Natural Ventilation and Bio-architecture: Baan Dumneon, holiday home in Thailand

[Morakot]

Baan Dumneon, holiday home in Thailand

19-06-2013 floornature.com

On the basis of the principles of bioarchitecture, Methus Srisuchart and Ginggal Metchanun have built a holiday home in the Damnoen Saduak district near Bangkok, which they entered in the Next Landmark international architecture contest organized by Floornature. The building’s orientation, use of local materials and the flexibility of the walls permitting natural ventilation are the principles underlining the design of the project, with its form inspired by traditional Thai homes.

http://www.floornature.com/projects-housing/project-baan-dumneon-holiday-home-in-thailand-8647

[joeaverage]

it is interesting, but hardly unique, would most certainly be happy there myself

Edited July 4, 2013 by joeaverage

[Morakot]

Thanks Joe. Well it's a concrete example of the idea of natural ventilation.

How pleasant would this environment be in terms of its ambient climate?

[Artisi]

Natural ventilation is all well and good, but what ever the ambient temperature outside, the inside temperature will over the course of the day rise to be the same so I don't see any good reason to encourage the inflow of hot air into the house. The ideal design is to have a construction that will dump the internal temperature to whatever the lowest temp. is during the night and to maintain this lower temp. for as long as possible during the day while excluding the increasing outside temp. with building orientation,shading and insulation. That means closing all windows, doors etc that allow hot air to enter the building. It's not rocket science - just common sense.

[Naam]

a big [not so] natural help to obtain and maintain a pleasant indoor environment, when ambient temperatures rise above 30ºC, would be the installation of airconditioning.

[doglover]

_{Solid concrete walls is the way to go for a naturally ventilated home. The following link is a good source of info for a non-air conditioned home. Possibly even Naam could be somewhat comfortable, part of year, in a home like this?}

_{http://terra-pacific.com/?page_id=1083}

[Naam]

_{Solid concrete walls is the way to go for a naturally ventilated home. The following link is a good source of info for a non-air conditioned home. Possibly even Naam could be somewhat comfortable, part of year, in a home like this?}

_{http://terra-pacific.com/?page_id=1083}

when i read "concrete thermal mass helps cooling the home" and that in context with "homes in the tropics" i feel like

[Naam]

1. The following link is a good source of info for a non-air conditioned home.

2. Possibly even Naam could be somewhat comfortable, part of year, in a home like this?

1. the link leads to a company located in Hawaii which has a rather moderate climate with ambient temperatures never reaching really high tropical temperatures as we face in Thailand. add to this the rather steep drop to minimum temperatures and placing the home at an elevation exceeding 500m above sea level the room temperatures might suit people who can't afford airconditioning.

but whatever, the claim "concrete thermal mass helps cooling the home" is an oxymoron which rapes the laws of physics in an utmost pervert way!

2. no! Naam (who spend several times a week on Hawaiian islands) wouldn't find the average relative humidity in Hawaii comfortable and would insist on airconditioning instead of ventilation.

[Morakot]

Hilarious some of the discussions... excellent link Mr Doglover!

I fully agree 'concrete thermal mass helps cooling the home' especially when the concrete is placed in a fridge prior to cooling the home. As to whether there is generally a reverse proportionality in relation to the hight of dwelling above sea level to wealth needs to be seen. Anecdotal evidence from Hong Kong for example suggest the exact opposite.

Edited July 5, 2013 by Morakot

[David48]

How do you rate, in a tropical climate such as Thailand, the cooling thermal effects of a concrete slab on ground which is shaded from direct sunlight?

.

[Naam]

How do you rate, in a tropical climate such as Thailand, the cooling thermal effects of a concrete slab on ground which is shaded from direct sunlight?

.

the indoors of a house on a concrete slab is much hotter than a house on stilts. this is what some ignorants in Thailand believe.

reason: they possess a wealth of "no idea"

[David48]

How do you rate, in a tropical climate such as Thailand, the cooling thermal effects of a concrete slab on ground which is shaded from direct sunlight?

.

the indoors of a house on a concrete slab is much hotter than a house on stilts. this is what some ignorants in Thailand believe.

reason: they possess a wealth of "no idea"

Sooo ... are you agreeing that a shaded slab has a cooling effect?

Or a house in stilts with the air circulation is cooler and a slab on ground is actually hotter?

.

[Morakot]

How do you rate, in a tropical climate such as Thailand, the cooling thermal effects of a concrete slab on ground which is shaded from direct sunlight?

.

the indoors of a house on a concrete slab is much hotter than a house on stilts. this is what some ignorants in Thailand believe.

reason: they possess a wealth of "no idea"

Yes and no, I'd say.

On stilts it would be much hotter during the day as the temperature rises and cooler at night when it falls. On a slab it would be more constant without so much the either positive or negative spikes.

