Abstract: A thermoelectric heat pump fluid circuit apparatus (10) for alternately delivering hot and cold fluids to an end device (12) such as a therapeutic wrap or pad. The apparatus includes a heat pump (14), a fluid circuit (16) coupled with the heat pump and having a fluid contained therein, a pump (18) interposed in the fluid circuit for circulating the fluid therein, and a valve (20) interposed in the fluid circuit for selectively delivering fluid from the fluid circuit to a device coupled with the apparatus.

Abstract: A method of selecting optimum values for the factors H and .mu. in a thermoelectric heating/cooling device. A system model is formulated by relating the heat transfer characteristics of the heat exchangers on the hot and cold sides of the device to the thermoelectric properties of the TE couples. The model yields a set of governing differential equations that take into account the relative flow directions of the fluids and the position dependence of the temperatures. The equations can be solved and the solutions used in an iterative procedure to select optimum values of H and .mu. that will meet the specified heating or cooling requirements. In a less rigorous method, the average temperatures on the hot and cold sides of the device are used, and these temperatures are mathematically expressed by equations that normally provide results within acceptable margins of error.

Abstract: A freezing point method and device (10) are disclosed. The method and device pertain to an inflection point technique for determining the freezing points of mixtures. In both the method and device (10), the mixture is cooled to a point below its anticipated freezing point and then warmed at a substantially linear rate. During the warming process, the rate of increase of temperature of the mixture is monitored by, for example, thermocouple (28) with the thermocouple output signal being amplified and differentiated by a differentiator (42). The rate of increase of temperature data are analyzed and a peak rate of increase of temperature is identified. In the preferred device (10) a computer (22) is utilized to analyze the rate of increase of temperature data following the warming process. Once the maximum rate of increase of temperature is identified, the corresponding temperature of the mixture is located and earmarked as being substantially equal to the freezing point of the mixture.

Abstract: An air conditioning system utilizes a novel air thermodynamic cycle and performing apparatus for simultaneous and efficient removal of the sensible and latent heats from the room return air. The system employs a pair of heat exchangers having a desiccant material thereon, the refrigerant, room and outside ambient air flows being selectively routed to the heat exchangers to allow one heat exchanger to operate as an evaporator to effect cooling and drying of the room return air while the other heat exchanger acts as a condenser of the refrigerant and regenerates the desiccant material thereon. The heat exchangers are switchable between evaporator and condenser modes allowing for continuous conditioning of the room return air.