Adveco – Smoothing The Learning Curve For Achieving Sustainability

Considering the Government’s commitment to attaining Net-Zero by 2050, there is a clear and present requirement on educational organisations to actively demonstrate how they are addressing the challenge to reduce emissions. The clear agenda is to adhere to a course of action that curbs global greenhouse gas emissions so that temperature rise remains ideally below 1.5 degrees Celsius within the established timeframe.

Around 40% of UK greenhouse gas emissions are accounted for by heating, cooling, ventilation, the provision of hot water and lighting the built environment. To help achieve climate-neutral building stock by 2050 educational organisations need expert support when it comes to implementing immediate and practical measures.

The impetus is to reduce construction impacts with whole life carbon assessments, and critically, reduce operational energy use, prioritising reduction in energy demand and consumption over all other measures. Addressing in-use energy consumption should raise awareness of energy efficiency, reduce bills, and save carbon by driving an increase in renewable energy supply and prioritising on-site renewable energy sources.

Schools, colleges, and universities will typically exhibit significant, but varied, hot water and heating usage pattern. As well as the need for sustainable, low emission technology, what cannot be ignored are the financial implications of these changes, whether in the form of new built facilities, or, and far more likely, the refurbishment of existing, yet ageing facilities. As a result, one of the most difficult challenges facing education facility or energy managers is obtaining a clear indication of the total cost of ownership so that operational savings and payback periods can be factored into development investments that will actively reduce emissions.

Increasing efficiency across the Educational built environment to reduce emissions

Under the tenth draft of the Government’s Standard Assessment Procedure (SAP), released in July 2018, emissions related to electricity have dropped by more than 50%, a significant change that takes emissions down to 0.233kg CO₂/kWh. Before this substantial change, electricity was considered 2.4 times dirtier than gas, today that ratio has dropped to almost one to one.

These developments are obviously having a considerable impact on the mindset towards electricity as an energy source for heating and hot water to serve the built environment. For a starter, new commercial builds with a small requirement for domestic hot water (DHW) load will benefit in a big way from installing any heat pump technology.

That said, there remains strong differences about the expected share of renewable energy supply. Independent research clearly argues for a multi-dimensional approach with an energy mix consisting of renewable energy and gaseous fuels with a high share of renewable energies. Studies which are more “almost all electric" argue in favour of nearly complete dominance of the heat pump, while the technology-open scenarios predict large proportions of heat pumps, but also assume the use of gaseous fuels which, looking forward, will contain larger shares of renewable energies, with expanded production and integration of ‘green’ hydrogen gas and other synthetic fuels. In the short to mid-term this is more realistic and may remain so as new technology is introduced through 2030 to 2050.

For new builds exhibiting a large DHW load, university accommodations and school sports facilities being a prime example, then there remains a solid argument for employing a gas fired water heater. However, the smart approach is to create a hybrid system incorporating air source heat pumps (ASHP) providing pre-heat for the DHW system with considerable carbon advantage.

This is where we need to urge some caution regarding heat pumps, because ASHPs will often be over promised in terms of their efficiency, with coefficient of performance (COP) typically cited for a unit. The COP should be seen as an optimal scenario figure, gauged at a single ambient temperature, and usually rated for warmer climate and lower flow temperatures of water, so the numbers can be blurred to look much better than the actual reality of using ASHP in the UK. Far better to look at the seasonal coefficient of performance (SCOP) which provides a more realistic figure for efficiency of the unit. As a specialist in the provision of domestic hot water (DHW), we are especially conscious of the need to present meaningful figures that represent applications in the real world.

