Roof / attic ventilation fan

[sometimewoodworker]

1 hour ago, 4MyEgo said:

 

The only ones I could get my hands on at the time were Q=Con, the white blocks, they are in millimetres 75D x 600L x 200W, quite light to work with and cost me about 18 baht each, personally they are crap as they are hot inside the house on the side the sun is/was on most of the day, but now, with the roof that covers the outdoor area and external kitchen, those blocks are cool, so the inside of the house is cooler.

 

Wouldn't recommend them to anyone, but if there is nothing else around, you have to build with what you have.

 

I'm sure you could have got cinder blocks or red bricks and been much hotter.

 

I, and every one I have spoken to or know of using them, have found them significantly cooler than any other building material.

[petesc55]

I've lived in the southern US most of my life, including Florida, and have lived in cement block or other masonry type homes more than a few times.    Providing you have adequate ventilation, (fans) they seemed to be inherently 'cool'.    I've not had to deal with a metal roof before, though, or a dwelling surrounded by a lot of exterior concrete.   (paving, adjacent buildings, etc).   You do get noises and smells with open windows, and I'm assuming screening.   The biggest issue with the house my GF owns is she closes every window at night for security reasons, and additionally locks every interior door while she is sleeping and home alone.  Outside temps are reasonable, inside is an oven.

[kamalabob2]

Solar powered attic roof ventilation fans are readily available in Thailand. There are different styles of solar power roof ventilation fans that I have seen in Buriram including models with a rechargeable battery so the fan runs at night. Most every building product is really in Thailand, just not on show at the local Home Mart. You can see these fans at the energy Expo in Bangkok or the annual Architect Expo in Bangkok. I have seen the square solar powered fans and the round solar fans. 

[4MyEgo]

8 hours ago, sometimewoodworker said:

 

I'm sure you could have got cinder blocks or red bricks and been much hotter.

 

I, and every one I have spoken to or know of using them, have found them significantly cooler than any other building material.

 

So are you saying the white block ones I built the house with are good, compared to the cinder blocks or red bricks ?

[sometimewoodworker]

39 minutes ago, 4MyEgo said:

 

So are you saying the white block ones I built the house with are good, compared to the cinder blocks or red bricks ?

Sure like night and day compared to any other regularly used material. The insulation value is good, they don't heat up like the others so you don't have much, if any, heat radiating from the walls after the sun goes down, they don't absorb water, they are much better at reducing sound, they are cheaper to build with and about 3 times faster.

[4MyEgo]

3 minutes ago, sometimewoodworker said:

Sure like night and day compared to any other regularly used material. The insulation value is good, they don't heat up like the others so you don't have much, if any, heat radiating from the walls after the sun goes down, they don't absorb water, they are much better at reducing sound, they are cheaper to build with and about 3 times faster.

 

Thanks for clarifying that, everyone at the time said they are the best available, and I am sure I read a bit on the forums to confirm that too as I am pedantic when it comes to doing something, i.e. I research the net more than others, suffice to say, I am ok with them, but when the sun would hit the rendered walls on the opposite side to where we built our bedrooms, i.e. hallway, kitchen, lounge room, and spare front room, we wouldn't use those areas and would retreat to the rear family room, and dining room off the kitchen when we had to eat.

 

But now with a small outlay of 140,000 baht, we have built the outdoor covered area, as mentioned 80m2 which covers 3 rendered walls and the almost completed external kitchen off the internal kitchen, which runs 12 metres along the house, incorporating the enclosed storeroom, laundry and motorbike port which keeps the sun off the rendered walls to the house, the only area I have to do something with now is the front spare room (refer to photo) because that's an oven, but when I put 3 x 600mm x 1200mm soffit barges over the 1800mm wide window it knocks the sun dead in its tracks and cools that room down by 90%, so whether I build a cover over that wall will depend on how it feels in summer, and what I can come up that will be asthetically in keeping with the house design.

