Attic Insulation

[kokesaat]

We built a single story house, raised about 0.5-1.0 meters off the ground (open underneath), e-w long axis, large overhang on southern and eastern sides. White rolled steel roof with 1/4" reflective insulation glued to the underside. About 4" of ceiling insulation.

We close all windows about 8AM this time of the year. Keep doors closed as much as possible. Okay, the inside heats up, but always several degrees cooler than outdoors. Yes, we need air for comfort and sleeping.

One odd thing I've noticed. We have a small bedroom in the middle of the house facing the north. We keep the room closed off during the day. The temperature never exceeds 84-85 degrees! If we leave the window open, the room will heat up to the outdoor temperature.

[jaideeguy]

The simple fact is that your house can never be much cooler than the ambient air temp without aircon down here in he*l. All these 'passive' suggestions can postpone the heat a little, but it eventually becomes at least as hot as outside and at some point during the day, it will match the outside temps, then becomes an oven....radiating down the heat from the attic and walls mostly.....usually later at night.

The only solution that i can come up with is to move to the higher elevations. I was up at a friend's mountain land last week and the temps were quite civilized at 1,000mtrs. In the heat of the day, the shade temps were cooler than it ever gets down here in he*l.

[MESmith]

The simple fact is that your house can never be much cooler than the ambient air temp without aircon down here in he*l. All these 'passive' suggestions can postpone the heat a little, but it eventually becomes at least as hot as outside and at some point during the day, it will match the outside temps, then becomes an oven....radiating down the heat from the attic and walls mostly.....usually later at night.

The only solution that i can come up with is to move to the higher elevations. I was up at a friend's mountain land last week and the temps were quite civilized at 1,000mtrs. In the heat of the day, the shade temps were cooler than it ever gets down here in he*l.

That's why the Brits developed the hillstations in India - the whole government moved up to Shimla during the hotter months.  How about building some gated communities on top Doi Inthanon......

[WinnieTheKhwai]

In the middle of a national park? That will go down real well with the eco brigade.

[MESmith]

In the middle of a national park? That will go down real well with the eco brigade.

How about a few more "eco friendly" zip lines then?  We can all live in tree houses 

[jackr]

If you have soffit and gable end louvres and decide to go the roof fan route, be sure to block off those gable end vents.

Was also thinking about bunging a turbine on the roof and on hot days, when there's no air movement, have a ceiling fan at the highest part upstairs which should have the effect of increasing the pressure in the attic slightly and driving the turbine.

Could also consider bunging a marble floor down if you own a place. No matter how hot it gets outside, the floor downstairs is always amazingly cool (more so than granite) and there's no aircon down there.

[uptoyoumyfriend]

what a lot of nonsense

The simple fact is that your house can never be much cooler than the ambient air temp without aircon down here in he*l. All these 'passive' suggestions can postpone the heat a little, but it eventually becomes at least as hot as outside and at some point during the day, it will match the outside temps, then becomes an oven....radiating down the heat from the attic and walls mostly.....usually later at night.

The only solution that i can come up with is to move to the higher elevations. I was up at a friend's mountain land last week and the temps were quite civilized at 1,000mtrs. In the heat of the day, the shade temps were cooler than it ever gets down here in he*l.

no-sorry -the only solution to issues is that people that don't really understand something don't throw their opinions around and confuse the ones looking for truth and information.

if you just want to experience how it can be always cooler in the house than the ambient air temperature visit the little building next to the cmu arts canter-it's adobe. and houses a little cafe now(dindee?).generally the ground is a lot cooler than the air in the hot season that's how!

building on stilts is great for floods and gives you a cheap space to store or sit but the building itself will loose the thermal storage capacity of the ground it sits on.

it's never hot in caves,is it?

and with proper ceiling construction there is no radiation from above either.

just go visit a temple . or go sit under a tree.it is a lot cooler there the whole day long .

air conditioning yes- electricity and gadgets no! duh!

if you should be building or planning to do so i will be very happy to explain the concept to you and point out some inexpensive and eco friendly measures to keep the/your place nice and cool.

it is a lot easier when you plan for it rather than after the facts...as usual.

but even afterwards there is a lot you can do.

[jaideeguy]

Yes, agree that the ground temps are lower than air temps......if you go a few inches down...the deeper the cooler, but the surface of exposed to sun, ground is a heat sink that absorbs the heat, only to radiate it out later, like our cement heat sink houses that most of us live in.

