keeping house cool

i am not a great lover of air conditioning and i have been thinking how to keep my bungalow cool during the hot season. if i put insulation down in the loft would it help keep heat coming down from up there during the day or would it just stop the house cooling down at night ? has anyone tried useing extractor fans to get the hot air out of the house at night and with luck bring in cooler air from outside.

I built a house in the Philippines in just that manner. Single story with an attic, huge squirrel-cage fan in the attic emptying out side. Vents in the ceiling of the rooms below and the fan draws air up through the vents. Of primary importance was the exhausting of the hot air in the attic. Made a very noticeable difference.

Pakawala I was looking at putting those squirrel cage things on the roof to reduce the heat in the house, but couldnt find anyone willing to share information like cost, ease of putting them in, effective use etc ...so i gave up!

We havnt got aircon in the house yet, I go to bars for that!

Hey you, the house i have in Udon has insulation in the attic space and too be honest its a giant oven, when its hot outside its cool inside, and when its cool outside is hot inside! Its got a metal roof, in hindsight a tiled roof would of been better but more expensive. When i am back in Udon the aircon will be on the agenda, just replacing all the windows at the moment and putting secuirity bars on them..lets see if those make any difference.

Well I have a bungalow and have insulation in the roof, certainly maintains the house at an almost constant temp, however does stop it getting too hot, but then it does not cool down so fast either at night. Use fans to keep air circulating.

Advantage, when very humid or whatever in bedrooms only when put on aircon cools down a treat very quickly and stays cool all night so aircon on only for 2 hours at most.

I do have a tiled roof, so that is also and advantage. All bedrooms have aircon if req ( very rarely use) but living rooms none.

Last February I insulated the attic space in our 2 level home and notice a significant change. On the west side of the house which is mainly the master bedroom I used 6" insulation. The room still gets hot, but once the room is cooled with the A/C I don't run it all night as I did prior to insulating. On the east side of the house which covers two bedrooms I used 4" insulation and has significantly kept this side of the house cool enough to get by on fans. I also noticed that the lower level of the house is cooler as a result of less heat transfer from the attic space. Prior to the next hot season I plan to add an additional 4" to the west side of the house and 3" to the east side.

The insulation is available in 2", 3", 4" and 6" x 60 cm rolls. You can find it at HomePro and Home Mart. However, HomePro carries two brands, one which is the typical fiberglass type and less expensive than the other which as far as I can tell is still fiberglass, it's available in green rolls and more expensive. The important thing to look at is the R-value of the insulation. Both brands have the same *R-value for the same thickness of insulation. I went with the least expensive. HomePro frequently runs a sale on insulation and best to wait for the next sale which will save you some baht. I believe the 6" typically sells for 450bt and on sale I got it for 325bt which was a significant savings for 12 rolls.

*During Udon's hot season, the recommended R-value is 38 or higher. The 6" rolls available here have an R-value of 23. For more info on R-value, just google "R-value".

Most Thai bungalows have an attic that is basically a solar oven on top of the living space. The roof design has no ventilation to exhaust the hot air from the attic. At best they have allowed for some airflow under the eaves. Creating some means of ventilation will greatly reduce heat uptake in the living space. The ventilation could be air vents added near the top of the roof or forced air exchange with fans.

Any insulation on the ceiling will help to reduce the heat uptake in the living space. In the hot season the attic space will never cool to a level that would be comfortable for human habitation so you need not worry about getting cool air from it.

One bungalow I lived in had a west facing wall that was painted a dark brown. When the sun shown on that wall it became too hot to touch on the inside. I repainted it glossy white. While the wall was still hot it wasn't as hot as before the repaint. Keeping the sun off of the outside walls will do a lot to keep a place cool. Vegetation or sunshades hanging from the eaves can help.

If you are not using air conditioning, air flow through the living space is essential. Without a natural breeze fans need to help exchange the air. With air conditioning just the opposite; you want to stop air flow through the air conditioned space. Windows in Thailand are seldom air tight and the space under doors is another major leakage area. Some caulking at the windows and sweeps added to the doors will go a long way in helping the air con units cool a room.

Stay cool

hey you wrote:i am not a great lover of air conditioning and i have been thinking how to keep my bungalow cool during the hot season. if i put insulation down in the loft would it help keep heat coming down from up there during the day or would it just stop the house cooling down at night ?

Yes and Yes. I did this last year in my bungalow and noticed a big difference. The rooms stay cooler during the day, BUT they do hold the heat in for the night. 1 or 2 hours of a/c and it's cool all night. The net result IS a gain.
(The insulation helps to keep in the cold air)

hey you wrote:has anyone tried useing extractor fans to get the hot air out of the house at night and with luck bring in cooler air from outside.

This most definately works as heat builds up in the loft space and makes your house feel like an oven. Insulation combined with an extractor fan blowing out the hot air will help a lot.

Also, insulating the loft will cut down on noise from outside too!

