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Aurel Wünsch @aurel.indoorco2map.com · 3h

Sind jetzt eigentlich auch Saitan-Byrger, Tofu-Würst, Erbs-Worscht und Blumenkohl-Schnitsl verboten? Wie hoch muss die Levenshtein distance sein zum fleischlichen Original?

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Aurel Wünsch @aurel.indoorco2map.com · 21h

Und wenn man dadurch eben Anfahrvorgänge verringert und der Wirkungsgrad der Kraftwerke die man dafür nutzt etwas höher ist als der von den Spitzenlastkraftwerken dann ist der zusätzliche Brennstoffbedarf auch gar nicht so hoch trotz Speicherverluste.

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Aurel Wünsch @aurel.indoorco2map.com · 21h

Der noch hottere Take ist aber dass man die Batteriespeicher auch mit Gas/H2-Kraftwerken laden kann mehrmals in der Dunkelflaut solange die Residuallast zwischendurch unter der Leistung der regelbaren Kraftwerke liegt und dadurch dann trotzdem zumindest etwas Kraftwerkskapazität einsparen kann.

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Reposted by Aurel Wünsch

Aurel Wünsch @aurel.indoorco2map.com · 2d

One of the multiple goals of indoorco2map.com is to gather data about the current state of ventilation to estimate what's needed additionally (energy and costs) to achieve good ventilation in every indoor space (excluding residential areas). This thread will give a very rough estimate for Germany.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

You can have an ACH of 0.1 and near to outdoor level of "used" air if there is just a few people in a very large room or you can have an ACH of 10 and still horrible air if it is a extremely cramped location - that's why L/s per person is way more useful as metric in this use case.

Aurel Wünsch @aurel.indoorco2map.com · 2d

Bei Fragen oder Probleme gerne nachfragen (egal ob öffentlich oder via DM), Daten von Konzerten sind bislang eher spärlich - da gibt es einen gewissen Bias in der Nutzergruppe ;)

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Aurel Wünsch @aurel.indoorco2map.com · 2d

What's not included yet is the cost for adding mechanical ventilation systems to indoor spaces which currently are just naturally ventilated (and very often very badly so), which probably will be a lot higher than the energy costs, but it will also provide more thermal comfort and climate resilience

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Aurel Wünsch @aurel.indoorco2map.com · 2d

Usually I would check it more thoroughly before posting but if I made a huge mistake then Cunninghams law will accelerate progress towards a solid estimate anyways and given the importance of this topic I'll rather risk looking silly than wasting time.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

If you want to check the calculation, play around with the parameters to check for robustness or expand on it, here is the spreadsheet: docs.google.com/spreadsheets....

VentinationSimpleModel_V3.xlsx

docs.google.com

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Aurel Wünsch @aurel.indoorco2map.com · 2d

And then we just do some additions and multiplications and we get an additional electricity demand of around 5.2 TWh for the ventilation system and an additional heat demand of 7.5 TWh - which assuming a 50/50 share between Heatpumps and Gas Heatings is another 1.2 TWh Electricity and 4 TWh Gas.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

There are a few more (somewhat reasonable informed) assumptions about the exisiting ventilation levels, about the time every person spends in these ventilated areas: around 8 hours per day (another 8 sleeping and the remaining 8 either at his own home or homes of friends/relatives or outdoors).

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Aurel Wünsch @aurel.indoorco2map.com · 2d

Mechanical ventilation systems often include heat recovery which vastly reduces the heat demand of ventilation, they can reach values of more than 80% recovery but we assume here just 70% and that just 40% of the systems have such a system.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

The remainder is assumed to have natural ventilation and that 25% hit the target during the summer halfyear and just 3% during the winter. For the share which doesnt reach the target we calculate teh additional demand from adding mechanical ventilation to the target levels.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

While very efficient systems can reach values of 0.5 W/(L/s) we will conservatively use 1.75 W/(L/s) from a 15 years old study. We assume that around 25% of the non-residential shared spaces (weighted by occupancy) have mechanical ventilation already and of these 35% already reach 14 L/s per person

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Aurel Wünsch @aurel.indoorco2map.com · 2d

The energy demand for a mechanical ventilation system is often expressed as specific fan power (SFP) in W/(L/s). The target level used is 14 L/s of fresh air per person in the room, which results in a CO2-level of around 800ppm assuming light activity. We will assume dynamic adjusted ventilation

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Aurel Wünsch @aurel.indoorco2map.com · 2d

There are three ways ventilating using mechanical systems results in energy demand. Firstly the electricity needed for the ventilation system itself, mainly for the fans, secondly the increased heating demand from moving a higher amount of cold air into the rooms. We ignore cooling demand for now.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

While there is certainly a lot of potential to improve ventilation levels by just opening windows more (either manually or automatically), for the sake of simplicity the ventilation improvements calculated all use mechanical ventilation.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

Disclaimer: I'm working on a more complex approach but I am reasonable certain that this simple approach used here gives a good estimate and isn't too far off (hopefully not more than by a factor 2). Currently we will just look at the energy amount and costs. Spreadsheet linked at end of thread.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

Given the direct societal cost of a single sickday of a working person in germany just from missing the work (non-including indirect costs or longterm effects) is around 250€ at least properly using the existing systems seems to be a no-regret option: break even is just 0.02 less sickdays/person.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

Breaking it down to a single supermarket visit you end up with an astonishingly small sum of around 0.2 to 0.3 cent - which I think is so low, that the share of people who would be willing to pay for that is 90% or higher.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

If I did not make a massive mistake the result is that the energy cost would be around 15 Euro per person and year to have really good air in every non-residential indoor space or 5 Euro per person and year when limiting it to places which already have mechanical ventilation systems.

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Aurel Wünsch @aurel.indoorco2map.com · 2d

One of the multiple goals of indoorco2map.com is to gather data about the current state of ventilation to estimate what's needed additionally (energy and costs) to achieve good ventilation in every indoor space (excluding residential areas). This thread will give a very rough estimate for Germany.

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Reposted by Aurel Wünsch

Al Haddrell @ukhadds.bsky.social · 3d

Many things will affect how well a student will do in school. Some you can control, others you can't

One that affects every student (and teacher), and that we can control, is indoor air quality

In this video I walk through how and offer some solutions
t.co/sSU5efGhHr

https://youtu.be/CGjcvfTD5SQ

t.co

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Aurel Wünsch @aurel.indoorco2map.com · 3d

Gerade weil ja die die gegen Emissionsminderung sind, dann in der Regel gründen politischer Konsistenz kaum bei der Klimaanpassung von einem Szenario mit hohen Klimafolgenschäden ausgehen werden oder können - das würde ja der Haltung bei den Emissionen widersprechen.

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Aurel Wünsch @aurel.indoorco2map.com · 3d

Und auch da wird man wie bei der Emissionsminderung um die Intensität der Maßnahmen erbittert streiten - "tun es nicht auch 50cm weniger", "kann die Überflutungsfläche nicht kleiner ausfallen" - ausreichende Klimaanpassung wird alles andere als ein Selbsläufer..

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