 

 

[sometimewoodworker]

20 hours ago, 4MyEgo said:

 

Thanks for clarifying that, everyone at the time said they are the best available, and I am sure I read a bit on the forums to confirm that too as I am pedantic when it comes to doing something, i.e. I research the net more than others, suffice to say, I am ok with them, but when the sun would hit the rendered walls on the opposite side to where we built our bedrooms, i.e. hallway, kitchen, lounge room, and spare front room, we wouldn't use those areas and would retreat to the rear family room, and dining room off the kitchen when we had to eat.

 

But now with a small outlay of 140,000 baht, we have built the outdoor covered area, as mentioned 80m2 which covers 3 rendered walls and the almost completed external kitchen off the internal kitchen, which runs 12 metres along the house, incorporating the enclosed storeroom, laundry and motorbike port which keeps the sun off the rendered walls to the house, the only area I have to do something with now is the front spare room (refer to photo) because that's an oven, but when I put 3 x 600mm x 1200mm soffit barges over the 1800mm wide window it knocks the sun dead in its tracks and cools that room down by 90%, so whether I build a cover over that wall will depend on how it feels in summer, and what I can come up that will be asthetically in keeping with the house design.

 

 

 

 

I can immediately see a way to reduce the temperature by at least 8 to 10 degrees on the outside  maybe quite a bit more.

 

when my paint room was built I asked them to leave a patch of wall unpainted, the render was a bit lighter in colour than your wall, the wall that was painted is white. The unpainted, grey render was reading 10 to 15 degrees hotter than the white. The inside temperature was between 2 and 4 degrees hotter in that area. That wall is one of the few single 75mm AAC block walls (almost all the others are double) 

 

 

[4MyEgo]

16 hours ago, sometimewoodworker said:

I can immediately see a way to reduce the temperature by at least 8 to 10 degrees on the outside  maybe quite a bit more.

 

when my paint room was built I asked them to leave a patch of wall unpainted, the render was a bit lighter in colour than your wall, the wall that was painted is white. The unpainted, grey render was reading 10 to 15 degrees hotter than the white. The inside temperature was between 2 and 4 degrees hotter in that area. That wall is one of the few single 75mm AAC block walls (almost all the others are double) 

 

Unfortunately all of our walls are all single 75mm rendered and painted block walls, as much as I would have loved to have cavity brick wall built, the decision went the other way, I also wanted to do the same to the current external kitchen single wall, but hey, if she wants to "cook" in an oven, sel-a-vee.

 

From my experience Thai's put too much emphasis on cutting back on the costs, as if its not cheap enough to build for a farang as it is, if I dug my feet in, would have went cavity, all day, everyday of the week, suffice to say the additional costs to cover the single wall areas with a covered outdoor area and external kitchen were always in the plan, so I suppose if you weigh the cost up for the same effect, i.e. cavity Vs single brick, we would probably be ahead 72,000 baht at 4,000 blocks, chicken feed when considering the overall benefit.

 

So I gather from what you are saying, would be to paint the front wall white, as the sun would theoretically bounce off of it, taking into consideration the walls that are covered by the metal sheeting, i.e. outdoor area and external kitchen don't see the sun. 

[sometimewoodworker]

1 hour ago, 4MyEgo said:

 

So I gather from what you are saying, would be to paint the front wall white, as the sun would theoretically bounce off of it, taking into consideration the walls that are covered by the metal sheeting, i.e. outdoor area and external kitchen don't see the sun. 

Exactly, though it isn't theoretical. I have empirical evidence from my own wall. From my wall data you should get a reduction of something over 2 degrees on the internal wall.

 

If if you want your own test then just paint a random board half grey and half white. Put it in the sun and check it.

Edited October 5, 2017 by sometimewoodworker

[4MyEgo]

37 minutes ago, sometimewoodworker said:

Exactly, though it isn't theoretical. I have empirical evidence from my own wall. From my wall data you should get a reduction of something over 2 degrees on the internal wall.

 

If if you want your own test then just paint a random board half grey and half white. Put it in the sun and check it.

