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## Homework Statement

I am working on a problem where I need to determine the time taken for an air heater with an 8kW output to heat a volume of air of 9m^3 by 25C. I am neglecting all losses at the moment. It almost seems too simple in my mind that I'm concerned I'm overlooking something.

## Homework Equations

cp = 1005 J kg-1 K-1

ρ

*=*1.534 kg m-3

Q = cp * m * dT

## The Attempt at a Solution

Q = 1005 * (1.534 * 9) * 25 = 346875.75 J = 0.35MJ

As 1kWh = 3.6MJ:

0.35 / 3.6 = 0.097kWh required for a dT of 25C to heat a 9m^3 volume of air.

The time required would therefore be 0.097 / 8 = 0.012 hours or approximately 43 seconds.

Am I along the right lines here?