Rinnai has just completed the installation of two HDC1500i continuous flow hot water heating units at a busy laundrette serving businesses and the public in Stafford. Rinnai were chosen on the recommendation of another laundrette owner, in Lancashire, who praised the efficiency and major cost savings because of switching to cascaded continuous flow hot water units as they guarantee almost unlimited supplies of hot water at peak demand whilst savings on fuel costs.

Word of mouth is the best possible marketing and a site survey was duly arranged and completed to confirm the best solution in controlling operational costs and efficiencies. The existing system was a heated stored water system – this meant that the site was paying to heat water it was not instantly using.

It was clear from the site survey that Rinnai units configured to maximise both space and energy efficiency – and critically – the system’s reliability – would yield seriously large cost savings to the owner.

Given that the Rinnai units were being wall mounted and externally flued, this gave extra storage space to the premises as there was no need for a dedicated plant room.

Comments Ray Gallimore, proprietor of the Weston Road Launderette, “The old storage system had become completely impractical, inefficient and needlessly expensive to run.

“For example, the washers tend to be used sporadically. During a busy weekend there could be a demand for eight to ten people battling to use the machines at once, during the week there might be one or two.  That meant we had to store a decent volume of hot water ‘just in case’ in the form of a storage water heater.  Needless to say, keeping the stored volume at optimum temperature 24/7 was often wasted energy, a really bad, expensive idea all round.”

Clearly the site needed to change the system to one that could cater for these fluctuations without running up huge energy bills and the solution wasn’t hard to find.

“I was made aware of Infinity water heaters installed in similar applications to mine and in general their experiences with their products and their personnel, such as the local Rinnai sales consultant, were consistently positive and professional.”

“The beauty of working with Rinnai is the service they offer. We presented the project to Rinnai’s Technical Sales team who came up with the design, configured the sizes of unit required and delivered the system complete and to a very tight timescale – this was key as the existing water heater had developed a leak and I was extremely mindful that the business had to remain operational to satisfy local demand.  We are very happy with Rinnai and will be spreading the word,” adds Ray Gallimore.

Now two HDC1500i internal mounted water heaters with secondary circulation provide hot water for 12 commercial machines, plus a sink and a wash hand basin.

“The Rinnai system has resulted in an energy reduction and gas saving due to higher efficiencies and because we are no longer maintaining large amounts of stored hot water. It’s not rocket science to work that out!”

“In terms of gas usage running costs compared to the old wasteful storage system, our bills have virtually been halved since the Rinnai system went live five months ago which is absolutely tremendous,” says Gallimore.

Rinnai’s heavy-duty condensing range uses two heat exchangers to capture residual heat from flue gases to pre-heat incoming water, with the HDC1500i turning in 105% net efficiencies*. These figures add up to considerable on-going energy savings when compared with traditional gas fired stored water systems.

With a Rinnai condensing unit, temperature is regulated to within +/-1ºC via ‘smart’ internal controls without any variation of temperature at the outlet even when water is drawn off elsewhere. All models have full electronic ignition, no pilot light and operate on demand only, so there is no gas consumption when the unit is idle.

The units are easily configured in a manifold arrangement, ensuring there will never be a shortfall of instant hot water whatever the demand.

Rinnai, the UK’s leading manufacturer of the ErP A-rated Infinity range of continuous flow condensing gas-fired water heaters, supplies the best energy efficient range of low-NoX water heating units currently on the market.

Advanced condensing heat exchangers combined with innovative burner technology ensures that every cubic metre of gas is used to the maximum on HDC 1500i.

Legionella proliferation is answered by Rinnai: the company has developed additional ‘SMART’ controls for secondary return DHW systems in the form of an advanced temperature control system which allows for safe running of water at 42°C core temperature during the day and 60°C at a time when the building is closed. By the time the building reopens, core temperature is 42°C for safe use.

Another Rinnai innovation addresses an age-old industry problem with hot water delivery – lime scale build-up. The company’s integrated scale control system is an innovative solution and comes in the form of an LC (lime check) code on the display of the controller.

Almost all water-fed appliances, including plate heat exchangers, boilers and water heaters will accumulate scale deposits when used within hard water areas over time. Lime scale consists of calcium carbonate (calcite) with lesser amounts of other calcium salts such as the sulphate. Sometimes lime scale deposits contain corrosion debris and this scale build-up can affect the water heaters by reducing their efficiency and overall performance.  Ultimately, ongoing use with hard water may shorten the lifespan of conventional water heating appliances and systems. To safeguard against this Rinnai units continually self-monitor for lime scale deposits around the heat exchanger. If a lime scale build up has being identified, a message is sent to the built-in interface panel on the front of the appliance.  The message is displayed as ‘LC’, which alerts the end user that it is time to call a Rinnai service agent to perform a lime scale flush to clear the potentially harmful deposits.  This avoids and eliminates the adverse effects associated with lime scale build up, including lower energy efficiencies and rapid product de-generation.

Rinnai’s HDC range offers condensing technology with up to 107% gross efficiency, ultra-low-Nox of less than 20 ppm, a widely expansive modulation range of 54kW-4kW and high flow rates of 37/ltr/min. Add to these benefits are the peace of mind of an extended warranty, a top A-rating exceeding the demands of  eco-labelling legislation, the flexibility of external wall mounting and delivery to site with all relevant accessories and the knowledge that the HDC range is future-proofed against future regulatory and legislative changes.