Thanks for the heads up, I will try the experiment 1st, although I don't know about painting that section of the house white, unless I do both sides, which might have to be the way to go, but not before seeing how we go this summer again with the soffit barges over the window to block out that sun again, as I was impressed as how such a cheap cost effective method worked n knocking about 90% of the heat out of that room, suffice to say, I believe the 1800mm x 1100mm of 2 metres allows so much heat into the front of the 4 metre wide x 3 metre high (10 metre) rendered block wall exposed to the sun after you take out the 2 metres of window, which is covered in the soffit barges in the photo below.

 

Cheers

 

 

[sometimewoodworker]

It looks as if you have grey sunscreen shutters over the windows.

 

If that is correct then painting them white should be a great help and would give a great heat reduction, as they will be getting much hotter on the inside than your AAC block wall, and would look good too.

[mortenaa]

On 10/3/2017 at 9:05 AM, 4MyEgo said:

 

I disagree, the thermal reflective insulation was installed under the tiles, i.e. not between the batten and the tiles, it was installed from inside the roof, picture monkeys swinging in your ceiling space, it has a height of over 6 feet in some areas, therefore there is room for the hot air to travel in between the battens and the tiles till it finds its way out through the eaves.

 

4 vents, two on either side of the front of the house allows air in and out, as do the whirly birds, you cannot get all of "any" heat out of a ceiling unless you use one of those extraction fans at either end of your house running 24/7 or when it heats up, with a sensor, which I would love to install if I could find them here.

 

The ceiling batts will also help when I install them.  

Think of a fridge. Install a roof on it, to shade it from the sun. Then you rip out the insulation, and move the insulation to the roof. How do you think that would work?  

In my house, they spray insulate all over the gypsum. That keep both unwanted sound pollution away, and helps keep the cool air from escaping. My eaves are ventilated, to let hot air rise into the attic, and escape through the bricks. The missing link is now a few fans to increase the airflow.

[EnlightenedAtheist]

On 10/11/2017 at 2:46 PM, mortenaa said:

Think of a fridge. Install a roof on it, to shade it from the sun. Then you rip out the insulation, and move the insulation to the roof. How do you think that would work?  

In my house, they spray insulate all over the gypsum. That keep both unwanted sound pollution away, and helps keep the cool air from escaping. My eaves are ventilated, to let hot air rise into the attic, and escape through the bricks. The missing link is now a few fans to increase the airflow.

Excellent explanation.

 

Not to scare you, but you might want to watch this: 

 

 

Btw, what kind of tile would you recommend? I hear those heavy/trap tiles keep the heat that is released into the roof area later on at night. At the same time, you want to prevent the radiation from penetrating into the attic too. How about metal tiles that have concealed clips? The metal heats up quickly, but cools down quickly too. Does it let too much radiative heating through though?

[Ahab]

I just bought two solar powered attic fans from Rungangthai hardware in Buriram (about 12,000 baht each and 620 cubic feet per minute capacity, PM me if you want a contact number/email). I highly recommend a light colored roof (white is the best, every other color is a significant absorber of heat), with a radiant barrier sheathing. Proper attic ventilation and radiant barrier sheathing are critical for keeping your attic space (and in turn the inside of your house cooler). I have personal experience with our house in Hawaii and this absolutely makes a huge difference (we did not have A/C in Hawaii, only ceiling fans) and the temperatures are similar 85-90 degrees F.

[Ahab]

The fans in post #33 are the ones I just bought.

[Ahab]

On ‎6‎/‎26‎/‎2017 at 10:25 PM, Kwasaki said:

Sorry I would not be convinced that is necessary underneath roof tiles. ? ?

Then you will have a hot house. This stuff works much better than insulation in a tropical climate.

