Whole house fan

[CGW]

Summer will be here soon! would like to fit a "whole  house fan" anybody any thought on where the best place to fit would be? either in the house or on the gable end of house? Gable end is my preference, though not sure it would be as efficient at moving air?

Also any idea on sizing, bigger is better?

Edited January 8, 2017 by CGW

[AJBangkok]

I bought 3 of these 84 inch helicopter fans for my patios 

 

http://www.mrken-fan.com/products/view/design/607

 

there is another company called big ass fans who make bigger fans but they are very expensive.

[Naam]

54 minutes ago, AJBangkok said:

I bought 3 of these 84 inch helicopter fans for my patios 

http://www.mrken-fan.com/products/view/design/607

there is another company called big ass fans who make bigger fans but they are very expensive.

these fans can't be used as "whole-house" fans.

[Naam]

sketches how to install whole-house fans.

 

https://www.google.co.uk/search?q=whole+house+fan&lr=&hl=en&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiKy9GD17LRAhVLPY8KHZ3BDNcQ_AUICCgB&biw=853&bih=475

[carlyai]

The trouble I see with 'whole house fans' (at least in Isaan where I live) is they circulate hot air.

Better to have airconditioning.

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[Naam]

5 hours ago, carlyai said:

The trouble I see with 'whole house fans' (at least in Isaan where I live) is they circulate hot air.
Better to have airconditioning.
 

i say you need both and it helps to reduce cooling cost especially during the cooler months when in the early mornings the temperature is 24-25ºC.

[wayned]

When I built my house in Southern Mississippi in the US many moons ago I installed both Air Con and an very large exhaust fan in the ceiling in the hall that drew air from the house and blew it into the attic which was then exhausted though gable  and eve vents.  In the summer the temperatures are much like here but the humidity is higher.  We used air con in the summer months but the exhaust fan was great during the cooler spring and fall months.  As said, you need both!

[CGW]

I am just starting to look into this, so any comments are welcome.

As stated "whole house fans" are not designed to be run all the time, only when the ambient temperature makes it feasible, which is going to be early morning and evening, we are in Isaan where we don't have as much humidity as the "south" and the temp drops a lot lower at night for a good part of the year.

I have no problem using air-con to keep the house comfortable, but I am sure replacing the hot air with cooler air in the void space is going to help.

The house is a single story "L" shape, can see the first problem already which is we have no gable end vents! and realistically no option to install, we have only one gable end as such and this would be too exposed to the weather to fit a vent, especially given the skill level of the workers here!

Thinking aloud! possibly a extractor fan fitted high on the gable will drag cooler air from the "ridge" around the house where the tiles end?

[Naam]

1 hour ago, CGW said:

The house is a single story "L" shape, can see the first problem already which is we have no gable end vents! and realistically no option to install

there's always an option CGW. the whole-house fan doesn't have to be installed in the attic. we have a home without gables (4 hip roofs) and the fan is installed above a side entrance door but tilted in angle because of the size. that we have two additional attic fans which reduce the heat load of the home goes without saying. 

 

[carlyai]

I am just starting to look into this, so any comments are welcome.
As stated "whole house fans" are not designed to be run all the time, only when the ambient temperature makes it feasible, which is going to be early morning and evening, we are in Isaan where we don't have as much humidity as the "south" and the temp drops a lot lower at night for a good part of the year.
I have no problem using air-con to keep the house comfortable, but I am sure replacing the hot air with cooler air in the void space is going to help.
The house is a single story "L" shape, can see the first problem already which is we have no gable end vents! and realistically no option to install, we have only one gable end as such and this would be too exposed to the weather to fit a vent, especially given the skill level of the workers here!
Thinking aloud! possibly a extractor fan fitted high on the gable will drag cooler air from the "ridge" around the house where the tiles end?

I'm not sure where in Isaan you are, but if you were there last year, you will remember how hot it was. I don't have a whole house fan but the mob of fans I have were just circulating hot air.

If the air is very hot outside, just blowing it around inside, outside or where ever, is just hot air.

I think in Isaan, you probably could use a whole house fan, but for a good night's sleep, you need an air conditioner.


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[Naam]

Just now, carlyai said:

If the air is very hot outside...

only ignorants use a strong whole-house fan

[CGW]

24 minutes ago, carlyai said:

I'm not sure where in Isaan you are, but if you were there last year, you will remember how hot it was. I don't have a whole house fan but the mob of fans I have were just circulating hot air.

