How to adjust your underfloor heating for optimal comfort
Understanding how underfloor heating works
A simple decrease of 1°C in your heating can reduce your energy bill by 7%. Underfloor heating attracts many households with its ability to maintain an ideal temperature between 22 and 23 degrees. However, without proper adjustments, this system can consume more energy than necessary. To fully benefit from your installation, it is important to understand its operating principle and the mechanisms that influence its performance.
The two types of underfloor heating: electric and hydraulic
Two main systems equip modern underfloor heating, each with its technical specificities and advantages.
The hydraulic underfloor heating works with a network of pipes integrated under the floor covering, in which low-temperature water circulates (usually between 30° and 40°C). A distributor distributes the hot water between the different zones, while a pump ensures its constant circulation. This system connects to a heat source like a boiler or a heat pump.
Conversely, the electric underfloor heating uses heating cables, mats, or resistive films installed under the covering. The electrical supply to these elements generates heat, and their regulation is done via ambient thermostats supplemented by floor probes.
While the electric system has the advantage of simpler installation and minimal maintenance, its operating cost is usually higher due to the price of electricity. Hydraulic heating, despite a higher initial investment, proves to be more economical in the long term.
Another important advantage of hydraulic heating: coupled with a heat pump, it can become reversible and cool your interior in summer, a function impossible with an electric system.
Heat diffusion: principle of radiation
Underfloor heating fundamentally differs from conventional radiators by its thermal diffusion mode. While radiators mainly operate by convection (air circulation), underfloor heating acts essentially by radiation.
In this system, heat is transmitted to the environment mainly by radiation (70 to 80%), supplemented by a part of convection (20 to 30%). This method offers several considerable advantages:
- Homogeneous distribution of heat, eliminating cold zones
- Sensation of more intense heat at equal power compared to radiators
- Preservation of air quality (less dry, less dust circulating)
The principle is based on the natural upward movement of heat. The floor first warms the feet, then gradually the whole body, creating an enveloping sensation of comfort. With a surface temperature limited to 28°C in occupied areas, this system provides gentle and pleasant heat.
Contrary to some misconceptions, a properly adjusted underfloor heating does not cause a sensation of heavy legs or discomfort. The diffused heat corresponds to the natural curves of physiological comfort, ensuring optimal well-being without drying the ambient air.
To guarantee the energy efficiency of your installation, good insulation of the dwelling remains essential. The insulation under the heating elements also plays a crucial role in preventing heat loss downwards.
Adjust the temperature room by room with a thermostat
To fully enjoy the advantages of your underfloor heating, precise temperature regulation is essential. The thermostat is the central element of this control, allowing you to adapt the heat to the specific needs of each space in your home.
Ideal temperatures according to the rooms
Heating specialists recommend differentiated temperatures according to the use of the rooms, thus optimizing comfort and energy savings. Here are the values generally recommended:
- Living room: between 20°C and 23°C
- Bedroom: between 16°C and 19°C
- Children's room: 18°C at night and up to 23°C during the day
- Kitchen: between 18°C and 20°C
- Bathroom: between 22°C and 23°C
It is important to understand that there is no universal ideal temperature. Thermal comfort varies according to your personal sensitivity, the insulation quality of your home, and local climatic conditions. A notable advantage of underfloor heating: the radiant heat it provides often allows you to reduce the set temperature. Thus, 18°C with underfloor heating can offer a sensation equivalent to 19°C with a traditional system.
Optimize the use of the programmable thermostat
Underfloor heating requires a specific thermostat, different from those used for conventional radiators. For effective management, we advise you to install a thermostat in each main room.
These devices offer you several essential functionalities:
- Programming of time slots adapted to your lifestyle
- Automatic adjustment of temperatures according to your daily activities
- Reduction of consumption during your absences
However, don't forget to take into account the characteristic inertia of underfloor heating. This particularity advises against too frequent changes in heating periods on the same day. Similarly, when programming, correctly anticipate the restart time: allow 2 to 4 hours between the end of an economic period and the beginning of the desired comfort period. Concretely, to benefit from a pleasant temperature at 7 am, program the heating restart for 5 am at the latest.
Mastering temperature variations
Thermal stability is the key to economic use of your underfloor heating. Once the ideal temperature is defined for each room, limit the manipulations of the thermostat as much as possible.
