How To Insulate/ventilate A Simple Thai House

[Swelters]

I've looked into the thermal comfort question in some depth while living and building in Thailand, also studied results of studies undertaken in places like Florida that have similar conditions if not building histories. My conclusions applicable to many typical Thai houses -- I'm thinking here of the simple upcountry semi-Thai modern house -- boil down to a few simple recommendations which I offer here for the community members who are building single family homes in Thailand. There are a few loose ends and of course I welcome and hereby seek comments and criticism.

Researching the subject of home insulation on the web for application in Thailand is a difficult task for several reasons: the science of insulation/ventilation is inherently tricky because of it sometimes leads to findings that are not obvious and even counterintuitive; manufacturers promote their stuff with little regard for truth (especially in Thailand, but true enough too in the US and Australia); building experience in non-tropical climates has led to some practices that are sensible in the country of origin but dead wrong in Thailand; practices elsewhere have evolved in political environments that created mistakes that were later “papered” over with other mistakes creating compounded wastes at consumer expense.

A typical house is shown in the figure at the end of this post. The house has one of those blue tile roofs you see everywhere in Thaialnd and a dropped ceiling, so you are not looking up at the underside of the roof.

If you don't insulate or ventilate or shade this house and you will end up with the following conditions at about 3 pm on a typical April afternoon:

Roof temperature, top and bottom: about 50 degrees C

Interior temperature: 45 plus degrees

Evening cooling-off period: hours.

You would die in this house--literally if you stayed very long.

Where to start?

The fundamental rule here is “no sun exposure to the extent possible.”

Some basic considerations:

1. Note that house is sited in a way that minimizes side exposure to morning and afternoon sun. (Of course I recognize that you usually don’t have too much choice in this regard.)

2. Tree shade is nature's almost perfect way of eliminating sun exposure, and gives you an added bonus of transpirative cooling from the tree leaves. The morning and afternoon walls/window exposure is limited in the case illustrated by vegetation and those nice thai roof overhangs.

3. For commercial spaces or flat roofs, a double thickness of black nursery netting, hung a meter or so above the roof surface, can do wonders. But you and your neighbor would probably not enjoy looking at it. (This goes for white coated roofs too, beloved by scientists and theoreticians, which also will much reduce the heat being delivered into the roof but don't look good.)

4. If the roof is unshaded, insulation is needed and, done right, will save the day.

5. Foil insulation, ie reflective barriers, are the usual inexpensive choice in most contemporary thai houses. Foil alone if correctly placed is a reasonable first step, it will be of some help but don’t expect it to be enough.

6. Rolls of foil mounted on heavy reinforced paper cost about xx baht per square meter. This is what you want. Expect no improvement but higher cost from bubble-backed foil or foil backed by polyethylene foam (usually 1 cm thick.). The claims of R values and related data presented with these latter two products are misleading. To put it politely.

7. The foil should be draped a little below the roof so there is a little space between the roof and the top of the foil. The shinier side must be DOWN and there must be a clear air space below this of at least an inch or two. (I've shown a meter or so in the diagram.)

8. Depending on a lot of complicated physics having to do with air movement, this roof-foil-air space sandwich will provide an effective R value (British units, be careful of this in Thailand, they may be giving you metric) of between 3 and 17. I am betting it's closer to 3. You want at least 10, and many authorities would plead for 20 or 30.

9. Therefore, the foil almost certainly should be supplemented. There are several ways to do this.

10. A lot of ventilation is one way. If you have good sized louvered openings on both ends of the building, or some big wind turbines (second choice, usually), AND a nice breeze between 8 and 16 km/hr, you will change the air every few minutes in the attic space, the air in the attic will not rise more than a couple of degrees above the outside air temperature and you will have done the job. The goal is 20 air changes an hour.

11. With only a little ventilation (ie a few holes here and there, the usual practice in the US and elsewhere, or, more usually, dead calm in the late afternoon so vents don't do much at all) you are short on effective ventilation and will need further insulation, otherwise the air will heat up and the ceiling will become hot too. This will feel bad on the top of your head (which, at least on the surface, doesn’t know about that wonderful foil up there in the attic) and also start to warm the air in the room by as much as 20 or 30 watts per square meter (which will heat air in a room at about two degrees C per minute.)

