Time to heat up a certain volume of air in an enclosure

Hi

I have a need to estimate the power of a heating element required to heat up a certain volume of air in an enclosure within a certain time. I have been using Q=mcT to do this estimate. I understand that using this formula entails making some assumptions.

Is one of those assumptions being that the heat source is evenly distributed throughout the whole volume? If so, the Q that I get from the equation would be much lower than is required. My heating element only occupies a certain area. With this area, is there a rough way of estimating the power of the heating element required?

There's a bunch of heat transfer equations and calculators here: [url]https://www.engineersedge.com/heat_transfer/heat_transfer_table_content.htm[/url]

Check out "Heat Loss Through a Wall Equation and Calculator just substitute heat transfer numbers for window [url]https://www.engineersedge.com/heat_transfer/heat_loss_aluminum_framed_window_13824.htm[/url].

[FONT=arial]As [/FONT][B]air warms [B]up, the molecules start to vibrate and bump into each other, increasing the space around each molecule. Because each molecule uses more space for motion, the [B]air expands and becomes less dense (lighter). ... The opposite effect[B]happens when air cools.[/B][/B][/B][/B]