how flowmax works

Hot Water

Flowmax differs from conventional cylinders in that the water stored is not the same water that is delivered to the taps. It should be thought of as a store of heat. This primary heat store is is typically maintained at 75oC. A 50mm thick layer of CFC free foam insulation keeps heat loss to a minimum.

The heart of the Flowmax is the plate heat exchanger. Mains pressure cold water is heated instantaneously as it passes through this heat exchanger. A flow switch detects hot water demand, and switches on the store pump to assist heat exchange. Hot water can leave the plate heat exchanger at over 60oC. A thermostatic mixing valve ensures water is delivered at a safe temperature.

The store is vented via a feed and expansion tank. Only the inside of the plate heat exchanger is at mains pressure.

Flowmax electric units are heated by two immersion heaters and provide hot water only. Boiler models are heated by gas or oil and in addition to hot water can also provide heat directly to space heating (typically radiators)

Space Heating

Previously, in a combined space heating and hot water system, operational control has focused on the boiler. Flowmax changes the this and allows the thermal store to be the heart of the central heating system.

Space heating is supplied directly from the store. The store thermostat maintains the store temperature at 75oC and with this ready store of hot water the space heating demands are met far quicker than in conventional systems. As the temperature of the water in the thermal store is reduced, the thermostat activates the boiler. The store is heated until it reaches its set temperature and the thermostat shuts the boiler off.

If a timed pump overrun is fitted then the pump will continue to run, for a short while, to extract heat from the boiler circuit and maximise system efficiency. With the thermostat ON and the thermal store controlling the system, inefficient boiler cycling is eliminated, lowering fuel consumption and maintenance bills.

*Further technical information is available in the flowmax installation instructions which can be obtained by contacting range.

 
© 2006 Range Cylinders Limited.