Rinnai Hybrid Systems – A Practical Path Of Net-Zero Energy Provision?

Rinnai Director Chris Goggin evaluates the benefits of installing hybrid heating and hot water systems. Hybrid configurations can improve energy costs whilst offering performance that does not inhibit the continuity of daily operations that commercial properties require​​.​

There are currently a multitude of low carbon technology options that the UK customer can select for commercial purposes. Mainstream media outlets often only mention singular technologies such as heat pumps, solar and natural gas boilers. One of the emerging options within the heating and hot water market is the hybrid system.

A hybrid energy system is considered to be a bridge technology in the way traditional fuels and carbon neutral technology is incorporated into one assimilated system. Rather than relying on one fuel source such as renewable electricity, hybrid options instead use two forms of power or heat generators to complete daily functions inside commercial applications.

Hybrid systems consist of a combination of traditional fuel sources like natural gas, oil or LPG and a renewable technology such as solar thermal or heat pump. Hybrid systems are designed to optimise factors such as outside temperature, current energy prices, property heating and DHW demand. Once this information is collected the system ‘brain’ can decide on selecting the appropriate fuel and technology that minimises carbon output and costs. For smart DHW hot water systems such as continuous flow water heaters used with heat pumps, the renewable heat generator provides the base load as the water heaters “top up” the temperature. This approach is inherent within the system and to ensure optimal performance.

Read more about smart Rinnai hybrids in action https://www.rinnai-uk.co.uk/about-us/case-studies/hybrid-solutions

Using two separate energies compacted into a singular system offers a range of benefits for the end-user. The first advantage is from a financial viewpoint: as electrical costs are higher than natural gas, utilising a system that accepts both renewable electricity and traditional fuel sources means that costs could be lower and more manageable when compared to exclusively electrical. From a capital expenditure perspective, the cost will be lower than a full electric system creating lower whole of life costs.

In terms of operational performance, a hybrid heating and hot water system combines the strengths of two energies and technologies that ensures energy efficiency and supports operational consistency. A hybrid system will preferably incorporate the heat pump or solar thermal technology during mild weather whilst using the other appliance during periods of cold conditions. This will optimise the strengths of each technological approach in separate weather condition circumstances.

A further benefit for the end-user is that both lifecycles of each technology is lengthened. As each technology does not have to apply full effort to satisfy demand, component and overall system longevity will be increased due to a lessening of required workload.

Hybrid systems offer a practical route for net-zero objectives to be accomplished. As not all customers can fully financially or practically commit to decarbonising practises, an alternative mix of technologies that incorporates both renewable and traditional technologies as well as fuels is offered to bridge this gap. This practical approach introduces customers to alternative and clean energies whilst maintaining control over energy costs by still relying on traditional and more cost-effective methods of energy usage.

A hybrid system comprises a number of features, components, technologies and fuels. The main elements of a hybrid heating and hot water system is listed below.

1. Heat Pump: The renewable backbone of the system. Most hybrid systems utilise air source heat pumps (ASHPs) due to their ease of installation and affordability. Ground source heat pumps (GSHPs) are also viable for specific applications, particularly in commercial settings.
2. Condensing Gas Boiler / Water Heater: A high efficiency water heater serves as the auxiliary or backup heat source. Modern condensing water heaters are designed to extract as much heat as possible from combustion gases, increasing energy efficiency.
3. Solar Panels: When solar thermal collectors are included, they can contribute heat to the system directly or to a buffer tank. This heat can then be drawn upon before the system calls for either the heat pump, gas boiler and water heaters making it more energy efficient.
4. Control Unit / Smart Thermostat: The 'brain' of the hybrid system, responsible for deciding which heat source to use based on real time conditions. Many units are integrated with weather compensation and predictive algorithms.
5. Buffer Tank / Hot Water Cylinder: Optional but recommended for systems that provide domestic hot water (DHW). The buffer tank helps to smooth out demand fluctuations and improve efficiency. Other cylinders can include buffers for minimum water content and for additional hot water demand.
6. Sensors and Meters: These measure temperature, flow rates, and energy consumption, feeding data back to the control system to enable automated switching.

Hybrid heat pump systems provide practical, economic and technical solutions and are best exemplified at a recent installation at a luxury complex at Farringdon in the City of London. At this site a hybrid water heating array of Low-GWP 50kW heat pumps plus bespoke thermal water stores, with optimised coil transfer to maximize heat pump performance, have been combined with 10 cascaded Hydrogen blends ready (I2HY20 certified) continuous flow water heaters.

