Extremely high pellet consumption (200kg in 3 days) in a Kfw70 multi-family house!

You are right about Q - but you still have to insulate accordingly for the heat transfer coefficient. Do you have a controlled residential ventilation system?

In our latitudes, the annual heating demand can be assumed to be about 150kWh per m² per year. 10kWh correspond to approx. 1m³ natural gas, as well as 1L heating oil and 2kg pellets. In your case, 150/10*2=30kg per m² per year. 30*550=16500kg pellets per year Depending on the heating appliance, insulation, and heating habits, the value can vary slightly. That means if you end up with 16-17 tons of pellets per year, your heating engineer will probably not find anything unusual.

yes, that's true. Wood has a primary energy factor of 0.2 (in comparison: gas 1.1, electricity nowadays only 1.8) and thus greatly improves the primary energy demand, which you can then nicely read off in the energy certificate. It has almost nothing to do with actual consumption anymore. How much is needed for heat is more a question of the calculated heating load, which in turn has to do with heated area, number of people (hot water demand), and insulation quality or transmission heat loss.

if you have 500 kg in summer (for what??? - you have DHW anyway) and 1 ton in the transitional month, 2 tons for a cold month is well within range.

I also find that (naively) true. I don’t really understand the drama either.

In the rented house, we scale up 5,000 kWh of gas in warm months per year (only for hot water), in October with heating it is calculated to be over 45,000 kWh. If we actually come out under 30,000 kWh in annual consumption, I am more than satisfied (framework data: built 74, 180 sqm living space, conservatory (fully heated), converted attic)

On the side... The collectors on the roof bring 0, absolutely nothing in the current weather. Neither for hot water nor for heating.

So you inevitably have to rely on pellets.

By the way... The collectors on the roof bring 0, absolutely nothing in the current weather. Neither for hot water nor for heating.

So you inevitably have to rely on pellets.

By the way... The collectors on the roof bring 0, absolutely nothing in the current weather. Neither for hot water nor for heating.

So you inevitably have to rely on pellets.

that's how it is. the same principle applies to air heat pumps

do you calculate the same way at work?;)

Always in favor of the citizen! :D

I probably just multiplied the 2 tons by 10, because 3 days x 10 = 30 days / 1 month... somehow mixed something up.