I think that 'cool' is relative feeling that when you go from 105f to 95f, you 'feel cooler'.........but to me 95f is still too hot for my comfort.

"it's never hot in caves,is it?"

I've been in caves that are hot.....but agree that most are cool[er].

"i will be very happy to explain the concept to you and point out some inexpensive and eco friendly measures to keep the/your place nice and cool."

ok, please explain.....I do know a little about adobe and straw/mud houses and tell myself that I'll explore these methods of construction IF I ever build again, but I wonder how the adobe would hold up under the rainy season?? and same with straw/mud.....and wonder about the mould and insects that would probably inhabit it.

And, the OP was refering to retrofiting an existing house with [some] passive cooling concepts, most of which I have tried and have gotten little relief........marble floors, 2 big spinners on roof, double 2 inch hollow block walls with 2 inches of airspace between and yes insulation in attic [which was a rat/lizard and bird breeding habatit. If any conclusion could be drawn from my efforts.......the cooling effects have only been minimal at best.

You are correct in that It is best to build the house eco-friendly to start with....but what if you live in a moobaan with cement streets surrounding you as well as your neighbor's cement houses radiating off the heat of the day of relentless tropical sun??

hey, I'm open to 'cool ideas' and will check out that adobe house.

[WinnieTheKhwai]

How about active cooling from a cool river or stream coming from the mountains, would that work as an active cooling solution? It just so happens that we (errm, the Mrs.) has land on a stream that comes straight out of the mountains and feels freezing year round. I wonder if I could tube either air or water through that and then back into the house.. Not sure if that even exists, or what it's called. I think that might work for Thailand, but not sure how significant the savings would be because after all an air-conditioner is also just a big pump & fans.

Then I wondered about wind towers, as designed in ancient Persia, but for that you kind of need cool winds first, which we don't have in Thailand and especially not in the hot season.

Edited April 27, 2010 by WinnieTheKhwai

[Diablo Bob]

Great topic.....

Coming from the SouthWest in the US, we are used to the summer heat. Unfortunately, many of the solutions we would use would not be pratical or effective in a high humidity environment. For instance, in new construction, hydronic cooling would work quite well in a low humidity environment but would cause other problems here in Thailand, such as the walls sweating.

I did some research on Mediteranian style homes, in particular Spanish, and found that they tend to have an area with a vaulted ceiling, this area acts like a chimney and vents hot air out of the building. They also were using a minimum of 3.5m for the ceiling height. All air movement is forced towards the "Chimney" using ceiling fans.

Great ideas for new construction, but doesn't address a retrofit situation.

Many posters have addressed most of the available solutions. There is no magic solution. I have no suggestions but I do have a word of caution about insulation. Insulation can work with you or against you. Once an insulated room is allowed to get hot, unless you have a way of venting that room, it will stay hot because of the insulation. The insulation slows the migration of the temperature equally in both directions......

In my opinion, unless you address ventilation you will never find a solution.

[Diablo Bob]

How about active cooling from a cool river or stream coming from the mountains, would that work as an active cooling solution? It just so happens that we (errm, the Mrs.) has land on a stream that comes straight out of the mountains and feels freezing year round. I wonder if I could tube either air or water through that and then back into the house.. Not sure if that even exists, or what it's called. I think that might work for Thailand, but not sure how significant the savings would be because after all an air-conditioner is also just a big pump & fans.

Then I wondered about wind towers, as designed in ancient Persia, but for that you kind of need cool winds first, which we don't have in Thailand and especially not in the hot season.

Actually could be passive cooling if the water is pumped through tubes imbedded within the walls and ceiling. It is commonly called Hydronic cooling.

Edited April 27, 2010 by Diablo Bob

[jaideeguy]

You are in a lucky situation Winnie and Bob offers a simple solution, if your stream is above your house, then you could simply run it with gravity.......but condensation problems??

Approximately what elevation [altitude] is the land?? If 800+mtrs, then you shouldn't need to worry about cooling your house.

[jaideeguy]

in fact, if you're wife's land IS high elevation....... would she like to lease/rent/sell a small portion?? Pm me if she would.....

Thanks

Edited April 27, 2010 by jaideeguy

[Diablo Bob]

You are in a lucky situation Winnie and Bob offers a simple solution, if your stream is above your house, then you could simply run it with gravity.......but condensation problems??

