In various situations there is a need to distribute heat in outdoor areas. For example, in horticultural applications crop yields can be devastated by frost damage experienced at the wrong time of a growing cycle. Heavy rainfall and water sitting on the skin of a fruit can also impact on the quality of the produce generated by a grower. Crop yields are also dependent on successful pollination, with ambient temperatures having a role to play in this process with various crops.
Some attempts have been made to control the temperature experienced inside orchards and other similar crops. One technique currently used is the distribution of large numbers of localised heating devices or pots over the orchard floor. However, these stationery heat sources only distribute heat very locally and with a limited lateral extent. This approach requires a large number of individual heat sources to be laid out and activated over the extent of the orchard, and then subsequently collected again after the weather improves.
An alternative approach is to tow a heat source connected to a fan through an orchard. Although this approach does not require large number of individual heat pots to be deployed and collected, it does require a driver to continuously run a vehicle over and through the orchard—potentially through the early hours of the morning when frost risk is at its greatest. Furthermore, these towed heating systems again have a limited ability to distribute warm air laterally and generally only provide a narrow swathe through the orchard with little persistence. If the heat is too great close to the plants it can damage the crop. With lack persistence the heater needs to operate over a repeating track that returns within about four minutes which severely limits the area that a machine can cover effectively.
In some circumstances a temperature inversion may occur in the air surrounding an orchard. In these circumstances an upper warm air layer forms above the orchard while colder air is resident in and on the plants. Helicopters and wind turbines had previously been used to force the warm air above the orchard down into the plants, and although this approach is effective in preventing frost and generally raising orchard air temperatures, is also expensive in terms the cost of machinery required and the energy consumed by this machinery. Furthermore, this approach generates a significant amount of noise at time periods where local residents may be sleeping.
It would therefore be of advantage to have an improved heat distribution apparatus and method of operating same which addressed any or all of the above issues. A heat distribution apparatus and method of operating same which provided the public with at least an alternative choice would also be of advantage. Improvements over the prior art which allow for the distribution of warm air in or above the canopy of an orchard would also be of advantage, as would improvements which allowed for control of the volume and temperature of air distributed to various sections of an orchard.