Position and movement of sun in the Thailand

[FrederikKitten]

I'm planning on buying a house that is positioned like this.

 

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?

 

[HauptmannUK]

The sun's position/track varies throughout the year.  There is plenty of free software on the web to enable you to produce the solar ephemeris for your location.  

[HauptmannUK]

https://www.sunearthtools.com/dp/tools/pos_sun.php

 

This might help.

[KhunBENQ]

7 hours ago, FrederikKitten said:

I'm planning on buying a house that is positioned like this.

 

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?

Thailand is 1600 km north to south. So some significant variation.

Generally the hottest side is to the west with afternoon sun.

To the north there is the smallest amount of sunshine. The further north you are the less sun from the north.

Of course sun light intensity and direction during the day varies over the year.

Least variation in the deep south closer to equator.

Most variation in the top north close to the northern tropic (of cancer).

 

[KhunBENQ]

If you want to dig deeper, I like this site (example Bangkok):

https://www.timeanddate.com/sun/thailand/bangkok

 

From your diagram it's quite sure that the west (south west) side will heat up the most.

[OneMoreFarang]

Many people who come from somewhere north of Thailand, i.e. Europe, always think about the south wall as the sun side. That is almost irrelevant in Thailand because the sun doesn't shine from the south.

And in Thailand the sun shines from about 6am to 6pm. So no sunlight for a long time from the west side in the evening. 

[KhunBENQ]

4 minutes ago, OneMoreFarang said:

That is almost irrelevant in Thailand because the sun doesn't shine from the south.

Ask a Chiang Mai resident where the sun shine comes from in December

As written Thailand 1600 km N/S (1000 miles). Makes a significant difference.

As a Phuket residence about position of the sun: what's that? It's upward

 

[Liverpool Lou]

8 hours ago, HauptmannUK said:

The sun's position/track varies throughout the year. 

I thought that it always rose in the east and tracked to set in the west?  It does over my house, all year. 

 

What other tracks do you see it following?

[Liverpool Lou]

 

8 hours ago, FrederikKitten said:

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

In the northern hemisphere, the south-facing part of a house is usually considered to get the most sun.

[KhunLA]

Yes, the southern wall will have exposure all day, most months.  North will get some, part of the year, due to the axis.  Depending where building, you may want a little sunshine coming in during those months.

 

If wanting to keep house cool, aside from curtains of course, then shading / extended roofs are the way to go.  I found E & W need a bit more extending, though not exposed as long, than S wall, on our builds in Udon Thani & Prachuap Khiri Khan.

[KhunBENQ]

45 minutes ago, Liverpool Lou said:

I thought that it always rose in the east and tracked to set in the west?  It does over my house, all year. 

It's a bit more complicated.

Sun paths for northern Thailand June and December:

 

 

 

In June ALL of Thailand gets sun from the north more or less.

In December ALL of Thailand gets sun from the south more or less.

South is currently a shady place around our house.

[FrederikKitten]

5 minutes ago, KhunLA said:

Yes, the southern wall will have exposure all day, most months.  North will get some, part of the year, due to the axis.  Depending where building, you may want a little sunshine coming in during those months.

 

If wanting to keep house cool, aside from curtains of course, then shading / extended roofs are the way to go.  I found E & W need a bit more extending, though not exposed as long, than S wall, on our builds in Udon Thani & Prachuap Khiri Khan.

Yes, that's why I'm asking. To start planning where to plant trees etc. 

 

Do these expensive exterior colors really make a difference in temperature inside?

[KhunBENQ]

Phuket in June, sun from the north all day.

 

[KhunLA]

16 minutes ago, FrederikKitten said:

Yes, that's why I'm asking. To start planning where to plant trees etc. 

 

Do these expensive exterior colors really make a difference in temperature inside?

Depends on the building material, or you talking simply paint.  

Lighter colors reflect, darker absorb.  Basic science.

 

Bad to good block for exterior walls; red brick ???? - cinder - insulated ???? (super/k/q block) goes by various names.

 

Roof (vented), I'd go with insulated rolled steel (BlueScope), then insulation 37/38 above ceiling tiles/board.  Tinted glass (in glass, not film).

 

All available here.

[Tropicalevo]

24 minutes ago, FrederikKitten said:

Yes, that's why I'm asking. To start planning where to plant trees etc. 

I would not plant trees until you live in the place.

Once in, you will know what works.

They will soon grow.

[Crossy]

Our south-west corner (spare bedroom) gets the most solar radiation. Lots of trees in the way now after Madam went on a planting spree.