12. You can complete the job by adding some fluffy or fibrous stuff on top of the ceiling, #2. Just buy the rolls of 3 or 4 inch thick insulation from home Pro, about 100 baht per square meter. ) Or make your own from the hundred different recipes that are out there (sawdust, glass wool, rock wool, burned rice husks, etc etc, with due consideration to fire and insect concerns). This will add an R increment of about 10 to the system, and your ceiling should not be warm at all.

13. Maybe easiest of all, forget about the foil and the ventilation (except a little ventilation, maybe an air change every half hour or so, achievable with some screened louvered vents). Put in 3 or 4 inches of fluffy insulation right under the roof, whether or not you have a ceiling. Shown as #3.

I confess that some of these basic conclusions are based on my own mistakes, which you can find described in our blog at

http://www.thaivisa.com/forum/blog/swelters/index.php?

I hope these can be remedied and will present any exciting cures as I try them out.

Edited December 12, 2006 by Swelters

[Totster]

Excellent post swelters.. topic pinned

totster

[chownah]

1. Note that house is sited in a way that minimizes side exposure to morning and afternoon sun. (Of course I recognize that you usually don’t have too much choice in this regard.)

Can you please explain your views on how to site the house. It is not clear to me from the picture.

Chownah

[pete_r]

Thanks Swelters, it's great information just on time. I've moved into a new house with no insulation whatsoever only last weekend.

[Swelters]

1. Note that house is sited in a way that minimizes side exposure to morning and afternoon sun. (Of course I recognize that you usually don’t have too much choice in this regard.)

Can you please explain your views on how to site the house. It is not clear to me from the picture.

Chownah

Sure.

If you have a long thin house you'd want to orient the long axis east-west to minimize the side areas facing the morning and (especially) afternoon sun. In the limit case (knowing you mathematical bent) you'd have no exposure at all! This is a standard recommendation, but hardly practical in most cases.

Less commonly thought of is the idea of siting in the afternoon shadow of some tall thing. Turned out this way in our place, by accident, not design; shade aftere 3 pm in April.

serendipitous aftternoon shadow from nearby ugly apartment building

[astral]

Great topic.

I have unpinned this topic and added it to the list of useful links, which is pinned.

[pumpuiman]

You left out the "blown in" insulation. I had this done to my new home in Isaan. Foam insulation is applied directly to the underside of the roof tiles. I did some research and found it to be the best option for me.

It was about 60,000 bhat for the whole house. It's a 2 storey 4 bedroom 2 bath.The roof on the first floor is only over the kitchen and one bedroom.

Trying to post pic but having trouble....sorry

[Tony Clifton]

Before we moved into this house, the townhouse we lived in had inner walls that were never exposed to direct sunlight on the outside but were still very hot to the touch even at midnight

The attic was so badly built and ventilated and the air up there was so hot that it heated up the upper sections of walls in the attic with the heat radiating all the way down through concrete and re-bar, turning the house into a 24 hour oven. The closer to the ceiling you'd touch any inside wall, the warmer it got. The attic we have now is well ventilated with a constant breeze flushing it out constantly. You can sometimes notice the same heat radiation happening where the ceramic floors unexposed to direct sunlight will feel hot to the touch, the heat being transferer through connected concrete walls that are exposed to direct sunlight.

Dropped ceilings do radiate some heat (gypsum) but upper sections of walls exposed in the attic are a killer, simply starting by insulating those would make a big difference.

Edited December 22, 2006 by Tony Clifton

[The Skipper]

I had a fan in my attic vent connected to a thermostat.

[tartempion]

I am building right now and put foil under roof tiles.

I am waiting for the ceilings and electricity to be finished to add 3 inch "Stay cool" rolls from Home Mart.

You will need to wait for March 2007 though to evaluate results.

We now live in a rented house near udon Thani, it's an oven (not right now, rather cold, LOL)

The front door is oriented East and main sleeping room West with double wall because of afternoon heating up from the sun.