Approximately what elevation [altitude] is the land?? If 800+mtrs, then you shouldn't need to worry about cooling your house.

Yep, sweating is the term we use..... wouldn't be a problem if the humidity is 25% or less, actually it is related to the Dew Point, which is related to the relative humidity.

[MESmith]

It's quite surprising that modern homes here don't have louvred wooden shutters on windows that receive direct sunlight.  Close during the heat of the day to keep the glass cooler & hopefully the room too.  My computer room has a 2m wide picture window & in the afternoon gets quite warm.  The double walls feel cool on the inside, but the slatted blinds on the inside aren't enough to keep the room cool, so it must be the sun on the glass.  Have today fitted a cheap wooden roll blind (as sold on Chiang Moi rd rattan shops) on the outside to keep the window shaded.  This afternoon will find out how effective it is.  Unless it rains again

[MESmith]

in fact, if you're wife's land IS high elevation....... would she like to lease/rent/sell a small portion?? Pm me if she would.....

Thanks

Count me in, too, for the hot season mountain commune 

[WinnieTheKhwai]

You are in a lucky situation Winnie and Bob offers a simple solution, if your stream is above your house, then you could simply run it with gravity.......but condensation problems??

Approximately what elevation [altitude] is the land?? If 800+mtrs, then you shouldn't need to worry about cooling your house.

The stream is indeed slightly higher, but this poses a problem as well of course (potential for flooding) so at least the main living area of the house should be well above the water line.. So then even if you pipe water in, it also has to go out again; can't just have it turn all the land into a rice paddy. (Or, maybe I can, I dunno..)

The land is close-ish to mountains but not actually high elevation. We looked at higher elevations as well, but I'd be a little worried about things like mud slides. Plus ownership tends to be trickier; (Thai) villages tend to be in flat valley type areas, and that's where the land with proper papers (Chanote or NS3) tends to be. And then there's issues like electricity.. All in all it sounds great to live in the mountains, but there are some risks and practicalities to consider. So we chose to get land near mountains, not actually on them. Don't let that stop you of course, and to be honest part of me is also is still dreaming about that living room that completely opens on one side towards a magnificent view of the valley below it..

Edited April 27, 2010 by WinnieTheKhwai

[jackr]

I did some research on Mediteranian style homes, in particular Spanish, and found that they tend to have an area with a vaulted ceiling, this area acts like a chimney and vents hot air out of the building. They also were using a minimum of 3.5m for the ceiling height. All air movement is forced towards the "Chimney" using ceiling fans.

Got one of those, also known as a cathedral ceiling, and the house is defo cooler than the one we had around the corner, which didn't have one. I was eventually going to bung a turbine on the roof and then have a fan at the apex of that ceiling to both vent the hot air and hopefully drive the turbine on a windless day, which would help vacate the attic also via the louvred sofits.

[Diablo Bob]

The stream is indeed slightly higher, but this poses a problem as well of course (potential for flooding) so at least the main living area of the house should be well above the water line.. So then even if you pipe water in, it also has to go out again; can't just have it turn all the land into a rice paddy. (Or, maybe I can, I dunno..)

Two structures come to mind when you describe your stream. One is "Falling Waters" designed by Frank Lloyd Wright in Western Pennsylvania, where the house is constructed with a stream and waterfall inside the house....... with proper planning any flood issue can be designed around.

The other structure is Scotty's Castle in Death Valley, California. A desert spring supplies water onto a rock wall inside the house and essentially works as a giant evaporative cooler. Even when Death Valley is 50c+ outside the inside of this house is around 25c....... <deleted> amazing!

[jaideeguy]

jackr...... "I was eventually going to bung a turbine on the roof and then have a fan at the apex of that ceiling to both vent the hot air and hopefully drive the turbine on a windless day, "

If you're talking about those wirly roof spinners, you don't need a fan, as they work strictly on convection.....heat rising and causing a draft upwards. The hotter it gets in your attic, the faster they spin. I've had a couple on my roof for three+yrs and they are still spinning. Was told that they occasionally need lubrication on the steel ball bearings they ride on, but lately they haven't slowed down.

[jackr]

Could be right there . Reckon a ceiling fan would also aid the suction, to boot, and also vent the top of the house internal.

