Biosphère Urbaine : La douche économe en eau et en énergie/en

Introduction

Project The BIOSPHERE EXPERIENCE association is experimenting on sustainable and desirable futures in which humans live in symbiosis with other living species. In 2024, Caroline Pultz & Corentin De Chatelperron spent four months experimenting with what a low-tech lifestyle in an urban environment might look like: a lifestyle without waste, reducing water consumption ten-fold, meeting the UN's 2050 targets for greenhouse gas emissions, while remaining desirable and accessible to all. Armed with experts, volunteers, and interns, they imagined and designed a forward-looking ecosystem-apartment called Biosphère Urbaine, located in the Paris region in Boulogne-Billancourt. To complete the ecosystem, their colleague Emma Bousquet-Pasturel has set up a vast citizen support network around the apartment. At the same time, Emma has been tasked with launching a participatory science program bringing together hundreds of French and international citizens to test the low-tech systems of the apartment-laboratory in their own homes. This tutorial is for a low-tech module of the apartment-laboratory , designed as part of the experiment in Boulogne-Billancourt. To access the tutorial for the participatory science program: Sciences Participatives : La douche à brumisation The water and energy efficient shower : The experimental apartment created for the Urban Biosphere has all the features of a “standard apartment” and is equipped with everything needed for everyday living. This allowed Caroline and Corentin to design and test various devices for the kitchen, toilet, and shower. This tutorial will focus mainly on the bathroom and the topic of efficient showers. This topic takes into account both water consumption and energy consumption for water heating. The hot water tank: It has been shown that cold showers significantly improve sleep quality, release happiness hormones, and reduce muscle inflammation after exercise thanks to their temperature. Contrary to popular belief, cold showers do not weaken the immune system — quite the opposite, in fact! But since it is always nice to take a hot shower after a hard day and it also has its own benefits and uses, we have developed an economical heating and storage system. A brief history of the system presented in this tutorial : In residential housing, heating accounts for the largest energy expenditure, followed by hot water (i.e. water heaters). According to ADEME, “Domestic hot water accounts for approximately 35% of household water needs and more than 12% of energy consumption.” Finding a solution that would allow residents to continue enjoying hot showers with less impact was therefore essential. The solution found and tested in the Biosphere apartment is twofold: first, reducing the volume of water to be heated, and second, manufacturing a hot water tank that uses solar energy and has low heat loss. The hot water tank was made by Corentin, Smat, and Frédéric especially for the experiment. It has a capacity of 2 liters, is very well insulated, heated by a 150W resistor, and powered by the Biosphere's solar panels. {

Description

Taking a hot shower is a real pleasure, but it has a significant environmental impact. A mist shower allows you to enjoy the same pleasure while reducing water consumption and providing a new showering experience. Instead of water flowing freely over your body, it is gently misted. The solar-powered water heater ensures the ideal water temperature with low energy consumption and minimal heat loss. This tutorial covers the steps involved in making an energy-efficient hot water tank.

Vidéos

Material collection and purchase

Depending on the level of finish, the adaptation of the model, and the use of recycled materials, we estimate the cost of an energy-efficient water heater to be between €50 and €150. Before making your purchases, we strongly recommend that you read the entire tutorial, as the list of materials can be adapted depending on what you have at home. For tools and equipment, we encourage you to check out places such as recycling centers or tool libraries before buying anything. You may find what you need there, as well as advice from enthusiasts.

Tips and precautions

Before starting fabrication, ensure that your workspace is secure and that your tools are stored efficiently. *Use tools that are in good condition and suitable for the work to be done. *Read the tool instructions carefully and pay attention to the pictograms on the packaging. *Work in a clear, well-ventilated, and well-lit area. *Wear the necessary protective equipment: gloves, shoes, goggles, clothing, helmet, protective mask, earplugs (earmuffs/earplugs), etc. *Unplug power tools and close products when not in use. *Ask for help if you need to handle heavy loads (tools, materials, etc.). Regarding specific precautions for hot water tanks, here are the regulations in France: {

Sizing according to your needs

Sizing the hot water tank is an important step that will ensure a sufficient volume of hot water according to usage, the number of people in the household and the type of washing desired. For the purposes of this tutorial, we are assuming a requirement of 5 litres and a 2-litre hot water tank. Here's how to size it : *Etape 1 : Set the maximum amount of water for one shower {

Preparation of the heating core

The heating core of this energy-efficient water heater is the area that concentrates all the technology of this system. It is the part that must be made with the most care in order to guarantee both watertightness and overall safety. In order to make the tank that will hold the heated water, you need to use a watertight container (or one that can be made watertight) and drill holes for the water inlet and outlet. {

Preparation of the water tank structure

The structure of the balloon will serve as an insulated cell for maintaining temperature and improving heating performance. Here, a PLA tube and two custom-made wooden covers (with a groove to position the tube) will be used to insulate the balloon and serve as a base for positioning the fasteners, which must be adapted to suit the location where the balloon will be installed. Position the heating element inside this structure, right in the middle, and fill with insulating material such as wool, hemp or similar.

Electrical connections

Connecting the electrical supply couldn't be easier! Simply connect the heating element directly to the power source (+ to + and - to -). To make cleaning and maintenance easier, we recommend using quick connectors.

Plumbing and water connections

The connection to the other elements of the network and the plumbing are the same as those described in the tutorial: Participatory Science: The mist shower. All the details and possible variations are explained in this tutorial. Here, for the Biosphere's water heater, the following components were used : * A plumbing pipe with a valve; * 3 misters with adjustable jet power (position depending on your use: 1 above the head with medium jet, 1 at upper body level with medium jet, 1 with powerful jet for the hand shower); * Plastic connection pipes and red plastic taps. * The choice of connections for the heating core and other elements of the system will allow an easy connection to both the water supply and the misters. Translated with DeepL.com (free version)

Installation

Installing it as close as possible to the shower will help conserve hot water by minimising losses. It can therefore be installed on a custom-made structure or directly on the wall, as was done for the Biosphere. Here, two wooden ‘brackets’ have been positioned underneath, and the upper part is held in place by a strap attached to the wall. The structure and fastenings must be strong enough to withstand stress and not pose a risk of falling and injuring someone. Here is an image showing a complete installation created as part of an experiment (not conducted by Biosphère Urbaine). # Water tank # Overhead mist sprayer # Body-level mist sprayer # Rinse shower (with a more powerful jet) # River in which soapy water is filtered by bacteria via a biofilter to be re-used in a closed water circuit, known as bioponics.

Tests

Before enjoying hot water and this new washing experience, it is recommended that you test the system and check that it is watertight and that the heating system is working properly. These tests can be carried out as you complete each step, but a final check should be performed. Water test : To do this, once the unit is plugged in and connected to the water supply, open the water inlet valve and let the water run through all the pipes. Then check that there are no leaks or water running out. {

Use

For instructions on how to use it, particularly in combination with the mist sprayer, please refer to the detailed instructions in the tutoriel. To sum up : * Turn on the two medium-jet misters to mist the body (note that the first three seconds are cold). * Once the body is moistened, turn off the taps (or leave them on) and apply soap. * Rinse with the powerful jet shower head. {