PHPI takes a look at Alpha’s Flowsmart system – answering the questions is Darran Smith, Technical Manager for Alpha.
What kind of property has FlowSmart been designed for?
Alpha’s FlowSmart system increases the combination boiler’s ability to deliver hot water, making it a serious alternative to a conventional boiler for properties with above average hot water demands – whether it be family homes or small commercial buildings.
Combi boilers have long been accepted as the most energy-efficient and space-saving boiler option available. Not surprisingly, they are therefore the popular choice for the majority of new domestic installations in the UK. However, the combi’s inability to supply large volumes of hot water simultaneously to a number of outlets often results in the conventional boiler and hot water cylinder set-up being the preferred option.
For those looking to upgrade their heating system to achieve substantial hot water demands, options such as heat pumps may well be appealing from a sustainability perspective, yet out of reach logistically at this current time. Equally, there may be a temptation to wait for the introduction of hydrogen into the gas network.
But while we await government intervention to make this possible, there are simple and practical solutions which can be applied now to enhance the performance of existing gas boilers and render them more efficient. Cue FlowSmart, which brings together the energy and space efficiency advantages of a combi, with the hot water delivery rate of a system boiler, in one convenient package.
By incorporating a GasSaver and small thermal store, FlowSmart allows a combi boiler to deliver a flow rate of 18 litres of hot water per minute, at 50ºC or above, for up to 30 minutes – more than three times longer than a typical system boiler set-up. Together with its superior energy efficiency and ease of installation, this makes FlowSmart a great energy-efficient option for large households.
How does it work?
The system incorporates a combination boiler, a GasSaver flue gas heat recovery unit (either built-in or as a separate ‘top box’) and a 50 litre thermal store (available as a wall-hung or floor standing unit).
When there is a hot water demand, cold mains water flows into the GasSaver where it is pre-heated using heat reclaimed from boiler flue gases. The pre-heated water then passes through the thermal store which draws heat from the boiler’s primary circuit (also known as the central heating system). There, it is heated further before then passing through a blending valve, where it is controlled to an optimum 30ºC before entering the boiler.
With less work to do to raise the water’s temperature, the boiler can satisfy high hot water demands for long periods, without detrimental effect to flow rate. This negates the need for a large, permanent store of hot water.
Is it more efficient than a solution which combines a system boiler with an unvented cylinder?
FlowSmart delivers exceptional energy efficiency, consuming less electricity and using up to 25% less gas to provide hot water than a conventional system boiler set-up with a 200-litre unvented cylinder. This is because water is only heated as needed and energy isn’t wasted in maintaining a stored supply of hot water. Energy efficiency of the FlowSmart is also enhanced by the flue gas heat recovery technology within the GasSaver.
What kind of controls are needed?
As the system is based around a combination boiler, most modern time and temperature controls are compatible with FlowSmart allowing simple and personalised set-up and operation of the heating.
To maximise efficiency an intelligent control such as the Alpha Climatic is recommended. Classed as an Enhanced Load Compensator, it is capable of measuring and maintaining the temperature inside the building by modulating and limiting the boiler flow temperature depending on the measured room temperature.
What do heating engineers need to know about the installation of the unit?
FlowSmart is a compact and energy efficient solution featuring a combination boiler. It can deliver enough instantaneous hot water to satisfy even the most demanding household – and without any negative effect on flow rate.
From an installation perspective, the small thermal store takes up much less space than a cylinder, enabling the complete FlowSmart system to be sited together in an average airing cupboard. There are limited pipework requirements making for a very simple process.
