with KW.
The watts consumed by the unit is not particularly related to the
amount of heat it can move. It all gets down to the efficiency of the
process (SEER) so using watts would result in two "watt" numbers if
you used it for both factors. Salesmen simply find it easier to use
watts for the energy consumption and tons or BTU for the amount of
heat it moves for that amount of input power.
More common is to sell by the ton and deal with the energy consumed by
using the SEER number. Customers understand they may need 3 tons and
will shoot for the balance between a lower price and a higher SEER.
They won't see KW until they start getting electric bills but we also
have a government mandated sticker that will estimate that for all
sorts of things.