The pressure is off for energy savings
Mark Fletcher reports on how the support of one of the world's largest plastics companies helped a small Irish firm create a device that promises to cut significantly consumer heating bills
A device has been developed that promises to slash heating costs. The subject of multiple patents, it has been developed with substantial help from DuPont, the only plastics supplier approached that seemed willing to help with this novel idea.
By using a process which, according to the development company, Ecoplus, is "as old as the Pharaohs", in combination with some advanced design and engineering plastics, the Ecoplus PRT promises to save up to 25% on domestic fuel bills. With introduction of energy ratings for domestic housing on the horizon, this device could go a long way towards an 'A grade'.
It uses the phenomena of pressure reduction to remove virtually all traces of liquid-borne gases, improving flow by as much as 30%. This means that radiators not only heat up quicker, they are hotter and have a much more evenly distributed heat signature. The end result being a central heating system which requires far less fuel usage, running for a far shorter time to achieve similar, or even better, heating performance. The company admits that pressure reduction tanks are not new but then challenged us to find one that was not only this size but also sub £1,000. The Ecoplus PRT costs just euro 495 including VAT.
Ecoplus explains that the unit works in the opposite way to washing powder. Washing powder creates gas bubbles which entrains particles. If you remove the gas, through natural agitation in this case, not only do you remove the ability to carry particles but you also reduce cavitation, noise and pump pressures. Eureka questioned the company on the prospects for the brown goo you get in central heating systems. This, apparently, simply coats the inside of the pipes like a very thin coat of paint, remaining separated from the water. The result is "a solid snake of water across the entire system which produces a less than 1% difference in the temperature signature across an entire radiator".
The PRT is a fairly simple looking device and, according to Ecoplus, it does not get all that complicated inside either. But, behind this façade lies an engineering design process fraught with complications and hurdles that were ultimately resolved and overcome through interaction with a forward thinking Ashford-based moulding company in collaboration with DuPont.
The PRT's design process started two years ago with the development of a steel prototype. Unfortunately some issues became immediately apparent, weight being the most obvious – the unit weighed in at 30kg. Other issues revolved around the manufacturing steps and the quality issues derived from them. Quality was a problem even when NC controlled cutting equipment was used. The first 10 trial units exhibited measurable variables and plate deformity, even NC welding and jigs were used. Ecoplus soon realised that its best plan of action was "lose the processes to lose the variables". With 28 processes in the original design, it really had its work cut out.
It was realised, at an early stage, that the use of plastics would be one of the best possible routes, however two local companies said that it couldn't be done with the pressures involved. Not put off, Ecoplus got in touch with a number of plastics suppliers and the only company that came up trumps was DuPont. Phil Carolan, chairman of Ecoplus went as far as telling Eureka that "some plastics companies thought we were idiots". So the company opted for a tried and trusted material which had already seen action in the heating industry.
Ecoplus technical director, Carl Steinborn, said: "We had heard that Zytel HTN had been used for the manufacture of components in domestic heating systems, so we knew it must have excellent high temperature, hot water and pressure resistance. Together with Dew Analysis of Winchester, we analysed the design of the PRT, using data from DuPont, to a safety factor of three. Shrewsbury-based Rapra Technology also ran a series of stress analysis and fatigue analysis tests, where the material was tested under typical boiler cycle conditions, and is currently being tested to its ultimate limits." The new unit came in a 3.5kg – a positive lightweight compared to its steel predecessor. The PRT is also believed to be the largest moulding performed using Zytel.
Once the material was selected the design was tailored without altering the efficiency of the unit. One problem which the company then came across was a means of incorporating metal feed pipes that would not crack the plastic due to the differing thermal coefficiencies. Using a system incorporating dovetails, Ecoplus was able to overcome this problem and has since patented its solution.
Colour was another problem as pressure vessels are required to be coloured red. Even though the PRT was a pressure reduction vessel the company decided that red would be the most suitable livery. Unfortunately, it was feared that any addition of colour would upset the chemistry of the plastic. Clariant came up with a "Kit-Kat" red which fitted the bill and the subsequent testing by Rapra dictated that there was no significant impact on the molecular structure.
By examining its design process and materials usage Ecoplus was able to take the 28 steps used to manufacture the steel prototype down to three with the plastic version. The replacement of metals as core materials is an ongoing push for DuPont. In its presentation at the Ecoplus launch it enlightened us that, of all the components made from metal that could be made from plastic, only 3% have made the switch. There's an important message in here somewhere.
Since its introduction in Ireland, the comments have been favourable with the unit dictating a certain amount of useful "plumbing discipline" in new builds. One builder even went as far as saying that the PRT's cost was easily offset by the additional plumbing work that was no longer required to bleed and balance new central heating systems. The company is also developing smaller units for boats and mobile applications and it is also investigating the PRT's effect on other water-borne contaminants as well and its effect on completely different fluids – telling us that it has experimented with red diesel.
To prove its environmental credentials, the company is planting a tree for every PRT registered, this will boost the 15Ha of mixed forest already planted, the idea being that it goes towards creating a carbon neutral process.
Ecoplus
DuPont
RAPRA
Clariant
Quote: "Go with the people that tell you the truth, not the ones that tell you what they think you want to hear." Phil Carolan, Chairman, Ecoplus