Position and movement of sun in the Thailand

[KhunLA]

44 minutes ago, Old Croc said:

It's not as simple as East-West.

Learn about the solstices.

The longest & shortest days here aren't that far apart ... 1.5 hrs +/-

[treetops]

On 7/25/2022 at 5:00 AM, Old Croc said:

It's not as simple as East-West.

Learn about the solstices.

Good answer.  Although rising in the east and setting in the west is correct, there is also a tilting effect in the earth's rotation so that on June 21st the sun is over the Tropic of Cancer and on December 21st it's over the Tropic of Capricorn.  Only exactly in the middle of these is it over the equator.

 

With Thailand being south of the Tropic of Cancer there is always a north/south effect as well as the more noticeable east/west.

[KIngsofisaan]

The sun rises in the east and sets in the west.

 

The afternoon setting sun (west) is the hottest.

 

If you oriented the house so the corners are facing East and West, you would minimize the heat as much as practical

[Old Croc]

17 hours ago, treetops said:

Only exactly in the middle of these is it over the equator.

The equinox.

[Old Croc]

16 hours ago, KIngsofisaan said:

The sun rises in the east and sets in the west.

 

The afternoon setting sun (west) is the hottest.

 

If you oriented the house so the corners are facing East and West, you would minimize the heat as much as practical

In December, when the sun is positioned somewhere over Australia, for me the sun sets closer to the south-west rather than directly west.

Distance, the changes in it's axis  and curvature of the earth make a little  difference to the hard and fast rule of East and West.

 

My advice, considering It's going to be hot for long periods where ever you live in Thailand, is to plant grass and shade trees around the house and build large eaves in the areas you have most windows and doors. Mine are 2 meters wide on the sides closest to North and South.

 

[kokesaat]

If you have a well-shaded porch, preferably at all times of the day, you have a place to dry clothes even in the wettest days of the rainy season.  You have a place to chill during the cooler winter months in Isaan.   You have a place to admire your yard/butterflies/birds/squirrels/lizards.  We live, we like to say, in the jungle......but spend mornings on our porch drinking coffee and evenings long after the sun has gone down watching the fireflies.  Mosquito time is typically 6pm-8pm.  After 8, I think the bats take care of the rest.  

[freedomnow]

On 7/24/2022 at 3:37 PM, FrederikKitten said:

Cart port is just a concrete slab. I think once I put a roof and walls/sides over the cart port it will take a lot of heat of the house.

 

In 10 years I lived here I never had air conditioning, this house will not have aircon either. That's why I'm thinking about stuff like this, that would other people ignore... . ???? 

 

OP did you ever get a clear idea on the sun peak heat sides of the house through the year...as my place is almost identically orientated.

 

Also were you in the north, BKK or far south of Thailand..?

As I'm in the north.

 

If I expanded the house up 1/2 floors i'd be looking to put q-con blocks on maybe only 1 or 2 sides of the upper floors but not sure that is a good idea...or double leaf walling on the fiercest wall/walls.

[Gottfrid]

On 7/24/2022 at 2:13 AM, FrederikKitten said:

1. In Thailand, which side of the house gets the most sunlight/is most hot during a day?

2. Does it change during a year?

1. The roof! (In other words, the top of your house)
2. Yeah, somehow. I read it has something to do with the movements in out solar system.

[freedomnow]

On 8/16/2022 at 11:05 AM, Gottfrid said:

1. The roof! (In other words, the top of your house)
 

White or silver roofing material would reflect the highest amount of heat and air intake and out-take vents or turbines would also further bring down the roof internal temperature...assuming it's got a significant cavity inside....Q-con blockwork or twin leaf walls on south and west walls as i mentioned before...I guess those areas would help along with significant extended shading beyond the house (walls) footprint....and/or also a higher wall on the perimeter near enough to shade.

But in reading, I know there are some skilled former or current building trade guys in the thread that can take that further - or negate some of what I said.

 

[Gottfrid]

2 minutes ago, freedomnow said:

White or silver roofing material would reflect the highest amount of heat and air intake and out-take vents or turbines would also further bring down the roof internal temperature...assuming it's got a significant cavity inside....Q-con blockwork or twin leaf walls on south and east as i mentioned before...I guess those areas would help along with significant extended shading beyond the house (walls) footprint....and/or also a higher wall on the perimeter near enough to shade.

But in reading, I know there are some skilled former or current building trade guys in the thread that can take that further - or negate some of what I said.

 

You are just taking it too far. SPF 213 will do it.

[KhunLA]

We went with lots of extended overhang.  Inside red is living space.  House had to be built E-back/veranda (blue) area to W-front & carport.

 

S-has storage room (blue), length of, before interior living space.  Takes all the heat, what little there is.

 

E-has , unshaded, wall length wall in closet, take most exposure heat.

