Occupants

As was mentioned in section 4.1, human beings give off heat at a metabolic rate which depends on their rate of working. The sensible and latent proportions of the heat liberated for any given activity depend on the value of the ambient dry-bulb temperature: the lower the dry-bulb temperature the larger the proportion of sensible heat dissipated.

Typical values of the sensible and latent liberations of heat are given in Table 7.16.

The figures for eating in a restaurant include the heat given off by the food.

Deciding on the density of occupation is usually a problem for the air conditioning designer. A normal density for an office block is 9 m2 per person, as an average over the whole conditioned floor area. The density of occupation may be as low as 20 m2 per person in executive offices or as high as 6 m2 per person in open office areas.

Some premises may have much higher densities than this; for restaurants, 2 m2 per person is reasonable, but for department stores, at certain times of the year, densities may reach values of 4.3 to 1.7 m2 per person, even after allowance has been made for the space occupied by goods. In concert halls, cinemas and theatres, the seating arrangement provides the necessary information but in dance halls and night clubs estimates are open to conjecture. Occupation may be very dense indeed. A figure of 0.5 m2 per person is suggested tentatively.

Posted in Engineering Fifth Edition