Don't force your air on me. Looking for non HVAC resources.
November 26, 2017 1:40 PM   Subscribe

So, for reasons that I won't get into and that aren't open for debate, I cannot deal with forced air units -- heating or cooling. Radiant heat is okay and fans are doable. But anything that pushes air into the room beyond what a ceiling fan does just isn't gonna do it. We're building a house in a few years and need ideas/resources about airflow that don't require HVAC.

Like I said above the fold, the reasons are irrelevant and not open for debate. HVAC is out, so are ductless units that push air into the room. Heat pumps are a no-go. Anything that requires a filter... not happening.

Radiant heat is fine. Ceiling fans are already in the plans. I'm not interested in hearing how "efficient" anything is, to be honest. Efficiency isn't what's being discussed here. Unless it involves how to efficiently move air through a house without forcing it through ducts or anything with a motor bigger than a ceiling fan.

I need resources for house designs and ideas about how build a new house designed around air flow. We live in an area of WA state where it doesn't get very hot nor does it get below freezing very often (though it does upon occasion). Also, keep in mind that we don't have to heat the entire house, just the living area and enough to keep the pipes from freezing on those occasions when it does freeze.

Whenever I try to google this, I get HVAC sites or "green" sites that have super elaborate setups that are way expensive... like low grade geothermal heating, or hot water running through all of the floors... and that's not what I'm looking for. I just want to figure out how to make the new house work for me when it comes to heating and cooling. Like, will a sunroom on one side be good for storing heat? and are vents in the roof are a viable option? I dunno. I'm not an engineer.
posted by patheral to Home & Garden (27 answers total) 6 users marked this as a favorite
 
For heat there are options, like baseboard heaters (which can be electric or hot water/steam), with no fans at all. But cooling without blowing air is going to be the trick; you might be stuck with just venting and passive options like insulation and shade.
posted by Dip Flash at 1:50 PM on November 26, 2017 [1 favorite]


Electric radiant baseboard heaters and ceiling fans seem like a fit for the heating and cooling needs in a temperate-ish climate, and you can create zones so only parts of the house are warmed to habitable temperatures. Nearly every home I'm ever lived in had that setup.

You can use blinds to effectively cut the heat from morning sun in the high parts of summertime.
posted by notorious medium at 1:52 PM on November 26, 2017


There's electric underfloor radiant heating, which would definitely be less elaborate and expensive than hydronic heating, and probably nicer than electric baseboards.

There are also radiant gas wall heaters.
posted by ShooBoo at 2:00 PM on November 26, 2017


Since you are looking primarily for heating, if you have enough sun exposure during colder times of the year, I'd look at solar space heating. I think the simplest approach is a low solar mass sunspace, but there are a variety of other approaches on the Build It Solar DIY space heating page. The site also has ideas for circulating warm air outside the sunspace without HVAC, which could also be helpful if you choose to use radiant heat or baseboard heaters in selected areas of the house instead of passive solar.

For cooling, at minimum, ensuring high efficiency roof vents in the attic is a good start (keeping the attic cool allows the rest of the house to remain cooler). Shading in summer is a good approach for cooling in temperate climates (e.g. deciduous trees, overhangs, louvres see passive heating and cooling for more ideas). Windows and openable skylights can allow flow-through ventilation even without wind due to the stack effect.

Do add mechanical ventilation for bathrooms and kitchen venting, even if you don't have any other mechanical ventilation in the house.
posted by dttocs at 2:01 PM on November 26, 2017 [3 favorites]


Here's the thing: split-unit ductless HVAC units - ie, most heat pumps - don't force air through ducts or by using a motor greater than a ceiling fan. CFM - or the amount of air that is recirculated through the device every minute, generally recirculate anywhere from 130 - 500 cubic feet of air per minute (CFM). Ceiling fans, on the other hand, actually recirculate far more air when set on their top setting - often over 5000 CFM.

