What's the best white paint to reflect sunlight radiation (heat)?

[GammaGlobulin]

Dear folks,

 

I am now planning to completely board-up my bedroom windows...with plywood....painted with white paint.

 

The purpose is two-fold.

 

a.  I want to reduce sound transmission into my bedroom.

b.  I want to reduce radiation from the sun which heats up my room, and costs me extra money just by making my AC work harder.

 

So then, in Thailand, what is the brand of paint which is most reflective?

 

Speaking of radiation, nobody likes this.

 

 

 

I need to block all radiation, except for the neutrinos, from the sun getting into my bedroom, not only visible light but also infrared.

 

So, what is the best brand of paint available here in Thailand?

 

Thank you.

 

Gamma

 

 

[degrub]

You need plywood with foil on one side to block re-radiation of infrared. Paint by itself will reduce the heat transfer by a little bit only. There is still significant amount of conductive heat transfer through the plywood because the white surface of the plywood heats up.
 

Foil side on plywood must be facing interior and only exposed to dead calm air to minimize convective heat transfer. Ideally, this would on the inside face of the roof as well if there is not an apartment above yours. 
 

Actually, the better location for the foil is the inside face of the window glazing. Then you don’t need any painting at all. Install the noise absorbing plywood mass so that there is an air gap to the glazing. Caulk the gaps around the edges to block the significant sound leakage through cracks. You must use thick , stiff plywood to get enough mass and avoid a diaphragm effect ( think speakers). Probably 15 or 20 mm with thickness higher for longer spans. Also, you can screw on a strong-back stiffener , maybe 50x50 mm if both dimensions of the glazing are long.

if you paint the outer face of the plywood, look for a white coating designed to be applied to flat roofs. Otherwise , any white paint with high TiO2 content. 
 

The room walls and structural bits in contact with each other will conduct heat from the outside to the inside surface of the room walls no matter what you do with the windows. Air leakage through the wall component joint gaps will bring in heat and moisture as well. If the outside surface is masonry, it will contimue to radiate heat long after the sun goes down, particularly on West facing walls.

 

 

Maybe it would be easier to move ?

 

[GammaGlobulin]

4 hours ago, degrub said:

You need plywood with foil on one side to block re-radiation of infrared. Paint by itself will reduce the heat transfer by a little bit only. There is still significant amount of conductive heat transfer through the plywood because the white surface of the plywood heats up.
 

Foil side on plywood must be facing interior and only exposed to dead calm air to minimize convective heat transfer. Ideally, this would on the inside face of the roof as well if there is not an apartment above yours. 
 

Actually, the better location for the foil is the inside face of the window glazing. Then you don’t need any painting at all. Install the noise absorbing plywood mass so that there is an air gap to the glazing. Caulk the gaps around the edges to block the significant sound leakage through cracks. You must use thick , stiff plywood to get enough mass and avoid a diaphragm effect ( think speakers). Probably 15 or 20 mm with thickness higher for longer spans. Also, you can screw on a strong-back stiffener , maybe 50x50 mm if both dimensions of the glazing are long.

if you paint the outer face of the plywood, look for a white coating designed to be applied to flat roofs. Otherwise , any white paint with high TiO2 content. 
 

The room walls and structural bits in contact with each other will conduct heat from the outside to the inside surface of the room walls no matter what you do with the windows. Air leakage through the wall component joint gaps will bring in heat and moisture as well. If the outside surface is masonry, it will contimue to radiate heat long after the sun goes down, particularly on West facing walls.

 

 

Maybe it would be easier to move ?

 

 

Thanks.

Good advice.

 

I was thinking of buying a space blanket and attaching it to the underside.

I know I need a reflective paint, as well....

 

 

[SAFETY FIRST]

7 hours ago, GammaGlobulin said:

Dear folks,

I miss your Linux topic 😞

[GammaGlobulin]

1 minute ago, SAFETY FIRST said:

I miss your Linux topic 😞

 

Sorry.

But, we can't have everything in life.

Obviously.

 

[sometimewoodworker]

12 hours ago, GammaGlobulin said:

I am now planning to completely board-up my bedroom windows...with plywood....painted with white paint.

 

The purpose is two-fold.

 

a.  I want to reduce sound transmission into my bedroom.

Do not use plywood. Use at least 25mm MDF, on floating fasteners of possible, better would be 2 sheets with proper sound deadening mastic between them and a heavy rubber sound seal layer correctly isolated from the walls and each other, with a complete mastic seal between the boards.

[degrub]

Here is a calculator to give you an estimate of the MDF weight so you have an idea what you are dealing with.

 

https://www.woodworkhubby.com/how-much-does-mdf-weigh/

 

[GammaGlobulin]

1 hour ago, sometimewoodworker said:

Do not use plywood. Use at least 25mm MDF, on floating fasteners of possible, better would be 2 sheets with proper sound deadening mastic between them and a heavy rubber sound seal layer correctly isolated from the walls and each other, with a complete mastic seal between the boards.

