Roots Air Hybrid Units.

Three stage evaporative cooling systems

1.Stage -1 (Indirect Normal cooling):    The fresh filtered air is made to pass through the cooling coil of 4 Row deep (Sensible cooling) where in the dry bulb temperature as well as wet bulb temperature is reduced. This heat is rejected through cooling tower via pump and piping. This is with 100 % fresh air and is used only during summer.

2. Stage -2 (Indirect Chilled water cooling):    The fresh filtered air is made to pass through the cooling coil of 4 +2 Row deep (Sensible cooling) where in the dry bulb temperature as well as wet bulb temperature is reduced. This heat is rejected through chilled water via pump and piping. This system is used during monsoon and the return air is taken.

3. Stage -3 (Direct Evaporative cooling    The fresh filtered air is made to pass through the cooling coil of 4 Row deep (Sensible cooling) where in the dry bulb temperature as well as wet bulb temperature is reduced. This heat is rejected through cooling tower via pump and piping. This air after passing from indirect cooling is now directly cooled by passing it through the cellulose pads (direct air and water contact – adiabatic cooling) and is further cooled. This system is used during summer with 100% fresh air.

4. Components:   

  • Mixing Chamber with damper.
  • Filters.
  • Chilled water cooling coil – 4 Row plus 2 Row.
  • Cellulose cooling media.
  • Fan with motor and drive .
  • Water recirculation pump for cooling media with piping and valve.
  • Cooling Tower with Pump and piping and valves.
  • Double skin enclosure with frames and support.
  • Chilled water inlet and outlet valves.
  • Accessories.

Operation

Summers     During summers, the fresh filtered air is made to pass through the chilled water coil with 4 Row deep (Indirect Cooling) (being connected to cooling tower) and there after through cooling media (Direct Cooling). By doing

this we get the outlet temperature lower than Wet Bulb Temperature i.e. more than 100% Saturation efficiency. At this time 100% fresh air is supplied.

Monsoon: During monsoon, the fresh filtered return air is made to pass through the chilled water coil with 6 Row deep (Indirect Cooling) (being connected to chiller giving chilled water). By doing this we get the lower outlet temperature. At this time 10% fresh air is supplied with 90 % return air.

Winter:     During winter, the fresh filtered return air is supplied. By doing this we get the higher outlet temperature. At this time 10% fresh air is supplied with 90 % return air.