Strangely enough the builder has not included vents in the roof, arguing rain and insects might come in under the roof, any comment on this?

[Swelters]

I am building right now and put foil under roof tiles.

I am waiting for the ceilings and electricity to be finished to add 3 inch "Stay cool" rolls from Home Mart.

You will need to wait for March 2007 though to evaluate results.

We now live in a rented house near udon Thani, it's an oven (not right now, rather cold, LOL)

The front door is oriented East and main sleeping room West with double wall because of afternoon heating up from the sun.

Strangely enough the builder has not included vents in the roof, arguing rain and insects might come in under the roof, any comment on this?

Where are you going to put the "stay cool" (which I assume is that puffy blanket stuff at least 3 inches thick, don't use the 1-cm thick bubble stuff)? If you put it right under the roof (but leave about an inch space so you get the benefit out of the foil) you won't need much ventilation. But why not put in a louvered vent with insect screen anyway, both ends of the roof? I would.

But you can also put the "stay cool" on top of the dropped ceiling, in which case the attic space will definitely get very hot without strong ventilation (BIG vents). I've had experience with good Thai builders, but they just don't get too excited about heat, it doesn't bother the Thai.

But when the temperature plunges below 76 F........now mahk!

[crackers]

Please give ideas we have a small house which has a roof like a shed .The roof is made from the cheapest grey corrigated roof panels(same as used on cheap apartment blocks) .Ther is no ceiling inside so when we look up we see the roof.Any ideas for cheap insulation please

I've looked into the thermal comfort question in some depth while living and building in Thailand, also studied results of studies undertaken in places like Florida that have similar conditions if not building histories. My conclusions applicable to many typical Thai houses -- I'm thinking here of the simple upcountry semi-Thai modern house -- boil down to a few simple recommendations which I offer here for the community members who are building single family homes in Thailand. There are a few loose ends and of course I welcome and hereby seek comments and criticism.

Researching the subject of home insulation on the web for application in Thailand is a difficult task for several reasons: the science of insulation/ventilation is inherently tricky because of it sometimes leads to findings that are not obvious and even counterintuitive; manufacturers promote their stuff with little regard for truth (especially in Thailand, but true enough too in the US and Australia); building experience in non-tropical climates has led to some practices that are sensible in the country of origin but dead wrong in Thailand; practices elsewhere have evolved in political environments that created mistakes that were later “papered” over with other mistakes creating compounded wastes at consumer expense.

A typical house is shown in the figure at the end of this post. The house has one of those blue tile roofs you see everywhere in Thaialnd and a dropped ceiling, so you are not looking up at the underside of the roof.

If you don't insulate or ventilate or shade this house and you will end up with the following conditions at about 3 pm on a typical April afternoon:

Roof temperature, top and bottom: about 50 degrees C

Interior temperature: 45 plus degrees

Evening cooling-off period: hours.

You would die in this house--literally if you stayed very long.

Where to start?

The fundamental rule here is “no sun exposure to the extent possible.”

Some basic considerations:

1. Note that house is sited in a way that minimizes side exposure to morning and afternoon sun. (Of course I recognize that you usually don't have too much choice in this regard.)

2. Tree shade is nature's almost perfect way of eliminating sun exposure, and gives you an added bonus of transpirative cooling from the tree leaves. The morning and afternoon walls/window exposure is limited in the case illustrated by vegetation and those nice thai roof overhangs.

3. For commercial spaces or flat roofs, a double thickness of black nursery netting, hung a meter or so above the roof surface, can do wonders. But you and your neighbor would probably not enjoy looking at it. (This goes for white coated roofs too, beloved by scientists and theoreticians, which also will much reduce the heat being delivered into the roof but don't look good.)

4. If the roof is unshaded, insulation is needed and, done right, will save the day.

5. Foil insulation, ie reflective barriers, are the usual inexpensive choice in most contemporary thai houses. Foil alone if correctly placed is a reasonable first step, it will be of some help but don't expect it to be enough.

