Question

Design an HVAC system for an office building. All of the offices should be maintained at 72°F.

Model a corner office, 6m by 6m and 2m high. Make the exterior walls glass and the interior walls are drywall at the ambient temperature. Model a cold winter day as -5°C with a 10 m/s wind and a hot summer day at 40°C with a 4 m/s wind. Model a person as a 37°C vertical cylinder with 1 m² surface area 170 cm high. Ignore heat transfer to the top of the cylinder.

Include convection and radiation. The person is losing heat by natural convection to the environment at its ambient temperature (27°C) and gains or loses heat by radiation to the windows. The window temperature will be at whatever the steady-state conduction temperature is assuming natural convection on the inside and forced convection on the outside. The window is 1 cm thick glass with thermal properties of ordinary window glass. The area affected is only half the person’s surface area.

Compute the radiation loss or gain for the person and the total heat loss from the person in each season

Answer 1