cooling the floor / walls / ceilings instead of the air

Air conditioning, fans, and anything related to keeping it cool, such as insulation. This would include any posts generally discussing how to keep it cool, such as which types of blocks are better insulators.... ideal wall thickness for keeping an A/C house cool, etc.

Moderators: Sometimewoodworker, MGV12, BKKBILL

cooling the floor / walls / ceilings instead of the air

Postby Attila » Fri Sep 02, 2005 4:45 am

Hi,

since I don't like cold air blowing in my face I don't plan to install a conventional a/c system.

However I did stumble over this now:

"Capillary Tubing Systems for Chilled Ceilings"
http://www.clina.com/
(The website is in spanish though, sorry)

I have seen houses where similar systems had been installed in the floor, but for heating. It felt very comfortable, much much better than small and hot radiators or blowing hot air in the room.

But how about cooling this way?
Has anyone seen that working?
Is such a system available in LOS?

Regards,
Attila
Attachments
suelo2-clina.jpg
installing a tubing system in the floor
suelo2-clina.jpg (26.84 KiB) Viewed 6899 times
suelo1-clina.jpg
cooling the floor
suelo1-clina.jpg (27.92 KiB) Viewed 6898 times
radia-clina.gif
"Capillary Tubing Systems for Chilled Ceilings"
http://www.clina.com/
radia-clina.gif (19.83 KiB) Viewed 6897 times
Attila
 
Posts: 408
Joined: Sun May 15, 2005 5:50 pm
Location: Thailand

temperature of the water

Postby dozer » Fri Sep 02, 2005 6:54 pm

Wouldn't the effectiveness of this depend on the temperature of the water being used to cool the house? Would the water need to be cooled first?
dozer
Site Admin
 
Posts: 1940
Joined: Tue Mar 15, 2005 4:21 pm

Re: temperature of the water

Postby Attila » Fri Sep 02, 2005 7:58 pm

dozer wrote:Wouldn't the effectiveness of this depend on the temperature of the water being used to cool the house? Would the water need to be cooled first?


I found the value of 16?C for the cool water. A cooled ceiling or floor would so have about 17 - 19?C.

So yes, if you do not happen to have water with 16?C or less, may be from a well or an underground reservoir, then you need to cool it first. The advantage, if I got it correctly, is that you do not need to cool down the water as much as you would have to cool down the air in a conventional a/c.
Attila
 
Posts: 408
Joined: Sun May 15, 2005 5:50 pm
Location: Thailand

Postby the limey » Fri Sep 02, 2005 8:53 pm

aircons blow out at 20degrees centigrade, marble and granite keep your floors cooler by at least 5 degrees below the ambient temperature, heat rises, underfloor cooling I doubt would work, but pumping that water onto your roof during the peak times would cool your house down.
the limey
 
Posts: 192
Joined: Thu Jun 09, 2005 4:08 pm

Postby Attila » Sat Sep 03, 2005 9:45 am

the limey wrote:aircons blow out at 20degrees centigrade, marble and granite keep your floors cooler by at least 5 degrees below the ambient temperature, heat rises, underfloor cooling I doubt would work, but pumping that water onto your roof during the peak times would cool your house down.


Yes, for cooling they do indeed recommend to install it in the ceiling or in the wall.

The cooling effect is mainly through radiation and not only through convection as it is in the usual air blowing a/c system.

Hydronic Radiant Cooling (HRC) is very simple. Most conventional systems rely on convection (air movement) to transfer heat generated within an enclosed area and exhaust warm air from the space. HRC systems rely predominantly on radiation to transfer heat. The heat is transferred to cool surfaces -- ceilings and floors -- rather than being released into the air. With a radiant system, air can actually have a higher temperature than in a conventional system and produce the same comfort perception.

Comfort relies as much on radiant heat transfer as it does on air temperature. Conventional air conditioning units are only designed to control air temperature. Because radiant energy travels through space without cooling the air itself but rather objects, hydronic radiant cooling systems separate ventilation from thermal conditioning, providing fresh air and conditioning independent from each other.

The human body transfers heat in three different ways: radiation, convection, and evaporation. Thermal comfort is when these three factors are in thermal neutrality. Ideally 50% of body heat is cooled by radiation, 30% by convection and 20% by evaporation (sweat and breathing). With an ideally designed conditioning system, the occupant would not know if it is cooling or heating.


the limey wrote:...heat rises,..


yes, heat rises in form of hot air. The heat as energy itself travels as radiation, and thus goes in any direction. When accepting the percentage values quoted above, then the radiation effect should be bigger anyway, so even a cooled floor, may be in combination with a ceiling fan to get some air circulating and getting cooled by the cool floor should work good enough.

Installed in a wall or ceiling the effects seem to add up even more nicely. Again a ceiling fan could optimize the system. :D

I wonder if such a system has been installed here somewhere. I've seen floor heating systems (not here in LOS of course :wink: ), and they work great, but I haven't seen this system as cooling system in action yet.
Attila
 
Posts: 408
Joined: Sun May 15, 2005 5:50 pm
Location: Thailand

Postby runker » Sun Sep 04, 2005 11:34 pm

Sorry I don't have any sort of diagram to post but I saw an interesting design in my son's enviromental science text book. The system illustrated in the book has warm air being pulled through gravel located under the house and then blown into the house.

The idea is that the gravel will absorb the heat from the incoming air reducing the air temp of the air being blown into the house. A heat pump of sorts.