6. Rolls of foil mounted on heavy reinforced paper cost about xx baht per square meter. This is what you want. Expect no improvement but higher cost from bubble-backed foil or foil backed by polyethylene foam (usually 1 cm thick.). The claims of R values and related data presented with these latter two products are misleading. To put it politely.

7. The foil should be draped a little below the roof so there is a little space between the roof and the top of the foil. The shinier side must be DOWN and there must be a clear air space below this of at least an inch or two. (I've shown a meter or so in the diagram.)

8. Depending on a lot of complicated physics having to do with air movement, this roof-foil-air space sandwich will provide an effective R value (British units, be careful of this in Thailand, they may be giving you metric) of between 3 and 17. I am betting it's closer to 3. You want at least 10, and many authorities would plead for 20 or 30.

9. Therefore, the foil almost certainly should be supplemented. There are several ways to do this.

10. A lot of ventilation is one way. If you have good sized louvered openings on both ends of the building, or some big wind turbines (second choice, usually), AND a nice breeze between 8 and 16 km/hr, you will change the air every few minutes in the attic space, the air in the attic will not rise more than a couple of degrees above the outside air temperature and you will have done the job. The goal is 20 air changes an hour.

11. With only a little ventilation (ie a few holes here and there, the usual practice in the US and elsewhere, or, more usually, dead calm in the late afternoon so vents don't do much at all) you are short on effective ventilation and will need further insulation, otherwise the air will heat up and the ceiling will become hot too. This will feel bad on the top of your head (which, at least on the surface, doesn't know about that wonderful foil up there in the attic) and also start to warm the air in the room by as much as 20 or 30 watts per square meter (which will heat air in a room at about two degrees C per minute.)

12. You can complete the job by adding some fluffy or fibrous stuff on top of the ceiling, #2. Just buy the rolls of 3 or 4 inch thick insulation from home Pro, about 100 baht per square meter. ) Or make your own from the hundred different recipes that are out there (sawdust, glass wool, rock wool, burned rice husks, etc etc, with due consideration to fire and insect concerns). This will add an R increment of about 10 to the system, and your ceiling should not be warm at all.

13. Maybe easiest of all, forget about the foil and the ventilation (except a little ventilation, maybe an air change every half hour or so, achievable with some screened louvered vents). Put in 3 or 4 inches of fluffy insulation right under the roof, whether or not you have a ceiling. Shown as #3.

I confess that some of these basic conclusions are based on my own mistakes, which you can find described in our blog at

http://www.thaivisa.com/forum/blog/swelters/index.php?

I hope these can be remedied and will present any exciting cures as I try them out.

[JohnC]

Having read the posts on this I am considering having my roof sprayed with the foam insulation for two reasons, 1) the house gets very hot by mid afternoon and 2) in the wet season there are some leaks which we cannot find! I have had two quotes which initally were around the same price but the the second quote added VAT so the 60,000 baht became 63000 whereas the first quote was vat incl! In addition the second company recommended the addition of a roof exhaust temp control sestem at a cost of 15000 baht!

A couple of questions, 1) does anyone have recent experience of carrying out the above work and is it worth the effort & cost and 2) The only companies in Pattaya that install it are A.R.C. and Lohr Trade, both use the same materiel originating from Germany and offer the same three year guarentee. anyone have any experience with either of these companies??

[barryofthailand]

Having read the posts on this I am considering having my roof sprayed with the foam insulation for two reasons, 1) the house gets very hot by mid afternoon and 2) in the wet season there are some leaks which we cannot find! I have had two quotes which initally were around the same price but the the second quote added VAT so the 60,000 baht became 63000 whereas the first quote was vat incl! In addition the second company recommended the addition of a roof exhaust temp control sestem at a cost of 15000 baht!

A couple of questions, 1) does anyone have recent experience of carrying out the above work and is it worth the effort & cost and 2) The only companies in Pattaya that install it are A.R.C. and Lohr Trade, both use the same materiel originating from Germany and offer the same three year guarentee. anyone have any experience with either of these companies??

