Temperature and Humidity Control in Air-Conditioned Buildings with lower Energy Demand and increased Indoor Air Quality

Air-conditioning is not only a matter of temperature control. Thermal comfort and good indoor air quality are mainly a matter of humidity. Human health and well being may suffer seriously from inadequate humidity and/or too low temperatures in a room. A case study involving supermarket air-conditioning and ventilation was carried out for the different climates of major cities in Spain.

Such climates can be characterized as cool and dry, hot and dry, cool and humid and hot and humid. In this study, the indoor air temperature had to be maintained for all climates at 23oC with a relative humidity of 40%. For indoor air temperature and humidity control, the use of an ice slurry (´Binary Ice´)was compared to conventional chilled water.

The use of Binary Ice instead of chilled water makes the air handling and air distribution installation much simpler, recirculation of air becomes obsolete, and a higher portion of ambient air can be supplied, thus improving the indoor air quality still further. Reheating of air is not necessary when using Binary Ice.

The introduction of chilled air into a room requires a different type of air outlet, however. When using Binary Ice, energy savings are high for climates with low ambient air enthalpies and lower for high ambient air enthalpies. The cooling demand can be reduced up to 50% and the energy demand of the refrigeration plant is also affected positively.

When using Binary Ice the annual operating costs, including depreciation of the investment, are ultimately lower. Binary Ice as secondary refrigerant for air-conditioning purposes is an economical and technically feasible solution in any climate. Whatever chilled water can do in an air-conditioning installation ? Binary Ice can do it better.