What would you say if I told you the heat that your students/ patrons (if duel use) release in the gym could actually be converted and used to heat the school’s water for free? Yes, it’s true!
*Queue a stampede of headteachers ready to sign up*
Energy use in commercial and domestic buildings is already, if you’ll pardon the pun, a hot topic in the UK. Schools are no different. As both national and local government press forward with environmental legislation and fossil fuel prices escalate, the construction sector is looking for techniques and technologies which can help them meet new rules on cutting CO2, reducing whole-life energy use and employing renewable energy sources.
Enter the humble heat pump. This technology is already well known in the air conditioning market, and has proved very efficient when used for cooling. However, heat pumps can also be used for domestic heating and hot water, and are highly efficient in doing so!
Most heat pumps work on the same principle as a domestic refrigerator, using a vapour compression cycle. The main components in the heat pump are the compressor, the expansion valve and a heat exchanger.
So, heat pumps can transfer heat from natural sources (such as air in the gym) to warm a building. In cooling mode, a heat pump will take heat extracted from a building and move it elsewhere (known as the ‘heat sink’). This can be put back into the surroundings, transferred to another part of the building, or used in conjunction with a boiler to provide domestic hot water to a temperature of around 45C.
Having a heat pump combined with a R2 heat recovery system on a commercial building can provide hot water virtually free of cost as it’s using the waste heat from the heat pumps.
In summer conditions, the air conditioning is switched on and extracted heat is added to the heat pump boiler which supplies the building’s domestic water requirements at 45ºC. A boost heater is then used to heat the water for disease control of Legionella. In cooler months, when the system is in heating mode, excess heat from the system can be diverted to increase the domestic water temperature. Hey presto: hot water is provided free all year round.