What amount of heat is needed to heat the air from 15 to 20 ° C in a room that is 5 m long, 4 m wide, and 2.8 m high?

Let us determine what value will equal the volume of air that is in the room, which, according to the condition of our assignment, has dimensions of 5, 4 and 2.8 meters, respectively:

4 * 5 * 2.8 = 56.

Let’s determine what value will be equal to the mass of air that is in such a room:

m = V * p;

pair at 15 ° is 1.225 kg / m3;

56 * 1.225 = 68.6.

Let’s determine what value will be equal to the amount of heat that we need in order to heat the air to 20 °:

Q = c * m * Δt;

with air at 15 ° = 1005 J / kg * deg;

1005 * 68.6 * (20 – 5) = 344715 J.

Answer: 344715 J.