I love seeing architecture that uses wind to cool and condition buildings, but it's not very helpful for older buildings. I wonder if we can mimic some of the benefits by creative planting of trees and plants?
I've seen mentions of whole house fans in the ArsTechnica comments and was intrigued as to whether that would be useful for my house. Here in the UK, our houses are designed to keep warm and don't have any A/C built in and that's becoming more of an issue as summers get hotter. However, I've discovered that OnlyFans is not the correct website to find whole house fans.
I have a little house in the back yard surrounded by some large birch trees. The insulation in that little place is pretty good, but I wouldn't say stellar. In the summers, our main house gets exceedingly hot for the same reason yours does. The little house in the shade however is nice and cool all summer.
So if you can get away with it, sure, plant some trees. :)
Planting trees isn't much of an option for us. We're in an old (1890s) mid-terrace house and our front "garden" is barely big enough to hold our recycling bins.
There's a type of optical filter tape which you can buy that reduces the amount of energy getting in and out - less than 20% goes through, most of it in the visible spectrum.
It has a blueish tint though and really doesn't do much if it's the ambient temperature that's too high.
An acquaintance of mine works with a builder that specializes in zero energy homes. They mostly build in a climate similar to the UK. The houses are insanely insulated and airtight, but they have an air exchange unit that cycles fresh air in through a heat exchanger so the house temperature stays steady.
These houses are honestly quite pleasant to be in. The insulation has the side effect of being very good noise dampening as well. I was talking to the owners of one and they said they'd never used the backup electric heater. The one time things got a little cold they light a candle in their bedroom and everything was fine.
So I think in temperate climates, the answer is air tightness and thermal control, not whole house fans.
That's what the air exchange unit is for. It brings fresh air in and exhausts stale air, passing the heat from the stale air to the fresh air as it does so. I would love one in my 1970-built house.
In the types of old houses described in your link, this type of thing was designed to be done by one or more open fires, which drew fresh air in through cracks and crevices and exhausted up the chimney.
I'd argue that houses in the UK are not very well designed to keep warm which is why they overheat in the summer. I live in the Baltics, in a modern 4 bedroom house, and our annual energy consumption for heating is around 6000kWh - that's around half the average of a similar sized house in the UK, even though our winters are much colder.
My house is a bit older so doesn't have it, but new houses must have a heat recovery ventilator. Almost all of these have a 'summer bypass mode' which bypasses the heat exchanger, so effectively draws warm air out of the house. This is useful in the summer, as here although it can get to 30c+ in the day, at night it almost always drops to below 20c. The way our houses are built we have a lot of thermal mass, so if you can cool it down during the night, it will make it a lot more comfortable during hot days.
A lot of the UK houses are quite old and so they used the materials that were common at the time. My house is a mid-terrace house built around 1895 for mining workers, so it was built as cheaply as possible and doesn't seem to have a proper 90-degree angle anywhere.
It's going to become a much bigger problem in the UK as we're struggling with having enough housing anyway and making them energy efficient is going to take a lot of money and work.
I had heard that one reason UK housing was particularly bad insulation wise, and notoriously draughty was because they were all heated by open coal fires. The “bug” of being draughty became a “feature”. There is perhaps a lot to be understood about the British through it’s love of old buildings that are entirely unfit for modern purpose. The Houses of Commons/Palace of Westminster is a great example of this.
Whilst we do love our old buildings, I think it's important to remember that we do actually have old buildings. We visited Tombstone, Arizona on holiday and were surprised to see some historical building (can't remember which one) that was built in the early 1900s - that's younger than our house. The problem is that we've got loads of old houses and not much room left in populous areas (and most people don't want to live in the less populous areas such as Wales or up North) so people will live in old houses as it's cheaper than knocking them down and building anew.
I own an old (1890's) terrace house in the UK. The only part that overheats is the modern loft-extension that I built 5 years ago. For the main part, it's like a cave; it retains heat in the winter, and remains cool in the summer.
It has single-leaf brick walls, which should be bad; but the frontage is quite narrow, which makes it pretty energy-efficient.
Same. Our downstairs is nice and cool during the summer (not so much when it was getting near 40 degrees last year), but our upstairs gets much more light and can get too warm.
I can see how it sounds like that (and I take it you're being humourous).
