Constantly challenging performance, the Department for Education (DfE) is expected to increase the focus on property-related efficiency, especially in terms of delivering sustainability across the estate. But understanding how a school property’s assets contribute to that overall performance, and how individual assets perform against technical criteria for sustainability has never been more challenging.
The complex technical issues that surround commercial grade domestic hot water (DHW) and heating applications within schools demands strategic, real-world understanding. Not only are there physical limitations when it comes to technologies on offer, there are considerable variances in capital expense and ongoing operational costs that without doubt contribute considerably to the annual costs of running a school.
The challenge of meeting sustainability goals
For education sites which typically exhibit a large DHW load, there remains a strong argument for employing gas-fired water heating. And, just as electricity is becoming greener, so too can the gaseous fuels when blended with hydrogen and other synthetic fuels. With publicly funded organisations increasingly being mandated to demonstrate clear and real investment in sustainable and low carbon technology schools face a complex, real-world and political challenge.
Far too often, school hot water systems suffer from poor application design where a lack of understanding of different types of hot water system leaves systems oversized to prevent perceived hot water problems. Inefficient and less environmentally friendly, such systems will prove more costly to build and operate for their entire lifespan. This can be further exacerbated by the introduction of Air Source Heat Pumps (ASHP) and Solar Thermal systems.
With ASHPs offering greater efficiencies in low-temperature systems, the high-temperature demands of domestic hot water (DHW) for school applications can be a challenge. It is recommended to calculate emissions at a working water temperature from the ASHP of 55°C, this is then hot enough to provide realistic levels of preheat for a commercial DHW system. Schools’ applications using heat pumps are going to be complex and, when compared to gas-fired alternatives, are going to have higher up-front costs. Offsetting this additional capital investment though are new efficiencies and sustainability that reduce CO2 emissions.
Now is also a good time to reconsider the integration of a solar thermal system as part of the premises. Not only a proven and extremely reliable technology, for the past 15 years solar thermal has offered a clear path to reducing CO2 emissions for schools that rely on large amounts of hot water.
Solar Thermal provides an effective way to offset the new financial burden that comes from moving from cheap gas to currently far more expensive electricity. A ten-year return on investment becomes very achievable, and, with zero emissions, the undisputed carbon and cost savings make this technology increasingly more viable.
Solar has always been used as a preheat with coldest water possible to maximise the efficiency and output: this gives maximum free heat with no carbon emissions. But there is a good case now for using solar thermal with heat pumps and electric if set up as a mid-heating system which can lower both carbon and cost.
None of the above are a single, all-encompassing answer for schools seeking to achieve Net Zero, but when used together they can provide estates managers with reliable, business critical hot water and heating systems that deliver value for capital investment, exhibit lower ownership costs over their lifetime and will help to meet current sustainability targets. They also provide a clear path for integration of new technologies, such as high temperature heat pumps and hydrogen ready appliances which will ultimately help to deliver Net Zero by 2050.
At Adveco, our dedicated application design team provide accurate, bespoke sizing, for both new build and refurbishment projects. Once correctly sized, we can recommend, supply, commission, and service the optimal appliances whether they be gas, electric or a mixed hybrid approach that incorporates solar thermal, heat pumps and heat recovery systems. This is the best way of ensuring schools hot water demands are met in the most cost-effective and sustainable manner.