Room Cooling + Roof Vent

[pulnamin4]

I live in Isaan in a typical Thai house, .. concrete walls, steel roof structure, , roof made of << concrete >> tiles.

No insulation at all. In the room we have the usual suspended ceiling.. The room gets very warm ( hot).. i am looking for ways to cool the room without using AC .. ( pointless to use AC without any insulation >>..

Q1- Would replacing a few suspended ceiling tile with a mosquito screen help ? The air would flow from the room to the roof area.

Q2- How about installing a roof vent to extract the warm air from under the roof ? As anyone seen any roof vent in Thailand ? If yess where ? Are they efficient ?

Q3-- I know some people install insulation mat ( mattress ) over the suspended ceiling, but i could not find anyone who has done it ..to ascertain if this is a viable solution.

Q4 -- Suggestions, recommendations, pictures are welcome.

Thanks in advance.

[ClutchClark]

I think with the type of roofing tile you have, some sort of ridge vent would be more typical.

Applying the reflective material on the underside of the rafters facing outwards can help reflect heat energy from entering the living space.

If you have gable ends then adding gable vents is beneficial -- but may already exist.

Is it possible for you to incorporate a fast growing vegetation into the adjacent outdoor space? Something to provide shade to even a portion of the roof or exterior wall?

[namdocmai]

We have a new markethall with a high roof (and vents) and i noticed they sprayed some yellow/brown foam on it from the underside. That works and is very easy.

Also i see the aluminium/stainless turning chimneys on many buildings in the city, i guess that will work as well.

Big tree's to keep the house in the shade sure works.

Those rockwool mats will work on a suspended ceiling but maybe mouses or rats or other pests will like to live there?

[Donnie Brasco]

Roof vents, are effective and if properly installed to correspond with the pitch of your roof they are not that unsightly.

Try exhaust fans to create fore and aft cross-ventilation as well.

Ensure all these new roof openings are bird and bat and critter proof.

The latter will use less electricity than Aircon but their ambient noise may take some getting used to.

You might also also try foam-spray insulation and or even painting the roof silver.

Then treat yourself to some aircon.

[Rooo]

Moved to housing forum.

[metisdead]

A post linking to another forum has been removed:

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[stat088]

We have a new markethall with a high roof (and vents) and i noticed they sprayed some yellow/brown foam on it from the underside. That works and is very easy.

Also i see the aluminium/stainless turning chimneys on many buildings in the city, i guess that will work as well.

Big tree's to keep the house in the shade sure works.

Those rockwool mats will work on a suspended ceiling but maybe mouses or rats or other pests will like to live there?

I installed the insulation bats about 10 years ago. I did not notice any drop in the temperature and we had a problem with mice and other rodents. Have to make sure the trees are not making contact with the house.

[h90]

I put fiber insulation Aluminum coated on to of the ceiling.

(Where is more light the Aluminum corroded away )

That made the roof even more hot. You can't touch the steel anymore as your fingers would burn.

Where the roof (and is closed only with the thin ceiling) goes over the house, I installed a fan that blows air from outside into between roof and ceiling. That helps a lot. The hot air is "pressed out". Works of course only if the hot air can't go down into your living area.

(I am not sure if that is clear....if not I can make photos)

[sfokevin]

In the US we have large whole house exhaust fans that is in the ceiling in the middle of the house and sucks air into the windows then from the house out and into the ceiling cavity... I have not seen them here but would like to buy... Has anyone seen them here?

Edited November 2, 2014 by sfokevin

[namdocmai]

In the US we have large whole house exhaust fans that is in the ceiling in the middle of the house and sucks air into the windows then from the house out and into the ceiling cavity... I have not seen them here but would like to buy... Has anyone seen them here?

Yes Watsadu and the lot all have those. They are for in the walls but you can also use them in the ceiling.

These fans make noise though, i prefer the snail models who can be very quiet.

Those stainless turning chimneys will turn from the hot air and wind i think, there is no engine in them. If you install them on the highest point they should suckk out the hot air.

Also it's better to suck air out instead of blowing air in like another member posted.

[sfokevin]

In the US we have large whole house exhaust fans that is in the ceiling in the middle of the house and sucks air into the windows then from the house out and into the ceiling cavity... I have not seen them here but would like to buy... Has anyone seen them here?

Yes Watsadu and the lot all have those. They are for in the walls but you can also use them in the ceiling.

Yes I've seen those they are noisy as you say and not really very big... I was thinking of buying a cheap large box fan at Mackro and McGyvering something in the ceiling

[namdocmai]

In the US we have large whole house exhaust fans that is in the ceiling in the middle of the house and sucks air into the windows then from the house out and into the ceiling cavity... I have not seen them here but would like to buy... Has anyone seen them here?

Yes Watsadu and the lot all have those. They are for in the walls but you can also use them in the ceiling.

Yes I've seen those they are noisy as you say and not really very big... I was thinking of buying a cheap large box fan at Mackro and McGyvering something in the ceiling

Well isn't it strange that we have to DIY for something as simple as that? Is there nothing for sale in Thailand? Some easy to install system which is safe and will last forever without any chance of fire or whatever?

Those stainless steel things on the roof are driven by wind, but you need wind what we miss here sometimes. Then we can put an electric fan on the roof to suck air out of the house. Hot air always rises so will be hanging under the roof. Cold air will fall down.