It's a mid-terrace house, which means that the side walls abut onto the neighbours' houses. The side walls are much bigger than the front and back. So not much of the external walls are exposed to the external environment, which is why it behaves like a cave.
To be clear, it's not like a heat-pump; it just maintains a reasonable temperature.
You basically want something to catch the solar radiation and either reflect it or convect away the heat. Some sheet material affixed a few inches away from your walls would give the same or better results as the trees.
London's Gherkin building uses twisting tunnels through the floors that channel air up and mean AC isn't needed most of the year. The tunnels correspond to the dark stripes on the outside.
There's also this excellent article from Scientific American: Passive cooling systems in Iranian architecture, by Mehdi N Bahadori, February 1978
"They have no energy sources other than the sun and wind, and yet they circulate cool air through buildings and traditionally provided cold water and ice for the hot summer of the country's arid regions"
Nearby here in Oslo they're building a (smallish) tower[1][2] for combined office and residential use, with the aim to not use any external electricity for ventilation, cooling or heating. Instead they will rely on natural ventilation combined with a solar-powered heat pump, or so is the goal.
Will be interesting to see how it works out in practice...
This is the difficulty with all cooling solutions that isn't an AC. The efficacy of each method depends heavily on the climate for which it was developed. What works in dry SoCal doesn't work in humid Japan, and what works in Japan might not work in Dubai.
The future of energy-efficient cooling is not going to be one solution that fits all. There are going to be different solutions for each region. Summer weather can vary wildly even in the same place, so many solutions will end up using software to actively adjust its own mode of operation based on sensor readings, just like a modern HVAC system. You don't want your cooling apparatus getting all moldy when it rains unexpectedly.
There are problems that can be solved with ventilation and then there are problems where you need a heat pump. If outside in the shade temperature and humidity are unlivable then "No A/C? Big Problem! You are probably going to die!".
Enough "passive cooling" articles. That's ventilation, just a part of HVAC. These articles makes it sound like the ancient Iran and the termites knew something an entire industry full of engineers doesn't.
Termites certainly know things that modern engineers don't, and the same is probably true of ancient Persians.
Just about everyone has the intuitive understanding that some old buildings do a very good job maintaining comfort, and that modern buildings often fail to do the same or only keep up at enormous expense. It's perfectly understandable that, in the wave of globalization and cheap energy that swept much of the world for half a century, we lost the craftsmanship to create these structures well, then the knowledge to do so at all, and all the while we didn't care because electricity was so cheap. Now we're clawing back stuff we used to be able to do as a matter of course.
Central air is miserable to maintain. I want to maximize my comfort with ceiling fans and window units, or maybe ductless.
Sorry, no, termites don't know crap. They don't have to shed nearly as much heat per unit of surface area and are perfectly fine in humid 35 degrees C.
We've known about thermal mass, convection, venturi effect and other stuff for ages, and it's not going to help you be comfortable (another thing termites have no concept of) beyond a certain envelope.
Have you read the article? The fungus described evidently is quite temperature sensitive (though at a temperature higher than what we’d like).
> Architect Mick Pearce famously based his design in the 1990s on the cooling and heating principles used in the region’s termite mounds, which serve as fungus farms for the termites. Fungus is their primary food source.
>
> Conditions have to be just right for the fungus to flourish. So the termites must maintain a constant temperature of 87° F in an environment where the outdoor temperatures range from 35° F at night to 104° F during the day. Biologists have long suggested that they do this by constructing a series of heating and cooling vents throughout their mounds, which can be opened and closed during the day to keep the temperature inside constant.
> old buildings do a very good job maintaining comfort, and that modern buildings often fail to do the same or only keep up at enormous expense
Old buildings did not have: thermal insulation, ventilation with heat recovery, timed ventilation, etc. While new buildings won't even get a building permit without all that. There's a minimum required energy efficiency.
I have to ask: what is your experience with civil egineering?
I have a 3-story house in the US Northeast. The AC that cools the 2nd and 3rd floor broke. instead of paying to replace it, I'm trying to use passive cooling techniques. The house was built in 1870, before ACs. I suspect the original residents had techniques for keeping it cool. For example, I suspect they had awnings on every window. They kept the windows open on the top floor to create cross winds that pushes the accumulated hot air out of the house. And I suspect they had large trees on the property to create shade and cool the air.
