Case study : Kibitzenau swimming pool in Strasbourg

A savings potential of more than 50,000 € / year

Kibitzenau swimming pool

Built in 1965 and renovated from 2012 to 2014, the Kibitzenau swimming pool was the first swimming pool in the Strasbourg area to be built since the Bains Municipaux at the beginning of the century.

With its Olympic pool and its training pool, it has enabled several generations of Strasbourg residents to learn to swim. It has been equipped with the Smart Poolingincluding the comfort terminal which collected the level of satisfaction of the users.

A public swimming pool with 2 pools

The Kibitzenau swimming pool is located in the Strasbourg area (1 rue de la Kibitzenau, 67100 Strasbourg). This swimming pool has two separate halls:

  • A hall of approximately 2800 m². for the 50 m sports pool, which can be separated into two 25 m pools by a removable wall.
  • A hall of 880 m². for the 25m leisure pool and the paddling pool.

Created in 1965, it was the first swimming pool in the agglomeration. The Kibitzenau swimming pool was completely renovated in 2014 with more recent and efficient installations, both in terms of the materials used in the pools (stainless steel) and the water and air treatment systems.

3d-piscine-kibitzenau-strasbourg
3D presentation of the ponds on the Kibitzenau site (source: technical notice produced by Groupe BAUDIN CHATEAUNEUF dated 2013)

2 heating sources

This site has two sources of heating:

  • 2 PACs (Heat Pumps) of 542 kW each mainly dedicated to heating the pools, heating the air in the AHUs and supplying the radiators. These are water-to-water type heat pumps that take heat from a 40 m deep well via a cold water loop that also supplies the AHU cold batteries for dehumidifying the indoor air.
  • 1 gas boiler 630 kW for supplementary air heating in the AHUs (Air Handling Units) and for the production of domestic hot water (in addition to the solar collectors).

The site's electricity consumption in 2019 was 2024 MWhe and 1204 MWhth for gas.

consumption-energy-pool-kibitzenau-strasbourg

Breakdown of energy consumption between gas (in kWhth) and electricity (in kWhe) and details of the electricity consumption items of the Kibitzenau swimming pool determined from the sub-metering readings over the period from 08/03/2022 to 22/04/2022

Building area

0
square metres

Reopening after renovation

0

Heating energy

Heat pump + Gas

How it works

pilotage-piscine-municipale-smart-pooling

Active Smart Pooling® control
Real-time modification of key plant parameters to meet all constraints at the lowest possible energy cost.

Classic settings
Over-consumption of energy for fear of damaging comfort or the building.

The current control of the Kibitzenau swimming pool equipment is carried out by using standard controllers included in the site's GTC to reach the set points fixed by the operation. The set points to be reached are generally :

  • Water temperature ponds
  • Air temperature of the hall
  • Relative humidity of the air in the hall
  • Hygienic air change rate minimal
  • Filtration rate water

Most of the instructions are set in a constant manner or according to a predefined schedule (increase in temperature for the baby swimmer activity for example) in order to respect various constraints, which are generally the comfort of the bathers and the safety of the building (in particular, a too high humidity rate which leads to condensation with the presence of chlorine on the walls of the building can harm its durability). Nevertheless, the following points should be borne in mind the operating conditions of the site are always changingThis is the case for all of our projects, and the application of constant instructions, even if they allow for the constraints of the site, does not always correspond to an optimal operating mode in terms of energy consumption.

The main function of the service Smart Pooling is to determine in real time from measurements, operating history and short-term weather forecasts the setpoint set that will allow the site's equipment to perform its main functions while minimising energy consumption. Energy savings are then generated without any material modification of the equipment, except for the installation of the Smart Pooling box which allows the management of the set points.

Comfort station

A comfort terminal has been installed, allowing the users of the facility (swimmers) to evaluate the comfort conditions of the pool live by providing two votes:

  • A vote on the comfort in the air
  • A vote on the comfort in the water

Each category has five options: too cold, a little cold, perfect, a little hot and too hot. Two kiosks have been installed: one in each hall.

The objectives of retrieving data from this terminal are as follows:

  • To check the real impact of the solution on bathers' feelings
  • Refining the management of comfort-related setpoints
  • Involve bathers in improving the consumption of their pool.

The voting proportions observed at the end of 2020 showed a trend towards a predominance of "Too cold". An average of 1500 votes per week has been observed since the installation.

In 2021, the trend was reversed to a predominance of 'Perfect' votes, water and air combined. In particular, it seems that the proportion of "Perfect" votes correlates well with the weekly activation rate of the Smart Pooling dynamic control.

The more active Smart Pooling is, the higher the proportion of "Perfect". 

bollard-comfort-pool-kibitzenau

Concrete results

Consumption comparisons between reference period and when Smart Pooling is activated :

Night-time operation

Amount of heat
(MWhth)
GHG emissions
(Tonnes of CO2,eq)
Gain
-30 %
-33 %
Without Smart Pooling
137
18
With Smart Pooling
96
12,1

Daytime operation

Amount of heat
(MWhth)
GHG emissions
(Tonnes of CO2,eq)
Gain
-24 %
-27 %
Without Smart Pooling
118
15,5
With Smart Pooling
90
11,3

Smart Pooling has made it possible to significantly reduce energy consumption at the Kibitzenau pool.

Over a full year and with all the possibilities of the system activated, the savings generated can exceed 50 k€.

territoire-innovant-strasbourg-label-or

A public policy rewarded with the highest distinction for interconnectedness

With a stated desire to reduce consumption in its public swimming pools and the introduction of the Smart Pooling of Sunny Shark, the City and Eurometropolis of Strasbourg has been awarded the highest distinction of the Interconnectés, the network of innovative territories: the Label Or 2023.

Extrapolating the results obtained to a full year, we obtain the following results:

Total balance heating optimisation + perspectives

Observed reduction in consumption

-24% to -30%

Savings potential

50,000/year

Bathers' comfort

+ of satisfaction

You too can adopt Smart Pooling® and reduce the energy consumption of your communal pool.

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