It is important to get this right, because today, it is the reduction in CO₂ emissions and the impact this has on the investment in sustainability that is most important. When assessing the value of an ASHP in terms of reducing CO₂ emissions, Adveco employs like-for-like calculations for 1 kWh of output, benchmarked against a modern, high efficiency gas-fired system. When specifying ASHP, water temperatures of 35°C are typically cited, but this is insufficient for the commercial applications typically seen in education. Even if a building has achieved Passivhaus standards through very high levels of insulation, unusual in new commercial builds and highly unlikely in legacy education structures undergoing refurbishment, 35°C is not hot enough to safely provide DHW. For this reason, Adveco recommends calculating emissions at a water temperature of 55°C where we can demonstrate an almost 70% reduction in CO₂ emissions in warmer areas.

For the UK, Adveco adheres to the Ecodesign established European temperature zones. For most of the UK the relevant defined temperature zone is ‘average’, where the lowest annual reference temperature for the ASHP SCOP is actually taken to be -10°C. For some Southern and Western UK regions, the ‘warmer’ Ecodesign temperature zone can be applied for calculation, where the lowest the reference temperature will fall to is 2°C. Even at -10°C, a commercial grade ASHP such as Adveco’s L70 can generate working water temperatures of up to 55°C, which offsets much of the energy demand otherwise required to heat the water and so reduces CO₂ emissions by almost 63%.

With a hybrid system, running costs are kept low by only heating the remaining water at the cost of gas or direct electric heating. This type of hybrid system approach also reduces the maximum available electric load the building needs, allowing for an incredibly carbon efficient hot water system, and in warmer weather reduces a buildings dependency on gas to nearly nothing. There are also benefits to be had from reducing grid demand at peak times, and then utilising the heat pump at its most efficient.

For older education properties where a new heating system is required, but wider renovation is either not feasible or required, a hybrid system can control and avoid issues of project congestion when refurbishing, as the heat pump is used to supplement the pre-existing fossil-based heating system. This helps to save costs as existing boilers can continue to be operated on the current installed heat distribution, heat transfer and flue systems.

A hybrid heat pump/gas boiler system is able to reduce the maximum power consumption of a system by smartly balancing the heat generators for greater efficiencies and lower operational costs whilst guaranteeing high system temperatures to ensure the comfort of those still living or working in the building during refurbishment work. The hybrid system, equipped with buffer tank, domestic hot water tank the heat pump can achieve a high proportion of cover for space heating and DHW heating increasing the profitability of the system whilst being optimised for CO₂ emissions by selecting the optimal (ecological) heat generator whenever possible.
A practical, measured approach

Proudly independent, Adveco brings a unique mix of application design, technology supply that embraces modern gas-fired appliances through to an ever-broadening range of renewables, offsite prefabrication and manufacturer grade servicing. That brings a consistency to bespoke heating and hot water systems, ensuring they are optimised to control initial investment and reduce operational costs for the lifetime of the system.

This year the company celebrates its 50th anniversary, and the changes to the way the UK is approaching heating and provisioning the demand for hot water is nothing less than seismic for the industry. It is a challenge we are relishing because gaining advantage whist being ecologically sound is core to everything we do as a business. The drive to adopt sustainable and renewable technology is encouraging, but there is still no single silver bullet, that is why a practical and measured approach is so important right now.

Whilst the National Grid has already begun to outline potential future energy scenarios, right now we need to be considering the effect of lower carbon intensity electricity on renewable technologies, and the place for highly efficient gas-fired systems with an emphasis on existing, as opposed to new builds. When an existing building needs to be improved then it cannot be cost prohibitive for the owner. This is where Government support, such as the recent Public Sector Decarbonisation Fund, becomes really valuable to schools, making renewables such as solar thermal cost optimal, if the project site has the capability to support an installation, or opening a door to introducing ASHP onto the site.

As with all refurbishments, the physical limitations of a site will always drive or preclude certain options. Without doubt, gas infrastructure remains the most common for the provision of heating and DHW. A practical, open minded approach to driving cleaner heat through a mix of replacement gas and renewables is what will really progress us towards the 2028, and ultimately 2050 Net Zero targets while also delivering considerable benefits to those being educated in these buildings.

Contact Adveco to discuss your school, college or university’s heating and hot water needs…

Tel: 
01252 551540