Roof / attic ventilation fan

[mortenaa]

Hi,

 

I'm building my first house. 

 

It will have natural ventilation through the eves, and use normal roof tiles, that should not trap the hot rising air inside. The ceiling will be sprayed with foam from Lohr, straight onto the gypsum. But I feel I should put some fans as well, close to the ridge of the roof. I'm looking for an electric fan, as showed on the picture, or similar.

 

 

Here is the link: https://www.amazon.com/Broan-356BK1600-Mount-Powered-Ventilator/dp/B002DHO36K/

 

Can I get a fan like this in Thailand? 

 

Thanks for any tip or personal experiences with fans and or insulation :)

 

[Kwasaki]

Ugly how will you weather it..

Why not just use ridge vent tiles.

If you have a gable end roof,  louver vent it at both gables.

[janclaes47]

Install reflective foil UNDER your roof-tile battens, combined with open eaves and a dry ridge system.

 

Wind will continuously blow between the foil and the tiles and prevent the attic space from heating up.

 

Make sure you have a waterproof foil  and your dry ridge is perforated to let the wind exit.

 

 

[Kwasaki]

1 hour ago, janclaes47 said:

reflective foil UNDER your roof-tile battens

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

[janclaes47]

3 minutes ago, Kwasaki said:

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

That's also why I said roof tile BATTENS.

 

You need the 2" space, otherwise no wind can go through and forms a barrier, if you have no foil the wind blows in your loft and stays there.

 

If in doubt I invite you to sit in my loft at noon and feel the difference.

 

If I go in my loft the steel frame is hot, the foil feels cool.

[Kwasaki]

41 minutes ago, janclaes47 said:

That's also why I said roof tile BATTENS.

 

You need the 2" space, otherwise no wind can go through and forms a barrier, if you have no foil the wind blows in your loft and stays there.

 

If in doubt I invite you to sit in my loft at noon and feel the difference.

 

If I go in my loft the steel frame is hot, the foil feels cool.

l believe you but so would many other types of vapour check membrane's,  just saying.

[janclaes47]

4 minutes ago, Kwasaki said:

l believe you but so would many other types of vapour check membrane's,  just saying.

I have no idea what vapour check membranes are, the OP asked a question and I answered.

 

Fact is that it is highly advised to have a foil under the tiles anyway, as I have never see a leak proof roof in Thailand.

 

So why not catch 2 birds with one stone, and make the eaves and ridges open, and create a air barrier.

[mortenaa]

Im not expert on this, but Im advised against any kind of foil. It just traps the air inside the loft. Its already small gaps between the roof tiles to let the air out. 2nd advice is to get a fan to get better ventilation. This is a common way to do it in Australia and southern states in the US. 

Im not scared of any leaks. These builders have built around 60 houses now, and still no leaks to my knowledge.

[r136dg]

IMO these whirlybirds work well. Mine's in a section of roof that's almost impossible to see (except from a good distance), but I don't care what they look like. Heat dispersing & functionality is where it's at for me. Our new house remains cooler than outdoor temps all day. Also light colored tiles help a lot & I had them put a gable in with a couple small windows (the kind that crank open sections of glass up & down). Half open in the raining season with no issues & definite air movement. I have no opinion on foiling/insulating the tile; however, we did ours.

The house we're currently renting has the red tiles & small vents in a tiny gable. Living area is substantially hotter than outdoors from 12:00-24:00. The attic takes all night to cool down.

[Crossy]

Do you have gables? Gable vents can provide a much larger ventilation area than ridge vents.

 

If you are going to install an electric anything in the roof space think about access to service it.

 

I would also be wary of foam insulation directly on the gypsum, think about your electrics. The insulating batts are likely cheaper and can be easily moved for access.

[Kwasaki]

8 hours ago, mortenaa said:

Im not expert on this, but Im advised against any kind of foil.

l use to advise but retired now,  foil OK if vented as said but breathable membrane is better,  that all l'm trying to say. 

[mortenaa]

3 hours ago, Crossy said:

Do you have gables? Gable vents can provide a much larger ventilation area than ridge vents.

 

If you are going to install an electric anything in the roof space think about access to service it.