As many have mentioned above, you can install a radiator (water/steam) or baseboard (electric) system for heating that will do zero CFM for heat, and that's fine. But when you talk about cooling, a zero CFM solution doesn't really exist. A split-unit cooler or heat pump doesn't bring in air from the outside through a duct, and many recirculate far less air than a fan, but it sounds like those are out, so it's difficult to make a recommendation without your specific reasons or requirements.
posted by I EAT TAPAS at 2:06 PM on November 26, 2017 [2 favorites]


Just to clarify... ceiling fans on their highest settings are pretty scary (they wobble like crazy -- I've never had one that didn't). I usually keep them on low to move the air around. I'm not worried about cooling the air down --
refrigerated (or cooled) air is part of the problem. I'm more concerned with keeping it moving through the house.
posted by patheral at 2:13 PM on November 26, 2017


I think you should read about passive solar and have transoms above every interior door.
posted by Mr. Yuck at 2:35 PM on November 26, 2017 [2 favorites]


When I renovated my home 4 years ago, I installed floor heating all over, powered by a geothermal system. I read your question and I'm still writing this, because you have no idea how much I'm saving on energy. Two years ago, I also installed solar panels and now I use a tenth of what I spent on heating and electricity before. Also, my house is now sound, where before I was always struggling with moisture (in a similar climate to WA). My house isn't optimally insulated - it would be even cheaper to heat with more insulation, but it would also need more ventilation.
The heating in my house needs the supplement of a fireplace in the coldest months.
I could achieve a similar effect with the same building design and a better insulation under the floor.
I too hate, hate, hate AC. So another thing I did was to make sure I can cross-ventilate the house. I was inspired by a house I stayed in in Veneto, Italy, where the summers are hot and damp and infested by mosquitos. A central suite of rooms was placed so even a slight breeze would move through when doors were opened and take the still air out of the other rooms with it. The air was cooled when it moved through the building*. Those rooms weren't pleasant to stay in when they were doing their ventilation job, but were grand at other times. My own house is long rather than cubic, so I have two places where I can create a draft. It takes out all the insects as well. The ventilation takes 10 minutes a day. During the hottest months, doors and windows are naturally open all day, but mainly those facing north, which contributes to a good indoor climate.
The ideal setting for cross-ventilating spaces is north-south, with a good overhang or porch in front of the south openings/doors. You can just have one room spanning the building, which can be beautiful, but if you have two rooms en suite, one can be a lovely warm south facing parlour during winter, and the other a great storage space all year.

*The floor in the cross-ventilation spaces is in part stone/tile. It doesn't need to be stone all the way. If it is very hot outside, you can pour some water on the stone floor to enhance the cooling of air, but to date, it hasn't been necessary here. The stone keeps the heat from summer a long time into winter, and then the cold from winter a long time into summer. This treats the moving air. If you have two interconnected spaces, the stone floor goes in the north.

So in short: make sure your house is well-insulated. Make sure you can cross-ventilate it. And provide good overhangs, to prevent excess heat during summer and excess moisture during winter. A north-south orientation is probably best, with the kitchen an utility spaces to the north and living rooms to the south.
posted by mumimor at 2:58 PM on November 26, 2017 [5 favorites]


You could just use radiators. I grew up in an older house that didn't have air vents for heat, just radiators. And I agree that insulation is important -- if your house isn't well insulted, you can hire someone to fill your walls with insulation, which my parents did at their current house because it was getting too cold too quickly in the winter.
posted by AppleTurnover at 3:27 PM on November 26, 2017


I rented a house once that had an attic fan. In the evening, open all the windows, turn the attic fan on and cool air is sucked thru the whole house. This was in Northern California where it cools off quite a bit in the evening.
posted by elmay at 4:20 PM on November 26, 2017 [6 favorites]


Radiant floor heating is the way to go, but if you're taking new construction with a natural gas hookup, go for hydronic. I have the electric version in Seattle (because I loved the hydronic one in my old place so much, but don't have gas here or sufficient amperage to install an on-demand water heater), and it was quite expensive to purchase and install, and my electrical bills are expensive. Still worth it. My place is awesomely cozy and warm.

Because there is no HVAC system to filler the air, I run an (expensive) air purifier at home. Air quality has improved notably, and I don't even live near a freeway etc. Don't skip that step.
posted by halogen at 4:55 PM on November 26, 2017


Four principles:

1. Controlled insolation (ingress of daylight): you want the structure oriented, and windows and eaves arranged, in such a way that the low-angled winter sun penetrates deep within the structure but the high-angled summer sun is shaded out.

