Attic Ventilation Fan.

[tpthai2]

Looking to get the heat out of the attic in anticipation of summer.

Installers say the "Whirly Birds" will not work due to my type of roof construction

so this points me to considering an attic drafting fan.

Any TV members have experience with this?

Your suggestions always greatly appreciated.

[masuk]

that type of exhaust fan is excellent, and goes either on the tiles or the roofing iron, and extracts the heat from the roof cavity.

A recent innovation is to use a solar powered type. IUn Thailand? I doubt it, tho the cyclone type are here.

http://www.solarwhiz.com.au/

[eyecatcher]

A whirligig will work on a pitched roof design as long as you have 2or 3 large vents in the masonry peaks or a continuous eaves vent., as it draws crossfire air through the roof cooling it.

But most heat in a roof here if radiant from the temperature of the tiles or tin sheet.

The most sensible thing to do is to try and line the underside of the roof covering with a quilt insulation simply wired in place.

Then 75% of the heat is kept out in the first place.....as a secondary defence then get an extract fan or two.

Remember a roof gets scorching hot here and anything smaller than an expensive powerful fan is going be running constantly and probably not last too long.

Another option that I see in the rural areas is a make shift water sprinkler on the roof. Just connected to a tap supply the pipe if taken to the roof with a couple upstairs with small sprinkler heads on. Turn the tap and you can cool down the roof in a few minutes.

Sorry to waffle on, hope you get some ideas though.

[ThaiWx]

One of our upstairs bathrooms has a access panel in the ceiling to the attic. I removed the panel door and replaced it with an exhaust fan and ran power for it in the attic. The fan draws cooler air from the windows below and blows this into the attic. We have the corrugated tile roof you see everywhere so the bottom edges have lots of area vent the slight increase in pressure for the fan. I would forget to turn it on sometimes so made an adjustable thermostat for it to turn on and off around 38°C. It helps to keep the heated air moving outwards.

[tpthai2]

Thanks very much for all your replies.

[BillyBobThai]

Global House has what you are looking for.

[xerostar]

I wouldn't bother with the whirlybird type of vent.

They may work a little because they allow hot air to escape from the roof cavity.

They look nice when they spin, but unless the central shaft is connected to a fan blade below, then nothing much happens.

In reality they're as useless as a propeller on a bicycle.

The motorized fan shown by BillyBob Thai would be most effective.

.

I've seen some roof fans that run on solar power, probably not available in Thailand.

In Oz you can buy round ceiling fans quite cheaply, ($15) but I've not seen them in Thailand,

Thailand hardware shops seem only to have the type that have to build into a brick wall.

The ceiling fans are very easy to install, just cut a hole in the ceiling plaster and pop them up (from underneath), plug into a switched 240 Volt source and they're ready to go!

[tpthai2]

BillyBob and Xerostar

Thanks for the Global House recommendation...

[Dante99]

The ceiling fans are very easy to install, just cut a hole in the ceiling plaster and pop them up (from underneath), plug into a switched 240 Volt source and they're ready to go!

Wouldn't you want the fan to be connected to something stronger than the plasterboard?

[BillyBobThai]

I had one in every house that I lived in back in the states. They work wonders but you need some way for the air to escape frrom the attic for them to work.

[ericpasansai]

I have two of these on my roof

[ThaiWx]

The ceiling fans are very easy to install, just cut a hole in the ceiling plaster and pop them up (from underneath), plug into a switched 240 Volt source and they're ready to go!

Wouldn't you want the fan to be connected to something stronger than the plasterboard?

You frame it in to the rafters.

[xerostar]

"Wouldn't you want the fan to be connected to something stronger than the plasterboard?"

It's the standard method of installation in Australia. The ceiling joists are normally 600mm apart and provide plenty of support.

They are standard fittings for most toilets and bathrooms in your average family home.

The used to be used above the kitchen stove as well, but they've been super-ceded by range hoods with oil trapping filters.

You usually cut the hole centered between the joists.

The screws don't go into the plaster at all.

They have plastic lugs that rotate out over the top surface of the plasterboard as you tighten the 4 screws.

As you tighten the screws, the lugs descend on the thread and clamp firmly onto the plasterboard.

If the ceiling has insulation like 'cool or cosy" which is quite fluffy and dusty, you need to provide a tubular dam (shaped like a cake-tin) to hold

the particles away from the fan and prevent the stuff from falling down into the room.

The fans come with an insect-proof plastic grill that snaps onto the fan from underneath to give a neat finish.

[Naam]

that type of exhaust fan is excellent, and goes either on the tiles or the roofing iron, and extracts the heat from the roof cavity.

A recent innovation is to use a solar powered type. IUn Thailand? I doubt it, tho the cyclone type are here.

http://www.solarwhiz.com.au/

that type of exhaust fan works efficiently only when there is a breeze. without breeze it even hampers the air flow.

[ericpasansai]

that type of exhaust fan is excellent, and goes either on the tiles or the roofing iron, and extracts the heat from the roof cavity.

A recent innovation is to use a solar powered type. IUn Thailand? I doubt it, tho the cyclone type are here.

http://www.solarwhiz.com.au/

that type of exhaust fan works efficiently only when there is a breeze. without breeze it even hampers the air flow.

that's not exactly true the hot air rising will start the motion of the heat extractor

[Naam]

that type of exhaust fan is excellent, and goes either on the tiles or the roofing iron, and extracts the heat from the roof cavity.

A recent innovation is to use a solar powered type. IUn Thailand? I doubt it, tho the cyclone type are here.

http://www.solarwhiz.com.au/

that type of exhaust fan works efficiently only when there is a breeze. without breeze it even hampers the air flow.

that's not exactly true the hot air rising will start the motion of the heat extractor

the hot air has to drive the "whirly bird" into motion which is hampering the rise. thermal physics and mech eng 101.

