Abstract: A device to compensate for the thermic effects of an external source on a sensitive element in a system for automatically controlling the temperature reached by foods in heated vessels. The device includes a conventional range and a potentiometer for controlling a gas or electric heating element. Two heat sensitive elements are employed, one sensing pan temperature, and the other sensing ambient temperature. Electric circuitry automatically adjusts the heating element to reduce the heat output as the ambient temperature rises, so that a more constant vessel temperature is achieved.

Abstract: In a multizone air conditioning system, a controlled leakage of refrigerant is provided from the high pressure side of the system to an inactive fan coil circuit to raise the pressure therein, such that when that circuit is later brought into an active state, the flow rate of refrigerant suddenly entering the circuit, and the resultant noise, is reduced. In one embodiment the controlled leakage is provided by an orifice formed between the high and low pressure sides of a valve, while in another it is provided by capillary tubes interconnected between active and inactive fan coil circuits.

Abstract: A low temperature air conditioning system provides primary air through smaller than normal ductwork and at a lower than normal temperature (such as 40.degree. F.) at peak load conditions. The primary air is mixed in branch ducts with return air taken from the conditioned space. Low pressure fans pull the return air into mixing boxes equipped with dampers which maintain the downstream temperature in the branch ducts at a normal supply air temperature (such as 55.degree. F.). Variable air volume terminal units discharge the air into the conditioned space. The small fans require only low horsepower and allow a smaller than normal central fan to be used. The cooling coil is cooled by a variable suction temperature refrigeration system which may be operated at night in conjunction with an ice storage system to minimize the demand for mechanical refrigeration during peak daytime hours. This arrangement permits the refrigeration machine to be smaller than normal and to consume less power during peak daytime hours.

Abstract: A circulating air building temperature control system includes a pumped air circulation conduit for distributing controlled temperature air throughout the building and collecting return air, and a fireplace for burning solid fuel, the air circulation conduit being positioned about the exterior of the fireplace chamber walls and sealed from the fireplace chamber. An outer housing is also provided to define an outer chamber positioned about the air circulation conduit, and connected to air inlets and outlets to limit the upper temperature of the outer housing wall even in the event of a hot fire and no circulation through the air circulation conduit.

Abstract: A heating system for a motor vehicle has temperature sensors for gauging the compartment temperature as well as for gauging the temperature of the effluent hot air. These sensors are connected in series, with the compartment sensor generating the more significant control signal. The flow of heating medium, for example engine water, is regulated by a valve under the control of a regulator which compares the sensors signals with a set-point value. The valve may be cyclically actuated by pulses of fixed frequency but having a width which depends on the results of the signal comparison.

Abstract: A furnace and method of operation are disclosed for the efficient, controlled combustion of a combustible material such as wood, coal, etc. The furnace includes a grate which grate permits a large amount of combustible material to be stacked within the grate and to be constantly compressed to insure efficient combustion. The furnace also includes a heat exchanger surrounding the grate, which heat exchanger is comprised of an intake jacket and an exhaust jacket disposed on opposite sidewalls of the furnace. The heat exchanger also includes a plurality of heat exchange tubes disposed above and behind the grate and connecting the jackets. Air is drawn into one of the jackets, is directed through the heat exchange tube where the air is heated, and is exhausted through the other jacket. A portion of the heat exchanger intake air is diverted through a perforated air delivery tube disposed adjacent to the grate to provide combustion air for the combustible material.

Abstract: An expansion tank is connected to a heating system by feed and drain pipes whereby the flow of water into and out of expansion tank is regulated by a valve and a pump. In the expansion tank there is a bellow which is in contact with the outer air.

Abstract: A purge arrangement for absorption refrigeration systems using a solution of lithium bromide as an absorbent and water as a refrigerant, and a heat transfer additive, such as octyl alcohol being added to and mixing with the lithium bromide solution. The purge arrangement includes means for automatically removing noncondensible gases or vapor from the system, said means including a vacuum pump connected to a receiver to draw noncondensible gases therefrom; automatic electrical control means for said vacuum pump; and an additive overflow conduit to prevent additive collecting in the storage receiver and to assure additive return flow into the solution conduit.