2. Cross-ventilation: you want your (insect-screened) windows and vents placed so that you have openings of controllable size all around the building and free flow of air within it, so that no matter which way the breeze is coming from, you can let it in on the upwind side and out on the downwind side.

3. Extreme thermal mass in the living spaces: you want such sunlight as comes inside to fall on large heavy structures that will be slow to warm and equally slow to cool, so that the temperature of the internal walls and floors remains as stable as possible.

Note that this is the opposite of what you want inside a structure specifically devoted to warming air, such as a low-thermal-mass sunspace. Sunspaces make good retrofits for buildings whose insolation into the main living space is less than optimal for whatever reason, but if you're doing clean-sheet design it's usually cheaper not to need them in the first place: you get better performance from a given amount of glazing area by arranging for the sunlight it admits to strike an interior warmth store directly, rather than relying on the movement of heated air to carry it there indirectly.

If a building's walls and floors have extreme thermal mass they will naturally tend to hold onto their existing temperature as hot or cold air flows past them. This will let you ventilate the building quite well without much effect on its average internal temperature. Just close down the vents during the hottest parts of the day or the coldest parts of the night, and the internal air will rapidly cool or warm to match the heavy walls and floors.

4. Highly insulated skin: having built a structure capable of adopting a comfortable internal temperature via the interplay of insolation and thermal mass, you want it to be able to maintain that internal temperature regardless of what's happening outside. So you want the exterior walls to be as resistant to heat transfer as you can afford.

Although these principles are often touted as being all about efficiency, they're really about designing comfortable buildings. A well designed passively heated and cooled building just is comfortable, all year round, without needing a bunch of mechanical add-ons to move heat around inside it. The building is adapted properly to its surroundings and just inherently fit for purpose; this is something that as a person who objects to mechanical air handling you are almost certain to feel directly.
posted by flabdablet at 5:25 PM on November 26, 2017 [6 favorites]


By the way, hot water running through all the floors (hydronic heating) is indeed gloriously comfortable. But I have been inside passive solar houses where the floors felt every bit as comfortable as that and the only way that heat got into the floor was from sunlight shining straight on it during the previous month.

Spending a bit on architects and engineers to get the relationship between glazing and thermal mass right can save you a packet from the resulting lack of need for mechanical HVAC design, installation and operation.
posted by flabdablet at 5:43 PM on November 26, 2017 [1 favorite]


A thought about insolation: it took me the longest time to understand what really should have been obvious from high school physics classes, which is that light - visible light - causes warming when it's absorbed by darker-coloured things. To a good first approximation, the heat of the sun is not something extra you let in through a window along with the light from the sun, it is the light from the sun.

Which means that if you've designed your glazing in such a way that the interior of your house doesn't feel gloomy on a winter's day, to the point where you're actually not tempted to throw on an electric light as well, then the interior will also be absorbing enough heat from that incoming daylight to keep it comfortable in winter - and all you need is enough thermal mass to bank that heat overnight, and enough insulation to stop it leaking away.
posted by flabdablet at 6:16 PM on November 26, 2017 [1 favorite]


I rented a house once that had an attic fan. In the evening, open all the windows, turn the attic fan on and cool air is sucked thru the whole house. This was in Northern California where it cools off quite a bit in the evening.

This. The house I grew up in had an attic fan. It worked great, especially in the evenings. Daytime, though, was more iffy. Summers can be pretty hot and humid here in Indiana.
posted by Thorzdad at 6:43 PM on November 26, 2017


One option for cooling is a swamp cooler... A fan blowing air past a wet towel or through water. Evaporative cooling without forced air. But cooling will be a much bigger challenge than heating, so you will want to build with that in mind - a style better suited for warmer climates- and then just pay a bit higher heating bills.
posted by Easy problem of consciousness at 6:47 PM on November 26, 2017


cooling will be a much bigger challenge than heating

A thermally massive interior and a well insulated skin helps here as well. Cross-ventilate at night when the outside air is at something approaching a comfortable temperature, then close up the house during the day. Your properly designed external eaves and shades keep out most of the sunlight, your insulated skin keeps out most of the heat from the hot air outside, and the interior stays more comfortable than a poorly designed building can achieve regardless of how frantically it pours energy through its AC.
posted by flabdablet at 7:05 PM on November 26, 2017 [3 favorites]


If you're seriously interested in passive solar design and you have a block with a slope that faces the equator, give some serious consideration to earth-sheltered designs.

