VRF Air Conditioner Case Study - cfes install the first Toshiba Modular Multi VRF System

The first installations have been completed in England, Wales and Northern Ireland. W H Smith's latest store in Fleet Street in the City of London was the first location to experience all the benefits of MMS, Toshiba's newest air conditioning system.

WH Smith selected MMS for both its new London and Belfast sites. The installations have been carried out by cfes. The WH Smith installation in the City illustrates several of the main features of the new product, including a number of technological breakthroughs for VRF technology.

Typically for retail units in the City of London, the WH Smith shop has very restricted plant room space and access. Because MMS is modular, a single linked system could be installed in the tiny plant room. The small footprint made it easy to fit it through the doorway. It is ducted to the outside without having had to change the condenser fans. The alternative would have been to use five separate "traditional" units for which there was in any case no room and additional fans would have had to have been used.

Toshiba MMS made this "nightmare" scenario into a relatively easy installation. MMS requires no multi controller box so connections were simple through the building to the five cassettes covering the two retail floors, the office and stock rooms and the half retail basement.

cfes have noticed a big difference in on site time. All are impressed by its flexibility. It is ideal for retrofits.

Clients are delighted by the limited disruption and the efficiency and quietness of the systems. When as in the WH Smith case, a single inverter unit can be grouped with up to four fixed speed units. These two pipe heat pump systems can offer from 22.4 to 128.8kW cooling (25 to 144.5kW heating) capacities.

MMS can handle a network of up to 40 indoor units on such a system. The unique oil management system monitors and balances the oil supply to ensure the reliability of the overall system. The 30 metre lift allows as many as ten floors to be covered.

The "outdoor" units use of new "cube" coils, "stealth" fans, the super quiet inverters and a special compressor enclosure all contribute to noise reductions which take its performance to around 3dB(A) below the nearest competitors' units.

One of the other technological design achievements has been the incorporation of dual pulse modulating valves (PMVs), into the outdoor units to ensure precise capacity control. This provides quick, uniform and non-intermittent cooling and humidity control in the conditioned space irrespective of whether the indoor units are located nearer or farther from the outdoor units or the complexity of the piping circuit.

The new system is electronically very sophisticated. On the refrigerant detection (rdc) side it has a refrigerant detection and containment system to protect the environment.

A very wide range of control options is also available. Individual room or unit control is possible and can be used with or replaced by centralising control. An analogue BMS interface can be provided or full digital Lonworks interfaces can be installed.

A feature rich Windows based management programme with internet and energy management options has also been developed. The system notices can be programmed as a screen message, e-mail, fax or mobile text message. Data can be downloaded and analysed in order to optimise output for peak efficiencies. A software based self-diagnostic tool guides engineers through installation and commissioning. Zero downtime can be achieved through parameter monitoring and trend analysis of the system.

To view more case studies please visit our cfes website.