[Morakot]

How do you rate, in a tropical climate such as Thailand, the cooling thermal effects of a concrete slab on ground which is shaded from direct sunlight?

.

the indoors of a house on a concrete slab is much hotter than a house on stilts. this is what some ignorants in Thailand believe.

reason: they possess a wealth of "no idea"

Sooo ... are you agreeing that a shaded slab has a cooling effect?

Or a house in stilts with the air circulation is cooler and a slab on ground is actually hotter?

.

I sum,

Exposed slab: constantly high heat release over 24hs

Shaded slab: constantly low heat release over 24hs

On stilts, day time: higher ambient temperature

On stilts, night time: lower ambient temperature

Shading and vegetation at surrounding stilt area might only have a minimal to moderate effect in compensating for the daytime increase.

[Naam]

How do you rate, in a tropical climate such as Thailand, the cooling thermal effects of a concrete slab on ground which is shaded from direct sunlight?

.

the indoors of a house on a concrete slab is much hotter than a house on stilts. this is what some ignorants in Thailand believe.

reason: they possess a wealth of "no idea"

Sooo ... are you agreeing that a shaded slab has a cooling effect?

Or a house in stilts with the air circulation is cooler and a slab on ground is actually hotter?

.

i'm not sure what you mean by "shaded" slab because a slab is always shaded by the home placed on it. but yes, i agree that the interior of a house placed on a slab is cooler than a house on stilts. but i wouldn't call that a "cooling effect due to its thermal mass". the positive effect is mainly due to the fact that the slab is not heated up by ambient heat.

[Naam]

I sum,

Exposed slab: constantly high heat release over 24hs

Shaded slab: constantly low heat release over 24hs

On stilts, day time: higher ambient temperature

On stilts, night time: lower ambient temperature

Shading and vegetation at surrounding stilt area might only have a minimal to moderate effect in compensating for the daytime increase.

again my question "vhat der héll is an ekspowsed slab?" schow sum mursy und do not let me die stoopid

[doglover]

1. The following link is a good source of info for a non-air conditioned home.

2. Possibly even Naam could be somewhat comfortable, part of year, in a home like this?

1. the link leads to a company located in Hawaii which has a rather moderate climate with ambient temperatures never reaching really high tropical temperatures as we face in Thailand. add to this the rather steep drop to minimum temperatures and placing the home at an elevation exceeding 500m above sea level the room temperatures might suit people who can't afford airconditioning.

but whatever, the claim "concrete thermal mass helps cooling the home" is an oxymoron which rapes the laws of physics in an utmost pervert way!

2. no! Naam (who spend several times a week on Hawaiian islands) wouldn't find the average relative humidity in Hawaii comfortable and would insist on airconditioning instead of ventilation.

It is obvious that anyone who could afford the home in the link I provided would have no problems affording air conditioning. But some people (even affluent ones) prefer fresh air over manufactured air.

In our (unaffluent) home we have dual exterior walls built from concrete block which provide greater comfort during most of the day, relative to ambient temperature, without air conditioning. So I am thinking solid concrete walls would extend this comfort longer, even in Thailand.

But it turns out the only option is aerated autoclaved concrete block, ceiling insulation, dual pane windows and big air conditioners.

(Of course us poor folk could just throw up a rice straw roof over an existing concrete slab)

[Artisi]

 

1. The following link is a good source of info for a non-air conditioned home.

2. Possibly even Naam could be somewhat comfortable, part of year, in a home like this?

 

1. the link leads to a company located in Hawaii which has a rather moderate climate with ambient temperatures never reaching really high tropical temperatures as we face in Thailand. add to this the rather steep drop to minimum temperatures and placing the home at an elevation exceeding 500m above sea level the room temperatures might suit people who can't afford airconditioning.

 

but whatever, the claim "concrete thermal mass helps cooling the home" is an oxymoron which rapes the laws of physics in an utmost pervert way!   

 

2. no! Naam (who spend several times a week on Hawaiian islands) wouldn't find the average relative humidity in Hawaii comfortable and would insist on airconditioning instead of ventilation.

 

It is obvious that anyone who could afford the home in the link I provided would have no problems affording air conditioning. But some people (even affluent ones) prefer fresh air over manufactured air.

 

In our (unaffluent) home we have dual exterior walls built from concrete block which provide greater comfort during most of the day, relative to ambient temperature, without air conditioning. So I am thinking solid concrete walls would extend this comfort longer, even in Thailand.

 

But it turns out the only option is aerated autoclaved concrete block, ceiling insulation, dual pane windows and big air conditioners.

 

(Of course us poor folk could just throw up a rice straw roof over an existing concrete slab)

Cavity walls would beat solid concrete walls hands down in terms of effective insulation. And don't forget it may take a long time for a dense wall, ie, concrete to heat up but for the same reason it also takes a long time to cool down.