Also the further the fan is away from your sofa the less you will hear it. Snailhouse fans are very quiet, one day i used the fan from the indoor unit from an aircon. Perfectly adjustable by a dimmer, you can even let a temperature sensor control the speed of it.

Also greenhouses have automated windows in the roof who don't use any electric to open/close. And if it starts raining it will close automatic.

There are many options but i would suck the hot air out of the room at the highest point and that's under the roof.

https://www.google.nl/search?q=roof+ventilation+fan&oq=roof+ventilation&aqs=chrome.3.69i57j0l5.7855j0j9&sourceid=chrome&es_sm=122&ie=UTF-8

https://www.google.nl/search?q=roof+ventilation+systems&newwindow=1&es_sm=122&tbm=isch&tbo=u&source=univ&sa=X&ei=U05WVJjFFY3GuAS-wILoAQ&ved=0CCIQsAQ&biw=1242&bih=585

Our house has 2 floors and sure the 2nd floor is always warmer then the 1st. When we use aircon downstairs we even don't close the windows at 2nd floor because the cold air will stay downstairs. When we don't use aircon i have 2 wall mounted fans from Mitsubisi who are very quiet. Don't buy Hatari because they are noisy.

Edited November 2, 2014 by namdocmai

[sdanielmcev]

1-no. The force of the heat will enter the living area..

2- Any vent in the roof also needs soffit vents.

3- No

Trees are your best defense. In tropical climes, concrete should not be used for wall construction.

A whole house fan could be your best solution, but you should use A/C simultaneously.

Traditional style Thai are built of wood on stilts (pier and beam.)

[cooked]

Q1- Would replacing a few suspended ceiling tile with a mosquito screen help ? The air would flow from the room to the roof area.

It is not simply a question of hot air, a lot of the heat which you feel in the room is radiated heat. The roof and the walls get hot and radiate heat into the interior for a long time after the sun has gone down. If you stand on a chair and touch the ceiling you will see what I mean.

Q2- How about installing a roof vent to extract the warm air from under the roof ? As anyone seen any roof vent in Thailand ? If yess where ? Are they efficient ?

WHIRLIGIGS. (turning chimney things). Yes they work and they don't need wind to work, rising heat also makes them turn which then extracts hot air.

Q3-- I know some people install insulation mat ( mattress ) over the suspended ceiling, but i could not find anyone who has done it ..to ascertain if this is a viable solution.

This is the best solution although it can be complicated to install as the suspended ceiling will likely be supported by a random mass of wires attached to the roof joists. Aluminium foil on both sides. Foam spraying is very efficient, costs a bit more

Q4 -- Suggestions, recommendations, pictures are welcome.

We bought A/C before we installed insulation and I can assure you that it was worthwhile. Similar construction to yours. Cost generally ฿1200 - ฿2000.- a month (65 M2). There are a load of other possibilities for cooling the house like fan ventilation of the roof space, requiring openings below the highest point of the roof, aluminium foil below the roof which requires removal of the roof, and installing battens to keep the foil 2cm away from the roof. Planting a tree is a good idea. (finding out how big and fast it is likely to grow first).

[IMHO]

Q1- Would replacing a few suspended ceiling tile with a mosquito screen help ? The air would flow from the room to the roof area.

That would likely make it worse - host air expands and would push it's way into the living space.

Q2- How about installing a roof vent to extract the warm air from under the roof ? As anyone seen any roof vent in Thailand ? If yess where ? Are they efficient ?

Some swear by them, others have mixed views. I'm not sold on them.

Q3-- I know some people install insulation mat ( mattress ) over the suspended ceiling, but i could not find anyone who has done it ..to ascertain if this is a viable solution.

Yes, this would help, but be mindful of nesting... Check your roof space for signs of existing occupants first

Q4 -- Suggestions, recommendations, pictures are welcome.

Thanks in advance.

1. Install vented soffits to allow airflow both in and out of the roof space.

2. Replace the ceiling with insulated board (Gyproc thermaline), or foil backed gypsum.

3. Retrofit a radiant barrier under the roof tiles.

4. Grow trees that can provide shade.

5. Install a powerful extraction fan to push hot air from the living space into the roof cavity (make sure it's a type with shutters that block airflow it when not on).

6. Install AC - it's not completely useless at all - quite the opposite - but it will cost you more to run than if the space was better insulated.

[ClutchClark]

Contrary to all of these posts suggesting power ventilation, it is entirely possible to have success with a passive design, which appears to be the OP's goal.

One question is does the home belong to the OP? Some of these "improvements" in ventilation would require construction modifications.

[AnotherOneAmerican]

In the US we have large whole house exhaust fans that is in the ceiling in the middle of the house and sucks air into the windows then from the house out and into the ceiling cavity... I have not seen them here but would like to buy... Has anyone seen them here?

Yes Watsadu and the lot all have those. They are for in the walls but you can also use them in the ceiling.

These fans make noise though, i prefer the snail models who can be very quiet.

Those stainless turning chimneys will turn from the hot air and wind i think, there is no engine in them. If you install them on the highest point they should suckk out the hot air.

Also it's better to suck air out instead of blowing air in like another member posted.

Sucking out exposes you to a Radon gas risk.

Blowing in doesn't

Just a thought.

[Naam]

In the US we have large whole house exhaust fans that is in the ceiling in the middle of the house and sucks air into the windows then from the house out and into the ceiling cavity... I have not seen them here but would like to buy... Has anyone seen them here?

available in any size.