Intelligent thermostats: Tenants’ experiences

Smart thermostats promise energy savings without any loss of comfort. Tenants and landlords – part of a Germany-wide pilot project by the companies in the noventic group – report on their initial experiences with digital technology.

Three years ago, Amy (68) and Frank Wattendorff (74) moved out of their condominium, which had become too big, and into a listed co-operative rental flat in Hanover. The couple have made themselves at home behind the historic brick façades. Smart thermostats installed by the Hamburg-based noventic group as part of a nationwide pilot phase for the 2022–2023 heating period ensure the right cosy temperature.

The aim was to verify the savings results from a preliminary project phase and to find out more about user acceptance. Because when it comes to the energy transition, one thing is clear: it won’t work without the housing industry. But it is also not possible without the tenants. They must be provided with suitable instruments for individual responsibility, with which they can check their own energy consumption and, if necessary, take countermeasures and make changes – so that the savings effects of further cost-intensive energy modernisation measures can also be realised. To this end, the housing stock of 14 housing companies in Germany was equipped with smart thermostats and the digital technology was operated, networked and controlled using codes from beyonnex.

Energy saving in apartment blocks

The smart thermostats from the strategic noventic holding tado° have already been successfully used in private single-family homes for ten years. More than two million smart thermostats have been installed in over 400,000 households to date. Their task: to save heating energy and CO₂ through intelligent control in order to ensure greater energy efficiency and therefore cost-effectiveness without any loss of comfort. Comprehensive consumption transparency, which is displayed in an app, and intelligent control solutions for radiators based on this help to achieve this. The effectiveness speaks for itself: an average of 15 per cent energy was saved in private households. Thanks to assistance functions such as temperature-accurate radiator control without overshooting, room-specific time programmes or window-open detection.

These positive effects – supplemented by the experience gained during the pilot phase – are now becoming a permanent fixture in the housing industry. After all, more than half of the residential buildings in Germany are apartment blocks. The urgent climate protection targets can only realistically be achieved if all energy-saving potential is utilised in apartment buildings. However, in order to successfully tap into this building segment, the solution must fulfil the high demands of the housing industry. Above all, it must fulfil the very different user requirements of German tenants. This applies to the issue of data protection as well as the willingness to accept and use digital solutions in their own four walls as support in everyday life.

Einfach per App regeln

Intuitive and easy-to-use tools are a must. With the intelligent thermostats, which sensitise tenants to their own energy consumption, this is done via a clearly designed app. The app visualises individual energy consumption in an easy-to-understand way. The room temperature is also controlled via this: “Setting the individual radiators is really straightforward,” says Frank Wattendorff. The couple control the living room, the two study rooms and the bedroom individually. At 11 p.m., however, all radiators are automatically lowered. The bathroom is even only heated from eight to ten o'clock and from nine to eleven o'clock. “We planned this to suit our daily routine,” says Frank Wattendorff, who expects this to “noticeably reduce our heating costs”. The couple also like to use the app when travelling. The heating remains turned down while they are away. “When we return, we turn it up again and it's nice and warm when we arrive,” reports Amy Wattendorff: “That’s a huge advantage, because it saves us a lot of energy and heating costs.” In addition to the costs, the lower carbon footprint also plays a role for the retired social education worker: “We are ecologically minded people, so it is important to us to reduce our emissions.”

Special solutions for manual operation

However, less digitally savvy people can also benefit from the advantages of smart thermostats, as they also work without an app and without storing personal data. Although this means that not all the functions of the fully digital version controlled via the tenant app are available, residents also benefit from ‘efficiency routines’ that work locally without cloud or app support. Smart thermostats help to save energy sensibly, for example by automatically closing the valves during ventilation or taking room time schedules into account. Tenants can still regulate the temperature manually on the thermostat, but now with precise temperature control.

Save energy through intelligent convenience

Steffen Karg confirms the Wattendorffs’ positive experience with the intelligent thermostats. As a board member of the Letter eG housing cooperative, he manages 265 flats in 36 buildings in Seelze, Lower Saxony, including a lighthouse project. He also reports positive feedback from tenants. “In my opinion, the biggest advantage of smart thermostats for tenants is that they can do something themselves,” says Karg. The tenant doesn’t have to wait “for the landlord to do something. They are not helpless when it comes to saving on heating costs.” Another plus point for Karg: “Our tenants can save energy without having to sacrifice the comfort they are used to.”