Regulating building temperatures efficiently, a PhD
Ground source heat pumps are seen by many as the heating and
cooling solution for the future. The technology is not especially complex –
buildings take advantage of the temperature underground to boost efficiency and
reduce the operational costs of running their heating and cooling systems. They do so by running liquid underground, allowing the
earth’s natural temperature to heat or cool it before using the newly heated
(or cooled) liquid to alter the building’s own temperature.
These systems have been installed around the world and have
already proven their potential to help when it comes to tackling the economic, social
and environmental challenges of heating and cooling the planet’s buildings.
However ground source heat pump systems (GHSPs) don’t perform as well as they
should, and there are still further efficiencies to be gained. LSBU’s Metkel
Yebiyo is working on the solution.
Metkel’s work centres on the Keyworth Building at LSBU, and
experimental testing of the 500kW GSHP system installed within it. The aim is
to investigate the practicalities of how GSHP systems work ‘in real life’, as
well as the relationship between the ground temperature and optimising control
Measuring the performance of the installation
“This has specifically involved the investigation of the
complex heat metering and monitoring system,” explains Metkel. “To accurately
measure the performance of the installation, we connected the system to
CLIMACHECK, an external monitoring instrumentation software system, and used a
range of transducers and thermacouples to record pressures and temperatures
around the system.”
Efficiencies highlighted with simulation software
Metkel has also modelled a GHSP system with the widely used software
package called Transient Energy System Simulation (TRNSYS). It simulates the
behaviour of transient systems such as GSHPs, and Metkel’s model is capable of investigating
control algorithms that will use ground temperatures and the energy profile of
the building served by the GSHP to predict the best storage and recovery
strategies to maximize system efficiency.
Adapting routine control systems could save millions
After extensive analysis and interpretation of the data, Metkel
has been able to identify generic problems with the control systems and
approaches that are routinely adopted for GSHPs. It’s a breakthrough that could
have considerable impact, helping businesses to make their heating and cooling
even more environmentally friendly, and saving millions into the process.
Implications for the renewables industry
The findings from Metkel’s research provide useful insights
into the impact of a number of interventions, including how an updated
installation method and improved control can improve the performance of ground
source heat pump systems, providing a great opportunity to work with the
government to encourage coordinated research and action to develop and
demonstrate innovative renewable technologies.
“My research has provided new practical insights into the
operation of the ground source heat pump and a real contribution to knowledge,”
says Metkel. I’m currently in the process of publishing these findings, which I
am looking forward to sharing.”