[sticklee]

How about active cooling from a cool river or stream coming from the mountains, would that work as an active cooling solution? It just so happens that we (errm, the Mrs.) has land on a stream that comes straight out of the mountains and feels freezing year round. I wonder if I could tube either air or water through that and then back into the house.. Not sure if that even exists, or what it's called. I think that might work for Thailand, but not sure how significant the savings would be because after all an air-conditioner is also just a big pump & fans.

Then I wondered about wind towers, as designed in ancient Persia, but for that you kind of need cool winds first, which we don't have in Thailand and especially not in the hot season.

Many thanks to all for wading in with ideas, questions and answers. Isn't this really what this forum is supposed to be all about???

Re using the cool water as a method to cool a building. In parts of Canada a heat pump is becoming a favourable alternative to a furnace and aircon system. Using underground conduit and a coolant, not unlike antifreeze, the ambient temperature of the earth is used to warm a cool interior in winter and, working in reverse, cool a warmer interior in summer. A relatively simple heat transfer system with a radiator and fan could be constructed to provide a constant source of cool air. Condensation shouldn't be so much of a problem to deal with..a catch tray and drain. I have seen many heat pump systems, some use a water source rather than ground heat, some incorporating Hepa filters, de-humidifiers etc. One advanced system I saw in a custom home near Vancouver had over 2 miles of underground piping. A $65,000 system...!!!

[uptoyoumyfriend]

i am happy to see that there is some interest because understanding is everything.

only mentioned the adobe building( by pun pun if i am not mistaken) as an example that can easily experienced on what is possible without electric gadgets-didn't really suggest to add mud to the outside of your rental although it would probably be fun and help to even out temperatures during the day.

adobe holds up very well in the rainy season the walls are usually stuccoed for that matter and the foundation a bit above ground and also from concrete.the walls absorb moisture and it is quite dry inside.

chiang mai is not really humid on most days so something air con with water evaporation might work the trick however is not to grow mold and fungus or bacteria.

in hawaii by the way they pump deep ocean water through heat exchangers before returning it to the ocean to reduce cost of air conditioning.

attic cooling insulation and shading will be very important if you have air con to reduce otherwise staggering bills.

high ceilings help.

i personally built designed my house myself, with 3.5 m ceilings ,wraparound porch for shade,a completely open attic with a solid ceiling ,cross ventilation and louvered windows(not many to the south) and the outcome is that we use the ceiling fan for sleeping only in the hottest days my guess is we have about 85 degrees/30 c max. the overall electric bill under 300/mth including the water system .

if you need 75 -deg / 20 c then Thailand may be a bit tropical for you.

drove around to look for foam backed aluminum (reflective ins for the attic or the porch) and found the best price at some home-diy shop on the second ring road past payap going towards city hall.

my offer to assist with advice was for those who look for it-

have been in typical and non typical construction for 30 years.

most importantly however:plant big trees

[Naam]

How about active cooling from a cool river or stream coming from the mountains, would that work as an active cooling solution? It just so happens that we (errm, the Mrs.) has land on a stream that comes straight out of the mountains and feels freezing year round. I wonder if I could tube either air or water through that and then back into the house.. Not sure if that even exists, or what it's called. I think that might work for Thailand, but not sure how significant the savings would be because after all an air-conditioner is also just a big pump & fans.

Then I wondered about wind towers, as designed in ancient Persia, but for that you kind of need cool winds first, which we don't have in Thailand and especially not in the hot season.

the wind tower buildings in ancient Persia did not use "cool winds" but just the natural air movement caused by the "chimney effect". adding water to the air movement generated evaporation cooling, i.e. perfect airconditioning in a dry climate. works in Tehran, Baghdad and Riyadh as well as in Tucson and Phoenix, Arizona. does not work in a rather humid climate like Thailand.

[Naam]

what a lot of nonsense

The simple fact is that your house can never be much cooler than the ambient air temp without aircon down here in he*l. All these 'passive' suggestions can postpone the heat a little, but it eventually becomes at least as hot as outside and at some point during the day, it will match the outside temps, then becomes an oven....radiating down the heat from the attic and walls mostly.....usually later at night.

