613results about "Chemical variable control" patented technology

Methods, systems and computer program products are provided for controlling a climate in a building. Sensed data is received at a local processor in the building. The sensed data is associated with the climate in the building, weather outside the building and / or occupants of the building. The received sensed data is compared at the local processor with corresponding predictive data associated with the climate in the building, weather outside the building and / or occupants of the building. One or more parameters associated with the climate of the building is adjusted at the local processor based on a result of the comparison of the received sensed data and the predictive data.

A dehumidifier system is connected to an interior space of a building through supply and return ducts, either directly and / or through an HVAC system. Controllable dampers can be used to select how the dehumidifier system is connected to the interior space and the HVAC system. The dehumidifier determines the dew point of the ambient air from temperature and relative humidity measurements taken at location(s) of relative humidity and temperature sensors. Based on the determined dew point, the dehumidifier system determines whether to operate. The temperature and relative humidity sensors can be located in the interior space or within the dehumidifier, where they project into the air stream flowing through the dehumidifier. The dehumidifier system operates in response in part to blower calls to the HVAC system and controls the HVAC system and a ventilation system to distribute the dehumidified air and outside air throughout the building.

A multistage furnace for heating residential or commercial spaces is operated by a single stage thermostat and a return air temperature sensor providing sensed temperature information to a controller. The furnace is started at a first, low firing rate and after a predetermined time is increased to a second firing rate if the rate of change of temperature of air returning to the furnace from the space is less than a predetermined amount. The method of operation is carried further to increase the firing rate to second and third rates based on predetermined rates of temperature change of return air from the enclosed space as sensed by the return air sensor.

The invention relates to a method for adjusting concrete rheology requiring only that load size and target rheology value be selected initially rather than requiring inputs into and consultation of a lookup table of parameters such as water and hydration levels, mix components, temperature, humidity, aggregate components, and others. Dosage of particular rheology-modifying agent or combination of rheology-modifying agents is calculated based on a percentage of a nominal dose calculated with reference to a nominal dose response (“NDR”) curve or profile. The NDR profile is based on a correlation between a rheology value (e.g., slump, slump flow, yield stress) and the rheology-modifying agent(s) dose required to change rheology value by one unit (e.g., slump change from 2 to 3 inches) such that exemplary methods can employ corrective dosing based on the NDR and the measured deviation by the system.

Controlling the reductive capacity of an aqueous alkaline slurry (23) in a wet scrubber makes it possible to accurately control the mercury emission from the scrubber to a desired value. One method of controlling the reductive capacity of the slurry is to measure the reduction-oxidation potential (“redox potential”) of the aqueous alkaline slurry (23) and to add or remove substances that affect the redox potential and thus the reductive capacity of the slurry. In wet scrubbers in which limestone is used for absorption of acid gases and where a gypsum slurry is circulated, it has been found to be an attractive solution to control the amount of oxidation air blown into the scrubber in order to control the redox potential and thereby the mercury emissions.

An energy-reducing method and apparatus for retrofitting a constant volume HVAC system, with or without an economizer, that provides heating, cooling, and ventilation to occupants within a building space. The present invention includes the introduction of a programmable logic controller and variable frequency drive (VFD) that takes control of the existing fan, heating, cooling, and optional economizer operation. The controller is programmed for the reduction of fan speed in the heating and cooling modes. The reduction of the fan speed in the ventilation mode when the 100% operation is not needed saves significant energy of the existing constant volume HVAC system where the fan motor is designed to run 100% of the time. The fan speed may be further reduced upon a reduction in sensed occupancy levels of the space, such as with a CO2 sensor. Additionally, the fan speed may be reduced in the heating and / or cooling mode to further reduce energy consumption. The controller may also be programmed and equipped with sensors to allow simultaneous mechanical compressor cooling and economizer free cooling operation, for the operation of the economizer in response to the monitoring of outside air and return air to determine the preferred source for cooling operations, to keep the outside air damper closed during the unoccupied heating modes such as morning warm-up, and / or to provide fault detection. The retrofit method and apparatus may be employed in a stand-alone or networked version.

A ventilation system for regulating atmospheric communication between a first space and a second space includes an airflow regulation device and a control system. The airflow regulation device is disposed in fluid communication with the first and second spaces. The airflow regulation device includes a regulator for regulating airflow and an adjustment system connected to the regulator for adjusting the regulator. The control system includes a first sensor, a second sensor and a microcontroller. The first sensor is in fluid communication with the first space to measure a first atmospheric condition. The second sensor is disposed in fluid communication with the second space to measure a second atmospheric condition. The microcontroller is in communication with the first sensor and the second sensor for comparing the atmospheric conditions. The microcontroller is in communication with the adjustment system for adjusting the regulator in response to differences between atmospheric conditions.