stop attic heat coming down into the house

[Artisi]

21 minutes ago, spidermike007 said:

Went out to Global House, bought 60 packages of R22 insulation at 200 baht a pack, hired a handyman, and he installed it in the attic. Took him a day. He laid all of the cables and wires on top of the insulation for easy access, and simply cut the sheets where needed, to accommodate the suspension wires as it is a typical suspended ceiling. House is now cooler, and far more comfortable. After I turn the AC off in the bedroom in the morning, that room stays cool for many hours. Used to be an oven within two or three hours. House overall is at least 2-3 degrees (C) cooler. Made a big difference, at a cost of only 13,000 baht. Could not install exhaust fans, as it is a rental house, and there is absolutely no place to vent the attic, without substantial work. It has made the house alot more pleasant to live in. Really worth it. 

Good result. You can now imagine what a properly designed insulation installation could achieve. 

[sometimewoodworker]

31 minutes ago, Artisi said:

Good result. You can now imagine what a properly designed insulation installation could achieve. 

Our whole house is usually about 5~10 degrees under the maximum outdoor temperature without running the AC in the daytime, the ceiling fans are often enough. 

 

Also the humidity is running about 20% lower than outside. 

Edited August 18, 2019 by sometimewoodworker

[Andrew Dwyer]

Went out to Global House, bought 60 packages of R22 insulation at 200 baht a pack, hired a handyman, and he installed it in the attic. Took him a day. He laid all of the cables and wires on top of the insulation for easy access, and simply cut the sheets where needed, to accommodate the suspension wires as it is a typical suspended ceiling. House is now cooler, and far more comfortable. After I turn the AC off in the bedroom in the morning, that room stays cool for many hours. Used to be an oven within two or three hours. House overall is at least 2-3 degrees [emoji767] cooler. Made a big difference, at a cost of only 13,000 baht. Could not install exhaust fans, as it is a rental house, and there is absolutely no place to vent the attic, without substantial work. It has made the house alot more pleasant to live in. Really worth it. 

Pretty much what I want to do.

 

The roof is typical modern moobahn roof

 

 

Pyramid shape, no gables, soffits not vented and a whirlygig on top won’t look very nice IMO.

 

I was in doubt that just laying insulation would have much effect without expelling the hot air.

Have the reflective stuff under the roof tiles only right now.

 

Any thoughts ??

[sometimewoodworker]

6 minutes ago, Andrew Dwyer said:

Pretty much what I want to do.

 

The roof is typical modern moobahn roof

 

 

Pyramid shape, no gables, soffits not vented and a whirlygig on top won’t look very nice IMO.

 

I was in doubt that just laying insulation would have much effect without expelling the hot air.

Have the reflective stuff under the roof tiles only right now.

 

Any thoughts ??

It will certainly help if you run AC sometimes and it will also reduce the noise level when you get heavy rain, though if you keep your windows open it's not going to do much.

 

FWIW the "reflective stuff under the roof tiles" is a radiant barrier and will already be reducing the heat gain in the roof space 

[Artisi]

2 hours ago, sometimewoodworker said:

Our whole house is usually about 5~10 degrees under the maximum outdoor temperature without running the AC in the daytime, the ceiling fans are often enough. 

 

Also the humidity is running about 20% lower than outside. 

Same here -- 

although must be honest, after a few days of extreme highs temp. with little change overnight, the internal temp. does start to rise - but that's expected, without running internal cooling (a/con) constantly you cannot expect the house to be below the minimum daily temp. just relying on natural cooling - however, the temp. in the bedrooms etc during the evening and overnight is easily brought down to acceptable levels without breaking the bank, and yes - ceiling fans are the norm day-time and usually early hours of the morning.

 

[spidermike007]

21 hours ago, Artisi said:

Good result. You can now imagine what a properly designed insulation installation could achieve. 

Yes, of course. Had the builder considered that. But, it would have cost him 10,000 baht. Oh no! Cannot do that. Plus it would have required some vision. Oh no. Do not have any of that! It is a rental, so there was only so much I was willing to spend. But, it did really help. 

