Created for Presentation on seminar course of MSc Engineering

1. An aquifer thermal storage system
in a Belgian hospital: Long-term
experimental evaluation of energy
and cost savings
D. Vanhoudt, J. Desmedt, J. Van Bael, N. Robeyn, H. Hoes
Flemish Institute for Technological Research, Belgium.
Sayed Rasul
ID: 1015102008
Journal of Energy and Buildings

2. Objective
An aquifer thermal energy storage
system(ATES) was monitored in combination
with a heat pump for heating and cooling of
ventilation air in a Belgian hospital. The Study
analyzed the technical, economical and
ecological performance of the
ATES and heat pump system. Which allow
us to conclude on the operation and the
economy and ecological effect of the
system.

3. Introduction
Hospitals and health care buildings typically have
high energy demand for heating and cooling.
Conventional HVAC installations are energy
intensive and expensive. To reduce the energy use
and the emission of greenhouse gases by these
installations, energy efficient solutions operating at
the lowest cost is needed. In this case study an
integration of thermal energy storage for space
heating and cooling of buildings by using an aquifer
thermal energy storage (ATES) system was studied
over a three years period.

4. System Description

5. Operation Mode: Cooling(summer)

6. Operation Mode: Heating (winter)

7. Operation Mode: Regeneration

8. Monitoring System
 Heat exchange by the groundwater circuit by
calculating the flow rate of the groundwater and
the inlet and outlet water temperatures.
 Heat supplied by two heat pumps by calculating
the operating time of fixed flow pumps and the
inlet and outlet water temperatures of condensers
(evaporators).
 Energy demand for heating and cooling of the
hospital is calculated by the AHU’s supply and
return temperatures and the corresponding flows.
 Electricity consumption of the two heat pumps and
the groundwater pumps.
 Ambient air temperature and relative humidity.

9. Results and Discussion
Ground Water Flow and Temperatures

10. Extraction temperature of ground water from warm
and cold well

11. Energy Balance
Heating
and
Cooling
supplied
by ATES

12. Monthly Heating and Cooling supplied in 3 years period
in relation to ambient temperature

13. Energy Flow

14. Primary energy saving and CO2 reduction

15. Economical Analysis

16. Conclusion
 Energy balance shows that 81% of the total cooling energy
was mainly provided by the direct use for groundwater,while a
22% of the heating of the ventilation was provided by direct
use of groundwater.
 The overall seasonal performance factor (SPF) for heating
was 5.9, while the cooling at an efficiency factor of 26.1.
 The primary energy saving for the acclimatization of the
ventilation air reached 71% as compared to reference
installation composed of gas-fired boilers and cooling
machines.
 CO2-emission reduction of 73% as compared to the
reference installation.
 The overall economic analysis indicated a payback time of
8.4 years without subsidies and an annual cost reduction of
k€54 a year.

17. Thank you for
your kind
attention
