Heat Used - Physics Question

nxdmsandkaskdjaqd

Could anyone help with a question relating to:

The amount of heat required to raise a building 500 cubic meters by 1 degree C (assuming no heat loss).

I have used the internet but do not believe the answer. The calculation is:

Specific Heat x Density x Volume x Temp Rise
1.00 x 1275 x 500 x 1 = 637000 Kj

When I convert to watts I have an answer of 176 watts, which I do not believe! 637000/3600 = 176 watts

Can anyone validate for me please.

Robert

Smiley_Dan

637000 kJ is 176 kWh, not Wh.

nxdmsandkaskdjaqd

Smiley_Dan wrote: »

637000 kJ is 176 kWh, not Wh.

Thank you for the reply, but that now seems way to high. The 500 cubic meter building is a typical mid sized house. Am I missing something that you could help on?

firefox1956

Well I no nowt about fisics but..........
500 cubic metres sounds a bl**dy big house !!
Are you sure it is not 50 cubic metres ??

nxdmsandkaskdjaqd

It's 10 meters X 10 meters x 5 meters high over 2 floors. Therefore 500 meters cubed.

Nada666

firefox1956 wrote: »

Well I no nowt about fisics but..........
500 cubic metres sounds a bl**dy big house !!
Are you sure it is not 50 cubic metres ??

I think you're confusing cubic metres with square metres.

10 x 10 x 5 is not large (take a couple off the height, though)

70 x 70 is!

(crossed posts!)

Robwiz

A mid sized house would have a floor area of around 90 m^2 over two floors so the volume would be more like 225 m^3.

Nada666

Robwiz wrote: »

A mid sized house would have a floor area of around 90 m^2 over two floors so the volume would be more like 225 m^3.

That is very small. Statistically for our hideous shoeboxes nowadays it may well be 'mid' but I can't imagine anyone living in one actually calling it 'mid-sized'. That's barely enough for one room and a hallway wide and another narrow room deep.

nxdmsandkaskdjaqd

I still think that my 500m3 is reasonable, but may not be mid sized.

It's the KW used on 500m3 that I need some input on.

Thanks

btr30

nxdmsandkaskdjaqd wrote: »

I still think that my 500m3 is reasonable, but may not be mid sized.

It's the KW used on 500m3 that I need some input on.

Thanks

I think your calculations are OK, but you have missed the important factor of heat loss. Also if you were to raise the temperature from 10 to 20 DegC it would take 10 times the Energy i.e 1.76 kW in your example.

nxdmsandkaskdjaqd

btr30 wrote: »

I think your calculations are OK, but you have missed the important factor of heat loss. Also if you were to raise the temperature from 10 to 20 DegC it would take 10 times the Energy i.e 1.76 kW in your example.

I didn't want to confuse this thread with the heat loss calculation, that's another matter. Just wanted to obtain some support on my method and result for the temperature rise calculation.