Problem:
You may have noticed that during the winter months, the air in our houses in Canada is quite dry. This causes numerous forms of discomfort including static shocks, dry skin, and houseplants requiring more watering. A house has an air temperature of 23°C with a relative humidity of 15%. The owner wants to increase the relative humidity of the air, so purchases a humidifier to do the job. The living area of the house has dimensions of 45 feet by 25 feet and the ceilings are 7.5 feet high (i.e., this is the floor to ceiling distance). The owner would like to increase the moisture content of the air and reduce the temperature so that the air will have a relative humidity of 55% at 20°C. How much water must be added to the total volume of air in the house? Express your answer to the nearest tenth of a litre.