 

Our bedroom on the north-east corner is pleasantly cool by the time we retire for the night. The coolest room in the house is our en-suite bathroom on the north-west corner, it gets pretty well no direct sunlight at all.

[Crossy]

Whilst planning your house ensure that your car-port is oriented north-south with the roof sloping towards the south.

 

You need somewhere for those solar panels

[FrederikKitten]

1 hour ago, Crossy said:

Whilst planning your house ensure that your car-port is oriented north-south with the roof sloping towards the south.

 

You need somewhere for those solar panels

That's exactly where the cart port currently is.  ????

[Crossy]

11 minutes ago, FrederikKitten said:

That's exactly where the cart port currently is.  ????

 

By accident or design??

[bolt]

my rough guess would be

warmish Yellow early morning

Afternoon HOT Orangey 

late evening warmish Yellow

[Photoguy21]

Only real thing you need to know is that the sun rises in the east and sets in the west as it always as far as we are aware has

[KhunLA]

Depends.

 

2nd house, I forgot about the axis, and in Dec, plotted it out, when sun comes up due E.  Then July, got a 20° N'ern angle to it, and blinding when coming out of the bedroom in the early AM.  As N wall was mostly glass.  Didn't really affect temp much, as tinted and AC on most of the time.  Probably used a bit more electric till about 1030 hrs.

 

Of course if build the house to block that, then Dec, setting sun would come in, and would depend where you are and which you prefer, if either.  

 

Pretty much a non issue, but something to be aware of.  Again, an extended roof, would solve that.  Present house has no exposure on S wall, E & W has long extended roof, with veranda on E side & might get 2 hrs in the AM, at most.  W almost none, as carport on that side.  Again, not that it matters, as well built & insulated w/AC on all the time.

[FrederikKitten]

1 hour ago, Crossy said:

 

By accident or design??

By previous thai owner. 

[FrederikKitten]

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... . ???? 

 

[kokesaat]

When we built our house 25 years ago, we used an online program similar to https://www.suncalc.org/#/40.1789,-3.5156,3/2022.07.24/09:59/1/3    The app is immensely more powerful today!    Also, install a compass app on your phone (Compass for android is really good).  Gives you specific coordinates, altitude, etc.

We live in Udon.  We ended up with the long end of our rectangular house oriented about 85/275.  Single story.  White steel roof.  Large 3m overhang on southern side and eastern side.  Carport on western side.  

Here's a few things we've learned over the years.   The sun never hits our southern facing wall.  Our northern wall gets maybe an hour of sun at the peak of summer.....no impact.    We underestimated the impact of the morning sun......should have built a bigger overhang there, but made up the difference with fast growing wall of green palms.  Our western facing carport prevents the sun from ever hitting our western facing windows, but we had to plant a wall of palms to keep the sun from baking our truck.  The palms solved both the eastern/western problem.  Our northern facing windows/walls are never affected by the sun.

We have a 7' wide porch along the entire length of the southern side and the width of the eastern side.  

In short, I'd say do whatever you possibly can to prevent the sun from hitting your exterior walls.....whether it's orientation, overhangs, trees, whatever.  If the sun hits your walls, you pay the price for the impact long after the sun has passed on as the walls retain the heat.

I'll be surprised if you can find a ready built that meets your needs, but good luck in your search.

[kokesaat]

22 hours ago, Liverpool Lou said:

I thought that it always rose in the east and tracked to set in the west?  It does over my house, all year. 

 

What other tracks do you see it following?

 

19 hours ago, Photoguy21 said:

Only real thing you need to know is that the sun rises in the east and sets in the west as it always as far as we are aware has

In Udon, the sun rises slightly NE in the middle of June and then goes on the decline to SE in the middle of Dec.  Roughly a 70deg to 120deg change.   I always thought the sun rises in the E and sets in the W......but actually, it's quite a dramatic swing.

[Photoguy21]

Just now, kokesaat said:

 

In Udon, the sun rises slightly NE in the middle of June and then goes on the decline to SE in the middle of Dec.  Roughly a 70deg to 120deg change.   I always thought the sun rises in the E and sets in the W......but actually, it's quite a dramatic swing.

I dont think the universe is different in Udon to the rest of the world. Maybe your sense of direction is askew.

[1FinickyOne]

On 7/24/2022 at 10:20 AM, OneMoreFarang said:

That is almost irrelevant in Thailand because the sun doesn't shine from the south.

ok - one of the more prolific, know it all posters on this forum once claimed that his wife thought the sun shone out his behind... 

[1FinickyOne]

My house is positioned similarly and we are strongly protected from the sun on the SW side by a large leafy tree... 

[Old Croc]

It's not as simple as East-West.

Learn about the solstices.