70 - 100 watt or m2.
For a modern home with good insulation we recommend 70 watts per m2.
However several factors are involved, the ceiling height, the number of windows, if the floor is cold, etc.
If you have a room that is well insulated, 70w per m2 will be enough.
If you live in a cold climate, and have cold floors, high ceilings etc - we would recommend you to have around 100 watts per m2.
You can choose which models you want, as long as you have enough watts of power in total. All our heaters are equally effective. 100 watts of consumption = 100 watts of heating.
If your room is 20 square meters and you live in an older house, we advise you to have 2000 watts total power. You can choose to have a single 2000w heater, but for larger rooms we often recommend that you choose two smaller heaters rather than a large one. If you place two 1000w heaters on each side of the room, you will get faster and better heat distribution, than if all the heat comes from a single 2000w heater.
Kwh consumption will not increase if you have powerful heaters, as the work of heating the room from 15 to 20 degrees is the same regardless of whether you have a 1000 or 2000 watt heater. The difference is that the more watts you have the faster the temperature will rise in that space. If the heater is too small and weak in relation to the size of the room, it will take a long time to reach the desired temperature and it can be difficult to maintain the desired temperature on colder days.