ᐅ House electricity consumption – what is your usage?

Our "background load" is about 180W when the mechanical ventilation with heat recovery (MVHR) is running. Our Hoval FR301 uses 180W at 100% capacity, which is rarely needed.

The annual electricity consumption is nearly 4100 kWh, of which 1500 kWh is self-produced and directly consumed from our photovoltaic system. We feed 9600 kWh into the grid from a 9.74 kWp system. The air-to-water heat pump has used 2200 kWh for heating and hot water. This is a KfW40 house with 143 m² (1540 ft²) of living space plus a basement.

In my opinion, a new build without mechanical ventilation with heat recovery is no longer up to date. Just as a wood stove has no place in a well-insulated new build anymore. And a photovoltaic system pays for itself—it's the only part of the house that ever recoups its cost.

Bookstar schrieb:

In summer, mechanical ventilation with heat recovery proves useless—I have already experienced this. But we only have 3-4 months of summer in Germany. The rest of the year, I really appreciate this simple machine.

You still have to ventilate in summer, and mechanical ventilation with heat recovery works differently then. It can cool the hot outside air with the cooler inside air when bringing it into the house. Of course, you can also ventilate only at night and keep everything closed during the day.

world-e schrieb:

In my opinion, a new build without a mechanical ventilation system with heat recovery is no longer up to date. Just as a wood stove has no place in a well-insulated new build, in my view. And a photovoltaic system pays for itself—it’s the only thing in the house that ever pays off.

From my perspective, that’s a rather bold statement. Being up to date would rather mean ventilating manually instead of installing a mechanical ventilation system, which automates the process but also consumes electricity and impacts the environment.

As you can see, opinions on mechanical ventilation systems are very subjective.

Ybias78 schrieb:

From my point of view, that is a very bold claim. Nowadays, it would be more common to ventilate manually rather than installing a controlled ventilation system, which does it automatically but also consumes electricity and impacts the environment.

However, a controlled ventilation system with heat recovery also saves heating costs. Otherwise, you end up ventilating the heat right out the window. But what is truly modern? A single-family house is never really ecological. Modern, rather, means comfort and having devices take over the work so you always have fresh air without any effort.

Ybias78 schrieb:

So, more comfortable than modern. You have to keep in mind that in most parts of Germany, winter is no longer what it was 10 years ago. It’s getting warmer, and as a result, controlled residential ventilation becomes less efficient.

Actually, it doesn’t. At least not as long as the heating period doesn’t shift. Every kilowatt-hour (kWh) of heat that is not lost through ventilation doesn’t have to be produced again and brought into the house. Generally, the energy consumption of controlled residential ventilation and the energy savings it achieves balance each other out.
It’s true that it’s not absolutely necessary; it’s more of a luxury. But once you start on this topic, there’s no end. Examples: a single-family house in general, car, chainsaw, etc.

1,500 kWh with 2 people, 2 cats, a few spiders, and few mosquitoes

Joedreck schrieb:


It is true, of course, that it is not strictly necessary but more of a luxury.

Amen