Free cooling added to R32 chiller
EUROPE: Daikin has added an energy-saving free-cooling version of its recently introduced EWAT-B series of R32 chillers.
The new EWAT-B air-cooled scroll chillers were introduced last year for cooling only and heat recovery applications from 80kW up to 700kW cooling capacity.
The addition of free cooling migration options with modular V layout is said to be capable of delivering between 25% to 75% of cooling demand, with an improvement in seasonal efficiency of up to 97%.
Unique to the chillers market, R32 is said to be the only refrigerant able to allow the migration to free cooling without the need for additional pumps or other add-on devices and does not require the addition of glycol, unlike standard water free cooling technologies, where its use is mandatory.
BlueVolution air-cooled chillers are the first to use the “mildly flammable” A2L refrigerant that boasts just one third that of the commonly used R410A alternative.
The new refrigerant migration system is available in two options, Light and Full, with specification depending on the height and temperature differential of the refrigerant between the condenser and evaporator, which affect the effectiveness of the process.
Both the Light and Full options allow natural migration from the evaporator to condenser, by-passing the mechanically-driven compressors and expansion valve. The advanced heat exchanger design eliminates the need for additional devices without affecting water pressure drops.
Connection and installation remains standard with the Light option, which can deliver up to 25% of nominal cooling capacity for the unit. Foot print is not affected and as an added advantage there is no legal requirement to add glycol.
The Full refrigerant migration system operates on the same principles with all the benefits of the Light version but incorporates an additional flooded evaporator per circuit. This works in parallel to the standard heat exchanger, improving performance by enhancing the height and reducing the approach between water and the refrigerant. The Full migration refrigerant system is also available with hydronic connection to the plant.
As with the Light option, no additional devices are required, however, a slightly modified layout is required to accommodate additional plant connections – four connections for a single unit and six for twin circuit units. The cooling capacity of the Full system is extended to provide up to 75% of the standard unit’s nominal cooling capacity.