The only solution that i can come up with is to move to the higher elevations. I was up at a friend's mountain land last week and the temps were quite civilized at 1,000mtrs. In the heat of the day, the shade temps were cooler than it ever gets down here in he*l.

no-sorry -the only solution to issues is that people that don't really understand something don't throw their opinions around and confuse the ones looking for truth and information.

if you just want to experience how it can be always cooler in the house than the ambient air temperature....

it is you who are trying to confuse people with your tree hugging and unfounded claims/theories. HOW MUCH cooler than the ambient temperature can a building be considering that inside the building are various heat sources (example: 75 kcal/h - 300 btu/h per average human = 7,200 btu/day)? tree hugging cannot bend the laws of physics. period! adobe and similar constructed buildings are only "cool" in those areas where the ambient temperature drops considerably at night. if the minimum ambient temperature is 30ºC it is only a short matter of time till the inside temperature even of the best insulated building is at least the same or higher as the minimum ambient temperature.

[Naam]

How about active cooling from a cool river or stream coming from the mountains, would that work as an active cooling solution? It just so happens that we (errm, the Mrs.) has land on a stream that comes straight out of the mountains and feels freezing year round. I wonder if I could tube either air or water through that and then back into the house.. Not sure if that even exists, or what it's called. I think that might work for Thailand, but not sure how significant the savings would be because after all an air-conditioner is also just a big pump & fans.

Then I wondered about wind towers, as designed in ancient Persia, but for that you kind of need cool winds first, which we don't have in Thailand and especially not in the hot season.

it would be a perfect solution Winnie, the parts do exist and are available in Thailand. virtually all big hotels use water cooling (a dozen different possibilities and combinations exist to cool down the water). in your case, with cool water readily available, you would need (number according to the size of your home) heatexchanger units (picture below) pump and piping from you cool stream to the units which only have a fan coil that uses a fraction of the amount (50-80 watts) of a normal aircon.

[uptoyoumyfriend]

it is you who are trying to confuse people with your tree hugging and unfounded claims/theories. HOW MUCH cooler than the ambient temperature can a building be considering that inside the building are various heat sources (example: 75 kcal/h - 300 btu/h per average human = 7,200 btu/day)? tree hugging cannot bend the laws of physics. period! adobe and similar constructed buildings are only "cool" in those areas where the ambient temperature drops considerably at night. if the minimum ambient temperature is 30ºC it is only a short matter of time till the inside temperature even of the best insulated building is at least the same or higher as the minimum ambient temperature.

I confess-i do go out and hug my trees and when the wife is not watching i fondle them too- besides of course to talking to them on a regular bases.

as for ambience:

<h3 class="r">Weather in North Thailand</h3>4 Jan 2010 ... Chiang Mai's average annual temperature is a pleasant 25 degrees C (77 degrees F). During the hot (summer) season, daytime highs can reach ...

www.chiangmai-chiangrai.com/weather_in_north_thailand.html - Cached - Similar

[Naam]

"Chiang Mai's average annual temperature is a pleasant 25 degrees C (77 degrees F)."

yeah right! using the average annual temperature (which includes the averages of the cold months) to argue airconditioning and building design in the hot months when temperatures reach 40ºC and above =

Your Honour, Ladies and Gentlemen of the Jury... i rest my case

[jaideeguy]

I think you are agreeing with me Naam, in that the [hot] temp outside eventually replaces the temp inside if you vent inside to the out thru the attic and you end up with hot inside.

In your 'heat generated by humans' equasion, you didn't consider heat generated by all the electronics we have running......computers, tv, lites, etc. that brings the [inside] temps up even higher.

But, there is the 'real feel' consideration, where fans cool somewhat by evaporation until you have hot air blowing on you....not too comfortable.

Another consideration is the relative temps of outside vs inside or hot vs cool[er] and that plays a part in COMFORT, and that's what it all boils down to.....we just want to be COMFORTABLE, right?.

Also, there is the psychological cooling effect that the Thais always speak about with naam [not Naam] running, standing in a pool, or fountain. It may cool somewhat [if not positioned so that you get reflection off water onto house], but I think the effect is mostly psychological. Again....if it makes you feel COMFORTABLE, then it's worth it.

[Naam]

"In your 'heat generated by humans' equasion, you didn't consider heat generated by all the electronics we have running......computers, tv, lites, etc. that brings the [inside] temps up even higher."

i used that of course just as one example of in-house heat source because a lot of people have no idea how much heat we radiate especially when we pinch the behind of our Mrs. another example are two huge fridge/freezers in our kitchen, each about 80% running time and drawing as much power as a 13k btu/h aircon, id est total heat source 2.2 kWh multiplied by a factor of minimum 2.5 and that 20 hours a day, cooking not even considered.

perhaps we should have built an adobe kitchen to cool our food stuff and drinks?