ᐅ Unusually high quote for ventilation system

OWLer schrieb:

See you again in 5 years in the thread "Help, mold everywhere in the house and guests say they get headaches here."
Ventilating only once a day goes against all recognized guidelines for ventilation concepts in new buildings.

I seriously wonder how houses built in the 2000s are still standing.
We have been living in our house for almost 10 years and have no mold.
The upper floor is aired out once a day, and the bathroom and bedroom are ventilated additionally as needed. The ground floor ventilates more or less on its own when we go in and out, let our cat outside and inside, etc., or when we cook, then ventilate again as required.
Currently, we have humidity levels around 40% relative humidity, so rather low. When it’s more humid outside, it can sometimes be a bit higher.

Of course, this does not provide the comfort of a ventilation system, and you cannot close the “ventilation windows,” but it takes me no more than one minute to open and close the windows.

I have spent 5 years living in a newly built house with a central ventilation system featuring a heat exchanger, before that 10 years in a new build with a decentralized system, and prior to that, always in houses without any ventilation system.

For me, the ventilation system with a heat exchanger is the factor that improves living comfort the most, reduces conflicts about ventilation to zero, and at the same time actually saves a significant amount of energy. Decentralized systems are, in practice, merely symbolic measures that are quickly turned off—in other words, we ventilate like in the Stone Age.

For the next house build, I would change very little compared to the current house, adapt some aspects to the hopefully available technical innovations, but what I would never, ever give up is a central ventilation system with heat recovery. We have made compromises in terms of comfort/luxury at many points in the house (for example, we received a five-figure credit for the bathrooms), but saving money on the ventilation system never even crossed our minds.

If the contract with this general contractor has not been signed yet, I would seriously reconsider at this point. Anyone who is so firmly stuck in the past that they generally advise against ventilation systems is giving a very clear assessment of themselves—and it’s not a good one.

Musketier schrieb:

but I don’t need more than 1 minute to open and close windows.

Let’s say you have 5 windows per floor and two floors. That gives you about 6 seconds to walk to the window, open it, and secure it against slamming on the leeward side. You also need to secure doors. There’s no way you can do all that in a minute.
Even if you subtract one or two windows, you’ll only reach that one-minute mark if you sprint through the house.

Musketier schrieb:

I seriously wonder how houses built in the 2000s are still standing.
We have lived in our house for almost 10 years and haven’t had any mold.
We ventilate the upper floor once a day and partially ventilate the bathroom and bedroom as needed. The ground floor ventilates more or less by itself when we go in and out, let our cat outside and back in, etc., or when we cook, then ventilate again as needed.
Currently, we have humidity levels around 40%—so rather low. When it’s more humid outside, the indoor humidity is somewhat higher as well.

Well, what is the energy demand of a house from the 2000s?
The tighter the houses are sealed, the bigger the problem that moisture can’t escape. Maybe less so in winter, but even then, you have to shower/bathe and wash clothes—probably drying them indoors. Depending on the lifestyle, a lot of moisture can accumulate. For example, we don’t put everything in the dryer, and I’m very grateful that in winter I can hang laundry indoors without worrying about moisture.

WilderSueden schrieb:

Let’s say you have 5 windows per floor and two floors. Then you have 6 seconds to walk to the window, open it, and secure it against slamming on the leeward side. Doors also need to be secured. There’s no way you can do that in a minute.
We could even subtract one or two windows from that, but you only get close to a minute if you sprint through the house.

As I said, we mainly ventilate the upper floor early in the day, which has 5 windows.
Securing them only happens when there’s really strong wind, and yes, I can do that in 30 seconds.
Usually, ventilation happens while passing through. For example, you make the beds and open or close a window at the same time.
On the ground floor, sometimes we specifically open the patio door, but otherwise the rest happens while going outside.
You might quickly take out the trash or compost, let the cat in or out, or our uncontrolled ventilation system—also known as the child—ends up chatting by the open door with the neighbor’s kid for longer, etc.

The house was built in 2014. Electricity consumption for heating is 2300 kWh, including hot water, pumps, and valves (if still in use) for 125 m² (1345 ft²).

In my enthusiasm for the improved quality of life I have experienced every day since building my new home, I initially tried to share this benefit with others who were in the process of making building decisions. The main counterargument I often heard was a defensive attitude along the lines of, “I have been ventilating this way for 40 years; if it was wrong, I would have noticed by now. So, I will continue ventilating through windows because otherwise, I would have to admit I was wrong.” I cannot and do not want to argue against that mindset. That is probably why we will still see window ventilation—even in houses built in 2023 and likely well beyond 2085. As a result, despite all evidence to the contrary, many newly built houses will continue wasting energy with every ventilation cycle, justifying it stubbornly with, “Gas is still cheap!!!111oneeleven.”

For me, a ventilation system with a heat exchanger should be one of the few non-negotiable features in every new house. And if in 10 or 20 years a new ventilation or heat exchanger technology comes onto the market, no problem: the current ventilation unit can be replaced with a new one, and I will be happy that I installed the ventilation ducts. Maybe even in a few years, it will be possible to connect it to my home automation system—who knows.