The systems were delivered direct to site in one complete consignment, ready for installation. This expansive complex comprises a new, luxury hotel, prestigious & contemporary office space alongside affordable housing units.

The site was originally a Victorian-era schoolhouse for poor children. It was a ‘Ragged School’ - the term 'ragged school' was used by the London City Mission as early as 1840 to describe the establishment of schools, ‘formed exclusively for children raggedly clothed'. From around 1845 until 1881, the London ‘Ragged’ schools gave rudimentary education to about 300,000 children who were the poorest in the local and surrounding community.

The expansive retrofit site will pay respect to this heritage with many of the original features retained in the 150+ bedroom luxury hotel, almost 20,000 sq ft of opulent capital city office space and nine new-build affordable residential units. The hotel group running the site already has one other unit in London with two others planned.

In addition to the City of London site, hybrid systems have successfully been installed and continue to offer seamless operational efficiency at alternative locations. A national chain of gyms has successfully piloted a LOW-GWP commercial ASHP (Air Source Heat Pump) with the aim of replacing their existing carbon intensive electric storage water heater systems which rely on multiple electrical immersions.

The flexibility of a bespoke hybrid system design has ensured that some of the existing electric water heaters can remain in place as part of a cost saving hybrid heat pump system – saving the end user on cost and reducing carbon emissions.

Each gym studio that has been measured revealed different kW load limits ranging from 8kW to 20kW. The gym owners were advised and then decided on the necessary decarbonizing technology required for each individual gym, these included:

• LOW-GWP R290 ASHP’s
• Electric Storage water heaters
• Optimised Heat Pump Cylinder Coil cylinder or plate heat exchanger.
• Unvented kit (cold water feed).
• System controls

Consultants, contractors, specifiers and installers are advised to consider using manufacturers and suppliers of decarbonising technology with proven records of successful installations of hybrid systems that equip locations with the ability to reduce costs and emissions.

Rinnai aim to inform all UK customers and end-users of a wide variety of technological options, including and specifically, hybrid systems - that can supply all properties with hot water and heating requirements whilst decreasing carbon output and operational costs.  

Contact us today for free support on your next heat and hot water project https://www.rinnai-uk.co.uk/contact-us/help-me-choose-product  

 

.RINNAI OFFERS CLEAR PATHWAYS TO LOWER CARBON AND DECARBONISATION PLUS CUSTOMER COST REDUCTIONS FOR COMMERCIAL, DOMESTIC AND OFF-GRID HEATING & HOT WATER DELIVERY

www.rinnai-uk.co.uk/about us/H3

• Rinnai’s range of decarbonising products - H1/H2/H3 - consists of hot water heating units in gas/BioLPG/DME, hydrogen ready units, electric instantaneous hot water heaters, electric storage cylinders and buffer vessels, a comprehensive range of heat pumps, solar, hydrogen-ready or natural gas in any configuration of hybrid formats for either residential or commercial applications. Rinnai’s H1/2/3 range of products and systems offer contractors, consultants and end users a range of efficient, robust and affordable low carbon/decarbonising appliances which create practical, economic and technically feasible solutions. 
• Rinnai is a world leading manufacturer of hot water heaters and produces over two million units a year, operating on each of the five continents. The brand has gained an established reputation for producing products that offer high performance, cost efficiency and extended working lives. 
• Rinnai products are UKCA certified, A-rated water efficiency, accessed through multiple fuel options and are available for purchase 24/7, 365 days a year. Any unit can be delivered to any UK site within 24 hours.
• Rinnai offer carbon and cost comparison services that will calculate financial, and carbon savings made when investing in a Rinnai system. Rinnai also provide a system design service that will suggest an appropriate system for the property in question.
• Rinnai offer comprehensive training courses and technical support in all aspects of the water heating industry including detailed CPD’s.
• The Rinnai range covers all forms of fuels and appliances currently available - electric, gas, hydrogen, BioLPG, DME solar thermal, low GWP heat pumps and electric water heaters More information can be found on Rinnai’s website and its “Help Me Choose” webpage. 

RINNAI FULL PRODUCT AVAILABILITY 24/7 FOR NEXT DAY DELIVERY of ALL HOT WATER HEATING UNIT MODELS INCLUDING 48-58kW UNITS-

SAVINGS OF

20% REDUCTION of Opex Cost,

30% REDUCTION of initial cost

15% REDUCTION in carbon

75%    REDUCTION of space

For more information on the RINNAI product range visit www.rinnaiuk.com