With the rising need for prevention of global warming throughout the
world, CO2 emission reduction in the business and household sectors
has become a challenge to be tackled with the highest priority.
Among various air-conditioning systems, multi-split direct expansion
type air-conditioning (or variable refrigerant flow (VRF)) systems
have received attention as a potential energy-saving solution.
However, VRF systems involve tighter limitations on piping when they are installed in a high-rise building compared to chiller systems or turbo refrigerators. There are still many challenges to be overcome in order to meet future demand or allow installation in various types of buildings.
Toshiba currently provides the Super Module Multi Series (SMMS) as part of its VRF system lineup. In addition to the SMMS, the company will release the SMMS i that can deliver even higher energy-saving performance and permit longer piping, with a view to substituting existing counterparts such as chiller systems. The SMMSi was released to the Japanese market first (in June 2010), and manufacture of the product for the European and Asian markets started in September 2010.
The SMMSi is an advanced series of the existing SMMS. The high-end model of the SMMSi has a unit capacity of 16 HP, while that of SMMS has 12 HP. The "full inverter" technology, which has gained favor with the SMMS, has been further improved and incorporated in the additional 14HP and 16HP high-power models of the SMMSi. These models have three internal compressors that can be individually driven by their own inverter control to help reduce energy consumption. As an energy-saving-oriented product, the SMMSi also focuses on the improvement of equipment efficiency during stable operation that may substantially affect the energy consumption of air-conditioning systems.
(1) Full-inverter system pursuing energy-saving
The Toshiba proprietary high-efficiency DC twin rotary compressors and vector control inverter technologies, which are also used in the SMMS, have been further improved. The 8 HP model achieves the industry's top class energy-saving with a coefficient of performance (COP) of 4.52. At 50% capacity, the same model shows a COP of 6.41 *Note 1, achieving higher efficiency during stable operation.
The 14HP and 16HP models are equipped with three high-efficiency DC twin rotary compressors, each of which can be controlled by a separate vector control inverter with Toshiba proprietary technology.
(2) Substantially higher freedom of piping design
The longest allowable piping distance between indoor and outdoor units is the industry's top level of 235 m (SMMS: 175 m). The maximum height difference between indoor and outdoor units, which is always a matter of concern for installation in high-rise buildings, is 70 m *Note 2 (SMMS: 50 m). With these advantages, New-SMMS outdoor units can be installed on even higher floors of buildings than before. The maximum height difference between indoor units has also been raised to 40 m (SMMS: 30m). Thus, the SMMSi offers a substantially higher freedom of piping design than the existing product series.
(3) Industry's top class compact units
The 16 HP model achieves the industry's top class space-saving, allowing an installation cost reduction of about 40% *Note 3 from the existing SMMS level. For the SMMSi, multiple outdoor units can be combined to provide an integral output up to 48 HP. While four units of the existing series are needed to make up a 48 HP system, only three units of the SMMSi need be combined.
These are part of the features of the SMMSi. The new product series is scheduled to be shipped from the Fuji Plant in Japan to the European market from the end of September 2010.
Note 1: Under test conditions of an outdoor air temperature of 7℃DB/6℃WB and indoor air temperature of 21℃DB
Note 2: In cases where outdoor units are installed on a level higher than indoor units (if the height difference between indoor units is 3 m or more, the maximum height difference between indoor and outdoor units is 50 m).
Note 3: When compared to a system consisting of two SMMS 8HP units.