This winter brings good news for homeowners: after several uncertain years, gas prices have finally moderated. The cost per megawatt hour has decreased from €50–55 last winter to approximately €30 this season. While this brings relief, it raises an annual question: what is the optimal temperature setting for heating to prevent a skyrocketing bill without sacrificing comfort?
The answer is not as straightforward as one might think. Comfort levels are influenced not only by the thermostat settings but also by factors like insulation quality, usage habits, the health of household members, and the technology available. Experts emphasize that effective heating isn’t just about raising the temperature; it’s about heating more efficiently.
The Optimal Temperature Range
The rank that decides everything: Numerous technical, institutional, and scientific studies suggest that the ideal indoor temperature range during the day lies between 19 and 21ºC. The Institute for Energy Diversification and Saving (IDAE) recommends keeping it between 20-21ºC while wearing appropriate clothing. The Aragonese installers association, Aessia, concurs, advising that the thermostat should be positioned thoughtfully, away from windows, radiators, and drafts.
Energy companies also align with these findings, and studies by organizations such as the World Health Organization and Lancet Planetary Health suggest a healthy minimum of 18ºC to avoid respiratory and cardiovascular risks.
To Turn Off or Leave On?
The eternal question: Should you turn off the heating or leave it on at a minimum? Each degree above 21ºC can increase your bill by 7%, according to IDAE. It’s advised to turn off the heating when the house is unoccupied and at night.
According to the IDAE, the key to efficiency lies in adjusting heating schedules to actual usage. For sleeping, maintaining a temperature of 15–17ºC is usually sufficient. In poorly insulated homes, it might be slightly more efficient to leave it on low, but often it’s better to turn it off and then back on when needed.
Beyond the Thermostat: Insulation Matters
Research from a study published in Nature Scientific Reports highlights that optimizing schedules and temperature settings based on occupancy can result in heating savings of up to 38% and a 14% drop in overall energy costs.
It is often the case that homes, even identical ones, use energy differently based on the occupants’ habits, time spent at home, and whether they own or rent. This reinforces the idea that managing heating effectively is more crucial than simply adjusting the thermostat.
The problem isn’t the thermostat, but the house: Many believe their heating system isn’t efficient, when, in fact, poor insulation is often to blame. Old windows, uninsulated walls, thermal bridges, and inadequate shutter boxes contribute to heat loss and higher costs.
Studies indicate that well-insulated homes can cut heating costs by 20% to 30%. Thus, two homes set to 20ºC can feel distinctly different; one may be comfortable while the other necessitates a higher setting to achieve the same feeling, impacting both comfort and wallet.
The Future of Efficient Heating
The immediate future: New Spanish regulations require that new or fully renovated homes feature mechanical ventilation that allows for air renewal without losing heat. In the most energy-efficient homes, known as passive houses, many retain warmth without heating systems, demonstrating a potential 90% reduction in energy demand.
The cheapest grade is that it does not leak: After reviewing various studies and expert opinions, it’s clear: aim for a daytime temperature between 19 and 21ºC and between 15 and 17ºC at night. Crucially, the most effective strategy is to turn off the heating when no one is home. Real savings come not just from adjusting the thermostat but also from improving insulation and using heat intelligently. This winter may be kinder financially, but the core lesson remains: it’s not just about raising degrees, but about preserving the warmth we create.
Image | freepik