The politics of air conditioning in Switzerland | Hacker News Reader

The politics of air conditioning in Switzerland

lenews.ch

26 pointsbookofjoe25 comments

So, I'm really surprised this is still a debate (other than how quickly to subsidize the changeover).

I thought the old heat pump/air conditioner myths had been busted long ago.

In e.g. the Netherlands and Germany people buy heat pumps (of which air conditioners are a subset) to save money and the environment.

It's all about Coefficient Of Performance. A modern reversible unit heats and cools two to five times as efficiently as comparable (resistive; COP=1) electrical heating.

In most of Europe, it's efficient enough to run on rooftop solar energy for half to three quarters of the year. Combined with decent insulation your net power usage can be very low indeed. Some of the newest ambitious house designs being built today even hit net zero. That wouldn't be possible without an aircon/heat pump as part of the design.

There's also a strategic angle. Do you want to heat your home with gas that's ever more tricky to come by, or would you prefer efficient electric heating that can come from any source including preferably renewables?

And of course the summer bonus: If you do have solar panels, you get to cool your home almost for free in summer, since summer solar production happens to coincide with summer heat.

I'm in Zurich in modern construction - all cement with stressed cement panel cladding too on the outside. 8 apartments. Triple pane windows. Heat-pump with ground temp heating/cooling that is practically free in price. The ground temp is too cold and we'd get condensation if the brine wasn't warmed up a bit. The apartment is 24c to 26c depending on the room. A bit chilly to me.

My neighborhood (wollishofen) is a bit infamous for all of the old construction being torn down and being replaced with buildings like ours. But those old places are heated with oil, they're leaky wood construction, they have no option for cooling because there are no vents. Think buildings from the 1800s to early 1950s.

I didn't read the article - tired of all the American articles in the press promoting ac for some reason.

> But those old places are heated with oil, they're leaky wood construction, they have no option for cooling because there are no vents.

Ductless mini split style heat pumps are a common retrofit option for older buildings without vents aren't they?

> I didn't read the article - tired of all the American articles in the press promoting ac for some reason.

When a heat pump is used for cooling it's effectively the same as an AC. The main difference AFAIU is that a heat pump can reverse for heating as well. I think when Americans promote AC they probably consider a heat pump to be just another AC variant.

There's no air involved. It's a completely enclosed system. Unless you count the cool/heat of the floors/ceilings affecting the air...

That seems likely normally not viable in most warm places because the humidity would quickly rot out the floors. Part of the ‘conditioning’ in the name is that quite a lot of water will ideally get removed from the air to control humidity too, and that needs to be drained away

Maybe it works in Switzerland due to high altitude reducing humidity?

I have a gas fired hydronic heating system but I still need AC for cooling(mixture of traditional and mini-split style units due to retrofitting requirements).

I'm also located in a high altitude location but for AC alternatives here we would typically see something like a swamp cooler.

The brine is at a temperature where there is no condensation. The ground temp is 11c but the brine is higher than that. Also there is an air circulation system that passes over the cooling fins to remove moisture, but it's nothing like using a dehumidifier, because I have a dehumidifier in my cellar and it takes out plenty of water.

Plus no one has wooden floors. We have cement/epoxy floors. Some neighbors have a wood laminate that's probably mostly epoxy. I don't think you can even get wood floors anymore here. Walls are cement/plaster. Ceilings too.i guess the doors are wood.

This is a very odd setup because you can never cool lower than the current dew point and cannot reduce humidity which is a very important function of AC as it makes air far more comfortable even at the same temperature. Any error will cause condensation to form. This is why AC is normally done in a way where the water in the air will condense on the cold coils and be collected and drained safely. In hot, humid conditions, a typical central air system can extract 5 to 20 gallons of water a day from the air.

That dehumidifier is also AC, just done much more wastefully (because it dumps the waste heat into your house instead of outside the house)

> There's no air involved. It's a completely enclosed system.

So it's actually a hydronic heating/cooling system? I don't think those systems are typically referred to as heat pumps generally.

It sounds like they are using radiant flooring for cooling and keeping the temperature above the dew point but this would only work if the humidity is always naturally low or you have a separate dedicated dehumidifier

As an American, I can't understand a few of these sentences. I am mostly confused that you say you have a heat pump that cools, and you are sick of AC promotion. There is some kind of disconnect here, because in the US, a heat pump is AC.

Separately, everybody I personally know (Northeast US) considers 26 C indoors to be hot (not warm - hot). It's amazing to me that people can feel temperature so differently.

Doesn't AC mean air? Air conditioning? There's no air involved here - it's basically antifreeze pumped through the floors/ceilings. The heat exchanger is an enclosed chamber where warm molecules exchange across into a cool chamber, in summer it's warm molecules from the brine that was in our floors/ceilings and the cool air is the 11c brine that runs through pipes in the ground. across a fin/radiator. It's all completely enclosed. The only "AC" is in the enclosed heat exchanger where warm and cold air molecules move between chambers.

Oh I should mention though, there is a compressor that compresses a volatile gas that is the carrier of the heat from the warm to the cold chambers. But it's so efficient that it's pretty much free to cool kostenlos/free cooling) using ground temp (11c here). Heating in winter does cost something because we like to be warmer than 11c.

A heat pump that cools and an Air Conditioner are the same thing

So an 'air conditioner' is the same class of technology, except (typically) it works air/air . A modern minisplit air conditioner can't get a CoP as high as your awesome ground source system, and with 11C ground the ground source system has a superpower the minisplit can't quite match.

That said, a minisplit is cheaper to purchase and install, is easier to retrofit on an existing home, and still has a CoP well over 1. This is why I think the semantic debate is a distraction when there's practical problems to be solved. I'd think we'd want all our homes electrically heated and cooled with CoP>1.

The debate should be between heat pump technology and older heating methods, not necessarily between cousins.

AC means any kind of refrigeration technology used to cool a building lower than the outside temperature.

It's because it's humid af in the northeast (and all through the East Coast). I moved to CA last year from FL and 75/78 here feels perfectly fine (I can sleep just fine) because it's completely dry. We literally have our windows open all day every day except today when it was like 90 (and tonight it'll be back down to 70 so we'll be able to sleep without AC).

after going through my first quake in valley, years ago, i shut windows at night, cause every strong breeze woke me up thinking a quake was coming. bummer.

As an American, what? A heat pump is a heat pump. An air conditioning unit is a subset of heat pumps (that is, a heat pump that can only run in one direction).

I'm just as confused as you are about the temperatures quoted though. I'm most comfortable around 19C or 20C. At 23C I start having trouble sleeping. At 26C I'll be openly sweating.

"promoting ac for some reason."

Because it literally saves lives during heatwaves?

seems like the wrong thing to target for the good of the environment as this gets in the way of people's possible legitimate health needs

> this gets in the way of people's possible legitimate health needs

Less people alive being good for the environment is maybe their logic?

Seems like these folks won’t be enjoying fat piles of data center tax revenues any time soon

.. if over a billion Chinese citizens have the same living patterns as Australians and Americans do right now then all of us are in for a very miserable time. The planet just can't sustain it" -- Barack Obama

so the same words for people in EU:

"If hundreds of millions of European citizens have the same summer air-conditioning habits as Americans and Asians do right now, then all of us are in for a very miserable time. The planet—and its power grids—just can't sustain it."

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