⌛ building a two story house in dumaguete????

Steve,
I was intrigued by your depiction of whirly bird roof vents. The ball spins from the hot air moving up and a very slight vacuum is created drawing more hot air upwards right? I don't understand how a roof without a vent is cooler? I can't see how the air from the spinning ball is forced down? Your house looks great and I look forward to your response.

 

I beg to differ, if the rotary vents are turning on a windless day, thats the heated air from the attic escaping causing the rotary vent to turn.
But rotary vents sometimes leak water in heavy rains :(

 

Sorry if I ruffled your feathers, Swampster. I was simply presenting another opinion on reducing heat in a tropical house. Asians, especially Filipinos, have been using eave vents and high peaked roofs to cool native houses for hundreds of years with no moving parts and remarkable success.

The turbine of a "whirly bird" works like a propeller, but in the opposite way. The energy required to turn the turbine comes from wind either wind or air pressure. You are completely right. When the wind is blowing, turning the turbine, a slight vacuum is created inside the roof, sucking the warmer air out of the attic. However, if the turbine is turning without wind, it is obviously the air pressure created by the warm air trying to escape out of the roof through the turbine that is providing the energy to turn the turbine. Air pressure is caused by resistance to flow. Thus, the resistance to flow in the turbine, causing the air pressure, is reducing airflow out of the attic. I am sure that Newton, Venturi, and Bernoulli would agree with this assessment, haha. Either way, we both agree that the point is, good ventilation is a key point in keeping your house cool. If you can prevent heat build-up in the attic, you will reduce the radiant heat transfer through the ceiling into your upstairs rooms.

I, personally, don't like those gaudy "whirly birds" on my roof. I have had several over the years and they often required maintenance due to squeaks or binding. Walking around my neighbourhoods, I always noticed this squeaking and jammed turbines on other houses, so I know I wasn't the only one with the problem. Maybe, with precision sealed bearings, I wouldn’t have had the problem and I am not sure about the quality of the whirly birds in my houses since I did not install them myself.

You are welcome to visit my house anytime and assess if the techniques that I mentioned in my previous post did, in fact, provide the heat reduction that I mentioned.

 

Reducing airflow? Only as in opposed to having a big hole in the roof.

When the rotary ventilator is turning that means hot air is escaping which means cooler air is being drawn into the attic from somewhere.

The purpose of the rotary turbine is to let the hottest air in the top of the attic escape without having to build a ductwork and fan system to draw it out artificially.

The biggest drawback with rotary ventilators, besides squeaking, is if they're not built just right they'll leak like a sieve in hard rains.

 

For anybody interested in houses designed for the tropics, google 'Troppo Architects'. They started designing houses in Darwin, northern Australia almost 30 years ago. There is no harsher climate than Darwin, and their houses are built to be cool in those conditions. Great designs.

 

Cool stuff, literally! Thanks for the heads up! :D

 

Try steel skeleton with hardiflex skin if you are afraid of earthquakes.

 

Steel frame is definitely the way to go, and in northern Australia, where termites and cyclones (typhoons) are a real problem, almost the only way to go.

Steel framing is also part of the philosophy behind 'cool in the tropics'. Light structures, whilst they take on heat faster than heavy structures such as brick/concrete, also cool rapidly when the sun disappears.

 

Im from Darwin and yes, we all mostly have whirly birds as we call them here. They do work well and yes, they can leak if they are not installed properly as we have 6 months of continuous hard rain throughout the year....

Troppo Architects have won numerous awards for housing deisgn in the tropics.

When I built a house in Tandayag last year, i wanted to build something like we have here, but could get the people to see my point in changing things the way I wanted it to.

The standards and quality of workmanship was also a challenge to find. All in all, the house was built satisfactorily and I am continuing to add Balinese villas in the back for corporate rentals.....but things are costing much more than I thought so its back to work fund my retirement project.....