By digging the building into the earth rather than having it sit on top, you get unbeatable amounts of thermal mass for free and you won't need to worry about much external painting, roofing or guttering.

The temperature of the earth below the frost line, and therefore the natural interior temperature in a dwelling carved out of it, tends to stay pretty close to the year-round average air temperature of the site, regardless of how much difference there is between the hottest daytime maximum and the coldest nighttime minimum.

In most places that turns out to be somewhat cooler than is comfortable for human habitat. Judicious use of glazing can then raise that natural temperature to whatever pleases you.

Cross-ventilation in an earth sheltered building can be achieved by using a stairwell or dedicated ventilation atrium at each end.
posted by flabdablet at 8:12 PM on November 26, 2017


I saw a very interesting passive solar heater , the interior portion was a four foot tall steel tank twelve feet long six inches thick filled with water, enclosed with ventilated panels shelf on top flush against the south facing outside wall , this wall had a peculiar small window at floor level, during the winter the full sun shines through this small low window and heats the tank inside . It worked too well some days and they had to decrease the opening , kept warm for months, for free.
posted by hortense at 8:26 PM on November 26, 2017 [1 favorite]


Water makes great thermal mass. You have to dump huge amounts of energy into water (or take huge amounts out) to shift its temperature. This is why electric kettles are so energy-hungry.

The materials commonly used for thermal mass also double as structure: mudbrick, concrete and so on. But the specific heat of concrete (the amount of energy you need to add to a kilogram of it to get one degree of temperature rise) is 0.88 kJ/kg°C; the specific heat of water is nearly five times that at 4.2 kJ/kg°C. So even though concrete is about twice as dense as water, any given cubic metre of your interior occupied by water has a bit over twice the temperature stabilizing power of the same volume of concrete.

That solar heater design, where the radiant heat of the sun is supplied at the bottom of the tank, also takes advantage of convection inside the tank itself. The water inside the tank will tend to stratify into a warm layer near the top where the air heat exchange vents are, and a cool layer near the bottom where the window is. That keeps both the air heat exchange and the radiant absorber working efficiently.

The volume of the tank - 3.6m x 0.15m x 1.2m = 0.65m3 - is about twice that of a typical domestic hot water storage tank.

All in all, it sounds like a nice bit of engineering if it was a retrofit to an existing dwelling, especially if that building had wooden flooring.

But here's the thing: even a design as elegantly simple as that is still more complicated than you need in a new build. Just allowing the same amount of sunlight to come in through the same area of glazing and get absorbed by a dark concrete floor or wall would work about as well and should cost less.
posted by flabdablet at 9:10 PM on November 26, 2017 [1 favorite]


Thanks for the information, y'all (especially flabdablet). Our property is on the hundred year floodplain -- which we knew when we bought it -- so we can't really dig into the earth. I'm pretty sure we should be building up, not down on the floodplain. Anyway, other than that, and the fact that this part of WA is cloudy most of the year (we average about 150 sunny days a year), y'all have given me a lot to chew on, and I appreciate it.
posted by patheral at 10:22 PM on November 26, 2017


Our property is on the hundred year floodplain -- which we knew when we bought it -- so we can't really dig into the earth.

And you say you're not an engineer? Fiddlesticks :-)

Anyway, a good design for you then would be to build something like a Queenslander, on concrete piles that will never rot out, set deep enough and strong enough to resist having the house pushed over by flood currents and to hold up a reinforced concrete slab thermal mass floor above the hundred year flood level. Insulate the crap out of the underfloor, the ceiling and the exterior walls, and make sure the attic incorporates nice big crossflow vents.

Add screens around the piles, creating a shaded space underneath that wants to stay cool in summer though it's ventilated enough to avoid getting fusty. Add operable floor, ceiling and attic vents that allow hot attic air to rise out and draw cool under-house air in behind it; and have operable, insect-screened windows that you can use for direct internal cross-ventilation on days when the outside temperature is pleasant. Keep the interior layout as open as possible and align internal doors to facilitate crossflow.

