What is evaporative cooling?
Evaporative cooling converts hot air into a cool breeze using the process of evaporating water similar to how you feel when you step out of a swimming pool on a breezy day. In a standard greenhouse cooling system, exhaust fans pull hot air out of the greenhouse creating negative pressure inside the greenhouse. Fresh outside air is drawn through wetted pads and is cooled. This system is also referred to as a negative pressure cooling system. Evaporative cooling is environmentally-friendly since it uses no CFC's or HCFC's and costs about 70% less to operate than conventional air conditioning systems.
Fan & Pad cooling systems:
A fan and pad cooling system consists of a continuous row of cellulose pads along one wall of the greenhouse. Water is distributed along the tops of the pads. Exhaust fans at the opposite side of the greenhouse evacuate hot air. As replacement air is drawn through the pads, the outside air is cooled by evaporation by as much as 20 degrees in non humid climates.
Agra Tech is proud to sell ACME exhaust fans, cooling pads, and distribution and return systems. For 60 years Acme Engineering & Manufacturing Corporation has grown to become a world leader in the design, manufacturing and distribution of fans, blowers and ventilation equipment.
Acme distribution systems:
PDR. Available for 4” or 6” thick pads. The system comes complete with water distributor and cover, return gutter, strainer, pump and misc fittings and fasteners to complete the system.
PDR Aluminum. The aluminum system utilizes quick snap-together components for easy installation using a minimum of tools. The heavy extruded gutter and supports are designed to support the pads and carry the water back to a sump. Maximum system size for 4” pads is 8’ x 100’ or 8’ x 80’ for 6” pads. The aluminum top cover is made in two pieces to facilitate cleaning the PVC pipe if clogged.
CAEG. New. The CAEG system is only available for 4” pads. The advantage of the CAEG system is that the water storage is in the gutter. A separate sump tank is not required. The sump pump is located in an extension of the gutter. The top and gutter are aluminum extrusions.
CSEG. New. The CSEG system is only available for 6” pads. The CSEG system is similar to the CAEG system except that it has a stainless steel top and is available for 6” pads.
Kool-Cel” pads. Kool cel pads are cellulose, 4” or 6” deep, 12” wide and available in 1’ increments from 2’ to 6’ tall. Two pieces can be stacked for 7’ to 8’ tall systems. The pads are made from especially formulated cellulose paper impregnated with in soluble anti-rot salts. The exclusive cross fluted design induces highly turbulent mixing of water and air inside the pad which contributes to its high evaporative efficiency and low resistance to air flow.
Swamp coolers are self contained evaporative coolers used for very small greenhouse compartments or rooms where a fan and pad system is not feasible. The swamp cooler has built in pads and a blower to push the cooled air into the greenhouse.