I'm slowly replicating these techniques plus some fans to help push hot air out, including a gabel fan in the attic. I started getting awnings, but not yet on every window, they definitely help. Started planting trees around the property and around the house to create shade. I did get two window ACs, one on 2 ND and one on the 3rd floor, to help when it gets to high 80's and above. I want to see how far I can take this. I'm definitely going with the approach of having more air flow vs. other passive techniques that lock in the air, e.g. closed attics.
It depends on a lot of factors. Many older homes today were converted from barns and other structures that were not designed to optimize climate.
But some homes were indeed designed with climate in mind. The broad rear side might face the south to be heated during winter. The whole house may be configured with one long hallway with windows or screen doors at either end to allow cross breeze. Windows on different floors may be designed to open part way to facilitate cross breeze. The fire place may be located deeper in the house near the bedroom, with subsequent rooms getting farther from the fire so in winter you can shut the doors and only heat your own room with the one fireplace.
An attic fan that can switch between blow and suck is essential to keep cool (and prevent mold using air flow). When it's cool in the early mornings, keep windows open to cool the house, then close them when the sun rises and close shutters. As the temps rise throughout the day, you crack a window upstairs and turn on a window fan (blowing inward) and one window downstairs (blowing outward) to create a downward breeze, or the reverse to pump heat up and out.
My ex hasn't owned an AC in 10 years. She just regulates the doors and windows and has window fans. House is 130 years old
For my NE house I’m looking into solar panels to run AC. It’s two birds with one stone - the panels generate electricity exactly when it’s needed the most, and then, the panels shade the roof, preventing heat from reaching it in the first place.
You will also want a battery. You'll see that most of the time your peak in usage doesn't match your peak in production. And selling back electricity for pennies and then having to buy electricity for way more.
Careful with the shade trees. I had to cut down 2 due to them messing with my foundation. Now I have no shade. It’s difficult to find ones that can shade from a proper distance.
> The house was built in 1870, before ACs. I suspect the original residents had techniques for keeping it cool
I think it's tempting to ascribe some lost ancestral knowledge to older house, but to be completely honnest a lot of them weren't designed with thermal considerations in mind (or rather, the thermal efficiency was accidently achieved by following some heuristics).
A lot of these older houses were simply badly insulated. They required a lot of wood or coal to keep warm during the winter or had the occupants wearing layers inside at all times but would cool down quite fast in the summer during the night, only to heat up again during the day.
Good, explicit thermal design appeared with mid-century houses. [0]
One thing to keep in mind is that in a lot of old houses, the top story was unfinished attic. It wasn’t livable space because it was too hot in the summer. Your 3rd story was probably like that.
My second story in craftsman bungalow wasn’t finished until the 70s. And that is probably when the window AC was put in that makes it usable in summer. The first story has lots of windows for cross breeze and stays nice in summer.
I live in TX and I sometimes wonder about the same- how did anyone lived here 100 years ago (or why they thought it would be a great idea). The best I could come up with - they just dealt with it. High temperatures meant staying in shade and sweating more. You can do only so much structurally but there are weeks when it doesn’t go below 90 in the night.
My grandfather grew up in a rural area that didn't have electricity or running water until he was a teenager. He would occasionally mention little tips and tricks to how they used to deal with not having some amenities. Many were simply less desirable options. He had these hard, flat wooden chairs that were in his house growing up. He said because of them, they tended to just keep working on the farm until they were tired enough to go directly to bed.
The truth is that with climate change, more and more people will need modern air-conditioning to be comfortable in their homes (or in some parts of the world, to survive).
We will likely see a massive expansion of air conditioning as more and more people come out of poverty and desire to be comfortable across the developing world.
We can’t conserve our way out of this crisis. We need abundant, zero carbon energy like wind, solar, and nuclear to support all the energy needs of humanity.
If we don’t have zero carbon energy people are not going to do without, they are going to burn fossil fuels. Take a look at Germany. Despite all their rhetoric about how much they care about climate change, they are burning coal which is the dirtiest of the fossil fuels.
