My house has windows on every side for similar reasons, but it's back firing big time. I have to keep them closed at all time because of noise, and they let the sun in, requiring even more A/C. We have blackout/insulating shades, but it's still not as good as straight up walls.

So millage will vary.

Similarly with light, in winter by the time I get home its pitch black either way, so it wouldn't change a whole lot. And in summer the light from the windows doesn't play well with TV/monitors/etc.

Cats like the windows a lot though.

Depending on the style of house it may look out of place but can you put awnings on the exterior above your windows? This usually has the effect of blocking sun when it's high in the sky and the hottest while still allowing the sun to hit the window when it's lower and cooler (morning, evening, winter months).

Not surprised - solar gain from having lots of big windows is one of the big reasons why some homes get far too hot here in the UK. They effectively turn the house into a big greenhouse. Supposedly the problem can be reduced a bit by having the windows aligned north-south so they avoid getting so much direct sunshine into the rooms over summer, though that's going to be very latitude dependent.

I am suffering that at the moment in Oxfordshire. Just a bit of morning sun heats my bedroom up to 28 C. Totally insane.

Leaving the windows open barely helps.

My grandmas flat, in Southern spain, did not have AC. But thanks to big walls and external blinds you could live comfortably even during 40+ C Summer days.

External blinds are a killer feature both for heat and cold insulation.

This is what eaves are for. Since the sun is lower in the sky in the winter, properly sized eaves will shade the windows in summer and expose them to sunlight in the winter.

>A lot of the need for AC (and having lights on) is just really, really bad modern house design.

Agreed, but people also seem uninterested in simple techniques to work with what they've got. I live in MA, in an old house that doesn't have much in the way of modern energy efficiency but we get by without AC on all but the hottest days of the year by doing really simple things. Open windows at night. Close them in the morning. Pull the blinds down on windows that have sun exposure. You get the idea. The only serious retrofit we've done so far is have a contractor add cellulose insulation to the attic. On 90+ degree days the second floor will reach 80+ by the evening so then we turn on the AC if a window fan is unable to bring the temperature back down to something comfortable. In our climate AC should be the backup plan, not the primary cooling system.

+1 on this, I live in an apartment without balconies and without external blinds, so one cannot survive without full AC in summer. At least the glass windows can be opened when it is not raining, some commercial buildings have fixed windows. My parents' house has Venetian blinds and we survived without AC, now they have AC but just for sleep time.

> If I close windows in the morning and open around 7pm,

I have explained the same things to my friends who come over to visit me. Some of them think I am crazy, others get it.

I have the benefit of a giant open loft, 2 story ceilings coming off the living room right into the master bedroom, with a giant ceiling fan sucking air in from outside and a large window open upstairs so the air has someplace to go.

If it gets to 90 it can be a bit uncomfortable, but the mid 80s is fine, it only gets a bit hot around 5pm or so.

I have friends who keep all their doors / windows open and use a fan throughout the entire day. Great job sucking the hot air into the house!

Although for older houses with lower ceiling that is pretty much the only way.

Have you looked at installing a attic fan to pull air from the lower floors upwards into the attic for venting? I recall This Old House doing a segment on this some time ago and a cooling option.

(edit) added link to youtube video

https://www.youtube.com/watch?v=Rwe8c6wr0AA

This is an easy upgrade for any home and can be done by a relatively competent DIYer or an HVAC contractor. The main point is that your attic is much hotter than anywhere in the house, so if you can get the attic close to outside ambient, it will help. I personally have my attic fans (one at either end of the house) set up on a separate thermostat from the rest of the house, where any time the attic temp exceeds 90F, the fans kick on.

Doing this will even make your AC system work better if you have one, since you won’t have the extremely hot air in your attic heating your ceilings

This is much less of a good idea than you think:

https://www.energyvanguard.com/blog/75600/The-1-Reason-Power...

A whole house fan is a very different story, but it’s only really useful in some climates.