Which is the bedroom, theoretically, we're out of, after sunrise, and back in, after sunset. 

 

Realistically, AC'd all day with solar, so don't care.

[FrederikKitten]

6 hours ago, KhunLA said:

We went with lots of extended overhang.  Inside red is living space.  House had to be built E-back/veranda (blue) area to W-front & carport.

 

S-has storage room (blue), length of, before interior living space.  Takes all the heat, what little there is.

 

E-has , unshaded, wall length wall in closet, take most exposure heat.

Which is the bedroom, theoretically, we're out of, after sunrise, and back in, after sunset. 

 

Realistically, AC'd all day with solar, so don't care.

Jesus, are you getting ready for a zombie apocalypse in this building? Btw in left corners of property you can still see a little bit of grass, maybe call the roof builders to finish it?

[KhunLA]

4 hours ago, FrederikKitten said:

Jesus, are you getting ready for a zombie apocalypse in this building? Btw in left corners of property you can still see a little bit of grass, maybe call the roof builders to finish it?

We own the lot across from us also ...

 

After last house on 2 rai, I'm done with lawn care.  Plenty off green around us.

 

[mistral53]

10 hours ago, KhunLA said:

We went with lots of extended overhang.  Inside red is living space.  House had to be built E-back/veranda (blue) area to W-front & carport.

 

S-has storage room (blue), length of, before interior living space.  Takes all the heat, what little there is.

 

E-has , unshaded, wall length wall in closet, take most exposure heat.

Which is the bedroom, theoretically, we're out of, after sunrise, and back in, after sunset. 

 

Realistically, AC'd all day with solar, so don't care.

The flat incline of the roof is nice for the solar panels efficiency, the flip side of course is the dirt does not wash off as well when it rains - did you find you have to wash the panels a couple times a year due to dust accumulation?

[KhunLA]

14 minutes ago, mistral53 said:

The flat incline of the roof is nice for the solar panels efficiency, the flip side of course is the dirt does not wash off as well when it rains - did you find you have to wash the panels a couple times a year due to dust accumulation?

System only installed 15 days, and rained almost everyday, so no cleaning yet ????

[unheard]

22 hours ago, KhunLA said:

E-has , unshaded, wall length wall in closet, take most exposure heat.

Which is the bedroom, theoretically, we're out of, after sunrise, and back in, after sunset.

Huge, structurally non reinforced overhangs are all great until you get hit with a series of powerful, high winds thunderstorms - you've created multiple weak spots all around your roof, starting with the most vulnerable veranda section.

Your west, most exposed to the afternoon sun side of the house is totally unprotected, with no overhang at all. A strange choice.

 

[unheard]

double post

[KhunLA]

19 minutes ago, unheard said:

Huge, structurally non reinforced overhangs are all great until you get hit with a series of powerful, high winds thunderstorms - you've created multiple weak spots all around your roof, starting with the most vulnerable veranda section.

Your west, most exposed to the afternoon sun side of the house is totally unprotected, with no overhang at all. A strange choice.

 

The roofs aren't going anywhere, and the carport (5.5m extending out) covers half the W exposure ????

 

Living space is 'within' the red'.  If reading, exposed part of W wall, interior, is walk-in closet and acts a nice buffer.  W has minimal glass exposure, and 2 section that do, will have curtains, maybe.  One is the entrance door, and the other, as small window in bedroom.  If so, it won't be to keep out heat, but sun glare.  So far, no prob.

 

Not that any of that is needed, since ACs are on at sunrise.  Sun stops coming in sliding glass doors to veranda at 0800hrs.

 

Veranda roof has plenty of steel w/finished under/ceiling, so wind will not get under it.  3rd house, and I've never lost a roof panel yet, whether crete or steel.

 

Weather has never been an issue with any of my properties, TH or USA.

 

Build it right the first time, and you usually don't need to repair later.

 

Thanks for the concern though ????

[unheard]

18 minutes ago, KhunLA said:

Veranda roof has plenty of steel w/finished under/ceiling, so wind will not get under it.  3rd house, and I've never lost a roof panel yet, whether crete or steel.

Have your houses been permitted?

Just being curious..

[KhunLA]

19 minutes ago, unheard said:

Have your houses been permitted?

Just being curious..

Permitted ?

 

Do you mean blueprints from architect/engineer & submitted for approval ?  Of course, and I will raise the specs when I feel the need, IF contractor doesn't.   2nd house we both agreed to put a bit more steel at couple spots.

 

I've been doing RE for 40 yrs.

[unheard]

43 minutes ago, KhunLA said:

Of course, and I will raise the specs when I feel the need, IF contractor doesn't.   2nd house we both agreed to put a bit more steel at couple spots.

Then I take back my "concern" with overhangs. ????

