ThermoSeat

As Industrial Design Engineers at the Delft
University of Technology, we analysed an emerging technology for the course Technologies for Concept Design, where new technologies come to light and applied to products.

The emerging technology that is discussed here, is the combination of pressure sensors, Peltier elements/PTC heaters and a thermostat. By implementing the pressure sensor and Peltier element into furniture of an inhabitant’s home, the thermostat knows when someone is in the room for a longer period of time and can activate the Peltier element to warm or cool. Dependent on the settings that the inhabitant can set for itself.

Part list:

• Arduino Uno
• 1x 4.7K Ohms resistor
• 1x 10K ohms resistor
• 1x One channel Relay module
• 1x 150W PTC ceremic heating element
• 1x 3D printed heating plate
• 1x Chair
• 1x cushen
• 1x DS18B20 temperature sensor
• 1x Force Sensor
• Couple of wires
• 1x 2-wires splitting cable barreljack
• 1x powersource 12V adapter
• 1x screwterminal barreljack female

This instructable is part of a course of a master at TU delft, TFCD 2015-2016 assignment 2.

Step 1: Design the Objects That You Want to Be Heated

We used a design on top of a balcony in front of a window. For our case we scaled it 1:10 and printed it with a 3D printer using ABS filament. On the buttom we placed the PTC Ceremic heater, we used a 150W 12V DC type, for every object a other amount of power is needed.

Step 2: Build the Circuit - Step 1 ThermoSeat Sensors

Now we have our thermoseat design and made it (in scale this time) we need to control when to heat, when it is on temperature and notice if someone is sitting on it. For measure the temperature we used a DS18B20 temperature sensor and placed it with the force sensor inside the seat.

The DS18B20 temperature sensor needs a 4.7K resistor, for more information and how to wire it Click here.

As for the flex force sensor we used a FSR 400 type from adafruit, they have a great manual on How to use Adafruit FlexForceSensor.

Step 3: Building the Circuit - Step 2 Breadboard

For controlling the ptc ceremic heating element as it takes a lot of powerconsumption we used a Relais. VCC of the relais is from the 5V of the breadboard, GND is connected to GND on the breadboard and Channel 1 is connected to digitalpin 3 on the Arduino Uno.

The datapin of the DS18B20 temperature sensor is connected with a pull-up resistor to digitalpin 2 of the arduino. The wiring of the DS18B20 is like in the picture made by codebender_cc.

Connect the +5V pin of the force sensor to 5V on breadboartd and put between both GND a 10K ohms resistor and connect this to Analog pin A0. (see picture 3).

Connect the GND from the Arduino to the GND of the breadboard and +5V from the arduino to the Positve row of the Breadboard. Connect GND of relais to GND of barreljack en Voltage in (+) of barreljack to Vin of the relais. This barreljack is connected to a 12V adapter for powering the PTC ceremic heating element.

Connect between powersource and barreljack a barreljack splitter (2-wires) to connect the arduino also powering without a computer.

See if this scheme is the same as the one on the last picture. Then proceed to the arduino code.

Step 4: Arduino Coding

In the Arduino program can be used either a peltier element or a PTC ceremic heating element.

It can be used withing a thermostat system which many can be found on Instructables.

After uploading it to the Arduino test the circuit, it should heat the seat/object when you sit on it or press very hard on it.

Step 5: Conclusion

By giving the inhabitant the option to create its own, small heating environment, thermal comfort is much more personalized and the use of high capacity radiators and underfloor heating is history. Resulting in a much more sustainable way of living, since domestic heating is one of the largest energy consumptions.

Although this might result in more expensive furniture, the extra costs can be easily returned when the energy bills will be a lot lower. It’s up to you to decide what helps you in the long run.