Expert Hot Water Replacement for Commercial Renovation and Refurbishment
Adveco has the specialist knowledge and exceptional experience you need to support the replacement of water heating when renovating or upgrading commercial buildings. Whether core goals are to reduce operating costs, cut carbon emissions or both. We can support your project with site assessment, application design and product supply.
Today, the UK commercial built estate consists of close to 2 million properties. Just 14.6% were constructed after 1996, meaning the broad majority will have been constructed to lower energy efficiency standards and will require substantial modernisation in the coming years. Especially if they are to address the sustainability goals of this country. These older buildings represent approximately a quarter of the UK built environment’s operational emissions.
Given that as much as 30% of daily energy demands can be attributed to domestic hot water (DHW) systems, addressing inefficient and usually fossil fuel-based technology is a great place to kick-start decarbonisation activities through a choice of relatively low-impact and affordable options.
Retrofitting Gas Systems for Better Performance
Despite the drive for decarbonisation, like-for-like gas retrofit continues to be popular. Gas-fired systems are well understood, are excellent for achieving high water temperatures necessary for safe commercial operation, and gas prices currently remain considerably lower than electricity.
While new build properties are prevented from adding new gas connections under current building regulations, the majority of existing commercial buildings will have been specified for gas connection and may continue to use it as an energy source for space and water heating. There remain no mandates to prevent the purchase of new gas boilers and water heaters, and proposed government bans set to be enacted in the 2030s have currently been repealed.
Most commercial buildings will therefore have used gas boilers and water heaters as a tried and trusted means of meeting daily hot water demands in a very cost-effective manner.
Given that existing systems will have long operational lives, replacing them with anything new is advantageous for all involved. The current generation of condensing gas water heaters offers greater efficiency when burning gas and transferring heat to water, through improved construction of the burner and heat exchanger and smarter operation that maximises heating to hot water demand and reduces lost heat in flue gases.
What to take into account when replacing Gas Water Heaters
A good replacement proposition for retrofit will meet a broad checklist of requirements if it is to be suitable for universal retrofit…
Planning Like For Like Replacement
Where is the building situated geologically? – This sets parameters based on the water quality. Hard water areas are better served by indirect heating to reduce limescale, whereas soft water locales will be prone to corrosion, so more robust construction from stainless steel or enhanced porcelain application would be recommended.
Understand the challenges of your buildings
Does the replacement unit fit through a standard door? Does it need to navigate steps? So how heavy is it?
Would two smaller units be more easily installed, meeting the same hot water demands and possibly be lower cost when compared to a single large unit?
How much pipework needs adapting or replacing? Are there isolation valves on the current heaters? Do they hold, or are they passing? And can you make the new pipework from the existing valve, or do you have to cut back further than the valve?
Have you accounted for proximity to a drain to pipe away condensate or provide for drain-down maintenance?
Is the building’s flue still fit for purpose and correctly installed?
An appliance that offers multiple connection points offers the best means of replacing an old water heater quickly without major alterations to pipework, reducing both system downtime and pipework costs.
It is also be sensible to consider a shorter unit. Although an appliance’s capacity may be reduced, efficiency gains can more than make up for the difference.
Flueing is a critical safety consideration with gas installations. Aluminium flue, for example, has an expected lifespan of around 15 years. If the old water heater is close to or older than this, it is imperative that the flue also be replaced. An old non-condensing negative draught flue is also not suitable for new condensing appliances.
It is important to remember that changes to regulations may make the original terminal location unsuitable. Always check flue connections and kits available for the replacement water heater to ensure it can meet or improve on the existing installation.
To ensure system longevity, the value of investment and ongoing efficiency look for advanced features such as onboard energy and water use metering, remote connection such as wifi for app-based control and management, or connectivity to the building management system (BMS) for remote fault alarm and monitoring/control.
Most modern gas appliances will also support a 20% hydrogen blend without modification, providing a bridge to future green gas alternatives available from the grid.
Introducing Low-Carbon Sustainability Into Gas-Fired Systems
Today, the UK commercial built estate consists of close to 2 million properties. Just 14.6% were constructed after 1996, meaning the broad majority will have been constructed to lower energy efficiency standards and will require substantial modernisation in the coming years. Especially if they are to address the sustainability goals of this country. These older buildings represent approximately a quarter of the UK built environment’s operational emissions.