Surround the house with deciduous shrubs and arrange a branched drain system that keeps these watered at all times by direct drainage from your bath and shower (let that water drain directly onto the soil, don't try to store it). Re-using only the bath and shower water in this way should mean you don't have to worry about the soil salting up from laundry detergent. In the summer, transpiration from the shrubs will help cool the air in the underfloor area and make it smell nice when it's pulled into the house, and the fact that they're permanently watered should protect you against grassfires.

Glaze and shade to insolate the floor slab with winter sun. You could also incorporate an internal thermal mass wall made of brick or mudbrick or concrete or rock, that also sees winter sunshine through the windows.
posted by flabdablet at 10:49 PM on November 26, 2017


You mentioned ceiling fan wobble. A ceiling fan that wobbles is either not installed right or not balanced right. Mine run at very high speed with no wobble, but it took some fiddling to get there. If you are having a professional install them, do not settle for any wobble at any speed.

I hate ac too, unfortunately I live in Houston Texas. Keep living the dream, and good luck with the new house!
posted by BeeDo at 7:34 AM on November 27, 2017 [2 favorites]


Surround the house with deciduous shrubs and arrange a branched drain system that keeps these watered at all times by direct drainage from your bath and shower (let that water drain directly onto the soil, don't try to store it). Re-using only the bath and shower water in this way should mean you don't have to worry about the soil salting up from laundry detergent. In the summer, transpiration from the shrubs will help cool the air in the underfloor area and make it smell nice when it's pulled into the house, and the fact that they're permanently watered should protect you against grassfires.

We're already on a well/septic system, so that shouldn't be too difficult to implement. But the water/drainage ideas are a whole nother kettle of fish because the current system was put together with rather... iffy standards. ^_^

You mentioned ceiling fan wobble. A ceiling fan that wobbles is either not installed right or not balanced right. Mine run at very high speed with no wobble, but it took some fiddling to get there. If you are having a professional install them, do not settle for any wobble at any speed.

Eh, I lived in The South forever and had ceiling fans in dozens of homes. They all wobbled on high speeds. Right now we have one ceiling fan, and it's in a room that does nothing to help air flow -- this is a 1980's manufactured home -- so we don't use it. But when we have the new house built they'll be installed by whomever is installing the lights/electrical fixtures, so hopefully, no wobbles. ^_^
posted by patheral at 8:37 AM on November 27, 2017


Passivhaus (Passive House) is a home building standard where the house design allows the home to be livable throughout the year without any active components. Things like thermal mass, placement of windows for heat in the winter but not in the summer, natural ventilation inside the building as well as cross-ventilation. It works better in areas where it doesn't get too hot or cold so Washington would seem to fit the bill. I'd hope you'd be able to find a couple of builders relatively nearby who do this kind of work.
posted by any portmanteau in a storm at 12:03 PM on November 27, 2017 [1 favorite]


this part of WA is cloudy most of the year (we average about 150 sunny days a year)

The diffuse light of a cloudy day can still heat a building. That's how greenhouses work.

If you have large glazed areas normally shaded by external shutters, but you can open those up to make the interior feel bright even on a cloudy day, you'll be collecting solar heat inside. Visible light comes in through the glass, is absorbed by whatever it strikes inside the house, and warms it a little. That makes the warmed object radiate much lower-frequency non-visible light, way down in the infra-red band. Your body can still feel that radiation as warmth, but window glass is nowhere near as transparent to low-frequency infra-red as it is to visible light, so the low-frequency radiant heat ends up trapped inside.

The trick with glazing is to spend up big on double-glazing, which is much more resistant to letting heat out via conduction than ordinary window glass. You can even get superwindows that perform very nearly as well as an insulated wall. Obviously these options will be quite a lot more expensive than ordinary window glass, but the difference should cost you rather less than a furnace and an air conditioner.
posted by flabdablet at 3:11 AM on November 28, 2017 [1 favorite]


I used to know someone who with the help of some friends jerry-rigged a Buckminster Fuller silo house like this: http://www.stuartmcmillen.com/comic/chilling-domes/#page-1

This was in north Florida. She said it was lovely and breezy inside.

Does it ever get hot enough to need this? Maybe you could make a small one for a studio/summer sleeping cabin thing.
posted by Don Pepino at 9:52 AM on November 28, 2017 [1 favorite]


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