Pete Mills, Commercial Technical Operations Manager at Bosch Commercial and Industrial, explains some of the most important considerations to make when it comes to heating and hot water in schools.
Ever-increasing pressure on the budgets of schools around the country means optimised energy performance is key to maximising the funds available for educational resources rather than the running costs of the building.
Finding the funds for repair or replacement can be a daunting challenge for schools suddenly faced with a heating system breakdown, so when it does come to deciding on an alternative system, energy efficiency and ROI should be top of the agenda to ensure any money saved can be spent elsewhere on-site.
Legacy boilers can be costly to repair and often, if restored, are unable to deliver the expected energy efficiency of today’s schools. Therefore, when a school’s heating system breaks down, the most straightforward solution is to replace any inefficient boilers with modern, efficient alternatives.
Even though many older systems operate at temperatures of 82°C flow and 71°C return, condensing boilers can be made to work efficiently for educational buildings through the use of weather compensation and effective control. Consideration can also be given to the possibility of rebalancing the system to 80°C flow and 60°C return for further savings.
With energy efficiency a top priority, schools should be turning to boilers which can automatically modulate their output down to as little as 20% in order to precisely match the demand for heat, helping to reduce fuel consumption and improve overall seasonal efficiency.
This is ideal for periods like the summer holidays where there may only be limited demand for heating and hot water. For schools planning development to include further facilities, a cascade system can also help to futureproof a school to cater for increased heating demand.
With some of the UK’s school buildings dating back to the sixth century however, it’s no wonder that some of these buildings are struggling to cope with the use demanded of them. Heritage school buildings, despite their beauty, come at a cost and present certain challenges when trying to incorporate modern energy efficient technologies. Their ageing infrastructure means installers are often welcomed with narrow plant rooms, and old pipework to contend with when trying to install new boilers. However, concerns with mixing the old with the new shouldn’t stop schools from replacing their heating system with a more efficient alternative.
Fortunately, the modern condensing boiler is also the perfect fit despite these restrictions. Bosch Commercial and Industrial’s GB162 boiler for example has compact dimensions when cascaded in systems up to 800kW, which make it especially suitable for plant rooms which are difficult to access and restricted in space. This in turn reduces installation time so there is minimal disruption to staff and pupils.
Integrating new boilers with pre-existing pipework can affect the operation and efficiency of any new heating appliances, but this can be easily avoided with the addition of a plate heat exchanger. This provides two elements of protection by separating old and new systems allowing them to work efficiently together.
Coping with fluctuating demand
With schools roughly shut for 12 weeks throughout the year, it can be difficult for school leaders to ensure they have a heating system in place that caters for fluctuating demand for hot water while a school is open and a significant drop in demand outside of term time. For example, showers for PE lessons and after-school sport, along with the wash-down of kitchen equipment, plates and cutlery after lunch, can cause dramatic peaks in the amount of hot water required. This rise and fall in demand can take its toll on older heating systems, which can struggle to cope and bring costs through the roof.
A continuous flow hot water system is suitable for coping with these peaks in demand, providing instantaneous hot water at a set temperature to ensure regulations are adhered to and only using energy when hot water is required to maximise efficiency. Providing heating and hot water via two separate systems will ensure than any peaks in demand for hot water can be easily catered for.
This continuous supply of hot water is perfect for schools with cafeterias, bathrooms and changing rooms with showers that can all demand hot water at the same time. What’s more, the instantaneous water heating technology frees the need for a storage cylinder, which saves space, reduces energy loss, and lowers the risk of legionella contamination. The condensing technology also allows for greater energy efficiency of up to 105%, resulting in significant energy savings.
The water heaters can be installed as single units or in a cascade of up to 12 units to provide a combined flow rate of up to 247l/min. This makes it ideal for schools, which can have surges in demand for domestic hot water depending on the occupancy of the building.
With energy saving a major objective for schools and pressure on budgets increasing, condensing boilers and a continuous flow hot water system could be the ultimate partnership to ensure a school can cater to demand, enhance its energy efficiency credentials and ultimately, stay open whilst improving the learning environment for students and staff.
For a more in-depth look at the considerations that need to be made when investing in a new heating system, Out of sight, out of mind? A report on the heating and hot water challenge in UK schools is available to download from: bit.ly/heatinginschools.