subject: Cutting Costs in a luxury home with an Efficient Heating System [print this page] Two 500 litre hot water storage tanks along with a couple of industrial-size boilers were part of the original design of a vast, exclusive private house construction near Port Talbot, Neath. However, a timely intervention by Alpha Heating Innovation resulted in a re-specification that saved on space, a considerable amount of installation, not to mention future running costs and energy consumption.
Incorporating a huge 814 litre capacity bath, a 10-jet body shower and 300mm shower head, this luxury home has an exceptionally high hot water demand.
Add to this three underfloor heating circuits and one above-floor heating circuit, and it quickly becomes evident as to why the original specification which called for large twin storage tanks with two 67kW boilers would be the minimum needed to keep up with the pace.
In fact, this installation was too big for the house so it was planned to fit the boilers and tanks in a neighbouring barn, with subterranean pipework feeding the house.
Thankfully, Alpha along with Ian Pugh of Pugh's Plumbing and Gas Services brought the FlowSmart system to the table', and with it came a number of benefits to the homeowner, Paul Thomas. Not least of these was a cost saving of approaching 30% compared with the original solution. Add to this the fact that the Alpha package provided a huge space saving allowing it to be installed in the utility room of the house rather than a neighbouring barn and it is clearly evident that the FlowSmart solution was the natural choice.
Running costs are another issue. Catherine Earl, Alpha's Marketing Manager, states: "The potential energy loss from storing 1000 litres of hot water is immense. We also have to consider the issues of temperature drop in an installation that runs from the barn to the house, and the risk of frost in winter months."
FlowSmart is a package from Alpha that includes a SEDBUK A' rated Next Generation CD35C combi boiler, a GasSaver flue heat recovery unit, and a thermal store which comes in 25 or 50 litre versions. In this particular project, two FlowSmart packages are working together eliminating the need for some 1000 litres of stored water, and practically halving the boiler output demands.
When there is a demand for DHW, the cold water feed is split, with part going to the GasSaver which is mounted between the boiler and the flue. Featuring technology developed by Zenex, the Energy Saving Trust recommended' GasSaver recycles heat from boiler flue gases to pre-heat this part of the cold feed.
This pre-heated water is then directed into a copper coil heat exchanger within the thermal store. Surrounded by hot water from the primary system, the exchanger transfers heat to the water passing through it, raising its temperature even further.
This water then passes through a blending valve to be mixed with the cold feed to achieve a controlled temperature of 30C, before entering the boiler. At this temperature the boiler has significantly less work to do, making the combi more than capable of delivering plenty of hot water for the most demanding of situations, while drastically reducing fuel consumption in the boiler itself.
Over a 20 minute period, FlowSmart with a 25 litre thermal store delivers 18 litres of hot water per minute at a minimum temperature of 50C. This compares favourably with a traditional system incorporating a 200 litre unvented cylinder which, typically at 18 litres per minute, delivers hot water above 50C for only 10 minutes, dropping to 30C after 20 minutes.
At Port Talbot there were three things influencing the design the huge bath, and high consumption shower, and the demanding heating system.
Water pressure is not an issue. The farm has its own spring-fed water supply which has plenty of pressure. Indeed, after the installation, a flow cup set to 21 litres/minute was easily overflowing.
For good measure, there is a hot water return circuit on the system, ensuring hot water flow from a tap is instant. As soon as the tap is opened, water surges out at 55C.
For the bath alone, Alpha had calculated that 40 litres/minute of water at 55C would be needed to fill the bath in 20 minutes. This has been accomplished by linking the two 50 litre capacity FlowSmarts together. Indeed, Alpha has tested this. Alpha Marketing Manager, Catherine Earl, states: "Despite its enormous size, the bath filled in 20 minutes, and the water temperature measured 55C too hot to bath in. Water delivery from the shower unit is equally impressive. These two factors combined with the installation, space and energy savings that FlowSmart brings make this installation a complete success."
The considerable challenges posed by the heating and hot water demands of this project have been more than met by Alpha Heating Innovation with its FlowSmart package. The result is a neat, ultra-high output system that was extremely economical to install, and yet promises the homeowner considerable savings in running costs for the future.
Cutting Costs in a luxury home with an Efficient Heating System
