Consider the following statements about mechanism of body heat loss:
1. The heat lost by human body to the surroundings mainly by convection and radiation.
2. Sensible heat loss and latent heat loss are two main component of human body heat loss to the surroundings.
3. Evaporative losses tends toward zero during winter season.
4. Sensible heate component of human body heat loss depends on the difference in water vapour pressures.
Which of the above statements is/are correct?
(i) The total heat loss, Q = sensible heat + latent heat sensible heat depends on convection, radiation and respiration.
(ii) Latent heat depends on evaporation of moisture.
(iii) In summer, evaporative losses are maximum.
(iv) in winter, evaporative losses are zero.
The reason for a person feeling more comfortable on a warm day if seated in front of an electric fan is that the
Due to electric fan, temperature difference for convection and evaporation increases. To maintain thermal equilibrium, the body starts perspiring to increase the evaporative loss.
Which of the following is considered comfort conditions in air-conditioning?
A human body feels comfortable when the air is at 21°C DBT with 56% RH. In general, for summer air conditioning, the RH should not be less than 60% whereas for winter air conditioning it should not be more than 40%.
The desirable air velocity in the occupied zone for comfort for summer air-conditioners is in the range of
As compared to cold storage plant, air- conditioner of an auditorium requires air at
The comfort chart is drawn between
Comfort chart is drawn between DBT-in x-axis and WBT-in y-axis.
The difference between the comfort air- conditioning and industrial air-conditioning lies in the
In comfort air conditioning, the air is brought to the required dry bulb temperature and relative humidity for the human health comfort and efficiency, while in industrial air conditioning the inside dry bulb temperature and relative humidity of the air is kept constant for proper working of the machine and for the proper research and manufacturing processes.
In room air-conditioning for comfort the supply air in summer should be a
Of these statement