Sent from my GT-I9300T using Thaivisa Connect Thailand mobile app

[Naam]

In our (unaffluent) home we have dual exterior walls built from concrete block which provide greater comfort during most of the day, relative to ambient temperature, without air conditioning. So I am thinking solid concrete walls would extend this comfort longer, even in Thailand.

the reason why you achieve more comfort is not the combined mass of the dual walls but the insulating aircushion between the two walls. most probably the concrete blocks used have cavities too which provide additional insulation.

[IMHO]

In our (unaffluent) home we have dual exterior walls built from concrete block which provide greater comfort during most of the day, relative to ambient temperature, without air conditioning. So I am thinking solid concrete walls would extend this comfort longer, even in Thailand.

the reason why you achieve more comfort is not the combined mass of the dual walls but the insulating aircushion between the two walls. most probably the concrete blocks used have cavities too which provide additional insulation.

Right, whether you're insulating against temperature changes or sound, an air gap is an incredibly effective insulator. The blocks pictured above are more effective at insulation than normal solid blocks/bricks.

Double-brick cavity walls improve upon this again due to less/no conductors between the outer and inner wall, with the added advantage of eliminating post protrusions inside the house (or disadvantage of losing floor space, if that's the way you think).

Cladding installed with C-Line (so there's an air gap between the fibrous cement and the wall) also adds insulating value, while also successfully hiding any flaws in the cement render, and (subjectively) improving looks.

In our latest house we applied all of these concepts - double 7.5cm Hebel AAC blocks with an air gap on all external walls, along with SCG cladding offset with C-Line. The bottom 1M of the house is finished with sandstone tiles attached with latex. The house was designed and situated on the land so there's only 1.5 sqm of glass that gets afternoon sunlight, and those rooms use solar-backed roman blinds, along with ACG Solartag glass and some trees to help. Inside the house we created two areas with extended height ceilings (5M high vs 3M for the rest) and both have extraction fans at their highest point to aid with expelling heat out through the eaves via ducts.

For the roof, CPAC Monier cement tiles sit on top of reflective foil (under the battens),with 6" fibreglass insulation on top of foil-backed, double 15mm gypsum sheets (though the thickness there was to help stop rattles caused by 3x home theatre systems with subs).

The end result is, we always achieve indoor temps substantially lower than daytime temps simply by opening windows and switching on ventilation fans just around sunrise when the air is coolest, then shutting them all again ~10 mins later. Heat creep during the day is usually somewhere between 2-5 degree range vs. ambient outdoor temp swings in the 7-12 degree range.

I guess the point I'm trying to make here, is that what works for us is unnatural, human controlled ventilation for only a short period of time every day

Edited July 7, 2013 by IMHO

[Morakot]

again my question "vhat der héll is an ekspowsed slab?" schow sum mursy und do not let me die stoopid

We hope you'll be staying with us for some time...

For the time being, check out the lovely pictures of some exposed concrete slabs, where a substantial part of it is exposed. Picture number 3 is actually quite OK; it seem to avoid the classic faux by minimising exposed concrete part and through some kind of thermal barrier between the main slab and the exposed part.

[IMHO]

In our (unaffluent) home we have dual exterior walls built from concrete block which provide greater comfort during most of the day, relative to ambient temperature, without air conditioning. So I am thinking solid concrete walls would extend this comfort longer, even in Thailand.

Double brick/block with an air gap will be substantially cooler than solid concrete, no matter whether they're 0.7 Baht red bricks, 3 baht blocks, or 23 Baht AAC's.

[IMHO]

again my question "vhat der héll is an ekspowsed slab?" schow sum mursy und do not let me die stoopid

We hope you'll be staying with us for some time...

For the time being, check out the lovely pictures of some exposed concrete slabs, where a substantial part of it is exposed. Picture number 3 is actually quite OK; it seem to avoid the classic faux by minimising exposed concrete part and through some kind of thermal barrier between the main slab and the exposed part.

Not quite sure what the question is here, but of course any slab exposed to direct sunlight is going to get hot, and if close enough to the house will radiate more heat towards it.

Being ground slabs they won't get as cool as air temps when they drop below ground temp either..

The biggest problem I see in all your example pics is a lack of shade though. Mature trees are pretty cheap, and very effective

Edited July 7, 2013 by IMHO

[David48]

I sum,

Exposed slab: constantly high heat release over 24hs

Shaded slab: constantly low heat release over 24hs

On stilts, day time: higher ambient temperature

On stilts, night time: lower ambient temperature

Shading and vegetation at surrounding stilt area might only have a minimal to moderate effect in compensating for the daytime increase.

again my question "vhat der héll is an ekspowsed slab?" schow sum mursy und do not let me die stoopid

OK ... I know that this example isn't from Thailand .. but you might understand my drift.

So, the 'exposed slab' refers to that part of the slab 'exposed to the sun.