[spidermike007]

21 hours ago, Andrew Dwyer said:

Pretty much what I want to do.

 

The roof is typical modern moobahn roof

 

 

Pyramid shape, no gables, soffits not vented and a whirlygig on top won’t look very nice IMO.

 

I was in doubt that just laying insulation would have much effect without expelling the hot air.

Have the reflective stuff under the roof tiles only right now.

 

Any thoughts ??

Yes. Just laying insulation of at least R22 onto the attic floor, will make a big difference. My house is infinitely more comfortable right now. Before it was an oven. I measured the ceiling temperature with a laser meter, and it is now about 2-3 degrees (C) cooler than before. Rooms almost that much cooler. And the other nice benefit, is that once we turn off the AC in the morning, the room stays cool for hours. Used to be a furnace within an hour. 

Edited August 19, 2019 by spidermike007

[SteveK]

On 8/17/2019 at 8:02 PM, sometimewoodworker said:

Yes, it works.

What's the easiest way to apply it? Get someone else to do it?

[sometimewoodworker]

3 hours ago, SteveK said:

What's the easiest way to apply it? Get someone else to do it?

That is what I did, as the roof panels aren't designed for elephants to walk on.

 

However it's just a paint so brush or roller is perfect.

 

I also used it on my Waterhouse floor (see my avatar) and walkway & it's ok to walk barefoot on even after hours of direct sunshine.

Edited August 19, 2019 by sometimewoodworker

[ThiAmo]

HomePro yesterday tried to convince me acquiring the Polynum Reflective foil

http://www.polynum-insulation.com/index.php?page_id=216 

for on-the-ceiling insulation instead of the

SCG Chang Glasswool insulation https://www.homepro.co.th/homePro/en/Construction-Insulation-Fiberglass-Insulation/CHANG-0-6X4M-PREMIUM-6"-GLASS-WOOL-INSULATION/p/213896 . 

At a comparable Rt-value (for example 38 v. 39) the Polynum is roughly 10% more expensive, however thanks to a robust structure of the material should have a longer lifespan (warranty 7 years) than the glasswool which only has a fragile protection around it. 

I understand that reflective foil insulation is usually applied either just under the roof or for insulating walls. 

Are there any members who have used the Polynum for insulating the ceiling and with what results?

Any input highly appreciated. Thank you.

 

 

[bankruatsteve]

3 hours ago, ThiAmo said:

HomePro yesterday tried to convince me acquiring the Polynum Reflective foil

http://www.polynum-insulation.com/index.php?page_id=216 

for on-the-ceiling insulation instead of the

SCG Chang Glasswool insulation https://www.homepro.co.th/homePro/en/Construction-Insulation-Fiberglass-Insulation/CHANG-0-6X4M-PREMIUM-6"-GLASS-WOOL-INSULATION/p/213896 . 

At a comparable Rt-value (for example 38 v. 39) the Polynum is roughly 10% more expensive, however thanks to a robust structure of the material should have a longer lifespan (warranty 7 years) than the glasswool which only has a fragile protection around it. 

I understand that reflective foil insulation is usually applied either just under the roof or for insulating walls. 

Are there any members who have used the Polynum for insulating the ceiling and with what results?

Any input highly appreciated. Thank you.

 

 

Reflective insulation is good for this climate.  It reflects radiated/convected heat.

[sometimewoodworker]

11 minutes ago, bankruatsteve said:

Reflective insulation is good for this climate.  It reflects radiated/convected heat.

It very much depends on where you put it as to its effectiveness, on a horizontal surface you often get dust which drops it usefulness quickly. Also it can't do anything for connected, physics 101.

[sometimewoodworker]

3 hours ago, ThiAmo said:

Any input highly appreciated. Thank you.

Dust will reduce it effect much more quickly than the fibreglass. Fibreglass will also reduce sound transmission by much more. 

[fredge45]

On 8/18/2019 at 12:11 PM, Andrew Dwyer said:

Pretty much what I want to do.