I have two friends who have used an Australian company out of Bangkok. They use a spray on material and spray it in the atic on the top side of the cieling. With a vented atic, two vents, no fans both of their homes in the hot season in Pattaya was at 26 degrees when it was 36-37 degrees outdoors. This really conserves on the air, and when using the air cools very quickly and cycles around every 30-45 minutes.

The neame of the company is cool and cozy, and yes they do have a website. They service the entire country as far as I know.

Barry

[qualtrough]

I planted bamboo trees on either side of our house so it is spared direct sunlight. Added bonus is that we only see green leafy trees outside the windows. On one occasion the trees were trimmed and the difference in temp. was so noticeable that it woke me up in the morning. We have a small yard area that is planted with mangos, palms, etc., and again not a lot of direct sunglight filters down, so you can walk around it during the day without getting burnt. At night it often feels cool. If you can do it maximize the vegetation.

[Naam]

I have two friends who have used an Australian company out of Bangkok. They use a spray on material and spray it in the atic on the top side of the cieling. With a vented atic, two vents, no fans both of their homes in the hot season in Pattaya was at 26 degrees when it was 36-37 degrees outdoors.

some people do a good job hiding their aircon units. others are good in spreading fairy tales

[barryofthailand]

I have two friends who have used an Australian company out of Bangkok. They use a spray on material and spray it in the atic on the top side of the cieling. With a vented atic, two vents, no fans both of their homes in the hot season in Pattaya was at 26 degrees when it was 36-37 degrees outdoors.

some people do a good job hiding their aircon units. others are good in spreading fairy tales

So your saying this cannot be true. this shows you do not know what you are talking about. I never make flaming posts, but what you are implying is not true.

Barry

[wpcoe]

I have two friends who have used an Australian company out of Bangkok. They use a spray on material and spray it in the atic on the top side of the cieling. With a vented atic, two vents, no fans both of their homes in the hot season in Pattaya was at 26 degrees when it was 36-37 degrees outdoors.

some people do a good job hiding their aircon units. others are good in spreading fairy tales

So your saying this cannot be true. this shows you do not know what you are talking about. I never make flaming posts, but what you are implying is not true.

Barry

Barry, I have no reason to doubt your veracity, but where exactly does 26 degree cool air come from when it's 36-37 degrees outdoors? When it's that hot outside, it barely gets down to 26 degrees at nighttime in Pattaya. If/when it does, then I could understand the lower floor (or lower to the floor) areas retaining that 26 degree air until about noon. But without air con, are the windows open? If so, doesn't warm air flow in (and up to circulate out the upper vents)? And, if so, how does it remain 26 degrees at ground level? It just sounds incredible. Maybe IS credible, but SOUNDS incredible.

[Naam]

I have two friends who have used an Australian company out of Bangkok. They use a spray on material and spray it in the atic on the top side of the cieling. With a vented atic, two vents, no fans both of their homes in the hot season in Pattaya was at 26 degrees when it was 36-37 degrees outdoors.

some people do a good job hiding their aircon units. others are good in spreading fairy tales

So your saying this cannot be true. this shows you do not know what you are talking about. I never make flaming posts, but what you are implying is not true.

i don't think i flamed you Barry. what i stated are indirect facts wrapped in (what i think) a joking remark. the laws of physics (especially heat transmission) are fixed. there is no way that any home can have a temperature 10ºC less than the outside temperature without artificial cooling. and i know quite well what i am talking about. it so happens that i'm a (retired) physicist.

[chownah]

there is no way that any home can have a temperature 10ºC less than the outside temperature without artificial cooling

Dear Mr. Physicist Ret.

Unless you would like to qualify what you are talking about here then you are absolutely incorrect. Caves in Missouri have often been used as homes in the past and they definitely are 10 deg C less than outside without artificial cooling at times.

Sincerely,

Chownah, Rice Farmer

Edited September 10, 2007 by chownah

[Crossy]

there is no way that any conventional home can have a temperature 10ºC less than the outside temperature without artificial cooling

Dear Mr. Physicist Ret.

Unless you would like to qualify what you are talking about here then you are absolutely incorrect. Caves in Missouri have often been used as homes in the past and they definitely are 10 deg C less than outside without artificial cooling at times.