[EnlightenedAtheist]

What about cellulose in Thailand? Someone wrote:

 

"Spray foam is nothing but highly deadly toxic garbage. I did a lot of research before insulating out newly built house in 2001. after researching I decided on cellulose and I could not be happier. its non toxic, made only of ground up newspapers. our small wood burning stove will run you out of the house unless it's set on the very lowest setting. A/C is not running except on the very hottest part of the hottest days. because cellulose is treated with borax it is a natural insect and vermin repellent. never had our house treated for termites and never had any termites even tho we live in a high termite area. also never had a single mouse in the house yet they are all around our property and are in our un-insulated shop/storage building. cellulose is also very fire retardant. you can find a video on youtube that actually shows three identical structures being burned to the ground. one with spray foam, one with fiberglass and one with cellulose. the cellulose building burned much slower and was the last standing."

 

Is borax safe? 

 

http://www.healthyhouseinstitute.com/a-1358-A--Hard-Lesson-Learned-About-Cellulose-Insulation-Installation

 

It does not look it is.

 

How about EPS (polystyrene). Probably not as good the spray foam and cellulose.Right?

[Naam]

1 hour ago, Ahab said:

Then you will have a hot house. This stuff works much better than insulation in a tropical climate.

no it doesn't work better. ideal is the combination of a power ventilated attic plus insulation of the ceiling below the attic. by the way, quoting 80-90ºC

Hawaiian ambient temperatures as comparable to Thailand demonstrates your lack of domestic climate experience. 

[Ahab]

10 hours ago, Naam said:

no it doesn't work better. ideal is the combination of a power ventilated attic plus insulation of the ceiling below the attic. by the way, quoting 80-90ºC

Hawaiian ambient temperatures as comparable to Thailand demonstrates your lack of domestic climate experience. 

Maybe you did not read the post correctly (I double checked), but it clearly stated 80-90 degrees F. I am a new convert to the Celsius temperature scale and my mind still works in Fahrenheit.  Outside of April the daytime temps have been around 30-33 Celsius on most days which equates to 86-92 degrees Fahrenheit. Roughly in the range I stated. So perhaps it demonstrates nothing regarding my climate experience (30 years in Hawaii, and 25 years visiting Thailand, 9 months full time).

 

If you like insulation, go ahead and insulate to your hearts content. Insulation will help, but no matter how much or how thick you apply insulation heat will eventually radiate into it, warm it, and enter whatever space you want to keep cool. Radiant barrier (with a thin layer of foam insulation) properly placed in a well ventilated attic space will do a better job at keeping the heat from the sun out of your house than most insulation. This of course might not be exactly true if you used a meter or two of insulation, but most all people cannot and do not use that amount of insulation in their houses in Thailand.

 

I don't think we disagree that much, I agree a well ventilated attic is key, I am not against using insulation in the ceiling above the living spaces. I just have favorable personal experience using radiant barrier sheathing in Hawaii and on our house here in Thailand. During mid day you can put your hand inches away from the underside of our metal roof and you will not feel the heat of the sun. Radiant barrier keeps the heat out, which reduces the amount of cooling that needs to occur with the use of A/C.

Edited October 16, 2017 by Ahab
add text

[Kwasaki]

13 hours ago, Ahab said:

Then you will have a hot house. This stuff works much better than insulation in a tropical climate.

Not necessary there are many variations in roof builds.

[carlyai]

 
15,000 Baht is still affordable if it does the job. Still cheaper than importing some solar fan from the US or Australia.

I saw a solar fan the other day advertised on Alibaba.

Sent from my SM-J700F using Tapatalk

[Naam]

13 hours ago, Ahab said:

Maybe you did not read the post correctly (I double checked), but it clearly stated 80-90 degrees F. I am a new convert to the Celsius temperature scale and my mind still works in Fahrenheit.  Outside of April the daytime temps have been around 30-33 Celsius on most days which equates to 86-92 degrees Fahrenheit. Roughly in the range I stated. So perhaps it demonstrates nothing regarding my climate experience (30 years in Hawaii, and 25 years visiting Thailand, 9 months full time).

i read it of course right, my mistake was typing "Celsius". nowhere on this planet one finds ambient temperatures of 80-90ºC.