[Smithson]

There's some very useful info in this thread. My opinion is it's all about shade and ventilation - as much of both as possible. Keep the sun off the walls or even better, don't have walls, just a covered area. Besides shading, trees are naturally evaporative coolers, pumping water from the ground and releasing it into the air. Insulation is useful, but if used incorrectly can trap heat, particularly in upstairs areas if the ventilation is inadequate. The tradition style was uninsulated, which cools quickly, but is unbearable during the day, so ppl stay under the house and then move upstairs at night to avoid the critters and possible get a cool breeze upstairs.

 

Concrete driveways trap heat. It's common to see houses where the whole block is concreted for ease of maintenance.  Besides storing heat, I believe they contribute to flooding in Pattaya and probably elsewhere.

 

Roof and ceiling height are also important, I think 3m should be enough for shaded areas, but am interested in others opinions as I am also designing a house.

 

Blinds are also useful for keeping sun off windows or out of shaded area at certain times of the day, to be rolled up later for more air flow. I like the matchstick blinds. We soaked ours for an hour in borax and they've lasted a decade. Made from natural materials they allow for ventilation.

[unheard]

25 minutes ago, Smithson said:

Roof and ceiling height are also important, I think 3m should be enough for shaded areas, but am interested in others opinions as I am also designing a house.

Good point regarding ceilings.

I rarely see the ceiling height being mentioned as a desirable feature in the "cool house" discussions.

My take is the higher, the better.

Warm air raises to the top and stays there while  the cooler air stays at the floor level.

Vaulted ceilings are ideal, or near ideal.

The ideal ceiling would be a vaulted ceiling with a couple of op-enable skylights, allowing the warmest air to escape.

[Smithson]

^ When I see a place that interests me, if possible I'll stand or sit inside for a while. Some warehouses are surprisingly cool, despite no insulation. It's all down to ceiling height and the ventilation provided by the louvers/vents placed near the roof. 

[LosLobo]

12 minutes ago, unheard said:

Good point regarding ceilings.

I rarely see the ceiling height being mentioned as a desirable feature in the "cool house" discussions.

My take is the higher, the better.

Warm air raises to the top and stays there while  the cooler air stays at the floor level.

Vaulted ceilings are ideal, or near ideal.

The ideal ceiling would be a vaulted ceiling with a couple of op-enable skylights, allowing the warmest air to escape.

I would suggest that an insulated flat ceiling with a big air space between it and the roof with possibility some roof vents would be better than a vaulted ceiling which would have minimal air space.

 

[unheard]

3 hours ago, LosLobo said:

I would suggest that an insulated flat ceiling with a big air space between it and the roof with possibility some roof vents would be better than a vaulted ceiling which would have minimal air space.

 

Depends on the type of the roof itself (insulated vs uninsulated).

The insulated roof (often no cost premium on new construction) won't transmit much, if any of heat to the ceiling in the vaulted type.

 

[LosLobo]

18 minutes ago, unheard said:

Depends on the type of the roof itself (insulated vs uninsulated).

The insulated roof (often no cost premium on new construction) won't transmit much, if any of heat to the ceiling in the vaulted type.

 

II don't agree. A flat ceiling with insulation with a large volume roof cavity, possibly also insulated and air vents would be cooler and more energy efficient than your proposal.

I have lived in an area most of my life where summer temperatures can exceed 47C and vaulted ceilings are not the norm due to that very reason. Also, rooms with vaulted ceilings have a much larger volume which means more energy costs with air-conditioning.

 

Also skylights in Thailand? I would suggest that it would be more beneficial to reduce the amount of light (and radiant heat ) coming into a room then adding to it. 

 

Doubt if energy will ever get cheaper in my lifetime.

I do agree though that vaulted ceilings do look nice!

 

 

[kokesaat]

If I had to prioritize things that have had the biggest impact on living here: 

Keep sun off the walls/windows of the house at all costs.   Large overhangs would be worth the additional cost.

White steel roof

At least 4" insulation over ceiling

13' ceilings (flat).

We run an 18k AC in the living room for about 14hrs per day, an 18k in the master bedroom for about 9hrs per day, and a 9k AC in a smaller bedroom for about 9hrs per day.  Thus far, 24years in, our electric bill has not been more than 3500/month.......Nov/Dec/Jan less than half that.

[unheard]

1 hour ago, LosLobo said:

Also skylights in Thailand? I would suggest that it would be more beneficial to reduce the amount of light (and radiant heat ) coming into a room then adding to it.

Modern skylights (I had Velux in a desert climate) don't allow any significant radiant heat to be transmitted to the inside.

They're certified and independently tested for U-factor and Solar Gain Coefficient.

They even come with optional motorized shades that completely block off any light when required.

[Smithson]

With skylights I think it depend on their height and the amount of ventilation. Our place was dark, we added some 1m polycarbonate sheets improved light and without a noticeable increase in heat.