Sincerely,

Chownah, Rice Farmer

Happy now?? :)

Edited September 10, 2007 by Crossy

[sleepyjohn]

there is no way that any home can have a temperature 10ºC less than the outside temperature without artificial cooling

Dear Mr. Physicist Ret.

Unless you would like to qualify what you are talking about here then you are absolutely incorrect. Caves in Missouri have often been used as homes in the past and they definitely are 10 deg C less than outside without artificial cooling at times.

Sincerely,

Chownah, Rice Farmer

But caves do have a cooling system....the evaporation of dampness inside which absorbs the latent heat of evaporation. This is common in caves but not in houses. (also read physics ha-ha)

I am sorry there is a similar thread happening at the same time in which I have argued against thermostatic fanned vents (Although an informed discussion of insulation is welcome). Unobstructed vented high ceilings haven't been mentioned yet have they?

If there is enough convective gradient then the mere fact that things start to get warm, presumably at the top before you feel it, starts the air flow doesn't it? Outside breezes should be welcome but unnecessary for convection.

Edited September 10, 2007 by sleepyjohn

[Naam]

there is no way that any home can have a temperature 10ºC less than the outside temperature without artificial cooling

Dear Mr. Physicist Ret.

Unless you would like to qualify what you are talking about here then you are absolutely incorrect. Caves in Missouri have often been used as homes in the past and they definitely are 10 deg C less than outside without artificial cooling at times.

Sincerely,

Chownah, Rice Farmer

Dear Mr. Rice Farmer,

i am very well aware that moving a house from Thailand into a cave in Missouri would keep the house much cooler. but that's beside the point we are discussing.

i repeat: there is no way that a house in Thailand can have without cooling an inside temperature of 26ºC when the maximum ambient temperature is 36ºC (and the assumed minimum temperature in the early morning is 30ºC). it takes only little logic (even for a scientific less experienced person) to realize that any insulation does not cool but -as the name says- insulates from heat. the temperature inside the house is always in relation to the outside shade-temperature or even higher if not ventilated as the heat sources inside the house (lighting, fridges, any usage of electrical energy AND of course human beings as well as pets) add to that.

[Iolare]

A few weeks ago I started a topic titled “Tropical Home Design” because I’m new here, and I was finishing up the design work on a house I’ll be building. I wanted to learn more about what were the important considerations in achieving the goal of a comfortable, livable house in a tropical climate like Phuket Island. I’ve also followed this thread and another one currently running titled “Building a House (I want a Cool House),” and I believe they’ve all been very useful to me in sorting out what is important in constructing livable house. I’m very grateful to TV for providing this forum, and for the collective experience of this group.

I’ve found that living in Chalong, Phuket, I am comfortable if I’m sheltered from the sun and rain, and if there’s a little breeze. It doesn’t matter if it’s even up to 32 C, I’m still comfortable. So for me, an open house with good shading and good airflow seem to be the key. In unusually hot or humid conditions, having A/C available would be nice, and I am planning on installing aircons, but I’m basing my design on living without A/C most of the time.

I appreciate Swelters list and all of the information in this thread, and I’m not trying to supplant it, but given my criteria of wanting a house that’s comfortable without A/C most of the time, here are the design elements in the order of importance as I see it for that kind of house:

1) Shelter the walls and windows with a wide roof overhang.

2) Insulate the living space from the roof.

3) make sure the doors and windows are positioned so that there is good airflow through the house, and also install ceiling fans.

4) Build with a high ceiling height.

5) ventilate the attic.

6) Orient your house so that the west side is not the view side and place the garage or less important rooms with small windows there. Also consider prevailing breeze direction in the orientation of the house and window placement.

7) Shelter the house with trees and other landscaping.

8) Be careful not to have too much concrete around the outside of the house, particularly on the south and west sides due to heat absorption and radiation.

9) Select a light colored roof

10) insulate and / or ventilate the side walls

11) Elevate the house on posts.

12) Insulated glass

13) Insulating paint.