Yeah I read through that posting and I’m still not convinced that the original poster there is on to much. To add to all of the disagreements in the comments there, I also noticed that my AC works much less hard on hotter days, and noticed a slight reduction in costs monthly electrical costs year of year. There are a lot of variables in play to go into an electrical bill however.

It seems plausible to me that if you have decent air sealing in your house and wildly inadequate ceiling insulation then an attic fan could help. Or if you have poor air sealing but you have enough space for outside air to enter your attic.

In a well-built house, the roof and ceiling shouldn’t be a major source of summer heat gain.

My parents have one and you can feel it all over the house. Works great if a little loud.

Do you have any renders by chance (assuming you used CAD to design it)? I want to build a house optimized for natural light as well (not sure about ventilation since the place it would be built is cold most of the year).

Yeah, it's not too hard to deal with 90F without AC, but we often get 99F (37C) during the day and 86F (30C) at night, so no amount of ventilation will save you from feeling overheated day and night.

What we really need is solar-powered AC. Ideally DC-driven air conditioning.

there are two common mistakes in many modern implementations of central air.

the first is the hardest to get done as most hvac companies resist, having the exhaust not be at the exact end of the the pipe. the pipe should end just beyond it.

the second is not having a return or sufficient returns in each room. if you are stuck with a central return then make sure doors are open if the room has no pass through vent to the hall with the central return; at most the master bedroom will have pass through vents to a hall so the door can remain closed.

the only omission from my current home is an attic fan but building codes precluded it at the time but I hear I can do it now if I want.

still I find even with central air a lot of comfort can be found by having a dehumidifier. down in the south it is not uncommon to wake to humidity higher than the temperature which makes it feel sticky and uncomfortable.

with regards to cooling needs and such, we simply have changed what we want and want we are willing to tolerate. its not a bad thing, we just have to find efficient ways to have it.

Building very tight house with good insulation is the key. Then of course you need an ERV to keep the air good and a separate dehumidifier is also great.

If you have cool nights and your heatwaves don't last too long large thermal mass is also very good and can be enough.

A dehumidifier is an air conditioner, but packaged in a way that doesn't allow it to work as one. (The upside is the easy installation.) Suggesting a dehumidifier to avoid AC is ridiculous.

how much power do you actually save with a dehumidifier compared to an efficient ac installation? afaik, most dehumidifiers need to cool the air anyway to lower the humidity. seems like any savings would be marginal.

Having lived where it cools off nicely at night, and then where it doesn't - this is just not a generally applicable solution.

When it only gets down into the upper 80s (thats around 31C for those afflicted with metric) at night with humidity at 90% or higher, AC is mandatory.

When its up around 98 (37C) with high humidity during the day, not having AC can be a killer.

> everyone acted like I was crazy for not building in central air conditioning. (This is in New Hampshire)

Really? In NH? How many days a year it even reaches 90?

I’m sure it’s nothing like the south east, but it gets pretty hot, mostly in July and August. Living in a hotter but drier climate now (which is on the whole more comfortable than back in NH), I realize that the humidity played an important part in it feeling hot and uncomfortable. Mid 80s in dry heat is many times more bearable than mid 80s in humid weather, and the same thing goes for the cold too.

Yeah I was going to say the same. I live in MA to the SOUTH, and almost no one here has central air except richer and/or older people.

Most American houses are barely fit for purpose. It's time for a major re-think of construction methods, styles, materials, and priorities.

Somewhere, the ghost of Bucky Fuller is sighing, and looking at one of his wrist watches...

https://exhibits.stanford.edu/bucky/feature/what-is-a-dymaxi...

Did you put an awning around the outside of the house? At least on the first floor? This is a common feature in Australian houses to keep the actual house shaded and cool.

Another interesting feature are houses that are built on brick pillars raised off the ground without a concrete slab. It’s amazing how even on a hot day they remain quite cool underneath and seem to cool off quicker at night. Many older wooden houses seem to be built this way.