 

OK....!!!!

Thank you.

Will do.....!!!

 

 

 

Whatever the doctor orders.....

 

No doubt this will cure my ills.

Thank you, once again.

 

(Is THIS MDF?  I think so.)

 

[GammaGlobulin]

41 minutes ago, degrub said:

Here is a calculator to give you an estimate of the MDF weight so you have an idea what you are dealing with.

 

https://www.woodworkhubby.com/how-much-does-mdf-weigh/

 

 

The HEAVIER the BETTER, for my purposes.

 

Higher density and more mass will provide better sound insulation.

 

[sometimewoodworker]

 

2 hours ago, GammaGlobulin said:

 

OK....!!!!

Thank you.

Will do.....!!!

 

 

 

Whatever the doctor orders.....

 

No doubt this will cure my ills.

Thank you, once again.

 

(Is THIS MDF?  I think so.)

 

There are various qualities of MDF that is a particularly low quality version, it is far closer to chipboard, the particles are big and it is probably quite lightweight (relatively) 

These are better.

 

go to a quality supplier, virtually all are in Bangkok, and find the most expensive (it’s still quite cheap) sheets the have that are the heaviest they have.

[GammaGlobulin]

4 minutes ago, sometimewoodworker said:

 

There are various qualities of MDF that is a particularly low quality version, it is far closer to chipboard, the particles are big and it is probably quite lightweight (relatively) 

These are better.

 

go to a quality supplier, virtually all are in Bangkok, and find the most expensive (it’s still quite cheap) sheets the have that are the heaviest they have.

 

So then...

What about Chiang Mai Suk Sawat?

OK quality there?

 

That is were I would buy....

And, I need good quality.

 

[sometimewoodworker]

3 minutes ago, GammaGlobulin said:

 

So then...

What about Chiang Mai Suk Sawat?

OK quality there?

 

That is were I would buy....

And, I need good quality.

 

No it’s cheap lightweight, closer to chipboard

 

https://www.thaimdf.com

HMR or HDF is probably closer to the quality you need.

[GammaGlobulin]

4 hours ago, sometimewoodworker said:

Do not use plywood. Use at least 25mm MDF, on floating fasteners of possible, better would be 2 sheets with proper sound deadening mastic between them and a heavy rubber sound seal layer correctly isolated from the walls and each other, with a complete mastic seal between the boards.

 

Also, how does MDF compare with plywood, concerning heat energy transmission.

I guess one can just google it.

 

[GammaGlobulin]

7 minutes ago, sometimewoodworker said:

No it’s cheap lightweight, closer to chipboard

 

https://www.thaimdf.com

HMR or HDF is probably closer to the quality you need.

 

OK.

No problem.

IF...that is....this company will deliver.

 

Tks for the contact.

 

 

(Note:  The local company charges a LOT to deliver...anyway....  So, ordering from BKK might not cost more.)

 

[GammaGlobulin]

What is the LOGIC in boarding up, COMPLETELY, one's bedroom windows?

 

The logic might be that:

 

a. During daytime, the sun shining in makes it impossible to read or use the computer.

b. During sundown hours, one can't see outside, anyway.

c. Window curtains do not do a good job of blocking light and noise.

d. MDF is cheaper than window curtains, and probably easier to install.

e. Also, good for preventing the entry of thieves.

f. Also, other advantages, such as the fact that curtains must be washed in a Samsung washing machine, while wood can just be hosed off from the outside, thereby saving costs of electricity and soap powder....etc.

 

 

 

 

[sometimewoodworker]

13 minutes ago, GammaGlobulin said:

 

Also, how does MDF compare with plywood, concerning heat energy transmission.

I guess one can just google it.

 

You reduce the heat that is transmitted to the board. Best is reflective silver, but as you probably can’t get that then a quality white paint. Again the best you probably can’t get is a correctly formulated barium chloride paint but you can make it.

FWIW PLYWOOD isn’t a good insulation material.

[GammaGlobulin]

1 minute ago, sometimewoodworker said:

You reduce the heat that is transmitted to the board. Best is reflective silver, but as you probably can’t get that then a quality white paint. Again the best you probably can’t get is a correctly formulated barium chloride paint but you can make it.

FWIW PLYWOOD isn’t a good insulation material.

 

Yes.

So, this is why I asked about the best brand of reflective white paint.

 

I might just hang a NASA space blanket outside, to worry the neighbors....temporarily.

 

 

[Yellowtail]

I think the TOA Roadline paint is reflective. And it is surprisingly nice to work with.