[Naam]

14 hours ago, Ahab said:

If you like insulation, go ahead and insulate to your hearts content. Insulation will help, but no matter how much or how thick you apply insulation heat will eventually radiate into it, warm it, and enter whatever space you want to keep cool. Radiant barrier (with a thin layer of foam insulation) properly placed in a well ventilated attic space will do a better job at keeping the heat from the sun out of your house than most insulation.

optimal insulation goes with a reflective radiant barrier (not foam) and not necessarily under the roof tiles only but also on both sides of the insulating material. available in Thailand in any building supplies shop. a problem with single story homes are the suspended gypsum board ceilings which make it rather difficult to install the insulation properly.

[Naam]

13 hours ago, Kwasaki said:

On 10/15/2017 at 7:54 PM, Ahab said:

Then you will have a hot house. This stuff works much better than insulation in a tropical climate.

Not necessary there are many variations in roof builds.

correct! there a huge difference between the steep gradient Thai style roof and the quite common 32º slope.

[4MyEgo]

On 29/06/2017 at 1:11 AM, mortenaa said:

This is exactly what I am looking for!

 

Thank you very much :D
 

Can I ask if you installed the roof extractor, as I have just put in two Whirly birds at the older section of the house as the mould for the tile replacement is the same as the tile removed and they are working well, however the new section of the house has flat concrete tiles and they don't make Whirly bird moulds to suite, which is bloody odd, suffice to say, if the item you enquired about works, I might give ti a ago, also if you did purchase it, was the electricity set up different to the electricity set here, and how did you over come it ?

 

Cheers

[Naam]

1 hour ago, 4MyEgo said:

Can I ask if you installed the roof extractor, as I have just put in two Whirly birds at the older section of the house as the mould for the tile replacement is the same as the tile removed and they are working well, however the new section of the house has flat concrete tiles and they don't make Whirly bird moulds to suite, which is bloody odd, suffice to say, if the item you enquired about works, I might give ti a ago, also if you did purchase it, was the electricity set up different to the electricity set here, and how did you over come it ?

 

Cheers

when building i installed two exhaust fans. one for the attic the other one for the house. "overcome electricity?" i don't understand.

[4MyEgo]

2 hours ago, Naam said:

when building i installed two exhaust fans. one for the attic the other one for the house. "overcome electricity?" i don't understand.

Meant the voltage, i.e. I believe Thailand has 220 volts and if the product is from Australia, e.g. it would be 240 volts, therefore not compatible, I am no sparky by far, hence the reason I asked.

[4MyEgo]

On 17/10/2017 at 2:33 AM, Naam said:

optimal insulation goes with a reflective radiant barrier (not foam) and not necessarily under the roof tiles only but also on both sides of the insulating material. available in Thailand in any building supplies shop. a problem with single story homes are the suspended gypsum board ceilings which make it rather difficult to install the insulation properly.

Our builder couldn't install them under the roof tiles as the batten thickness wasn't enough for the double bubble, as I call it, thermal reflective insulation, i.e. 6mm thick, 3mm on each side, if I recall correctly, suffice to say we were not going to change all the battens, so he said he would do it from within the attic, with me saying, but the attic is going to have a suspended ceiling, so what are you going to stand on, with him replying, my pen rye, much to my amazement, he made swinging harnesses with his crew, i.e. where he needed to swing and its been up ever since, I call it suicide and a lot more work, but hey, it worked and the attic is much cooler than it was previously.

Edited November 8, 2017 by 4MyEgo

[Naam]

1 hour ago, 4MyEgo said:

Meant the voltage, i.e. I believe Thailand has 220 volts and if the product is from Australia, e.g. it would be 240 volts, therefore not compatible, I am no sparky by far, hence the reason I asked.

Thailand's voltage is 220/240V and is 100% compatible with Australian products.  i took this picture 2 minutes ago.

 

[4MyEgo]

10 minutes ago, Naam said:

Thailand's voltage is 220/240V and is 100% compatible with Australian products.  i took this picture 2 minutes ago.

 

So all we would need then is either an adaptor or the sparky could hard wire it straight in as they say ?