I like to mentally toy with the idea of high rises or large apartment blocks having some kind of large retractable awnings on the sunny side of the buildings, or some kind of fake outside wall which can diffuse some of the suns light / heat.

Are there any resources where I can educate myself on this? I bought an apartment in a 28 storey building recently and I was struck with the lack of interest and thought on my questions on natural ventilation and natural lighting. I'm a long way from designing a house but I'd definitely want to educate myself on topics like how do you guess the air flow direction, what direction is the sunlight going to be during what months, what about rain fall, what are good insulators you can use, etc. you get what I'm getting at.

You can read more about the design and construction techniques used in zero-energy buildings.[0] They consider natural ventilation, sunlight, insulation, etc. in ways that conventional construction ignores.

[0] https://en.wikipedia.org/wiki/Zero-energy_building

Well, the easiest way to see what the air flow direction is at any time in any space, is to light a stick of incense, and then watch which way the smoke goes if you hold it quite still.

This works, as you say, until the air during the night is much colder than during the day. In one summer there were weeks when the air during the night was 27C and it obviously did not cool down.

Another downside is that when you do not have mechanical ventilation with heat recovery and your rooms are relatively well built (i.e. air tight) then you are left with bad air quality inside.

I think that best is to combine night cooling with mechanical ventilation with heat recovery.

> With this design, there have been 3 icky-hot days so far this year, when there was no wind and the night did not get very cool.

As you noted, this used to be a fairly standard design for homes in some areas.

Perhaps a "whole house attic fan" could help on those marginal days?

The same thing happens here in Arizona; the proper way they should be building houses here would probably be a monolithic dome with most of the home set below grade - although caliche would make that difficult in some areas (and it would be expensive regardless). The next best thing would probably be rammed earth with 2-3 foot thick walls.

Modern insulation is really good - much better than you get with rammed earth. Rammed earth isn't a particularly good insulator, it just has really high thermal mass, so once it heats up (and out here, it will heat up), it will continue leaking heat into the interior of your structure for quite a long time. Thermal mass doesn't prevent heat transmission, it just delays it.

The biggest heat transmission problem in most construction isn't the walls, it's the windows. The amount of heat transmission you get via glass - even high-performance triple-pane glass - is significantly higher than heat transmission through the rest of the structure. Your walls are going to be R20+, your attic insulation will be R35+. Your best windows are going to be equivalent to R6 or so, with the median windows being significantly lower.

Main energy gain happens because of the radiation.

I think that the best combination is high thermal mass structure followed by the insulation inside. This way the heat is not easily transmitted to the inside and the thermal mass can cool off to the outside during the night.

Of course when the heat finally does get inside then it is trapped because the house will act like a thermos and only way of cooling would be the by circulation of cold air.

Problem of windows can be solved by outside blinds (or shutters but blinds are better) and IR reflective coating.

There's newer double/triple pane windows that have blinds built in which are nice

Are you aware of anyone using eutectic salts in the walls in the desert? I remember reading an article from the 70s about it and it seemed well suited for desert environments where there's a large temperature swing from day to night. They would absorb heat in the day keeping the house cool and release it at night keeping it warm. If I remember correctly, the difficulty was finding salts that worked on the right temp range

I'm not sure why you're getting downvoted? I was in Tucson in the summer in a rammed earth house (about 2-3 feet thick as you mention) and it was comfortably cool inside. The whole house had very large eaves, as well [1]

[1] I don't recall the other design details that made it so cool in temperature, but it was all analog/natural (i.e. no AC)

"I built in an older style, with windows on every side, with a mind towards ventilation and light. Inexplicably most houses in the area, even $500k+ houses do not have these two things."

Many people do not have exterior walls on all sides. You must be generally aware, because your next sentence mentions a condo (in my case I have a townhouse).

>A lot of the need for AC (and having lights on) is just really, really bad modern house design.

You can design a house however you want, but without AC it's going to be hot and miserable here in Indiana when it's in the 80's or 90's with 80%+ humidity unless you have AC.