Thermodynamic Principles

Heating can be a significant cost associated with cricket production.  Heating costs can be reduced by working with nature and the following basic thermodynamic rules:

• Heat travels in an upward direction.
• Heat moves from areas of high temperature to areas area of low temperature.
• The greater the temperature difference between two areas (i.e. inside and outside the container), the greater the heat loss or gain.
• Heat loss is reduced as insulation increases.
• Heat can be gained by placing an object adjacent to a heat source or heat sink (e.g. brick wall, chimney).
• Reducing temperatures by just a few degrees can result in great reductions in heating costs. For instance reducing the operational temperature of a reverse cycle air conditioner/heater by 1 degree can reduce operating costs by around 10%.

Heating costs can be reduced by implementing the following location and efficiency considerations:

Location Considerations

Place the colony adjacent to or within the following locations:

• Next to heat sources such as fireplaces, ovens, hot water heating systems or clothes dryers.
• Against heat sinks (stored heat) such as brick walls which store heat during the day and release it at night.
• Next to a closed window that is exposed to sunlight. An open window can create drafts which removes heat.
• An existing heated reptile room.
• The warm side of a house/shed

Efficiency Considerations

Below are additional ideas to reduce heating costs:

• Depending on the type of heater in use, thermal gradients may develop in a room (i.e. containers close to or far away from the heater, higher temperatures near the ceiling, and cooler temperatures near the floor). Fan forced systems may help to reduce thermal gradients.
• Always keep breeder containers heated to optimal temperatures. Grow out containers however can be stored at sub-optimal temperatures (i.e. at room temperatures). Growth rates will be reduced and they may take longer to mature, however it will reduce energy costs.
• When using heat pads, place insulation foil and towel (towel to be placed between insulation and container) under the containers to prevent heat being radiated away from the containers.
• Place a towel over the top of the breeding containers in winter to reduce heat loss.
• Place a ceramic tile beneath a heat mat or heat cord. The thermal mass of the tile will help conserve heat.
• Use passive heating (solar heaters) to heat rooms up during the day and use other heating systems during cooler periods and at night.
• Use thermal and reflective insulation in the room or shed crickets are housed.
• Use switch and dimming thermostats (Refer to Section 6.3) to regulate temperature so excessive heat is not generated. In summer it may be possible to turn off your heaters all together.
• If you can’t afford thermostats, use timers to turn off heat sources during the warmer parts of the day.
• To reduce the number of timers of thermostats you need to buy, place a number of heat pads onto a “Master/Slave power board” which is connected to a single thermostat/timer (Refer to Section 6.3). Check that the power board is able to handle the electricity load being placed on it.
• Use efficient heating systems such as heating pads (refer to above sections)
• Turning off the heater when crickets get to the desired size. This will prevent them from getting larger than desired, increase their shelf life and reduce food and energy costs.
• For containers which are stacked above each other, reduce the heat settings for containers on the top row as heat rises and warms containers.
• For a batch system place pinheads into small pinhead grow out containers (Refer to Chapter 10.0), so that you can place two batches (two weeks supply of pinheads) onto a single heat pad.
• Close any curtains and blinds in a room.
• If heating a room, get a system that is efficient for its size. Small heating systems that try to heat large rooms run at sub-optimal rates which increase energy consumption.
• Store crickets at least 0.5-1m (1.64-3.28 feet) off the ground as cold air will sink to the floor.