Question

In summer air-conditioning, the room is maintained at the following conditions :
1. 21°C DBT, 50% RH
2. 21°C DBT, 60% RH
3. 25°C DBT, 50% RH
4. 25°C DBT, 60% RH

Answer 1

Correct Answer - Option 4 : 25°C DBT, 60% RH

Explanation:

Summer Air Conditioning	Winter Air Conditioning
For summer air conditioning, the relative humidity should not be less than 60%.	For winter air conditioning, the relative humidity should not be more than 40%.
In this system, the air is cooled and dehumidified.	In this system, the air is heated and humidified.
Air is passed through a cooling coil and it gets cooled below the required temperature and is also dehumidified.	Air is passed through a preheating coil to heat the air to control the evaporation of water in the humidifier.
Cooled air is passed through water eliminator and water collected in a sump.	Steam is mixed with the air in the required quantity to increase the humidity.
Reheating the coil is used to reach the desired comfort temperature.	Air passes through reheater to increase its temperature to comfort conditions.

• Required comfort conditions are 24°C & 60%.. 
• Atmospheric conditions in summer are 40°C DBT & 20%.