 

I would also be wary of foam insulation directly on the gypsum, think about your electrics. The insulating batts are likely cheaper and can be easily moved for access.

I dont have gables unfortunately. I already made a "walk-able" loft, for storage purposes etc, so access is already taken care of. Whirlybirds.. well, im scared its going to be squeaking after a while. That's why I have considered electric fans, with a timer/ thermostat etc.  

Insulating the gypsum is professionally done. Its only 600 per sqm, and its calculated into the price of the house. All lights and electric are put inside boxes, brought in from Europe for the purpose. They are glued to the gypsum, and sprayed after. All wiring in pipes. I will also insulated front door, double glazed windows all around. 

[mortenaa]

48 minutes ago, Kwasaki said:

l use to advise but retired now,  foil OK if vented as said but breathable membrane is better,  that all l'm trying to say. 

Never seen anything like it here. We use roofing paper in Norway, but we insulate against the cold. 

[mortenaa]

3 hours ago, r136dg said:

IMO these whirlybirds work well. Mine's in a section of roof that's almost impossible to see (except from a good distance), but I don't care what they look like. Heat dispersing & functionality is where it's at for me. Our new house remains cooler than outdoor temps all day. Also light colored tiles help a lot & I had them put a gable in with a couple small windows (the kind that crank open sections of glass up & down). Half open in the raining season with no issues & definite air movement. I have no opinion on foiling/insulating the tile; however, we did ours.

The house we're currently renting has the red tiles & small vents in a tiny gable. Living area is substantially hotter than outdoors from 12:00-24:00. The attic takes all night to cool down.

 

If you think the whirlybird works well, think of how much better an electric fan would have been :D

My tiles are similar color the ones on the picture.

[Kwasaki]

2 hours ago, mortenaa said:

Never seen anything like it here. We use roofing paper in Norway, but we insulate against the cold. 

You can use most anything that stops the odd spot of water that gets through roof cover.

 

There are breathable paper underlay not really looked for it here.

 

Read many Architect comments in the Asian area the one l like is always make the roof aesthetically pleasing and if it leaks don't worry it's good for washing the floor.  

[Naam]

On 6/26/2017 at 5:29 PM, mortenaa said:

Can I get a fan like this in Thailand? 

unfortunately these kinds are (to the best of my knowledge) not available. i installed a roof fan when i built 11 years ago but it's a commercial type which was quite expensive (15,000 Baht). i am presently travelling and don't have access to all my files. will try to find the company and what they offer nowadays when i'm back.

 

regards!

[Naam]

our former home in Florida sporting 11 roof mounted fans. 1 kitchen, 3 bathrooms, 1 study (smoker) and 6 for attic ventilation.

 

[mortenaa]

15 hours ago, Naam said:

unfortunately these kinds are (to the best of my knowledge) not available. i installed a roof fan when i built 11 years ago but it's a commercial type which was quite expensive (15,000 Baht). i am presently travelling and don't have access to all my files. will try to find the company and what they offer nowadays when i'm back.

 

regards!

 

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

[Naam]

54 minutes ago, mortenaa said:

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

i had to use a roof mounted fan because of four hip roofs. if your house has gables then installation is a piece of cake and the fan is 2,000 Baht max.

[mortenaa]

54 minutes ago, Naam said:

i had to use a roof mounted fan because of four hip roofs. if your house has gables then installation is a piece of cake and the fan is 2,000 Baht max.

My roof has no gables .. 

 

It's exactly like the house on the picture:

[Naam]

 

http://www.rosenberg.co.th/roof-fans

[mortenaa]

6 hours ago, Naam said:

 

http://www.rosenberg.co.th/roof-fans

This is exactly what I am looking for!

 

Thank you very much :D
 

[petesc55]

The house my GF owns has a serious heat build up in the attic, under the metal roof.

I brought a US sourced 12v fan to install in her gable, using a locally sourced solar panel.

It turns out the fan is also available via Lazada, under various names.      It's basically a 12v  electric radiator fan for cars.   About $25 US on amazon or lazada, in various sizes, and some colors.  (But all seem to have the 80 watt motor.)

