Geothermal Cooling / Hydronics

[Wildebeest]

Has any one heard of either one of these methods used in cooling a house in Thailand?

Its the same concept of radiant heating but using cool well water instead going through pipes embedded in the floor. 

Another method is used in Hospitals. 

Suppose to cut your electric bill by 25-75% from using the old aircon. 

Down side is the high initial cost of installation. Only cost after that is the electric to a small water pump.

Another down side, would the wife and family be comfortable sitting or walking on a cold floo

?

[chownah]

This has been discussed somewhat already so a search might turn up some discussion...try searching for groundwater or geothermal.

In short, the cost of a system to do this depends on how cool the ground is....and in Thailand the ground isn't all that cool...................and.................also................there is the humidity problem to overcome...when you cool the air in a room it raises the relative humidity....so.....etc.

Although maybe someday when all my projects are finished (hahahahahhah) I'll experiment with this...one thing I've noticed is that rain is usually very cool when falling so figuring a way to collect rain water and extracting its cool might work...or maybe not.

Yo! Swelters.....you are needed in aisle G!!!

You should check out a member named Swelters...he has a blog with alot of information about this and related sorts of stuff I think.

Chownah

Edited August 31, 2007 by chownah

[tjo o tjim]

About half of Suvarnabhumi's cooling is with radiant floor (for areas with solar exposure). The big issue is controlling water temperature to ensure you don't get condensation on the floor (keeping water temperature a few degrees above wet bulb temperature).

The strategy is most efficient when you have a lot of windows, which create a radiant heat load that is absorbed by the radiant cooling in the floor. If you try to use it for too much of the cooling, you end up with two problems: Comfort - your body wants to reject most of its heat from conduction and evaporation (perspiration). When you create an environment where most of the available cooling is just radiant, you tend to feel sweaty and as though the air is stagnant. This leads to the second problem-- you still need regular air conditioning, albeit a smaller system. This will help dry out the air (from perspiration as well as just controlling outside conditions). Ceiling fans can also help make the space more comfortable.

As for ground-source cooling, the basic premise is that the average annual outside temperature is equal to the ground temperature. Handy in climates with large daily or seasonal temperature variations. Can be very effective, but to cool 50m^2 you need about 100m of underground piping if my memory serves me. Without a compressor or heat pump, this can soften the blow of the hottest period of the day; with a small heat pump you can easily condition the space.

So, if your house doesn't have a lot of windows, radiant floors won't do much for you. If you use area rugs, radiant floors don't work. If you are in the habit of hammering nails or drilling holes into the floor, you may end up with a fountain. Another option is radiant ceiling panels, which can have measures to collect condensation included-- but I'm not sure how well this would really work in Thailand.

[Wildebeest]

tjo o tjim / chownah

Thanks for the input.

Yes the devils in the details. Require an air handler unit to control humidy and infuse fresh air from outside. And the average daily temp does control the sub surface temp, Maybe up north would be be

ter as the have an overall lower avg than say BKK.

Tjim , I wish you would not have used the "S" word in ur first line. That alone would scare anyone away. But you are obviously knowledgeable in the concept.

Cheers

[tjo o tjim]

For all the complaints on the evil "S", they did a few very novel things to cool it in an energy efficient way. My biggest complaint was something that was known 10 years ago-- that it's hot at the tops of the escalators. Never got a straight answer from the designer as to why it wasn't addressed.

As for the assumption that it would work better up North rather than BKK, the low water table in Bangkok might actually help in cooling a building fairly effectively. It can also work pretty well on the islands, where you don't need much of a temperature difference to improve comfort.