So, in Thailand, while the summer and winter sun angles are much less pronounced, they do exist.

So, be effectively 'shading' the slab, it doesn't receive any sunlight, hence any direct heat which I might re-radiate later, after the sun has passed.

My use of the term 'thermal mass' when referring to the concrete slab on ground is inncorrect ... I should have used the term 'thermal sink' which more succulently describes the heat transfer from the hotter ambient temperate to that of the cooler ground underneath.

.

[Morakot]

OK ... I know that this example isn't from Thailand .. but you might understand my drift.

So, the 'exposed slab' refers to that part of the slab 'exposed to the sun.

So, in Thailand, while the summer and winter sun angles are much less pronounced, they do exist.

So, be effectively 'shading' the slab, it doesn't receive any sunlight, hence any direct heat which I might re-radiate later, after the sun has passed.

My use of the term 'thermal mass' when referring to the concrete slab on ground is inncorrect ... I should have used the term 'thermal sink' which more succulently describes the heat transfer from the hotter ambient temperate to that of the cooler ground underneath.

.

Thanks David! This is a useful example. It's reversed trying to maximise the solar gain during the winter (colder time).

In the Thailand I guess you want to minimise it throughout the year. Unless you live in Chaing Rai in the mountains somewhere.

[Naam]

So, the 'exposed slab' refers to that part of the slab 'exposed to the sun.

So, in Thailand, while the summer and winter sun angles are much less pronounced, they do exist.

David,

the sketch and it's legend is a scientific presentation so overwhelming that it leaves me speechless and humbled. that's why i refrain to add my stupid layman's comments. my doctorate in physics might come in handy judging the application of phrik nam pla on a Wiener Schnitzel but it's surely not a qualification which enables me to comment on solar exposed or shaded slabs.

joke aside...

My use of the term 'thermal mass' when referring to the concrete slab on ground is inncorrect ... I should have used the term 'thermal sink' which more succulently describes the heat transfer from the hotter ambient temperate to that of the cooler ground underneath.

actually both expressions using the attribute "thermal" are correct. it iz bekaus vee "physicalists" do not differentchiate between hot and kold but konsider ze thermal status of any medium as heat even vhen vee diskuss temperatchures at ze absolute (known) zero of -273.15°Celsius (0ºKelvin).

important is to know that the concrete slab of a house works as a "heat sink" which helps to keep a house cooler in tropical ambient temperatures as opposed to the fairy tales about stilted houses circulating in Thailand.

[doglover]

In our (unaffluent) home we have dual exterior walls built from concrete block which provide greater comfort during most of the day, relative to ambient temperature, without air conditioning. So I am thinking solid concrete walls would extend this comfort longer, even in Thailand.

Double brick/block with an air gap will be substantially cooler than solid concrete, no matter whether they're 0.7 Baht red bricks, 3 baht blocks, or 23 Baht AAC's.

Ok. I repent.

Brilliant job on planning the design of your house BTW. Obviously not your first one in Thailand.

important is to know that the concrete slab of a house works as a "heat sink" which helps to keep a house cooler in tropical ambient temperatures as opposed to the fairy tales about stilted houses circulating in Thailand.

Indeed. But, as you, know most affluent homes have the slab poured on top of raised cross beams and there is an open cavity between the slab and the ground. Pipes are run inside these cavities to spray termite killing chemicals throughout the cavity. The heat sinking capacity of this set up is greatly reduced over the way villagers pour their slabs directly on the ground.

Edited July 7, 2013 by doglover

[bunnydrops]

Does anyone know the temperature of the ground in Thailand, say 1 meter down. I have seen, not here in Thailand, where they run large pipes underground on the property and bring cool air into the house by convection. My guess is that it would be around 29C.

[Morakot]

Bunny is this about some ground-coupled heath exchanger?

You know you need some kind of Habitat passif (as Naam would say) for such a system to have any effect. You might have to go really deep in a tropical country, me thinks...

[IMHO]

OK ... I know that this example isn't from Thailand .. but you might understand my drift.

So, the 'exposed slab' refers to that part of the slab 'exposed to the sun.

So, in Thailand, while the summer and winter sun angles are much less pronounced, they do exist.

So, be effectively 'shading' the slab, it doesn't receive any sunlight, hence any direct heat which I might re-radiate later, after the sun has passed.

My use of the term 'thermal mass' when referring to the concrete slab on ground is inncorrect ... I should have used the term 'thermal sink' which more succulently describes the heat transfer from the hotter ambient temperate to that of the cooler ground underneath.

.

Thanks David! This is a useful example. It's reversed trying to maximise the solar gain during the winter (colder time).

In the Thailand I guess you want to minimise it throughout the year. Unless you live in Chaing Rai in the mountains somewhere.

In Thai land it's pretty simple - you just want perpetual shade