As one comes down this list the issue of cost effectiveness comes into play. You don’t want to be paying extraordinary cost for marginal benefit. From that perspective, I’m thinking that while having double wall construction with venting to the outside might be a little better than a solid wall of Q-Con blocks, I don’t think it would make enough difference to justify the extra cost in a home where the roof overhand keeps the direct sun off the wall, and where there is no significant radiated heat or reflected sunlight against the side walls. Same goes for the special glass unless it’s in direct sunlight, and probably the special paint.

On the other hand, i’ve come to believe that attic ventilation is important enough to justify the extra expense of mechanical ventilation, and for convenience I choose thermostatic control. While I agree with Sleepyjohn’s assertion that keeping it simple with large roof vents and relying on natural convection should be adequate, I think in the case of my design there is a chance than it might not be, and so I’m hedging my bet there.

[wpcoe]

This may be a bit less extreme than living in a cave <g>:

I used to live in the Nevada desert and at night time the temps would drop significantly from the day time highs. If I were to sleep with the windows open at night I would not need air con, and if I closed the windows by 0900 or so before the desert heat started to rise, the well-insulated walls would keep the air inside cool & comfortable until early afternoon. Granted low humidity was a factor.

However, this is the humid tropics, not the arrid desert, and houses are not as well insulated as they are in the Nevada desert. I'm not a physicist, and I have a hard time understanding how a 26 degree temp could be achieved/maintained/contained when it is 35-36 degrees outside in the tropics.

[ClaudeFeller]

We used to have an aircon in the bedroom. After we bought "Stay cool" 3 inch we didnt need anymore, fan is enough. But our bedroom has a lot of windows. These are kept open whole day/night long.

Cheers from Samui,

Claude

[Bpraim1]

I am biulding a house in Issan sarting next friday.

As for insulation I will be useing PU Foam in the walls 35kg/m3 3" thickness, Roof will have 2'' PU Foam 3" StayCool Foil Pouched Fibreglass( this is more of an acoustic barrier to work with the PU Foam, As some of the house has dropped ceiling) Neighbours blast the news every moring at 6am for the village to listen too. I don't want to listen.

I have attached a ruff pic of how this will be done. Some may say I am in over kill mode and wasteing money, But I will not be sweating my a$$ off.

Plus this is my house to build not yours.

I write this just so people can see different ideas at insulating and building. As I will be useing aircon alot and live close to a main road ( alot of sound) I want my house heavly insulated.

Maybe it will work, maybe not, But for sure time will tell.

[Naam]

I have attached a ruff pic of how this will be done. Some may say I am in over kill mode and wasteing money...

Bpraim, if you plan to live comfortably with aircon in your home the sketch you submitted does not show any "overkill" at all. a misconception (in my personal view) is the 2" PU under your roof tiles. money and insulation should have been used to increase the insulation between your ceiling and the attic and concentration on proper (forced) attic ventilation which is much cheaper and technically much easier to achieve than with insulation.

[ajannick]

Hi,

I've been reading this thread with interest as I have just finished building a house. I have used no insulation under the roof tiles and think that I may live to regret this. I have a drop ceiling upstairs which I am thinking about putting the "stay cool" reflective roll on top of. Will this be enough?

On the issue of "mechanical ventilation", controlled by a thermostat, could anyone advise me how to go about getting this set up. I live in Sakon Nakhon there is a home mart here but have not found any company supplying this type of thermostatically controlled ventilation system. Could I make my own?

Any help or advice would be much appreciated.

Nick.

[chownah]

Bprain1,

Having vents in your eaves and none at or near the peak of the roof and with no fans will do almost nothing to vent hot air out of the attic space. If you are lucky enough to have a wind blowing in the right direction you will get some ventillation but really very little. I recommend some openings near or at the underside peak of the roof...either in the end gables (if you have end gables in your roof design) or verticle vents installed through the roof membrane. Also I think bigger vent area would be better. Square or short rectangles are more efficient generally at admitting air flow than long narrow ones. If your design requires long narrow ones then make them as big as possible. I have 15 cm wide strip venting running under the eaves the entire length of the house on both sides and almost square shaped ventilation openings at both end gables at the underside peak which are more than 1 square metre.

Chownah