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Comment by Glawen | Hacker News Reader

France actually enforces a law whereby every new construction need to be well insulated (rt2012 at the moment). To give an idea, to comply to this rule you need at least 15cm of styrofoam on the outside walls of your house. The next rules are coming next year, rt2020, where the construction need to be energy positive. So you will need solar panel, or heating system which give more kWh than it consumes.

Moreover there are funds available when you want to improve the thermal efficiency of your old house. I got my paid half of the bill to get a new heating system for example.

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We have similar rules here in Germany. I live in a fairly modern, well isolated house. To comply with all these requirements, we build more and more houses with floor heating here. It's easier to efficiently heat that way using heat pumps, for instance. I got the impression that on our upper floor the heat is so well conserved that we basically aren't able to cool the house down anymore during these heatwaves. It takes about three days after the heatwave has passed to get back to normal levels even when all windows are open all the time and a fan blows air through the whole building. That's a real problem.

Well that's the drawback, it is designed to keep the cold/heat outside the house, but once you let the heat inside in summer, you have a hard time to cool it down. It really is designed for winter.

What i don't get in these rules, is that they requires the house to be sealed, and void of air leaks. As it is sealed, there is no natural air flow anymore and you need to install a system which regenerates the air: it gets the air from outside and vent it inside. It just blows my mind.

I find it so unnatural that i only buy old houses, where I am free to choose the insulating materials and techniques. I am against these petrol based materials which release chemicals in your house.

Yes, you describe exactly the kind of house I live in. The problem with the upper floor is that there's a skylight which you can't shade. The sun can shine on the floor (with the floor heating underneath) and warm it up all day. You don't even need to open a window to let the heat in.

The air ventilation system uses a heat exchanger to keep the heat in during winter. I am still not sure as to what it does during summer. It surely doesn't feel like it makes it actively hotter, but it also doesn't cool it down.

We are required to have this system running all the time (on the lowest level). Otherwise the house would begin to mold quickly as there is absolutely no natural air flow when the windows are closed. In fact, I once deactivated the system because of bad air quality outside. It was unbearable within about two hours inside. It's really a bit weird, but on the other hand, I like that I don't have to think about opening the windows to ventilate the house and it helps keep the heating costs low during winter.

Reads both your comments. Scratches head. Wonders if you are for or against what I'm saying.

> It is possible to design a space that needs little in the way of active heating or cooling to stay comfortable.

I get your confusion. I was actually reacting to this part of your comment specifically. I am for what you are saying. I just wanted to mention that modern buildings aren't always designed like that. In fact, where I live, houses seem to be increasingly designed to only keep the heat in, not let it out — as rightly pointed out above. That's a problem. We basically can't stay comfortable in summer sometimes. It's not pleasant sleeping on the upper floor during a heatwave and there's little we can do other than buy an AC (which we won't).

As a sidenote: our company just finished a new building which is designed in a similar way, but has active cooling via the heat pump/floor heating system. I hope that will work better than what we have in our private home.

Thank you for your comments herer.

There are myriad things that impact both actual temperature and perceived temperature. I don't even try to talk about any of the more "woo" sounding things that impact perceived temperature.

I'm just talking about well established design principles that were a time-honored tradition globally until recent decades popularized throwing money at the problem, using insulation and adding AC to shittily designed buildings. And I get nothing but grief most of the time.

Tempted to start blog number umpteen to bitch about this in specific. I'm calling it "While The World Burns." Maybe if people here keep pissing me off, it will actually get content and traction and yadda.

Historically, people were only interested in rubber necking at what a goddamned social train wreck waiting to happen I was. Maybe I can harness that bullshit for a change instead of trying to avoid it. Swim with the current, not against it.

Would you care to expand ? I know that there are architectural trick to improve the heat management, for example i plan to plant a tree which will grow big enough to make shade on my window during summer.

But personally, I did not see yet an old building in Europe which is both warm in winter and cold in summer jusy by itself. The new insulation materials are really good now, there is no comparison with old techniques. My parents house is 200 years old, made of a wooden frame and brick. It is incredibly cold in winter, so cold that we need to burn wood as central heating is not powerful enough.

Here are some resources to read up:

https://cleantechnica.com/2018/03/31/passive-solar-house-des...

https://en.m.wikipedia.org/wiki/Passive_house

Given increased heat from global warming, we can also borrow techniques from places like Mexico and the Middle East for cooling a house using air flow. For example:

https://en.m.wikipedia.org/wiki/Solar_chimney

https://energyeducation.ca/encyclopedia/Solar_chimney

We've been doing this around the world since well before we invented AC. We just seem to have conveniently "forgotten," never mind that these techniques are actually still in widespread use.

You might like [1] and others in that vein. The passive house movement seems like a big deal in a few parts of the US (e.g. Northeast and some parts of the West coast). AC ends up being an important part of these homes as they're sealed so well that human-caused humidity (both direct and from showers, cooking etc) needs to be managed. You can get by with the equivalent of a small window unit for a 1500 square foot+ house though.

[1]: https://www.greenbuildingadvisor.com/

> It takes about three days after the heatwave has passed to get back to normal levels even when all windows are open all the time and a fan blows air through the whole building. That's a real problem.

I've experienced similar issues in the UK. It's a worse problem than being cold in winter - I can just wear more layers. Not being able to cool your house is frustrating as you can stick your hand out the window and it feels cool, but you're sweating buckets at 2am

You could get yourself some US-style porches.

One of the reason the US is porch-crazy is because historically it was too damn hot here. Rather than trying to keep the house cool, you said to hell with it, and spent as much time on the porch as possible, even sleeping on it when the house was too hot at night.

In the Deep South, deep wrap around porches also allowed you leave windows open on two sides of the house for a cross breeze, even in very rainy/stormy weather.

They still sleep on porches in India and "porch sleeping" was common across the US until not that many decades ago, even in New York City where they would sleep on the fire escape or roof in hot weather.

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