[GammaGlobulin]

On 11/29/2024 at 3:46 PM, Yellowtail said:

I think the TOA Roadline paint is reflective. And it is surprisingly nice to work with.

 

I think you are correct.

I need to buy next week.

 

I found this TOA product...for coating plywood which I intend using to cover windows as permanent "shutters" to block out all light and radiant heat from the Sun.

But, it looks like this tub is about 4 kilograms.

Too big.

 

Might this be the best product for reflecting heat radiation, when applied to something like thick plywood?

It looks good, as well, for avoiding moisture absorption into the plywood for outdoor use.

 

 

 

Or, would this be better, the Roadline, which you mentioned?

 

 

Need the best product for keeping room cooler, a room which is exposed to direct sun for half of the day.

This will reduce energy expenditure substantially.

 

Still, if this Roadline Paint is used, one worries that it might "sparkle" at night, like those hypnotic highway lines.

 

This is for my bedroom which I need to seal off before the Smoking Season.

So, something hypnotic might be good, unless it affects the neighbors.

 

 

Were you joking about using highway paint for the walls of my house?

 

Or, is this actually a good choice?

 

 

Note: What are the risks of White Line Fever if used in my bedroom?

 

 

 

[GammaGlobulin]

20 minutes ago, GammaGlobulin said:

Need the best product for keeping room cooler, a room which is exposed to direct sun for half of the day.

This will reduce energy expenditure substantially.

 

My Justification for Using Highly Reflective Paint:

 

 

I figure, I can save at least Bt.500.00 per month in lower energy costs relating to AC cooling cost reduction.

Probably about Bt.6000.00 per year, by my conservative estimate.

 

I just need to choose the correct coating for the plywood shutters I am fabricating.

 

Of course, the true savings will depend upon the heat differential between the outside temperature and the indoor temperature.

If I maintain the Hot Season temp, inside my bedroom, at 19-degrees C, as is normal....

Then, my energy savings will be more.

Obviously.

 

I figure, since we are not on the equator, and since the Sun is not always at it's zenith, then the average radiation hitting my plywood shutters should be about 900 watts per square meter, give or take.

 

Still, very worth the effort.....for sure.

 

Those reading my words...should...

Take heed, if they want to save a few baht.

 

 

 

 

[BritManToo]

19 minutes ago, GammaGlobulin said:

Those reading my words...should...

Take heed, if they want to save a few baht.

The easiest way to save money, is to not use air conditioning.

My electricity bill is just under 300bht this month, same as every other month.

[Ralf001]

On 11/28/2024 at 9:51 AM, sometimewoodworker said:

Do not use plywood. Use at least 25mm MDF, on floating fasteners of possible, better would be 2 sheets with proper sound deadening mastic between them and a heavy rubber sound seal layer correctly isolated from the walls and each other, with a complete mastic seal between the boards.

50mm thick cool room panels, kill sound and insulate.

Would be my go-to, bout Bt.500 sq/m.

[GammaGlobulin]

13 minutes ago, BritManToo said:

The easiest way to save money, is to not use air conditioning.

My electricity bill is just under 300bht this month, same as every other month.

 

Do you "borrow" electric power from your neighbor's line, or something?

 

Or, do you not use a water heater or a kettle for tea?

 

Maybe you use a human-powered generator to keep your fridge going?

 

 

[GammaGlobulin]

3 minutes ago, Ralf001 said:

50mm thick cool room panels, kill sound and insulate.

Would be my go-to, bout Bt.500 sq/m.

 

Tks!!!

 

I will check this alternative.

 

[GammaGlobulin]

17 minutes ago, Ralf001 said:

50mm thick cool room panels, kill sound and insulate.

Would be my go-to, bout Bt.500 sq/m.

 

These panels, as you suggest, would have excellent heat insulating properties....

 

 

However, for sound-insulation, something of higher density seems more logical, such as 3/4-inch plywood.

 

Just my guess.

 

 

As you say, these panels would be easier to apply than installing a plywood covering...maybe.

 

Something to consider, these panels, for energy savings on windows for a room, when one cares not about seeing outside...as happens to be my case, at the moment.

 

Maybe use both plywood and the panels....if they are designed to be used on the outside of an exterior surface.

 

 

 

 

[BritManToo]

29 minutes ago, GammaGlobulin said:

Do you "borrow" electric power from your neighbor's line, or something?

Or, do you not use a water heater or a kettle for tea

Maybe you use a human-powered generator to keep your fridge going?

Kettle/cooking/water heaters/aircon = under 300bht.

Fridge/lights/sockets/E-MTB = solar power

[GammaGlobulin]

Just now, BritManToo said:

Kettle/cooking/water heaters/aircon = under 300bht.

Fridge/lights/sockets/E-MTB = solar power

 

You neglected to mention you were using solar panels.

Now, your Bt.300 per month makes more sense.

And, very logical.