How much pellets to heat a 100 m² house?

Combining energy savings and respect for the environment, the pellet boiler is an interesting alternative to appliances running on gas and electricity. But is the equipment profitable? And more precisely : how many pellets are needed to heat a 100 m² house ? And incidentally, how many bags of pellets do you need to get through the winter warm? Find out in this practical guide. 

What is the average consumption of pellets for a house of 100 m²?

The average annual pellet consumption does not only depend on the size of your home, but also on a number of factors such as the quality of the insulation of your home, the quality of the pellets you use, the performance of your pellet heating system, etc. It is also necessary to take into account the intensity of use of pellet stove, and the type of use (supplementary heating or main heating). Let's take a closer look.

Supplementary heating: how much pellet consumption? 

Many people use their pellet stove primarily as a backup heater to enjoy extra warmth on cold winter days, or simply because they enjoy the cozy, cocooning feel of the flames in the evening. In this case, expect an average consumption of about 1 kg of pellets per hour. 

If you use a combination of different heating systems and have, for example, oil, gas or electric central heating, your pellet stove can be used to heat your home on an occasional basis. This is particularly useful during the mid-season periods, when it is not necessary to use your main heating system due to the relatively mild temperatures. In this case, you could turn on your pellet stove for up to 15 hours a day on the coolest days of spring and fall. Estimated consumption? About 15 kg of pellets per day for a 100 m² house.

What is the consumption of pellets for main heating?

For economic reasons, but also for ecological reasons, more and more of us are using the pellet stove as our main heating method on a daily basis. Your pellet consumption will fluctuate according to the seasons, with a peak in winter estimated at nearly 2 kg of pellets per hour, for an average duration of at least 15 hours per day. This may seem like a lot, but you should take into account the warm seasons when your consumption will be zero, or at least very minimal. 

Thus, when used as the main heating source, a pellet boiler requires an average of 2 tons of pellets per year to heat a house of 100 m². This is equivalent to about 2 pallets of 72 bags of pellets of 15 kg each, representing a budget of just under 600 euros per year (based on an average price per kg of pellets slightly below 0.30 €). This amounts to an average of two and a half bags of pellets per week. Compared to electric, oil or gas heating, wood pellet heating is probably the cheapest option on the market.

What is the consumption of pellets according to the size of the house?

It's hard to give exact figures because there are so many factors involved besides the size of your home, but here's a rough idea: 

• Consumption of pellets for a 70 m² house : count about 1,5 ton of pellets per year;
• Consumption of pellets for a house of 80 m². : count from 1,6 to 2 ton(s) of pellets per year;
• Pellet consumption for a 90 m² house : around 2 tons of pellets per year;
• Consumption of pellets for a 120 m² house : around 2.5 tons of pellets per year;
• Consumption of pellets for a 140 m² house : about 3 tons of pellets per year;
• Consumption of a pellet boiler for a 200 m² house : more than 4 tons of pellets per year.

These figures assume that your home is insulated in accordance with current standards, and are likely to vary depending on several factors: time of use of the pellet stove, temperature, power of the stove, the quality of pellets, etc. 

On another note, many users ask the following question: how long does a 15 kg bag of pellets last ? If we assume that the average consumption of a pellet boiler is 1 kg per hour, a 15 kg bag of pellets will last 15 hours on average. 

How many bags of pellets for a winter?

Depending on the size of your home and other related factors, your pellet stove may require, on average, 2 to 5 tons of pellets per year, which corresponds to 130 to 350 15 kg bags of pellets for one winter. 

How to optimize its consumption of pellets? 

The pellet consumption of your pellet boiler can be optimized, even in very cold weather. The first thing to do is to properly size the heating equipment, with a power adapted to the size of your home and your needs: for a house of 100 m², a pellet stove with an output of 6 to 9 kW is usually sufficient.

Next, consider regulating the heating of your home by installing a timer. This way, you can plan the times when you want to turn on your stove and set the desired temperatures. Also consider adjusting the temperature to 17°C at night, and 19°C during the day (beyond 20°C ambient temperature, each degree leads to an overconsumption of nearly 7 % according to ADEME estimates). And don't forget to turn down the heat in unoccupied rooms. Beyond the energy savings, these adjustments will guarantee you optimal thermal comfort. 

Another tip For example, if you have a long and regular heating period, you should avoid large temperature variations and thus an overconsumption of pellets. And in case of absence, remember to reduce the temperature of your house to 14 ° C, or even turn off your pellet stove completely in case of prolonged absence. 

Does your pellet stove have an eco mode? Do not hesitate to use it to moderate your pellet consumption. Also make sure you choose good quality pellets, ideally slow burning and respecting the European standards in force. 

Also, be aware that an optimal installation of your pellet stove can make a big difference in terms of consumption. Finally, make sure that the insulation of your house is in order, otherwise you will have heat loss, and therefore increased consumption of pellets. Your stove is constantly adjusting its output to reach the desired temperature. When there is heat loss, the consumption of pellets will naturally increase.

The importance of maintenance for optimal pellet consumption

To maximize the combustion of wood pellets and, consequently, the efficiency of your stove, regular maintenance is necessary. This maintenance consists above all of emptying the ashes regularly and cleaning the appliance periodically to prevent possible obstructions of the air openings. 

The quality of the pellets, or rather their poor quality, generally leads to the clogging of these orifices, causing the consumption of the stove to skyrocket, without the efficiency being affected. The solution? Opt for softwood pellets, which tend to produce less ash with better combustion. 

What about the connected thermostat to optimize pellet consumption? 

Pellet stoves have also experienced technological advances. Recent models embark can be controlled via a dedicated app or remotely. If you have an entry-level model (or are on a tight budget), you can opt for an external smart thermostat, which is compatible with most recent models. 

The objective here is to gain in comfort of use (remote control of the stove, vacation mode, feedback on temperature and consumption ...), but also optimize the consumption of pellets. According to ADEME, the installation of an adjustable thermostat could reduce pellet consumption by 20 %. Simply install the thermostat in the living rooms and program your stove on predefined time slots. 

How many pellets to heat a house of 100 m²: what to remember

To heat at lower cost while doing something for the planet? This is the interest of the pellet stove. For a house of 100 m², it takes only 2 tons of pellets per year, which is much more economical than electric or oil heating. 

But beware, it is not enough to feed the stove with pellets for optimal thermal comfort ... The secret lies in the insulation of your home, the quality of pellets and, of course, the use you make of the boiler. And to further control your consumption (up to - 20 %) and face the winter with peace of mind, equip yourself with a connected thermostat if your model does not offer one.