The seller I bought mine from says to use up to an 80 W panel to direct drive the fan.

I bought a 50 w panel at Amarn, (1650 baht)  and it seems to power the fan well in full sunlight.

 

I wanted to be there when the local handyman guy installed it while doing some other work on the roof, and to make sure he didn't destroy the solar panel or plug the wire ends of the 12v fan into a house outlet, but he was tied up out of town and not able to make it before I left for the US.     If he gets this up and runnning ok, I think this is a good solution for under $100.

This type of fan is being used for air circulation in greenhouses, as well as other ventilation tasks.

 

 

 

 

[VocalNeal]

I believe the biggest culprit here is radiant heat from the roof so the foil idea has merit.So does spraying the underside of the roof with insulation.

 

The room ceiling will act as a barrier but will also heat up eventually and then radiate heat downwards. 

 

The foil idea is similar to the old LandRover safari roof idea.

 

 

 

[4MyEgo]

On 27/06/2017 at 1:25 AM, Kwasaki said:

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

 

I used thermal reflective insulation under my roof tiles, best thing I ever did as it takes much longer for the heat to enter the ceiling space, as for the 60,000 baht outlay, worth every baht in my opinion, now after a year, I am looking into suitable ceiling batts, especially on our suspended ceilings, just before summer, but not before having installed an 80m2 covered outdoor area which provides shade to 3 of our external walls, and an external kitchen, with all of those areas covering the bricks that absorb the daylight heat, so its an added bonus, as I think a lot of people overlook the bricks absorbing the heat, like water to a spunge.

 

 

[4MyEgo]

On 27/06/2017 at 5:07 AM, mortenaa said:

Im not expert on this, but Im advised against any kind of foil. It just traps the air inside the loft. Its already small gaps between the roof tiles to let the air out. 2nd advice is to get a fan to get better ventilation. This is a common way to do it in Australia and southern states in the US. 

Im not scared of any leaks. These builders have built around 60 houses now, and still no leaks to my knowledge.

 

In my opinion having coming from Australia, I used thermal reflective insulation under the tiles, ceiling batts, whirly birds and cavity brick walls, something no one does here, obviously because of the added expense, although for my hip pocket isn't a problem, a problem for me would be allowing the ceiling heat in and the cool air from the air conditions out through the ceilings, now there is no point in sitting idol in a spot sweating like you have just been to the gym, anyway, that's my pennies worth. 

[sometimewoodworker]

4 hours ago, 4MyEgo said:

 

I used thermal reflective insulation under my roof tiles, best thing I ever did as it takes much longer for the heat to enter the ceiling space, as for the 60,000 baht outlay, worth every baht in my opinion, now after a year, I am looking into suitable ceiling batts, especially on our suspended ceilings, just before summer, but not before having installed an 80m2 covered outdoor area which provides shade to 3 of our external walls, and an external kitchen, with all of those areas covering the bricks that absorb the daylight heat, so its an added bonus, as I think a lot of people overlook the bricks absorbing the heat, like water to a spunge.

 

 

That's why we use AAC blocks 

[mortenaa]

8 hours ago, 4MyEgo said:

 

In my opinion having coming from Australia, I used thermal reflective insulation under the tiles, ceiling batts, whirly birds and cavity brick walls, something no one does here, obviously because of the added expense, although for my hip pocket isn't a problem, a problem for me would be allowing the ceiling heat in and the cool air from the air conditions out through the ceilings, now there is no point in sitting idol in a spot sweating like you have just been to the gym, anyway, that's my pennies worth. 

 

You would probably have triple the effect if you just insulated over the gypsum instead. Unless you don't use AC. The roof is much better to have as much ventilation as possible. Putting that foil will just trap the air.

[4MyEgo]

17 hours ago, sometimewoodworker said:

That's why we use AAC blocks 

 

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.

 

More focus when building should also be concentrated on windows, less glass is better because a lot of heat gets in through the glass in my opinion.

[4MyEgo]

13 hours ago, mortenaa said:

 

You would probably have triple the effect if you just insulated over the gypsum instead. Unless you don't use AC. The roof is much better to have as much ventilation as possible. Putting that foil will just trap the air.

 

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.