Roll on the cold season!!

well at least from your replies i am thinking on the right lines. thanks for r-value bit ,in the u.k. all we get is the insulation is of a certain thickness, i always assumed it was all made to the same standard.also in the uk it was recomended that you put down as thick a cover as you can. would two covers of 6inch r-23 get over the R value recoened for udon

hey you wrote:well at least from your replies i am thinking on the right lines. thanks for r-value bit ,in the u.k. all we get is the insulation is of a certain thickness, i always assumed it was all made to the same standard.also in the uk it was recomended that you put down as thick a cover as you can. would two covers of 6inch r-23 get over the R value recoened for udon

Yes to the above question. I know of a guy that went with 18" or 3 covers, a bit drastic if you ask me but he's got the money to burn.

How can anyone NOT be a fan of air con. I have heard of people catching a cold ( thermostat set at 15 celcius) or plugged up noses . (Filter not cleaned in 5 years). Air cons are cheap ,power is cheap. Jump aboard

This is all interesting stuff. I too have been looking at the same subject recently.

My house has the reflective foil immediately under the tiles which is designed to reflect the heat during the day. There is however no insulation on the floor of the roof/loft space, which does get very hot in teh day and still seems to stay hot well into the evening/night! I have been deliberating on the merits of adding that myself. The developer and others argued that that is less effective because it traps in whatever heat has accumulated during the day, though as mentioned above it would certainly make any AC fitted in the bedrooms more effective/efficient at night. I suspect the developer argued in favour of not installing a blanket of insulation because it saved him money.

We have little ventilation in/from the roof space, only having the slots in the facia board/soffit (?) which of course face the ground so don't encourage much through draught. I like the idea of having extractor fans extracting from the roof space, but am not sure how or where I could position them.

We have sun reflective window blinds and curtain liners inside rooms affected by the later afternoon sun, and they do help, though of course some heat will still be distributed inside the rooms.

It is also important to keep in mind that in LOS walls are only single skin, so quickly and easily transmit heat through to the inside. In this respect, as mentioned above, the positioning of trees and larger shrubs to shade walls and windows is therefore both helpful and important.

I have also looked at having a canopy installed over the larger front patio wall/window, as this is particularly prone to late afternoon sun.

Any other ideas/input are most welcome.

I still don't understand why there are almost NO flat roofs in Thailand.

during my travels in Africa and the Middle East, > 90 % of the houses had flat roofs.

always looked for an answer on this one

arjay wrote:This is all interesting stuff. I too have been looking at the same subject recently.

My house has the reflective foil immediately under the tiles which is designed to reflect the heat during the day. There is however no insulation on the floor of the roof/loft space, which does get very hot in teh day and still seems to stay hot well into the evening/night! I have been deliberating on the merits of adding that myself. The developer and others argued that that is less effective because it traps in whatever heat has accumulated during the day, though as mentioned above it would certainly make any AC fitted in the bedrooms more effective/efficient at night. I suspect the developer argued in favour of not installing a blanket of insulation because it saved him money.

Our house also has thin reflective foil under the tiles, but it's not very effective. IMO, insulation is the way to go, I can feel the difference before and after the installation.

We have little ventilation in/from the roof space, only having the slots in the facia board/soffit (?) which of course face the ground so don't encourage much through draught. I like the idea of having extractor fans extracting from the roof space, but am not sure how or where I could position them.

I think extractor fans would be great if you could find them here, have yet to see them. I have seen the rotary turbine type extractors like the one in the picture, but they're large and unattractive. I would probably go with something like the "stove pipe" in the second picture. Haven't seen anything like it here, but they wouldn't be difficult to manufacture.

Try these http://www.nextag.com/solar-vent/search-html

I was thinking of the through the wall type extractors, or even the through the ceiling type we have in our shower rooms. Would they not work(fit)? I realise the former have more power and thus move more air.

The big onion type ones, are a bit prominent, and remind me of mosques!!

What do you think of this as an idea:-

1. I get an extractor fan installed in the soffit above the front bedroom balcony (the hot side/corner of the house and being above the balcony easy to get at without ladders) and that extracts the hot air from the roof space.

2. I then get another one installed to the rear of the house, probably in the soffit (?) above the second bedroom balcony (so again, easy to access, and on the cooler side of the house, where the prevailing wind comes from), - this time it draws the air into the roof space to replace what is being extracted at the front. (Though I am not sure whether you can get extractor fans that work the other way round?!)

Ultimately, I guess if you had a reasonable/meaty extractor fan, the air would find it's own way into the roof space through the slots and gaps in the soffits to replace what was being extracted.

3. As an alternative to no 2, I could beef up the ceiling extractor in the main bathroom and/or the en-suite (above the shower) and let that provide replacement air into the roof space.

Then turn both/all such fans on during the daytime hot weather.

Both the en-suite and the main bathroom have small extractor fans pulling air up from above the showers in those rooms and up into the roof space. Currently the roof space is only ventilated by slots in the overhanging roof (soffits?) - those slots face/are parallel with the ground.