If the air is very hot outside, just blowing it around inside, outside or where ever, is just hot air.

I think in Isaan, you probably could use a whole house fan, but for a good night's sleep, you need an air conditioner.


Sent from my SM-J700F using Tapatalk
 

Yes it did get rather warm for a long period last year! when the sun went down the house was still "glowing" from the absorbed sun for many hours after, the idea is to help dissipate this heat quicker by forcing cooler air into the void.

I am under no illusion that the "whole house fan" will cool down the house to a acceptable level, only air-con can do that, but it will help, running it at dusk will replace the very hot air that has accumulated in the roof void with air, that is a lot cooler therefore helping the air con do its work, I only envisage running it for a hour or two a day not constantly.

[CGW]

54 minutes ago, Naam said:

there's always an option CGW. the whole-house fan doesn't have to be installed in the attic. we have a home without gables (4 hip roofs) and the fan is installed above a side entrance door but tilted in angle because of the size. that we have two additional attic fans which reduce the heat load of the home goes without saying.

Yes, I agree wholeheartedly there is always! a viable option! 20 years ago it would have been far easier as I would have just done all the work myself, now I'm too lazy & old so have to rely on hired help

What size is the fan, looks to be about 0.6m? I'm thinking I will need a extractor fan on the highest point of the gable to help move the air through.

[Naam]

23 minutes ago, CGW said:

What size is the fan, looks to be about 0.6m?

make that double = 1.20m (½HP). fan size depends on size, respectively air volume of your home.

[Naam]

26 minutes ago, CGW said:

20 years ago it would have been far easier as I would have just done all the work myself, now I'm too lazy & old

you and me could form a club

[Naam]

42 minutes ago, CGW said:

I only envisage running it for a hour or two a day not constantly.

my attic fan (NOT whole-house fan) is on a timer. starting at 11.00hrs one hour on, one hour off till one hour after sunset. the whole-house fan is used in the early mornings 0500 till 0700 hours.

[wpcoe]

One thing I haven't seen mentioned in this thread so far is the potential noise/vibration from a powerful whole house fan.  I had one in a house in the USA and the noise/vibration was so strong you would not be tempted to use the fan more than five minutes.*  I went to the local DIY megastores about replacing it and when they asked me why and I told them the noise/vibration, they said even the new ones are like that.  Is it a case of YMMV?  Otherwise, Naam, how can you tolerate two hours of fan use in the morning?

 

Also, be sure to have at least one door or window open before you switch the fan on.  It can not only pop your ears from the suction, it can burn out the fan motor if left running in a sealed house.  That's assuming, of course, your house is airtight like they are in the USA.

 

* FYI, running the fan for five minutes was enough to fully replace the interior air with outdoor air.    When the citrus trees were blooming, the house would practically reek of orange blossom aroma.

[CGW]

^ Good point to bear in mind, not sure how to overcome it? if the fan is well balanced would certainly help, but the "harmonics" it creates is a different problem - we shall overcome!

Our kitchen extractor "vibrates" the whole wall when on "full" we overcame this problem by never running it on full! it is mounted on a good solid wall as well!

I don't think you will find too many "sealed" houses in Thailand, be nice but probably overkill and would make problems of its own I imagine?

Edited January 9, 2017 by CGW

[Naam]

1 hour ago, wpcoe said:

Otherwise, Naam, how can you tolerate two hours of fan use in the morning?

everybody except me sleeps in the mornings when the fan is running. and i am sitting far away from the fan and its noise. we also air the house 24/7 with rather small noiseless 25watt fans even during the hot months. but this approach is not recommended for those who try to have an extremely low electricity bill.

[Naam]

1 hour ago, wpcoe said:

* FYI, running the fan for five minutes was enough to fully replace the interior air with outdoor air.    When the citrus trees were blooming, the house would practically reek of orange blossom aroma.

that is correct but then you have only fresh and cooler air for a short period of time. running the fan for 2 hours you are also cooling down walls and floors and this helps saving on airconditioning.

 

we lived 15 years in Central Florida (Volusia County) where heating was required on a number of days in winter. we reduced our electricty bill by sucking warm air from the attic into the house through the main airhandler of the central aircon unit by replacing the fan with a much stronger one and a rheostat for stepless speed control.

[CGW]

Something else that I have just thought off!

 

We have infrared sensors in the "void" space, what are the odds on the air flow "tripping" them? guess time will tell.............