Abstract: A heat cycling apparatus and method is provided for heating at least two chambers utilizing a pressurized heat source. The heated air is directed first to one chamber and then to the other on a predetermined repetitive time cycle.

Abstract: A heating system and method are provided in which a defined area to be heated or to be used for drying crop material may be connected through adjustable ducting to either a primary heat source, such as an oil or gas furnace, or to an alternate heat source comprising a shrouded engine, such as an internal combustion or turbine engine, from which heat may be extracted. A control system allows the engine heat source to be automatically activated in the event of an electric power failure or to be selectively used as the sole source or as a supplementary back up source of heat. The control system further allows the automatic activation of the electric system, should the engine system fail, thus cycling from one mode to the other when either is selected as the primary mode.

Abstract: A heat cycling apparatus and method is provided for a bulk tobacco curing barn having at least two chambers in which the tobacco is cured in bulk utilizing a pressurized heat source. The heated curing air is directed first to one chamber and then to the other on a predetermined repetitive time cycle. Crops other than tobacco may be cured or dryed with the same apparatus and method on an appropriate time cycle.

Abstract: Incoming fresh air, which is introduced for heating in the furnace of a bulk curing barn for tobacco, travels the length of the barn in heat exchange relationship in a direction opposite to that of the hot, moist exhaust air leaving the curing chamber. The incoming fresh air is further preheated by means of a solar roof immediately beneath which the fresh air flows on its way to the furnace. The curing chamber itself is made substantially air tight, is insulated, and has the floor thereof elevated above the ground, thereby preventing heat loss as much as possible. The barn is sometimes portable so that it can be loaded with tobacco adjacent or near the tobacco field and moved to whatever location desired for the curing operation.In a preferred embodiment, additional amounts of fresh air are introduced beneath the edges of a corrugated surface which forms the solar roof, which air streams are heated both by the solar furnace from above, and also by the hot exhaust air in an exit duct immediately therebeneath.