The most consistent issue we see in commercial hot water systems is oversizing, whether through lack of understanding of application design or concerns over providing suitable back up to ensure system continuity. The result of oversizing is however always the same, unnecessary capital costs for system supply and installation, and ongoing excess operational costs associated with higher energy demands and therefore greater carbon emissions.
As organisations seek to adopt greener building operations, replacing old gas-fired systems with like-for-like electric is another guaranteed way to gain an oversized system. It can also lead to undersizing if storage is not large enough to account for low, slow heating associated with heat pump based electric systems. Getting that balance right is key as per kW price of electricity remains much higher than that of gas. More importantly, if the new electric system is oversized the required amperage could exceed a building’s available electrical supply. Bringing in new supply means excavating, possibly as far as the substation. This can best be avoided by understanding your actual hot water demands and designing the replacement so that it is optimised to meet the specific needs of the building, this is why accurate data is so valuable.
To support commercial and public sector organisations intending to replace legacy gas systems with more sustainable electric applications Adveco has created a Live Metering service for domestic hot water (DHW) systems. Adveco Live Metering is a simple to install, non-invasive onsite process that generates consistent 24/7 data on existing hot water systems to accurately understand actual usage, including critical peak demands. Adveco’s specialist engineers will visit the site, providing an overall visual assessment, fit the meters and monitor for an agreed period, typically a month before returning to remove them. The data will then be processed, and a report generated incorporating design recommendations for a replacement system that meets the exact needs of the building.
Data collected with Adveco’s Live Metering Service has already enabled organisations to avoid excess capital costs whilst reducing emissions in line with decarbonisation strategies. It has demonstrated, for example, that a gas-fired hot water systems operating at 60 kW can be directly replaced by a system based around a smaller 12 kW ARDENT electric boiler and a cylinder optimised to meet storage requirements reducing carbon emissions by 2800 kg per annum. The demands of a system operating two 50kW gas-fired water heaters could be replaced with a 24kW electric water heater and heat pump supplying the preheat, reducing emissions by 5100 kg per annum. With both replacement designs rated at 120% they provide more than enough storage capacity to meet unexpected peak demands and carbon emissions are expected to continue to fall as grid electricity supplies continue to decarbonise in the future.
By optimising the use of air source heat pumps, electric boiler and hot water cylinders, not only are capital investments reduced, but so too is the system size and complexity, making for easier installation and potential to recover valuable plantroom space.
Confident that accurate modelling would prove its immediate value, Adveco factored a minimal cost for engineering assessment, data collation and interpretation. With an agreement that 50% of this charge would be waived should the project proceed with the recommended system from Adveco. This have proven to be cost-effective with thousands of pounds saved on capital outlay on the system alone, offsetting any initial assessment costs. Critically, where re-cabling from the local grid has been avoided, savings of more than £250,000 were seen. Preventing such soaring project costs is helping ensure important decarbonisation projects are not stalled or cancelled outright.
