Limitless, continuous hot water on demand from Rinnai

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Rinnai offers unlimited hot water.

Rinnai continuous flow hot water delivery units and systems can offer unlimited amounts of hot water for hand washing and hygiene in all healthcare applications and sites

Hot water for hand washing and hygiene is a critical component in combating the Covid-19 virus, especially in healthcare sites.

For many years gas fired storage/cylinder tank water heaters where a preferred mode hot water delivery. However, new technology in the form of continuous flow gives limitless amounts of hot water.

When a stored water unit comes to the end of its working life or has failed it is often assumed that replacing ‘like for like’ is the best option. If we look back 20 or 30 years, then you could argue that a like for like replacement was the best and easiest solution, but new technologies and practises are combating the current public health challenge. The technology in hot water delivery is continuous flow hot water heating with constant flows of temperature accurate and controlled delivery.

Any healthcare site needing a new hot water heating and delivery method should start with designing and sizing of the system. Before a system is updated it is best to check existing appliances are still enough to meet current hot water requirements

Says Pete Seddon for Rinnai, the leading UK supplier of continuous flow units, ‘This is something we can offer healthcare services and essential works right now. It takes this burden away from the site.

‘Now if we look at the ‘like for like’ out with the old one and in with a new Gas Fired stored water heater - there is actually a major amount of work involved in this.  Changing old for new does not mean it is better. Most plant rooms are limited in space which would require the old equipment removed before the like for like appliances can be installed.

‘Not only that but if the appliance being replaced was non-condensing and the new appliance was condensing then the flue would most likely require changing as well as the provision to discharge condensate. Plant rooms were very rarely designed to remove equipment which could require the old equipment being dismantled before it can be removed. This requirement to remove equipment before new is installed would have a major impact - and it takes so much time. And time is in short supply now,’ adds Pete Seddon.

‘The hot water system would have to be completely shut down to allow such major works to take place and a healthcare site cannot simply allow this to happen.

Due to the size and weight of these appliances it can make life very difficult for installers. They are usually manufactured from Enamel Lined (Glass Lined) Mild Steel which can make it extremely heavy but also very fragile. It would require multiple personnel to manoeuvre these out and in, may be specialist lifting equipment and for plant rooms high up cranes would be required. All of this does not sound easy which will add a lot of time and cost to the overall installation. Not only that but if specialist lift equipment and cranes are required you are going to need suitably trained personnel as well as permits.


‘So, what can continuous flow solutions offer that can make this whole process a lot easier? Well, we will start with their size and weight. This type of technology is normally a similar size to a modern-day combi boiler but only weighing at most 30kg. That is a one-man lift. In this box packs a punch as well with two sizes available in 47kW and 58kW. This would equate to a large volume of hot water for such a physically small appliance. (774 and 954 litres per hour at a 50-degree rise)

‘The other benefit is the ability to cascade these appliances so when more hot water is required you would simply add more continuous flow water heaters. This would mean that just a single installer could create a system that would produce vast amounts of temperature accurate hot water. Whilst also creating built-in redundancy – what is meant by this is that if one unit needs to be shut down the whole site still has ready access to hot water.

Also possible is a ‘plug and play’ cascade sequencing control system that will automatically control how many appliances are running at any one time, all the installer would have to do is plug it in and select the primary water heater. Continuous flow can easily cope with any size of healthcare site. Simple as that,’ adds Mr Seddon.

‘These appliances are generally considered wall mounted but by utilising a cascade frame this removes the requirement of wall space. The cascade frame is generally lightweight, and two engineers can easily carry into a plant room. No material handling nightmare’.

‘One of the big benefits we have seen with the utilisation of the cascade frames is the fact that a lot of the installation works can be carried out while the existing equipment is still in place. This would obviously depend on floor space within the plant rooms, but we have seen first-hand that this tends not to be an issue. The cascade frames would be bolted to the floor and the water heaters mounted on to the frames. This will then allow some of the pipe work to be started as well as some of the flueing installation. All that is left to do would be to connect the pipework to the existing system finish off the flue and then the system is ready for testing, purging, flushing etc. This would even be the case if the water heaters were wall mounted.

With a continuous flow system there are also externally sited units where is just no space in a plant room. These external hot water heaters are fully weather protected with and hold IPX5D rating. They also come with frost protection down to -20°C and will keep the appliance protected so long as the mains power supply is left switched on.

During the lockdown Rinnai continue to offer full support services to essential works such as all NHS facilities, care homes, schools and supermarkets etc, and is committed to maintining this until the end of the crisis and afterwards. 

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