James River Air Conditioning Company
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James River Air Conditioning Company
James River Air Conditioning is your local full-service heating, ventilation and air conditioning (HVAC) contractor. James River Air Conditioning was established in 1967 and has first-hand experience with both older and newer, state-of-the-art styles of HVAC systems. Since HVAC technology rapidly changes, we constantly stay on top of new developments in the industry and train our staff on new ways to help our clients.
Whether your need is large or small, the team at James River Air Conditioning has the resources to help. We are proud to be an active member of the RVA community, and we are committed to providing our commercial clients with world-class service and support.
Our commercial service team members are skilled in the repair, maintenance and installation of Electrical and Electronic Control systems. These systems work independent of other controls. They are hardwired interlocked to each other to accomplish a certain sequence of operation. The power required is either line voltage or low voltage depending on the application. This type of control requires limited amount of tools and ability to maintain. There is a broad application of products that can be used to meet any control application. Electronic Control devices are temperature controls, humidity controls, relays, valves, dampers, pressure controls, and thermostats.
James River Air Conditioning is also your best choice for the repair and maintenance of Pneumatic Control systems. In the past, Pneumatic Controls systems were the most cost-effective system to install in a commercial building. The high cost of properly maintaining this system is the draw back with this type of installation. The proper tools and technical ability to work on a pneumatic system is limited to either the manufacturer or an independent contractor that has invested in equipment and manpower to perform this specialized service.
Pneumatic control systems use compressed air to supply energy for the operation of valves, motors, relays, and other pneumatic control equipment.
No, due to the fact that pneumatic systems must be clean, dry, and oil free or controls contamination will occur and result in expensive repairs. Although cheaper, the regular shop air compressor is designed to migrate a little oil vapor from its crankcase to lubricate shop air tools and should not be used as a replacement to a control instrument compressor. Controls compressors run a third of the speed, run cooler temperatures and are not designed to sling oil. If your pneumatic compressor needs to be repaired or replaced, contact James River Air Conditioning for a professional evaluation.
A Building Automation System (BAS) is an example of a Distributed Control System. Building automation describes the functionality provided by the control system. The building automation control system is a computerized, intelligent network of electronic devices, designed to monitor and control the mechanical and lighting systems in a building.
BAS core functionality keeps the building climate within a specified range, provides lighting based on an occupancy schedule, and monitors system performance and device failures and provides email and/or text notifications to building engineering staff. The BAS functionality reduces building energy and maintenance costs when compared to a non-controlled building. A building controlled by a Building Automation System is often referred to as an intelligent building system. The term most commonly used in the HVAC industry is DDC or Direct Digital Control.
A Direct Digital Control System is often used to control HVAC (heating, ventilating, and air conditioning) devices such as valves via microprocessors using software to perform the control logic. Such building automation systems receive analog and digital inputs from the sensors and devices installed in the HVAC system and, according to the control logic, provide analog or digital outputs to control the HVAC system devices. These systems may be mated with a software package that graphically allows operators to monitor, control, alarm and diagnose building equipment remotely.
Central controllers and most terminal unit controllers are programmable, meaning the direct digital control program code may be customized for the intended use. The program features include time schedules, setpoints, controllers, logic, timers, trend logs, and alarms. The unit controllers typically have analog and digital inputs, that allow measurement of the variable (temperature, humidity, or pressure) and analog and digital outputs for control of the medium (hot/cold water and/or steam). Digital inputs are typically (dry) contacts from a control device, and analog inputs are typically a voltage or current measurement from a variable (temperature, humidity, velocity, or pressure) sensing device. Digital outputs are typically relay contacts used to start and stop equipment, and analog outputs are typically voltage or current signals to control the movement of the medium (air/water/steam) control devices. Usually abbreviated as “DDC”.
When Direct Digital Control System (DDC) controllers are networked together they can share information through a data bus. The control system may speak ‘proprietary’ or ‘open protocol’ language to communicate on the data bus. Examples of open protocol language are BACnet (Building Automation Control Network), LON (Echelon), Modbus.
When different Direct Digital Control System (DDC) data networks are linked together they can be controlled from a shared platform. This platform can then share information from one language to another. For example, a LON controller could share a temperature value with a BacNet controller. The integration platform can not only make information shareable, but can interact with all the devices. Most of the integration platforms are either a PC or a network appliance. In many cases, the HMI (human machine interface) or SCADA (Supervisory Control And Data Acquisition) are part of it. Integration platform examples, to name only a few, are the Tridium Niagara AX, Johnson FX40,TAC Vista and the Unified Architecture i.e OPC (Open Connectivity) server technology used when direct connectivity is not possible.
