Engineered Systems Magazine

VRV cooling

April 28, 2010

Daikin AC has introduced the improved VRV®-WIII, a compact water cooled condensing unit, designed to provide exceptional energy and cost savings as well as the ability to operate in geothermal and cooling tower/boiler combination applications. When used in geothermal applications, the relative stability of groundwater temperatures results in optimum system efficiency regardless of outdoor temperature.

"Daikin’s improved VRV-WIII gives engineers a solution for geothermal applications which also qualifies for a possible business investment tax credit," said Marc Bellanger, marketing manager for Daikin AC. VRV-WIII is an energy saving alternative to traditional centralized equipment that can serve any size commercial application. It is designed to keep running costs at an absolute minimum. Daikin's modular design allows contractors and engineers access to a wide range of water cooled applications in spaces where traditional centralized plants are not suitable or cost-effective. “The application scope of water cooled systems is very large, with recent successes including the new Nelson Mandela Bay Stadium in South Africa for a total of over 830 tons and also in smaller applications such as offices under 20 tons,” added Bellanger.

"Daikin's VRV-WIII (RWEYQ-P), is available in 6 system capacities, ranging from 6 to 21 tons and provides a very strong modular solution for large commercial applications," says Lee Smith, director of product, engineering and applications. "It is available in unified heat recovery and heat pump condensing units and utilizes the latest VRV technology. The new model improves switching from cooling to heating without system interruption and improved full load energy efficiency performance. The standard Entering Water Temperature (EWT) from 59°F-113° in both heating and cooling is possible for continuous operation. 50°F is possible for intermittent operation.”

The VRV-WIII has many cost saving features, according to the company. When applying the VRV-WIII in geothermal configuration, there is no need for an optional PCB, saving on start up costs and installation time. The VRV-WIII is also remarkably compact. It's lightweight structure and modular concept makes VRV technology the right fit for almost any space and increases installation flexibility due to the virtually limitless length and height of water piping. At only 330 lbs. and less than 40” high per module, the VRV-WIII can be transported in a standard elevator. The compact design of the condensing unit allows for a double stacked installation. The connection ratio of 50-130% allows engineers to optimize equipment around building diversity.

Up to 32 indoor units can be connected on one refrigerant piping network, from an expanded range of 11 indoor unit models in 51 variations. The addition of a Branch Selector unit for heat recovery unit allows heating or cooling to be selectable per indoor unit for optimal comfort. Plus the RWEYQ-P, like all Daikin VRV systems, can be connected to all current Daikin control systems, enabling each zone individual control or shutting down completely in unoccupied areas. It uses a 208-230 volt, 3-phase power supply and operates at low sound levels. Long refrigerant lines, up to 980 feet of total piping (liquid line), up to 390 feet from the condenser to the furthest indoor unit and up to 164ft height difference, result in the flexibility to install the equipment almost anywhere.