Zamil brings back old cool memories
Zamil Air-Conditioners has revived an age-old method of cooling through evaporation of water by using the adiabatic process in cost-effective units.
01 April 2010
ZAMIL Air-Conditioners has taken the simple ancient adiabatic method of cooling to produce innovative ventilation and air-handling units that are cost-effective and environment-friendly.
A simple analogy of adiabatic cooling is the chilling effect produced by blowing air on wet skin – caused by the air evaporation process.
This simple and efficient way of cooling has been used by people in olden times by hanging clay water bottles in front of an open window to cool the inside air by evaporating the water which runs out through the clay pores.
The concept has been revived by Zamil Air-Conditioners in its double skin air-handling units. These units are environmentally safe, energy efficient and ideal for our region, where many places meet the adiabatic cooling requirements, which are high dry temperature and low humidity ratio, says the company.
Air-conditioning systems have a major impact on annual operating costs (such as maintenance, energy and service) in buildings and only those systems that feature impressive technology and optimised engineering can contribute significantly to reducing annual energy costs without compromising on the performance and quality of the HVAC (heating, ventilation and air-conditioning) equipment.
Zamil’s double skin air-handling units incorporate an efficient adiabatic cooling system. The system consists of a special pump assembly; special spray nozzles assembly; special drip eliminator/stainless steel drain pan; and an electrical and control system.
The adiabatic cooling process is simply brought about by spraying water in a specially-designed section where the air stream comes in contact with fine water particles, which quickly evaporate and cool the air temperature, down by as much as 10 to 20 deg C lower than the incoming air.
Lowering the temperature of the incoming air to the coils or the energy recovery system, is said to result in saving as much as 10 to 30 per cent of power consumption solely by using water.
By means of a high-pressure pump and special nozzles, water is atomised into very fine droplets (10 to 20 microns). The flow of the water is strictly proportional to the speed of the pump motors, which is managed by a control system to ensure an ideal flow rate.
The efficiency of the adiabatic cooler using water in the liquid state can be increased by maximising the water droplet evaporation.
While evaporation cannot take place when the air is saturated or when the water droplet temperature is less than the air dew point, Zamil air-handling units, however, maximise the process by:
• Using a system, which atomises water droplets and improves the statistic distribution of the fine water particles;
• Optimising the duration of contact between the water spray and air;
• Providing an excellent angle of opening of the cone of atomised water produced by the nozzles; and
• Having no obstacles in front of the water spray, which could reduce the efficiency.
Compared with traditional adiabatic coolers, Zamil adiabatic coolers not only save energy, but considerably reduce water consumption of the system as well. This apart, the units have a high cooling and humidification capacity; are hygienically safe; have excellent cooling results; and are noiseless, according to the company.
Elaborating on the sequence of operation, a company spokesman says: “First, the temperature and/or humidity sensors measure the relative humidity (% RH) or receive an external signal from the building management system (BMS). The controller then calculates the water flow that has to be atomised and hence how many nozzles have to work and the speed of the pump. The nozzles then atomise the water in billions of small droplets.
“The droplets are carried by the airflow so that they fly in the air stream, during which they quickly evaporate until they reach the drop separator. The droplets that are not completely evaporated are caught by the drop separator and drained out.”
Zamil’s air-handling systems can be used for both adiabatic cooling and humidification in office buildings, the printing industry or warehouses, textile industry or warehouses, clean rooms (electronics), theatres and museums, industrial applications and hospitals.
