ᐅ House electricity consumption – what is your usage?

Ybias78 schrieb:

It is getting warmer, and because of that, the mechanical ventilation with heat recovery is becoming less efficient.

No, that is not the case. What exactly would change about the efficiency? As soon as it gets cooler outside—which I mean below 20°C (68°F), and that is most of the time during the winter months and partly in autumn and spring as well—the mechanical ventilation with heat recovery operates with the same values. It recovers about 90–95% of the energy. The heat exchanger does not change; it does not get bigger or smaller regardless of how warm or cold it is outside. In fact, the temperatures in Germany are ideal for heat recovery in a mechanical ventilation system with heat recovery.

The fact is:

Mechanical ventilation with heat recovery ensures a constant supply of fresh air throughout the entire house. This is simply not achievable with manual ventilation, unless you have dedicated staff looking after it.

People are not constantly at home, they sleep sometimes, and there are visitors at times—who wants to be running around opening windows all the time? And please don’t tell me that you ventilate beforehand and so on—that applies to only a very small percentage of cases.

Ybias78 schrieb:

Today, it would be more appropriate to ventilate manually instead of installing a mechanical ventilation system with heat recovery, which automatically does the ventilation and additionally consumes electricity/pollutes the environment.

No, exactly the opposite. Thanks to heat recovery, mechanical ventilation saves energy that would otherwise be lost through open windows. The electricity consumption is negligible by comparison. A typical mechanical ventilation system with heat recovery consumes about as much electricity as a 60W incandescent bulb—that is roughly 25 euros per year.

Being modern means reusing energy and not just letting it escape through the windows. Because ventilation is necessary at all times, mechanical ventilation with heat recovery is the clear frontrunner when it comes to environmental considerations.

Mycraft schrieb:

No, that’s not the case. What would change about the efficiency? As soon as it gets cooler outside — and by that I mean under 20°C (68°F) — which is most of the time during the winter months and part of autumn and spring, the mechanical ventilation with heat recovery operates with the same values. It recovers about 90–95% of the energy. The heat exchanger doesn’t change; it doesn’t become bigger or smaller, regardless of whether it’s warm or cold outside. In fact, the temperatures in Germany are ideal for heat recovery from a mechanical ventilation system.

The fact is:

Mechanical ventilation with heat recovery continuously provides fresh air throughout the entire house. That simply can’t be achieved with manual ventilation — unless you have someone dedicated to managing it.

Because you’re not always at home, you sleep sometimes, and you might have visitors. Who wants to be constantly opening and closing windows? And don’t tell me you do it beforehand, etc. That applies to only a very small percentage of people.

No, exactly the opposite. The heat recovery in mechanical ventilation saves energy that would otherwise be lost through open windows. The electricity consumption is negligible in comparison. A typical mechanical ventilation system uses as much electricity as a 60W incandescent bulb — roughly $25 per year.

Nowadays, it makes sense to reuse energy instead of airing it out the window. You always need to ventilate anyway, so mechanical ventilation with heat recovery leads when it comes to environmental considerations.

Just like Tesla. Although the environmental impact of building an electric car is rarely included in the calculations. You shouldn’t only count the operational phase of mechanical ventilation with heat recovery in an environmental assessment, but also its production, installation, etc.

As mentioned, it’s a luxury you can have, but you don’t have to.

Mycraft schrieb:

No, quite the opposite. With heat recovery, the mechanical ventilation with heat recovery system saves energy that would otherwise be lost through open windows. The electricity consumption is almost negligible by comparison. A typical mechanical ventilation system uses about as much power as a 60W incandescent bulb, roughly $25 per year.

It is modern and sensible to reuse energy instead of just ventilating it out the window. Since ventilation is necessary at all times, a mechanical ventilation system with heat recovery is definitely one of the best options when considering environmental factors.

We spent almost 10 years living in a house without mechanical ventilation with heat recovery, and for me, that was one of the main reasons for building a new home. There is nothing more frustrating than trying to properly ventilate a two-story house while working full-time. I failed miserably at it for years. Therefore, I don’t understand all the fuss around mechanical ventilation systems. Especially the argument “but it consumes a lot of energy!!1elf” completely ignores the heat recovery, which is quite efficient in modern mechanical ventilation systems.

Currently, we are monitoring the consumption of our air-to-water heat pump plus mechanical ventilation system since we have not yet moved in and nothing else is running except the system. The baseline power draw is between 140 and 148 watts. I find this acceptable considering that I don’t have to constantly reheat the air that I let out through the windows.

Mycraft schrieb:

A typical mechanical ventilation system with heat recovery uses about as much electricity as a 60W incandescent bulb. That is roughly $30 per year.

plus 1-4 filters from the manufacturer,
plus the popular maintenance contract for heating and mechanical ventilation with heat recovery,
plus cleaning of the duct system every 5-10 years

Ybias78 schrieb:

You must not only include the commissioning of the controlled residential ventilation system in the environmental statistics, but also its manufacturing, installation, etc.

Says the person who installs lead- and cadmium-containing photovoltaics on their roof. How will these and other highly toxic materials in your photovoltaic system be disposed of and recycled in an environmentally friendly way in 25–30 years?

Ybias78 schrieb:

Just like Tesla. Although the environmental impact of building an electric car is rarely considered. You shouldn’t only include the commissioning of the controlled residential ventilation system in the environmental statistics, but also its manufacture, installation, etc.

I wish people would actually look into these topics a bit before repeating common clichés.

Nida35a schrieb:

plus 1-4 filters from the manufacturer,

No, these filters are available as continuous material by the meter (roll goods). Anyone who voluntarily falls into a vendor lock-in is to blame themselves.

Nida35a schrieb:

plus the popular maintenance contract for heating and controlled residential ventilation

The controlled residential ventilation extra is absolutely optional here, and anyone with basic manual skills can change the filters and rinse the heat exchanger occasionally (max once per year). Of course, you can also skip that and pay someone to do it.

Nida35a schrieb:

plus cleaning of the duct system every 5-10 years

Only the exhaust air ducts, and only if no filters were used at the vents. Usually more like every 10-20 years, unless you live next to a highway or close to an open-pit mine. But that’s not the norm.