I'm guessing someone could probably find more information of this type of cooling doing a search on the inter net.
runker
 
Posts: 201
Joined: Thu Jun 30, 2005 8:42 am
Location: Maryland/ChiangMai

Postby Itchy » Mon Sep 05, 2005 6:20 pm

I'm working in an office with this sort of cooling right now (in Rome), it works fine most of the time but suffers one drawback which will be far more so in Thailand.

Condensation. Moisture in the air condenses on the cold surface, here in Rome that's not such a problem because the humidity is usually reasonably low - but on very humid days the walls and ceiling of my office are visibly wet, especially if I leave the office door open.

In Thailand the problem will be worse because humidity levels are higher. Take a look at the condensation draining from your a/c unit - that is the amount of water you would have on the cold surfaces.

An advantage of the a/c units that are usually used in Thailand is they cool the air in a chiller, where the condensation can be removed and drained away.

Incidentally, the following is a misconception:

marble and granite keep your floors cooler by at least 5 degrees below the ambient temperature


Marble and granite floors may feel cooler, but they are not actually colder than the ambient temperature (unless there is a new law of physics in play). They feel cold because of the conduction of heat from your skin when you touch them.
User avatar
Itchy
 
Posts: 173
Joined: Fri Jun 10, 2005 6:56 pm

Postby the limey » Mon Sep 05, 2005 6:40 pm

Itchy;

I think you will find that most internal floors are cooler than the ambient temp, things heat up during the day due to direct sunlight, some things take longer to heat up, as most ppl don't allow the sun to shine into their houses obviously that will be cooler, this is why ppl have roofs, some things,like copper are a good condutor of heat, and some things are not, marble and granite are not good conductors of heat....
the limey
 
Posts: 192
Joined: Thu Jun 09, 2005 4:08 pm

Postby Attila » Mon Sep 05, 2005 8:21 pm

the limey wrote:
some things,like copper are a good condutor of heat, and some things are not, marble and granite are not good conductors of heat....


Now that surprises me, I would have thought marble and granite would be good conductors of heat :?

However they have a bigger mass, especially together with all the concrete (floor / slab) they are usually connected to. Thus it takes some time to heat all up, or cool down again.

Other materials, such as carpet or wood, will get their surface temperature changed much more quickly, because they are very bad conductors of heat.

But of course, copper is a very good conductor of heat, indeed.
Attila
 
Posts: 408
Joined: Sun May 15, 2005 5:50 pm
Location: Thailand

Postby Nawty » Wed May 09, 2007 7:59 pm

I thought the new airport installed this type of system in all is flooring and I believe I read that they have o aircon systems, at least in the big main areas ??
User avatar
Nawty
 
Posts: 804
Joined: Mon May 07, 2007 12:23 pm

Postby jazzman » Wed May 09, 2007 9:15 pm

Another Thai based German site to the forefront:

http://www.siamgpi.com provides answers - in perfect English of course - to almost all technical topics concerning underfloor stuff, and other heating and cooling solutions particularly when combined with environmentally friendly and cost saving energy sources.
How to build a $20,000 / £14,000 house and a $???? MOTEL Updated 21 March 09 - with BOQ and costs
Don't let this happen in YOUR house.
jazzman
 
Posts: 2161
Joined: Wed Dec 06, 2006 9:11 pm
Location: Thailand

Postby grant » Fri May 25, 2007 9:22 am

The condensation can be addressed by installing some of the cooling matts along a wall inside a thin enclosure which allows condensation to occur and drain away. This will create a natural air flow of warm moist air into the top of the enclosure and cool dry air out the bottom resulting in a lowering of the realtive humidity in the room. Additional cooling matts in the ceiling can then be used to cool the room down further with the wtaer temperature controlled by a sensor that measures the humidity in the room to prevent condensation from collecting on the celing. Condensation collectors or valences can also be ceiling mounted. I am considering such a system for my home.
grant
 
Posts: 145
Joined: Sat Apr 21, 2007 3:48 pm
Location: Phuket

Postby Vansana » Sun Jun 03, 2007 10:57 am

Hi,
anybody looked into Geothermal heat pumps in combination with a borehole for cooling?
In Europe this works very well with heating, so it might do a good job with cooling as well.
Vansana
 
Posts: 23
Joined: Sat Feb 24, 2007 9:41 pm

Postby grant » Sun Jun 03, 2007 11:11 am

Vansana wrote:Hi,
anybody looked into Geothermal heat pumps in combination with a borehole for cooling?
In Europe this works very well with heating, so it might do a good job with cooling as well.


Vansana,

There is a company in Bangkok called BigRed Energy (http://www.bigredenergy.com) that markets heat pumps. Not sure if they have similar experience in Thailand for cooling. I'm also not sure if the below ground temperature in Thailand is cool enough to provide sufficient cooling. These are some issues I am looking into for my own villa.
grant
 
Posts: 145
Joined: Sat Apr 21, 2007 3:48 pm
Location: Phuket

Postby Vansana » Sun Jun 03, 2007 12:12 pm

.....it works well with a water temperatur in the bore of 12 degree. If the borehole is deep enought it should be ok.
About one liter/sec waterflow is required.

The only problem might be humidity i guess, so maybe a additional dehumidifier is required.

Van
Vansana
 
Posts: 23
Joined: Sat Feb 24, 2007 9:41 pm


Return to cooling systems

Who is online

Users browsing this forum: No registered users and 1 guest