 

The roof is typical modern moobahn roof

 

 

Pyramid shape, no gables, soffits not vented and a whirlygig on top won’t look very nice IMO.

 

I was in doubt that just laying insulation would have much effect without expelling the hot air.

Have the reflective stuff under the roof tiles only right now.

 

Any thoughts ??

To get the maximum result from your hard earned money go the whole route.  15 cm (minimum) ceiling insulation of the highest R value you can find, roof vents (they do not have to be whirligigs as passive vents will be just as effective), lots of soffit vents to let the cooler ambient air into the attic.

 

Recently we had a technician from the telecon folks go up into the attic to run some cable.  When he can back down he was commenting on how cool the attic was!

[tjo o tjim]

Do the vented clay tiles exist in Thailand?  They look like an irregular tile, but at least you et a little bit of airflow with a few and it is an easy retrofit.  They much less elegant solution is drilling a ~50mm hole in the tip of a tile, adding a screen, and toppin it with a partial tile.  No warranty...

[sometimewoodworker]

2 hours ago, sometimewoodworker said:

Also it can't do anything for connected, physics 101.

Don't you just love autocorrect ???? for "connected" read convection 

 

Woooops.

[ThiAmo]

6 hours ago, sometimewoodworker said:

It very much depends on where you put it as to its effectiveness, on a horizontal surface you often get dust which drops it usefulness quickly. Also it can't do anything for connected, physics 101.

 

6 hours ago, sometimewoodworker said:

Dust will reduce it effect much more quickly than the fibreglass. Fibreglass will also reduce sound transmission by much more. 

Thank you for your valuable input. 

Given the robust surface structure of the aforementioned reflective foil brand it should be possible to dust it periodically if at all necessary in a green environment like ours. 

If your timetable does allow it, would you mind to enlighten me briefly as regards your expression "connected, physics 101"? ????

[ThiAmo]

21 minutes ago, ThiAmo said:

"If your timetable does allow it, would you mind to enlighten me briefly as regards your expression "connected, physics 101"? ????

Sorry, I've just seen that you've given your "explanation" already ????

[sometimewoodworker]

18 hours ago, ThiAmo said:

Given the robust surface structure of the aforementioned reflective foil brand it should be possible to dust it periodically if at all necessary in a green environment like ours. 

The top surface on both kinds can certainly be cleaned, however there are significant difficulties involved that include, but are not limited to, getting access to all areas without damaging parts, not falling through the ceiling, the time it takes to clean it, actually getting the dust out rather than just moving it around.

 

Ceiling insulation and roof radiant barriers are install and forget.

 

But of course you are free to pay more money for a product that will need regular maintenance to perform well. ???? 

[ThiAmo]

23 hours ago, sometimewoodworker said:

But of course you are free to pay more money for a product that will need regular maintenance to perform well. ????

The better arguments are undoubtedly on your side, so I will follow your advice, hoping that possible rodents strewing about won't come to the idea of building their nests in the middle of the glasswool-layers.

Many thanks for your sound and unpretentious help on this forum.????

[GarryP]

I will be having a bungalow built up country in a couple of years and have started looking at different designs. One type of design that I am quite interested in is the so called "Modern Style" bungalow as per the images. However, I have great concerns about the type of roof and whether it would result in the house becoming an oven in the day time. I currently live in an uninsulated house in BKK and you just cannot stay upstairs in the day time. I am worried that the bungalow with that low roof would result in the house being like my current upstairs.  The air space is quite limited, which I assume is not good (but could be wrong). If I bought top of the line roof panels, something like Bluescope Zacs, insulated the ceiling with fiberglass insulation such as SCG Stay Cool rolls, and made sure the soffits had airholes in them, do you think that would be enough for the house to be reasonably comfortable without having the aircon on all day? 