To combine energy efficiency and optimal comfort:
Only slightly reduce the night temperature. With underfloor heating, the difference between night and day temperature should not exceed 1 to 2°C. A larger decrease would lead to excessive energy consumption to reheat the cooled thermal mass.
Adapt the heating to the actual occupation of the rooms. Favor a zone control system allowing you to individually regulate each space according to your needs. This approach is particularly relevant for large surfaces or multi-story houses.
Never completely turn off your underfloor heating in cold weather. To protect your building and prevent the risk of humidity, always maintain a minimum temperature of 15 to 16°C. A complete restart would consume more energy than maintaining a moderate temperature.
This personalized regulation will allow you to fully benefit from the comfort of your underfloor heating while controlling your energy consumption.
Adjust basic settings for optimal comfort
The performance of your underfloor heating largely depends on its fundamental settings. A few simple adjustments will allow you to optimize its operation while making significant energy savings.
Setting the flow temperature
The flow temperature - that of the water circulating in your circuits - is a determining parameter for the efficiency of your installation. Unlike conventional radiators that require water between 70°C and 90°C, your underfloor heating operates with significantly lower temperatures.
For a hydraulic system, a temperature between 35°C and 45°C is generally ideal. This value can be adjusted according to the insulation level of your home and the nature of your floor covering. In a perfectly insulated house, you can even lower this temperature further for better energy efficiency.
Programming adapted to your lifestyle
To combine comfort and energy savings, synchronize the programming of your heating with your daily routine. Your programmable thermostat allows you to define different time slots corresponding to your habits.
In practice, configure your system to:
- Reduce the temperature about 30 minutes before your bedtime or departure
- Increase the temperature about 30 minutes before your wake-up or return
Don't forget that underfloor heating reacts more slowly than traditional systems. It takes about 1 hour to 1 hour 30 minutes to compensate for a 1°C difference. For example, if you get up at 7 am, schedule the start of the temperature rise around 5 am.
Intelligent management of the night temperature
The question of night setback is debated among specialists. For underfloor heating, caution is required due to its high thermal inertia.
Contrary to popular belief, completely turning off your system at night is not recommended. This practice would lead to overconsumption of energy in the morning to heat the cooled floor mass.
The ideal night setback is between 1°C and 2°C maximum. A larger decrease would force your system to supply too much energy to regain the comfort temperature, thus negating the savings made during the night.
For health reasons and to protect your building, always maintain a minimum temperature of 15°C to 16°C, even during your extended absences. You will avoid any risk of condensation and mold.
These basic recommendations will allow you to obtain optimal thermal comfort while controlling your energy consumption. Your underfloor heating will become as economical as it is pleasant in daily life.
Optimize advanced settings for more efficiency
Once the basic settings are well mastered, adjusting the advanced settings of your underfloor heating can significantly improve its performance while reducing your energy consumption. These technical optimizations are particularly useful for hydraulic systems.
Understand and adjust the heating curve
The heating curve is a fundamental parameter that establishes the relationship between the outside temperature and that of the water circulating in your underfloor heating. The lower the outside temperature, the hotter the water must be to maintain a constant indoor comfort.
For optimal adjustment of this curve:
- Start with an average slope (between 0.5 and 0.7 for a well-insulated system)
- Proceed with progressive adjustments (0.1 points at a time)
- Wait at least 24 hours after each modification to evaluate its effects
Beware of common errors: a curve that is too flat will not provide enough heat during very cold weather, while a curve that is too steep will cause unnecessary and costly overheating.
The essential role of regulating valves and the flow meter
The regulating valve controls the flow of hot water in each circuit, allowing for balanced heat distribution between the different rooms. The flow meter, for its part, indicates the volume of water circulating in your installation, a valuable indicator for verifying the proper functioning of the system.
To obtain the best performance:
- Gradually adjust the valves until you reach a thermal balance between all the rooms
- Regularly check the flow meters to ensure that each loop receives a sufficient flow
- In the presence of a colder zone, slightly increase the flow of this circuit while reducing that of the warmer zones
Seasonal adaptations and management of absences
Your heating system requires different settings depending on the seasons and your periods of absence.
In winter, we recommend maintaining a flow temperature between 35°C and 40°C for optimal comfort. Adapt the heating curve according to the evolution of outside temperatures.
During the summer, if your installation is reversible, you can activate the cooling mode with a water temperature between 18°C and 20°C. For non-reversible systems, a complete shutdown is recommended, but don't forget to run the circulation pump for a few minutes each week to avoid any risk of blockage.
