With a heatwave forecast and overheating a significant issue in high-rise, high-density developments, Power On is urging developers to consider the merits of networked ground source heat pumps in not only providing low-carbon community heating and hot water but also providing effective cooling for buildings too.
Networked ground source heat pumps (NGSHPs) extract naturally stored thermal energy from the ground, which is transferred to a discreet heat pump unit within each dwelling. Remarkably, NGSHPs are also able to provide environmentally friendly and extremely low-cost cooling systems.
Neil Fitzsimons, Managing Director of Power On, explains: “With networked ground source heat pumps still being relatively new in this country, many people may not be aware that they can provide cooling too. Developers are in the perfect position to introduce this very ecologically sound and inexpensive way of providing cooling for high-rise developments.”
The positives of passive cooling
NGSHPs are able to provide heat in the winter as the ambient ground temperature is warmer than the air temperature and therefore can provide warmth when passed through a heat pump. With the ambient ground temperature in the summer being cooler than the temperature in the building, the same system can, therefore, be used for cooling by simply bypassing the heat pump in the warmer months. Known as passive cooling, all that is required is a small circulation pump and fan to distribute the cool air around the property, which can be achieved at a fraction of the cost compared to traditional air conditioning. During the summer, any waste heat from the building can be transferred back into the network for higher heat pump operating efficiency in the winter.
David Broom, New Build Partnerships Director at ground source heat pump manufacturer Kensa, says: “Passive cooling is a highly effective feature that’s entirely unique to ground source heat pumps. It provides much-needed comfort in the summer, uses very little energy, and does so without a bulky outdoor air conditioning unit. As UK summers become longer and hotter, this capability offers a sustainable way to cool homes that are increasingly at risk of overheating.”
Active cooling is also possible with NGSHPs, where the heat pump operates like a refrigerator, absorbing the heat from the building and releasing it to the ground. While this is more energy-intensive than passive cooling, it is still more efficient than traditional air conditioning.
More than meeting regulatory requirements
NGSHPs extract naturally stored thermal energy from the ground and meet the requirements of the Future Homes Standard by offering a 75-80% reduction on emissions. With cooling also an option, they can support the Part O Building regulations too, which focus on mitigating overheating in new residential buildings.
The issue of overheating in high-rise, high-density developments
High-rise and high-density developments are particularly susceptible to overheating for several reasons. These include the significant amounts of glazing often used in construction and also the internal heat gains from occupants, appliances and lighting, which all contribute to the overall temperature within the building. Windows may not be fully opening due to safety concerns, noise or air pollution, and limited shade at height and in urban areas can also be a factor.
Not only do NGSHPs provide cooling, they also do not contribute unwanted heat to the building. Unlike combustion-based heating systems (like gas boilers), NGSHPs do not burn fuel to produce heat. They are designed to transfer heat, not generate it, extracting heat from the ground and moving it to the building’s heating system.
Neil Fitzsimons concludes: “Networked ground source heat pumps are a low-carbon, low-cost innovation, ideal for high-rise and high-density developments. Their cooling capabilities are almost a by-product of the heating and hot water solution, making them a win-win option for the developer and the homeowner alike.”