[SimpleMan555]

On 5/22/2020 at 9:47 PM, GarryP said:

I will be having a bungalow built up country in a couple of years and have started looking at different designs. One type of design that I am quite interested in is the so called "Modern Style" bungalow as per the images. However, I have great concerns about the type of roof and whether it would result in the house becoming an oven in the day time. I currently live in an uninsulated house in BKK and you just cannot stay upstairs in the day time. I am worried that the bungalow with that low roof would result in the house being like my current upstairs.  The air space is quite limited, which I assume is not good (but could be wrong). If I bought top of the line roof panels, something like Bluescope Zacs, insulated the ceiling with fiberglass insulation such as SCG Stay Cool rolls, and made sure the soffits had airholes in them, do you think that would be enough for the house to be reasonably comfortable without having the aircon on all day? 

In the houses presented above in the architectural renderings, it might prove a challenge to keep the home cool all day without A/C, especially during the summer dry season.

To improve the thermal performance of the house, a few suggestions would include,

 

1. Use of a Radiant barrier in roof system.
2. Use a lighter colored exterior paint on the roof panels.

3. High performance windows, (E-glass, weatherstripping, thermally isolated framing etc) to block the          heat from entering through the windows.

4. Install Interior window coverings that are capable of blocking the heat.

5. Use Exterior plantings to cool the outside garden areas, and block sunlight as it moves
    throughout the day.

6. Interior fans to move the air and lower the 'Feels Like' temperature.

7. Limit large open paved areas of concrete and gravel as they are heat sinks that will feed heat back into
   the atmosphere as the ambient air temperatures lowers at night.

8. Increase the size of the roof overhangs to prevent sunlight from hitting walls/windows where possible.

9. Orientate the home on the property to take advantages of seasonal changes in the path of the sun (declination etc), and reduce the direct heating of the roof and walls. Basically you want to present the smallest target possible to the sun and protect areas such as bedrooms for increased comfort.

10. If you have an outside Thai kitchen, design it to have good sun protection, ventilation etc and not as something will we will do after the house is finished...The 'Family Chef' will thank you ????

I suggest you do some research on Tropical home design. I suggest you look  for sources from the USA and Australia as they both have areas with a climate to Thailand, and they have conducted extensive research on the subject.

Cheers!

 

[GarryP]

9 hours ago, SimpleMan555 said:

In the houses presented above in the architectural renderings, it might prove a challenge to keep the home cool all day without A/C, especially during the summer dry season.

To improve the thermal performance of the house, a few suggestions would include,

 

1. Use of a Radiant barrier in roof system.
2. Use a lighter colored exterior paint on the roof panels.

3. High performance windows, (E-glass, weatherstripping, thermally isolated framing etc) to block the          heat from entering through the windows.

4. Install Interior window coverings that are capable of blocking the heat.

5. Use Exterior plantings to cool the outside garden areas, and block sunlight as it moves
    throughout the day.

6. Interior fans to move the air and lower the 'Feels Like' temperature.

7. Limit large open paved areas of concrete and gravel as they are heat sinks that will feed heat back into
   the atmosphere as the ambient air temperatures lowers at night.

8. Increase the size of the roof overhangs to prevent sunlight from hitting walls/windows where possible.

9. Orientate the home on the property to take advantages of seasonal changes in the path of the sun (declination etc), and reduce the direct heating of the roof and walls. Basically you want to present the smallest target possible to the sun and protect areas such as bedrooms for increased comfort.

10. If you have an outside Thai kitchen, design it to have good sun protection, ventilation etc and not as something will we will do after the house is finished...The 'Family Chef' will thank you ????

I suggest you do some research on Tropical home design. I suggest you look  for sources from the USA and Australia as they both have areas with a climate to Thailand, and they have conducted extensive research on the subject.

Cheers!

 

Many thanks for your detailed response. A number of the points you raised, we have already taken into consideration, such as roof hangings, color to minimize absorption of heat. We will also be planting some tall plants/trees to provide shading and block the sun from the east. Unfortunately, the rear of our house will face WNW so it will catch a lot of sun in the afternoon. However, because no-one is behind us, we can go with a white roof and will try to find someone who can supply Bluescope with insulation.

 

I will also start looking into windows, preferably that have tinted glazing. Still not sure about going with double glazing or not. But if I try to do everything possible to control the temperature in the house, it is going to go way over budget.

 

Finally, there will be not outside kitchen.