During your extended absences, absolutely avoid completely turning off the heating during cold periods. Instead, opt for a "frost-free" or "vacation" mode maintaining a minimum temperature between 12°C and 14°C. This precaution not only protects your installation but also considerably reduces your energy consumption without compromising the security of your home.
Frequent errors to avoid with underfloor heating
Even with a properly configured installation, certain common errors can reduce the efficiency of your underfloor heating and cause costly malfunctions. Knowing these pitfalls will help you extend the life of your system while preserving its optimal performance.
Avoid temperature rises that are too rapid
Underfloor heating is a system with high inertia that requires a gradual approach. A classic error is to brutally increase the temperature to obtain a sensation of heat more quickly. This practice not only risks damaging your installation, but also leads to excessive energy consumption.
To avoid this problem:
- During the first commissioning, respect the initialization protocol that recommends a gradual rise in 5°C increments per day over a week
- After a prolonged absence, allow at least 1 to 2 days to gradually reheat cooled rooms
- Never attempt to compensate for a heating delay by pushing your thermostat to the maximum
Stay attentive to signs of malfunction
Neglecting the first signs of malfunction can turn a minor problem into a major breakdown. Be vigilant to the following symptoms:
Persistent cold zones despite a suitable ambient temperature may indicate a circulation problem in your hydraulic system. A thermal difference greater than 4°C between two adjacent zones requires a thorough verification.
Unusual noises such as whistling, gurgling, or clicking often reveal the presence of air in the circuit, a leak, or a malfunction of the circulator.
An unexplained increase in your energy bills may indicate a leak in your underfloor heating, forcing the system to overconsume to maintain the programmed temperature.
Select a compatible floor covering
The choice of covering plays a decisive role in the efficiency of your heating. Each material has a specific thermal conductivity that directly influences the performance of your installation.
To be absolutely avoided: thick carpets with a conductivity greater than 0.15 W/mK, as they prevent the efficient diffusion of heat. Similarly, avoid solid wood that is too thick (more than 15 mm) or certain species such as maple, beech, and white balata, which are too sensitive to thermal variations.
Also, be wary of large-format tiles: dimensions greater than 60x60 cm considerably increase the risk of cracking at the joints with underfloor heating.
Our advice for adopting underfloor heating
Underfloor heating is undoubtedly one of the most effective solutions for maintaining a pleasant temperature in your interior. Its ability to diffuse homogeneous heat while optimizing your energy consumption makes it a particularly wise choice for many households.
The mastery of the settings of your installation is crucial to fully enjoy all its advantages. The fundamental parameters such as the flow temperature, the hourly programming adapted to your lifestyle, and the seasonal adjustments directly influence the efficiency and comfort provided by your system.
By avoiding common errors and applying the good practices that we have detailed in this guide, you will considerably reduce your energy consumption while guaranteeing optimal well-being in each room of your home.
Don't forget that a correctly configured underfloor heating requires little intervention on a daily basis. Once the optimal settings are defined, let your system do its work and simply enjoy a gentle and enveloping heat throughout the year.
FAQ
Q1. Q1. What is the ideal temperature for underfloor heating?
The ideal temperature for underfloor heating is generally between 21°C and 25°C. It is important not to exceed 28°C at the floor level to avoid any sensation of discomfort.Q2. Q2. How to optimize the setting of my underfloor heating?
To optimize your underfloor heating, set the flow temperature between 35°C and 45°C, use a programmable thermostat adapted to your daily routine, and adjust the heating curve according to the outside temperatures.Q3. Q3. Is it preferable to leave the underfloor heating constantly on?
It is generally more economical to maintain a constant temperature rather than to frequently turn the underfloor heating off and on. However, it is recommended to slightly lower the temperature during the night or periods of absence.Q4. Q4. What errors should be avoided with underfloor heating?
Common errors to avoid include: abruptly increasing the temperature, ignoring signs of malfunction such as persistent cold zones, and choosing an unsuitable floor covering that could reduce the efficiency of the system.Q5. Q5. How to adjust my underfloor heating according to the seasons?
In winter, maintain a flow temperature between 35°C and 40°C. In summer, if your system is reversible, switch to cooling mode with a water temperature between 18°C and 20°C. For extended absences, use a "frost-free" mode maintaining a minimum temperature of 12°C to 14°C.