The DATA Mitigating Risk

A new unit on the market. Is it reliable?

The components and methods used in the construction are identical to its sister unit the DIGI. The only substantial difference is the use of a second plate heat exchanger on central heating rather than direct connection. Otherwise, the electronics, the core software, the sensors, the control valves, and manufacturing methods are identical.

The following contracts have used the system to date.

• Duwo student residences: Duwo Project
  • Uilenstede phase 1 (165 residences)
  • Uilenstede phase 2 (233 residences)
• Talent Square Tilburg (505 residences): Talent Square Project
• Elsevier Amsterdam (227 residences): Elsevier Amsterdam Project
• Balgair Castle Holiday Park, (26 residences): {{#l:Case Study Balgair Castle.pdf|The CAMPER External HIU, Case Study}}
  
• Eston Community village, (49 residences): Eston Community Village Project
• Dunbeg development, (75 residences): Dunbeg Project
• Denmilne Gardens, (25 residences): Denmilne Gardens Project
• Testing and Consultancy Stockwell park: Stockwell Park Project

The HIUs are showing themselves to be as reliable as their mechanical counterparts. The extra layer of information provided by connecting a PC or field computer to an HIU to analyse performance of the heat network has made the setting up of networks as a whole more reliable than previously possible, as we can now provide commissioning certification that network temperatures and pressures are on target.

The DATA has been on test with Nottingham City Council for over a year, with one installed in their HIU test facilities. It has performed perfectly as has been connected to remote monitoring to monitor network temperatures.

The very first UK installations of the DATA went into two properties in Essex. These have worked without a hitch since day one.

We provide on site backup and guarantee equipment for two years.

The manufacture of the range is through HSF of Holland, part of the Aalberts Group who also own Pegler Yorkshire, Flamco and Miebes, to mention just a few. HSF is the most advanced HIU manufacturer in the group, and holds some 80% of the Dutch market.

In summary, there are no new hardware technologies used in the DATA that introduce any additional reliability risks. All equipment has been proven in volume in Europe over the past three years.

The DATA does not yet hold a full WRAS approval

All components and materials in the DATA in contact with potable water are WRAS approved.

A WRAS full application is in progress and should hopefully be in hand in September.

We are also in discussion with water authorities, such as Thames Water, that we know to sometimes request full WRAS approvals rather than component certificates. This is to ensure they have in hand the full F2 applications details for WRAS including all component WRAS certification with a view to signing off in the short term based on components.

With hot water set-points and keep warm temperatures now within Legionella danger zones, rather than constant 60C keep-warm temperature, or no keep-warm as has been the traditional with combination-boilers (the most similar technology from WRAS perspective), WRAS have, as part of their obligation to ensure systems have no inherent risks pertaining to Legionella growth, told us they would be looking to introduce a new test sheet as part of the WRAS certification to cover this off.

Therefore, if WRAS take the view that Legionella must be addressed in some fashion, when a keep-warm mode is set below 55-60C, then only HIUs carrying an updated WRAS certification with the updated Legionella test sheet, or can demonstrate a Legionella protection system, would be signed of by water authorities.

In summary, we feel that our HIUs, having a Legionella protection cycle, as well as been possibly the first HIU to go for WRAS approval for use of a sub 55C keep-warm setting, offer less risk than any system on the market.

Tying the Client into closed billing or HIU communication systems

The billing industry is fairly split into two camps.

The first offer closed systems aimed to tie the client in and provide a barrier to competition. This camp is driven by the commercial sector.

The second is working towards open intercommunication of systems, from an HIU level through to cloud services, including billing, and telephone support. This camp is driven by customers, but also by the new generation technically adept service providers who are comfortable with open technologies as a business model.

We feel that HIUs, like billing, form part of a larger system. We are aiming for a market where the customer can bolt together their choice of HIU, their choice of billing provider, there choice of maintenance company, and if they feel like they want to take it in-house, they can, without having to replace the HIUs, or rewire the building. They should be able to start with a basic system, and build from there as needed, rather than be tied in to a system on day one that they then have to live with for years to come regardless of service levels.

The approach starts with using a Cat5 cable instead of a 2-core cable when connecting up M-Bus, taking the cable from each property to the riser (as opposed to a loop). The cost of the change is pretty insignificant, but in enables any type of infrastructure to follow, from a standard M-Bus ring to a full blow Ethernet system. With 4 twisted pairs, Cat5 (where Ethernet is not fed to flats) can drive M-Bus, RS485, pre-pay and another. It also enables systems to be used that require no access to properties for maintenance.

We have found that the simplest approach is a basic M-Bus with data sent off-site to a cloud based system that provides billing functionality. However, the best system would have to be a ring-Ethernet based system that enables a riser based system to drive services, or to feed the Ethernet into a billing providers hardware - typically a home display.

The full range of features that can be accessed through this approach, from billing to remote diagnosis of HIUs, is currently transitioning from field trials to production systems, and should be online come November in the form of a riser based Ring Ethernet Switch from Coheat that also drives additional services. With this in place, the client is always safe in the knowledge they have a systems build on standard protocols other can work with, and that can be replaced (if they die) with another make of standard equipment.

Risk of no operational movement on network temperatures

A heat network is designed to meet an estimated load, with a safety margin. Its bound to be a bit oversized, and can almost certainly be run at lower temperatures than the original design once online. There is also savings to be made by weather compensating a network.

With mechanical HIUs you setup the HIUs to the original peak design, and setup the network accordingly. If you later want to drop network temperatures what happens ? HIUs then struggle to meet the fixed temperatures they are setup to achieve, call for more heat, and the network becomes less efficient.

The DATA HIU simply tracks available temperatures and manages itself to ensure efficient operation of the network.

Therefore the DATA mitigates the risk of been left with a system where there is simply no option to drop network temperatures in the future.

Risk of installers not balancing radiators properly

Unbalanced radiators result, in the case of most HIUs, in higher return temperatures than designed for. This impacts on network efficiency and capacity. The only way to mitigate the risk, given end users can also play with balancing, is for HIUs to have built in return temperature limitation.

The DATA does, so the risk, of unbalanced radiators affected predicted efficiency, goes away.