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Are modern HIU systems costly?

The short answer is no. Modern electronic HIUs are no more expensive than good quality mechanical HIUs. That said, you will always be able to find something cheaper. It is indeed one of the reasons we see independent testing as so important. Without it a manufacturer can always sacrifice efficient operation for cost and deliver something cheap that delivers target hot water and heat outputs. These are the tactics used to value engineer, or break specifications by offering a saving. The problem is if you take into account the effect on running costs, something manufacturers and installers care little for usually, then the savings evaporate, and one is left with a legacy of a heat network that potentially costs double to run than it should.

What about the cost of the hardware for monitoring?

Again, the modern world has come up with a solution – open source Linux systems. Many will have heard of the Raspberry Pi. A £25 computer used in education with built in WiFi, Ethernet, Bluetooth (old and new), USB Ports, and HDMI desktop output. Well it can also be used to send data or alarms from heat meters and modern HIUs. They can also provide Mbus and Modbus connectivity, and as such offer a low cost means to bridge HIUs to other systems, monitor and control them.

With many billing platforms making use of the same software languages, the software functions developed on a Linux system, such as a Raspberry Pi or Arduino Yun, can be implemented on them also. This means that no additional hardware needs to be used at all to connet to HIUs.

Is there not a risk of being locked into a bespoke system?

Certainly not. We have based our communications technology on standard protocols that can be replicated on other systems, and the benefits of an intelligent HIU come as standard – you just need to make use of them.

We also assist in the connection of HIUs to 3rd party systems. As an example, to assist in the delivery of Ofgem’s MMSP – Monitoring and Metering Service Package – we worked with the Energy Saving Trust to develop and publish Python code to send data from heat meters and HIUs to the Trust’s EMBED database, and thereby enable contract-free monitoring of RHI installations using low cost electronics.

Will your system help to offset carbon costs?

With the new requirements for zero carbon domestic hot water in London, one needs to also consider the costs of offsetting carbon. Given there is potential in many instances to save 50% of the energy required to deliver DHW over a heat network, by using the right controls strategy, that’s one huge step towards achieving zero carbon. It makes the percentage of any zero-carbon generated on site twice as effective, with less carbon to offset.

It will also impact on CHP sizing. As CHP is sized to deliver the baseline load, so they run continuously all year, we are talking about the DHW loads as well as the heat lost from keeping the network hot at all times for DHW response. With 50% or more of this load gone, the CHP sizing should drop accordingly.

With average annual return temperatures from a heat network below 25°C now possible, the percentage of waste heat that can be used on a network increases significantly, as does the effectiveness of technologies such as heat pumps. Return temperatures this low enable a proper bivalent system to be used, with heat pumps raising temperatures from 25C to 50C, and gas boilers or CHP raising it further, typically to over 60C in the Summer and to 75C in the Winter. There goes another chunk of carbon and the costs associated with it.

Is Legionella a problem with low temperature HIUs?

All our electronic HIUs offer the option of Legionella protection as standard. This includes the DATA, DIGI, and SLIM HIUs. The anti- Legionella function on the DATA HIU was recognised by the industry last year when the system made it through as a finalist for the Combating Legionella Awards. The system is now fully WRAS approved and as well as been officially the most efficient HIU in the industry (as independently tested) it also offers the most advanced protection there is against Legionella.

Our wiki site

We have an extensive wiki site, is designed to be a general resource for technical and detailed information relating to our products and services.

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