You are correct Ken.  That is where I went wrong.  I knew something didn't
seem correct.

On Thu, Oct 4, 2012 at 10:41 AM, ken deboer <barlaz...@gmail.com> wrote:

> Jack,
> I think you went the wrong way with the total BTU inputted.  should be 36
> wh X ~3 btu/w  = ~100 btu.
> ken
> On Thu, Oct 4, 2012 at 5:13 AM, Jack Cole <jcol...@gmail.com> wrote:
>
>> I think I have pretty high heat loss as it is open to the air.  Here are
>> some pretty conservative calculations assuming no heat loss and complete
>> conversion of electrical input to heat.  Please check my math / conversions
>> to see if I am doing this correctly.
>>
>> 1 BTU is the amount of heat needed to raise 1 lb of water 1 degree F.
>>
>> A power supply at 12 V and 1 amp gives 12 wh.
>>
>> 1 BTU = .293 wh (see wikipedia BTU)
>>
>> A temperature change of 60F for 3.718 oz requires the following BTUs.
>>
>> 3.178 oz / 16 oz = .199
>>
>> 60 * .199 = 11.92 BTUs required to change the temp 60F assuming no heat
>> loss.
>>
>> Running 3 hours gives a total input of 36 wh.  So convert 36 wh to BTU.
>>
>> 36 * .293 = 10.5 BTUs total input
>>
>> I calculate COP by BTUs required to raise the temp 60F / input BTU.
>>
>> COP = 11.92 / 10.5 = 1.135
>>
>> Have I done the correct process with these calculations?
>>
>>

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