The idea of central AC/Heat to me is so dumb. I much prefer the style of having individual units in individual areas. There’s no single point of failure, if you only want one room to be extra cool it’s easy and faster to do. With central AC you have to set the temperature for the whole house and wait
I’m sure there are reasons it’s so common that I don’t know about, it’s not even close to an area of expertise for me. But moving from the US to Mexico I feel like concrete is the way to go vs drywall and wood framing. Sound insulation is so much better too.
The rationale for central HVAC is that your house is insulated. If you heat or cool a specific room, heat is going to flow from one room to another and you’re going to have to keep fighting that. Getting the whole house to a specific temperature is more efficient since it’s insulated from the outside and can more easily maintain a set temperature with less work from the HVAC system. In older houses it didn’t matter as much because the insulation was shitty enough that this didn’t really work, but with modern insulation it makes more sense.
Yeah but everything I hear is that new builds in the US are worse than ever in terms of quality.
I owned a brick ranch house in the US and had to have all the ductwork redone because it had accumulated mold. Cost me 3k. It just seems way more trouble than it’s worth.
> Yeah but everything I hear is that new builds in the US are worse than ever in terms of quality.
That's a meme. There's a lot of variability between houses (and the shitty old houses don't tend to survive long), but insulation is one of the things that has unambiguously improved over time.
Matt Risinger has a good video on the "old
houses were better" thing here, but his channel is full of great house-building content: https://www.youtube.com/watch?v=KBMMDY3LFAA
I can only speak anecdotally, the house I owned was built in the 50s, so it makes sense that insulation wasn't as good. But my parents' house was built in the 80s, and has always had serious problems with the upper level being much hotter than the lower level. Apartments have never been as much of an issue, but they're usually much smaller and I've generally only lived in 1 bedrooms or studios.
From what I have read, builds in the last 3 years have been horrendous due to supply and labor shortages. Maybe the sweet spot is to purchase something from before that era that is still new and get it thoroughly inspected.
I still appreciate the improved efficacy I get from individual units. But maybe I've just never lived in a properly that has good central AC. I will watch the video, thanks for the link.
> But my parents' house was built in the 80s, and has always had serious problems with the upper level being much hotter than the lower level.
Sounds similar to my parents', which was built in the 70s, in IL.
<story time>
Last summer I visited and ended up doing a bunch of deferred home maintenance on the place. One thing I discovered was that the central air return vents weren't installed correctly, after 50 years of them paying out the nose for unnecessarily high electricity bills every summer.
The construction technique used was clearly prioritizing low-cost and had the main return duct running the length of the house above the basement ceiling just opening up on top into the floor joists to reach rooms upstairs. The bays between the floor joists served as ducts branching out horizontally from above the main duct, and holes were cut in the upstairs subfloor where the stud bays in walls would serve as return ducts on the vertical axis.
When they hung the main duct they left a huge gap separating the thing from the joists, upwards of two inches wide towards the far end from the air handler which was also beneath the vertical branch for reaching the highest/largest (and hottest) return vent upstairs.
So despite having all these return circuits ostensibly present upstairs, the main return duct just pulled most of its air through this much closer and substantial gap drawing air from the lower level between the basement ceiling and the upper floor's joists.
Everyone had always assumed the cold downstairs was expected because Basement, and that the upstairs was just always hot in summer because of poor insulation and all the windows.
The way I identified the issue was by grabbing a long grocery store receipt and placing it across all the return vents while the AC was running (just get the blower on 100%). The receipt was nearly sucked through the basement return vent, and immediately fell off all of the upstairs return vents except the one directly above the air handler in the master bedroom. The one upstairs that worked doesn't depend on the long, leaky return duct. Then I fully blocked the obviously working return vents with cardboard, just to see if the non-working ones would start drawing enough to at least hold up the receipt - they didn't, zero change.
I was able to improve the situation with a can of expanding foam filling the gaps on the main return duct, through drop-ceiling access... If I visit again I'm ripping out the basement ceiling to fix it properly.
TL;DR:
If you've got a house w/central air that seems to not cool specific regions, get yourself a piece of thin paper like a shopping receipt and some cardboard and try some process of elimination to verify the return vents are all sucking air. Don't just focus on output vents blowing cold. You can do this preliminary check without any tools or creating a mess, fixing what you find might be a different story though.
