Tags: Incubation | Whitepaper
18 February 2016,
In modern hatcheries, electricity consumption by incubators can account for 35-50% of the hatchery’s total electricity costs. Electric motors in both setters and hatchers are the greatest consumers of electricity.
A frequency controller, or ‘Energy Saving Module’ (ESM), can be installed in the setter to adjust fan speeds. The ESM allows the hatchery manager to design single stage incubation programs for savings of 24-30% in energy consumption by the electrical motors, without adversely affecting hatchability and uniformity.
In most setters the fan has two functions: (1) air intake and (2) recirculation of air over the eggs and between trolleys. Air intake functionality is part of the ventilation system, controlled either by the air inlet valves (dampers) fixed set points, or by automatically controlling dampers based on RH and CO2 set points. Maximum ventilation capacity (m3/h) or air intake depends on fan speed and decreases at reduced fan speeds when energy saving programs are implemented.
The recirculation function of the fan directs airflow over the eggs, thereby controlling the uniformity of embryo temperatures. The shape and speed of the fan determine airspeed (m/s) and uniformity of air flow.
Both air intake and recirculation depend on the speed of the fan (revolutions/min). Consequently lowering fan speeds reduces air flow over the eggs and decreases maximum ventilation capacity. Reducing fan speed to save energy therefore requires care, since embryo temperature (and growth) depend on temperature set points, air flow and ventilation rates (French, 1997).
In the first 3-5 days of incubation, sufficient heat must be transferred to the eggs to compensate for evaporative cooling. It is therefore not advised that fan speed is reduced during these initial days of incubation. After day 13, maximum fan speeds support optimum development and prevent poor chick quality by overheating. From days 12-13 the embryos metabolize yolk lipids at high rates to support rapid growth. This increased yolk consumption requires sufficient oxygen and therefore increased ventilation. Furthermore, increased lipid metabolism by the embryos initiates higher metabolic heat production. In this stage of development, cooled air flow should be optimized, to avoid overheating the embryos.
In conclusion, to support optimal development, saving energy by reducing fan speeds in setters is not recommended from day 13 to day 18.