To measure how quickly my bathroom heats up, I built a small sensor setup using an Arduino Uno and a temperature & humidity sensor, later adding an ESP8266 for wireless data transmission.
I logged real-time data to thingspeak.com and visualized temperature and humidity separately in two graphs, each spanning periods of 4 and 48 hours.
After about two weeks of data collection, I found that, on average, the bathroom warmed by roughly 1°C every two hours. Placing towels over the heater slowed heating time by approximately 30%.
Without any heating, the bathroom naturally stayed around 19°C, meaning it took about six hours to reach a comfortable 22°C.

Although humidity wasn't the main focus of this study, the data could offer valuable insights for future work, especially given humidity's role in how we perceive temperature.

Heaters and thermostats are already ingeniously designed, so why bother improving them? Here's what users shared about the problems they face.

• heaters are often running unnecessarily long
• existing solutions can turn the heater on or off at a certain time but don't assist in reaching a desired temperature at a precise time
• without additional technology, there is no overview of temperatures/heaters in rooms
• there is no indication of how much time is needed to heat a room up to a certain temperature
• there is no indication of how the temperature behaves over time (gain/loss ratio)
• heaters don't adapt to personal schedules/routines

First patented in 1895 by Warren Johnson as a "Heat Regulating Apparatus", the mechanical thermostat addressed a problem that still persists today. Thanks to its clever design, the fundamental functionality hasn't needed major changes in over a century. While the original mechanism stands as a timeless example of excellent engineering, today's adaptations haven't fully realized their potential yet.

When gathering user feedback about the current state of heaters, most complaints revolved around the lack of modern, data-driven technologies. People shared that heaters often run unnecessarily long. Why? Usually because there's no easy way to know exactly how long it takes to reach a desired temperature (for example, warming your bathroom in the morning), causing users to leave the heater running longer than needed. Sometimes it's as simple as human forgetfulness – "Did I turn off the heater?"

Another common frustration was the lack of visibility into heater status. Just knowing which heaters are currently on would boost awareness and significantly reduce unnecessary energy consumption. This would not only benefit the environment but also save money. Having the flexibility to independently control each room remotely further amplifies these benefits.

In short, users want to spend less time thinking about their heaters while still getting maximum comfort and efficiency.

To better understand what users actually need from a solution that offers more control over their heaters, I created user stories.

As a user...

• I want to check the temperature of a room even when I'm not in the room.
• I want to know how fast a room heats up.
• I want the room to be the desired temperature when I enter it.
• I want to save money and the environment.
• I want to set flexible heating schedules/routines.
• I want to control the temperature of every room.
• I want to avoid unnecessary heating.
• I want to see how the temperature has been changing over time.

Based on user feedback, user stories, and my own ideas, I then created a set of potential features.

Brainstorming potential features and arranging them based on their fit within the overall information architecture quickly provides a detailed vision of the final product. While I typically start with rough wireframes, I prefer this approach early on because it lets me add, remove, and rearrange features rapidly – essential at this stage, where ideas flow quickly and capturing them promptly matters most.

Ideate, Prototype, Test – Rinse & Repeat