So I watched the video at 1.5 speed, and so much of what he is talking about is adding layers of insulation to mitigate rot that can happen when a structure is framed with wood, especially newer cheaper wood which isn't nearly as resilient as old lumber was. Not to mention the termite issue.
This dovetails with my other point, which is that masonry (not just as a facade) especially cement controls noise and seems to prevent needing all of these complex workarounds. I'd love to learn aside from "it's more efficient" (aka cheaper) the compelling reason for using wood vs cement.
It seems like it's just a foregone conclusion that of course we should be building houses with wood as the central element.
> I'd love to learn aside from "it's more efficient" (aka cheaper) the compelling reason for using wood vs cement.
It's less expensive in many ways. Materials cost less, it's faster to build, it requires less skill to build, maintenance is less expensive, and changes are less expensive. Unreinforced masonry is a significant earthquake risk, which may a factor.
Wood meets the requirements and it's less expensive, so there you go. There's downsides of course, but modern building requirements are tough to meet with any construction type; drafty houses make for expensive HVAC, but tend not to accumulate moisture which leads to bad things.
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[ 5.3 ms ] story [ 132 ms ] threadI've seen mentions of whole house fans in the ArsTechnica comments and was intrigued as to whether that would be useful for my house. Here in the UK, our houses are designed to keep warm and don't have any A/C built in and that's becoming more of an issue as summers get hotter. However, I've discovered that OnlyFans is not the correct website to find whole house fans.
So if you can get away with it, sure, plant some trees. :)
It has a blueish tint though and really doesn't do much if it's the ambient temperature that's too high.
These houses are honestly quite pleasant to be in. The insulation has the side effect of being very good noise dampening as well. I was talking to the owners of one and they said they'd never used the backup electric heater. The one time things got a little cold they light a candle in their bedroom and everything was fine.
So I think in temperate climates, the answer is air tightness and thermal control, not whole house fans.
In the types of old houses described in your link, this type of thing was designed to be done by one or more open fires, which drew fresh air in through cracks and crevices and exhausted up the chimney.
Very thick insulation Heatpump Solar panels
Very energy efficient overall.
Except... In the summer it overheats. Once it heats up you cannot get it to cool down at all. Horrible.
My house is a bit older so doesn't have it, but new houses must have a heat recovery ventilator. Almost all of these have a 'summer bypass mode' which bypasses the heat exchanger, so effectively draws warm air out of the house. This is useful in the summer, as here although it can get to 30c+ in the day, at night it almost always drops to below 20c. The way our houses are built we have a lot of thermal mass, so if you can cool it down during the night, it will make it a lot more comfortable during hot days.
It's going to become a much bigger problem in the UK as we're struggling with having enough housing anyway and making them energy efficient is going to take a lot of money and work.
The (US) city I live in has streets built in the mid-1600s.
Considering the great fire of London and the Blitz, is your canard really accurate?
I own an old (1890's) terrace house in the UK. The only part that overheats is the modern loft-extension that I built 5 years ago. For the main part, it's like a cave; it retains heat in the winter, and remains cool in the summer.
It has single-leaf brick walls, which should be bad; but the frontage is quite narrow, which makes it pretty energy-efficient.
Same. Our downstairs is nice and cool during the summer (not so much when it was getting near 40 degrees last year), but our upstairs gets much more light and can get too warm.
It's a mid-terrace house, which means that the side walls abut onto the neighbours' houses. The side walls are much bigger than the front and back. So not much of the external walls are exposed to the external environment, which is why it behaves like a cave.
To be clear, it's not like a heat-pump; it just maintains a reasonable temperature.
Did Maxwell's demon perhaps live in a cave?
https://www.bbc.com/future/article/20210810-the-ancient-pers...
"They have no energy sources other than the sun and wind, and yet they circulate cool air through buildings and traditionally provided cold water and ice for the hot summer of the country's arid regions"
https://sci-hub.st/https://doi.org/10.1038/scientificamerica...
Will be interesting to see how it works out in practice...
[1]: https://www.fremtidensbygg.no/nydalens-mest-spektakulaere-by...
[2]: https://www.avantor.no/?eiendom=vertikal-nydalen
It would be interesting to see something like this work in e.g. Houston: https://weatherspark.com/s/9247/1/Average-Summer-Weather-in-...