[NeverSure]

My experience with building in a hot climate (not in Thailand) is that hot air rises. When a house is built, insect proof vents are put at the eves letting air from the outside enter the attic at attic floor level. Then at the top (ridge) of the roof there are more vents. There is no power. As the air in the attic heats it rises and leaves at the ridge, pulling fresh air in from the bottom (eves.)

The floor of the attic is what's insulated to keep any hotter air in the attic from heating the house.

[pizzachang]

My experience with building in a hot climate (not in Thailand) is that hot air rises. When a house is built, insect proof vents are put at the eves letting air from the outside enter the attic at attic floor level. Then at the top (ridge) of the roof there are more vents. There is no power. As the air in the attic heats it rises and leaves at the ridge, pulling fresh air in from the bottom (eves.)

The floor of the attic is what's insulated to keep any hotter air in the attic from heating the house.

This is what I did and my house is much cooler all year - too cold for my wife in Dec. & Jan! R36 is great.

[Naam]

My experience with building in a hot climate (not in Thailand) is that hot air rises. When a house is built, insect proof vents are put at the eves letting air from the outside enter the attic at attic floor level. Then at the top (ridge) of the roof there are more vents. There is no power. As the air in the attic heats it rises and leaves at the ridge, pulling fresh air in from the bottom (eves.)

The floor of the attic is what's insulated to keep any hotter air in the attic from heating the house.

unfortunately very few houses are built in Thailand providing that natural attic ventilation.

[MartinBKK]

A few years on i may as well revive this thread to try and get some current information. I am interested in a solar vent for my roof as my house is incredibly hot in summer (i have already installed R36 ceiling insulation). I see they have these on Lazada but i would really rather deal with a local dealer who would take care of the entire installation. If anyone could recommend someone in Chiang Mai i would be grateful.

 

Thank you.

[connda]

I put in attic fans and they didn't any significant difference in the temperature in the house.
I then put in insulation in the air space of the roof.  Significant change in the both cooling (hot/rain season) and heating (cool/cold season).

[NotEinstein]

The heat within a roof space moves mainly via radiation and so using fans has a limited effect. Insulation provides the best relief, along with making sure there is enough ability for air to naturally flow up through the roof space and out of the vents, otherwise the hot air gets trapped. I see most new-build houses have no obvious soffit venting - a design flaw in my opinion.

[MartinBKK]

Thanks for the comments guys. All opinions and help gratefully received.

[YorkshireTyke]

Going to line my attic space also.

 

In Homepro online they have SCG 6'' x 4 metres R-38 at 438 Baht  and Sunshield Extra Cool 6'' x 4 metres R-37 at 379 Baht. Other than the price any real difference? Or other recommendations?

[Bill97]

19 minutes ago, YorkshireTyke said:

Going to line my attic space also.

 

In Homepro online they have SCG 6'' x 4 metres R-38 at 438 Baht  and Sunshield Extra Cool 6'' x 4 metres R-37 at 379 Baht. Other than the price any real difference? Or other recommendations?

One is fiberglass the other asbestos, both will kill you.

[tifino]

IO also agree the whirlybirds are a waste of time, in their standard factory form...   

 

yes they will 'spin' if air outside (wind) passes by   ( because of friction)... but the only air that goes 'up' through them is always simple Convection... (wind or not no different) 

 

Only way I have found to make them functional, is to install an electric fan inside them,. to push up the air. Take off all the fan's original plastic shrouding, and the motor/blades mechanism fits pretty neatly in the whirly's UpTube  

240 volt plugin adaptor styled  thermostats are getting popularly available these days, and can be set for Heat or Cool Temp detection.  I have the thermostats inside the actual roofspace, and set them currently programmed fpor switching ON at 28C ( which is the roof's hotspace equivalent of the LivingRooms cool space temp of 25C )  Noting my thermostat model will default back to switch at 22C, if there had been a power outage...   

 

 

[YorkshireTyke]

21 minutes ago, Bill97 said:

One is fiberglass the other asbestos, both will kill you.

This is from Homepro website. 

 

The thermal insulation from SCG is made of 100% recycled glass with HydroProtecTM substance that reduces water absorption 10 times. Plus, it is a fire retardant material with ASTM E84, BS476 certified. It is designed for installing on T-bar and smooth plastered ceiling boards to prevent the heat coming from the roof. It is wrapped with Aluminium foils for solidity and temperature resistance This thermal insulation comes with Green Label and Label No.5 certifications, so it ensures the safety of users or residents.

[Cake Monster]

If you have a pitched roof you could try the " Bar Room Door " type of louvered panels on the gable ends of the roof.

Dont forget to Mozzy screen them.

[Cake Monster]

8 minutes ago, YorkshireTyke said:

This is from Homepro website. 

 

The thermal insulation from SCG is made of 100% recycled glass with HydroProtecTM substance that reduces water absorption 10 times. Plus, it is a fire retardant material with ASTM E84, BS476 certified. It is designed for installing on T-bar and smooth plastered ceiling boards to prevent the heat coming from the roof. It is wrapped with Aluminium foils for solidity and temperature resistance This thermal insulation comes with Green Label and Label No.5 certifications, so it ensures the safety of users or residents.

These rolls of Insulation are not Aluminium Foil wrapped.

It is just paper and painted Silver.

 

[canthai55]

Always amazed that posters come on here and ask questions, when a minutes work on a search and checking the website will reveal all.

But then I have never needed much 'Hand Holding' 555