Given that as much as 30% of daily energy demands can be attributed to domestic hot water (DHW) systems, addressing inefficient and usually fossil fuel-based technology is a great place to kick-start decarbonisation activities through a choice of relatively low-impact and affordable options.
Gas to Electric Transition – For A More Sustainable Building
For true carbon reduction, we would propose employing a renewable pre-heat and then replacing gas with an electric water heater. With a variety of floor and wall-mounted electric boilers available up to 100 kW, most typical commercial applications can be serviced in a more environmentally friendly way. Operational costs will be expected to be higher while grid electricity remains more expensive than gas, but installation is far simpler and cost-effective with no flueing necessary and absolutely zero NOᵪ emissions.
Despite the best efforts of manufacturers, in terms of sustainable alternatives to gas water heating, there is still no single, cost-effective technology that meets the exacting demands for safe hot water provision. That is, providing the water at high enough system temperatures (+60°C) to ensure there is no danger of a Legionella outbreak without incurring other safety concerns, including additional risk of fire.
This is why the hybrid approach to water heating is so advantageous since it combines multiple technologies, such as electric and heat pumps and/or solar thermal, maximising efficiency to reduce energy demands, carbon emissions and running costs.
Air Source Heat Pumps
Air Source Heat Pumps
Air source heat pumps (ASHPs) have become the popular option for heating and hot water. The value in all-electric systems is that they can achieve carbon reductions of 42-47%, whilst saving 25-35% of the energy costs when compared to an equivalent-sized direct-electric only system (i.e., from the grid).
The technology works the same way as a fridge, only in reverse, drawing heat from often cold ambient air by compressing a refrigerant. This means the technology is very efficient when operating at lower temperatures, making it excellent for space heating where system temperatures can be low (35-40°C). The technology will struggle to meet the higher temperatures required for water heating, increasing the demand for electricity as efficiency drops, thus costing more to operate. The sweet spot is to push the heat from the ASHP to 50-55°C, giving the best value in terms of consistent heat generation versus cost. This is fed to the hot water system as preheat and then topped up to meet peak demands by the primary electric boiler, or an immersion, which acts as a system backup.
It is important to recognise that an electric boiler, when combined with the heat pump’s reduced operational efficiency, will still be much more expensive to run than an equivalent-sized gas-fired system.
The recommendation in this case is to keep electrical demand down by increasing the size of the hot water storage, which is then heated more slowly. A 30kW energy source can heat 750 litres/hour by 34°C, so when the system draws hot water at a faster rate than it can be heated to 44°C, such as for hot showers, you would get complaints that the water is ‘cold’. Integrating a larger volume cylinder helps to overcome this undersizing, allowing for a two-hour reheat cycle that maintains enough water at 60°C to meet daily demand, whilst slowly heating reserves through the night when demand is minimal to meet the morning peak.
This is an optimal hybrid system for small to mid-sized buildings, as it maximises the heat pump, enabling smaller, more compact, quieter and lower-cost ASHPs to be implemented.
Solar Thermal
Solar Thermal
The application of solar thermal pre-heat, or mid-heat in larger DHW systems, is a well-established means of reducing the energy demands of domestic hot water (DHW) applications, offsetting operational costs and actively cutting carbon each year by 148 kg of CO₂ per m² of collector installed on a building.
Traditionally, such a system would have employed gas-fired water heating to top up for peak and unexpected demands, especially outside of the summer months. Today, as buildings transition to all-electric water heating to address decarbonisation, the integration of solar thermal with more costly-to-operate electric DHW applications is even more advantageous.
No doubt being more sustainable comes at a cost. Combing varied technologies for effective DHW systems increases the complexity, especially in commercial buildings, leading to the need for bespoke system design, which inherently adds capital costs that can exclude those organisations with low- to mid-capacity DHW demands. However. Adveco is a specialist in combining technology in pre-sized packaged formats, simplifying specification and dramatically reducing capital costs, especially when compared to the latest generation of ‘high-temperature’ heat pumps and electric point-of-use water heaters. Our expertise in system design and controls ensures the efficiencies of all technologies are maximised for lowest possible operational costs. This is a critical consideration when dealing with physical refurbishment of existing, yet ageing facilities, in order to understand the necessary capital investment, operational savings and payback periods which are key to developing arealistic sustainability strategy.