Luckily it was fully equipped with fans and AC as it did not work at all out in the desert.
The future of energy-efficient cooling is not going to be one solution that fits all. There are going to be different solutions for each region. Summer weather can vary wildly even in the same place, so many solutions will end up using software to actively adjust its own mode of operation based on sensor readings, just like a modern HVAC system. You don't want your cooling apparatus getting all moldy when it rains unexpectedly.
Enough "passive cooling" articles. That's ventilation, just a part of HVAC. These articles makes it sound like the ancient Iran and the termites knew something an entire industry full of engineers doesn't.
Just about everyone has the intuitive understanding that some old buildings do a very good job maintaining comfort, and that modern buildings often fail to do the same or only keep up at enormous expense. It's perfectly understandable that, in the wave of globalization and cheap energy that swept much of the world for half a century, we lost the craftsmanship to create these structures well, then the knowledge to do so at all, and all the while we didn't care because electricity was so cheap. Now we're clawing back stuff we used to be able to do as a matter of course.
Central air is miserable to maintain. I want to maximize my comfort with ceiling fans and window units, or maybe ductless.
We've known about thermal mass, convection, venturi effect and other stuff for ages, and it's not going to help you be comfortable (another thing termites have no concept of) beyond a certain envelope.
> Architect Mick Pearce famously based his design in the 1990s on the cooling and heating principles used in the region’s termite mounds, which serve as fungus farms for the termites. Fungus is their primary food source. > > Conditions have to be just right for the fungus to flourish. So the termites must maintain a constant temperature of 87° F in an environment where the outdoor temperatures range from 35° F at night to 104° F during the day. Biologists have long suggested that they do this by constructing a series of heating and cooling vents throughout their mounds, which can be opened and closed during the day to keep the temperature inside constant.
Old buildings did not have: thermal insulation, ventilation with heat recovery, timed ventilation, etc. While new buildings won't even get a building permit without all that. There's a minimum required energy efficiency.
I have to ask: what is your experience with civil egineering?
So true.
I want to maximize my enjoyment of warm humid air while targeting 10% of the energy usage of those who fear it.
I'm slowly replicating these techniques plus some fans to help push hot air out, including a gabel fan in the attic. I started getting awnings, but not yet on every window, they definitely help. Started planting trees around the property and around the house to create shade. I did get two window ACs, one on 2 ND and one on the 3rd floor, to help when it gets to high 80's and above. I want to see how far I can take this. I'm definitely going with the approach of having more air flow vs. other passive techniques that lock in the air, e.g. closed attics.
But some homes were indeed designed with climate in mind. The broad rear side might face the south to be heated during winter. The whole house may be configured with one long hallway with windows or screen doors at either end to allow cross breeze. Windows on different floors may be designed to open part way to facilitate cross breeze. The fire place may be located deeper in the house near the bedroom, with subsequent rooms getting farther from the fire so in winter you can shut the doors and only heat your own room with the one fireplace.
An attic fan that can switch between blow and suck is essential to keep cool (and prevent mold using air flow). When it's cool in the early mornings, keep windows open to cool the house, then close them when the sun rises and close shutters. As the temps rise throughout the day, you crack a window upstairs and turn on a window fan (blowing inward) and one window downstairs (blowing outward) to create a downward breeze, or the reverse to pump heat up and out.
My ex hasn't owned an AC in 10 years. She just regulates the doors and windows and has window fans. House is 130 years old
Why would the AC attic need to suck air in? I never thought of that but will consider it now.
I think it's tempting to ascribe some lost ancestral knowledge to older house, but to be completely honnest a lot of them weren't designed with thermal considerations in mind (or rather, the thermal efficiency was accidently achieved by following some heuristics).
A lot of these older houses were simply badly insulated. They required a lot of wood or coal to keep warm during the winter or had the occupants wearing layers inside at all times but would cool down quite fast in the summer during the night, only to heat up again during the day.
Good, explicit thermal design appeared with mid-century houses. [0]
[0] https://www.youtube.com/watch?v=Qq-3cZ0cbws
My second story in craftsman bungalow wasn’t finished until the 70s. And that is probably when the window AC was put in that makes it usable in summer. The first story has lots of windows for cross breeze and stays nice in summer.
We will likely see a massive expansion of air conditioning as more and more people come out of poverty and desire to be comfortable across the developing world.
We can’t conserve our way out of this crisis. We need abundant, zero carbon energy like wind, solar, and nuclear to support all the energy needs of humanity.
If we don’t have zero carbon energy people are not going to do without, they are going to burn fossil fuels. Take a look at Germany. Despite all their rhetoric about how much they care about climate change, they are burning coal which is the dirtiest of the fossil fuels.
I’m sure there are reasons it’s so common that I don’t know about, it’s not even close to an area of expertise for me. But moving from the US to Mexico I feel like concrete is the way to go vs drywall and wood framing. Sound insulation is so much better too.
I owned a brick ranch house in the US and had to have all the ductwork redone because it had accumulated mold. Cost me 3k. It just seems way more trouble than it’s worth.
That's a meme. There's a lot of variability between houses (and the shitty old houses don't tend to survive long), but insulation is one of the things that has unambiguously improved over time.
Matt Risinger has a good video on the "old houses were better" thing here, but his channel is full of great house-building content: https://www.youtube.com/watch?v=KBMMDY3LFAA
From what I have read, builds in the last 3 years have been horrendous due to supply and labor shortages. Maybe the sweet spot is to purchase something from before that era that is still new and get it thoroughly inspected.
I still appreciate the improved efficacy I get from individual units. But maybe I've just never lived in a properly that has good central AC. I will watch the video, thanks for the link.
Sounds similar to my parents', which was built in the 70s, in IL.
<story time>
Last summer I visited and ended up doing a bunch of deferred home maintenance on the place. One thing I discovered was that the central air return vents weren't installed correctly, after 50 years of them paying out the nose for unnecessarily high electricity bills every summer.
The construction technique used was clearly prioritizing low-cost and had the main return duct running the length of the house above the basement ceiling just opening up on top into the floor joists to reach rooms upstairs. The bays between the floor joists served as ducts branching out horizontally from above the main duct, and holes were cut in the upstairs subfloor where the stud bays in walls would serve as return ducts on the vertical axis.
When they hung the main duct they left a huge gap separating the thing from the joists, upwards of two inches wide towards the far end from the air handler which was also beneath the vertical branch for reaching the highest/largest (and hottest) return vent upstairs.
So despite having all these return circuits ostensibly present upstairs, the main return duct just pulled most of its air through this much closer and substantial gap drawing air from the lower level between the basement ceiling and the upper floor's joists.
Everyone had always assumed the cold downstairs was expected because Basement, and that the upstairs was just always hot in summer because of poor insulation and all the windows.
The way I identified the issue was by grabbing a long grocery store receipt and placing it across all the return vents while the AC was running (just get the blower on 100%). The receipt was nearly sucked through the basement return vent, and immediately fell off all of the upstairs return vents except the one directly above the air handler in the master bedroom. The one upstairs that worked doesn't depend on the long, leaky return duct. Then I fully blocked the obviously working return vents with cardboard, just to see if the non-working ones would start drawing enough to at least hold up the receipt - they didn't, zero change.
I was able to improve the situation with a can of expanding foam filling the gaps on the main return duct, through drop-ceiling access... If I visit again I'm ripping out the basement ceiling to fix it properly.
TL;DR:
If you've got a house w/central air that seems to not cool specific regions, get yourself a piece of thin paper like a shopping receipt and some cardboard and try some process of elimination to verify the return vents are all sucking air. Don't just focus on output vents blowing cold. You can do this preliminary check without any tools or creating a mess, fixing what you find might be a different story though.
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This dovetails with my other point, which is that masonry (not just as a facade) especially cement controls noise and seems to prevent needing all of these complex workarounds. I'd love to learn aside from "it's more efficient" (aka cheaper) the compelling reason for using wood vs cement.
It seems like it's just a foregone conclusion that of course we should be building houses with wood as the central element.
It's less expensive in many ways. Materials cost less, it's faster to build, it requires less skill to build, maintenance is less expensive, and changes are less expensive. Unreinforced masonry is a significant earthquake risk, which may a factor.
Wood meets the requirements and it's less expensive, so there you go. There's downsides of course, but modern building requirements are tough to meet with any construction type; drafty houses make for expensive HVAC, but tend not to accumulate moisture which leads to bad things.