Air Handling Unit

What you are describing is an air conditioner.

The only other thing that I know of is a dehumidifier, this will remove moisture from the air. It won't make the air cooler, but it will make the air feel cooler, due to the dryness. Combine one of these with a small fan, and you should be close to the desired effect, without spending much money.

An desert cooler, and wet air cooler is a device that cools air through the evaporation of water. Evaporative cooling differs from air conditioning by refrigeration, you can also use the ALLUMINIUM ducting system from your floor lever to your hall room with PUF insulation over ducting, & this insulation will increase your efficiency, & it is much more efficient then cooling tower in industries, coz its DELTA T is much more high then cooling tower.

A swamp cooler in the Congo?

I have a bridge that I would like to offer for sale - located in San Fransisco - called the Golden Gate bridge. For a small down payment of a few million it is all yours!

I guess that's why they are called swamp coolers.

I believe the poster is requesting a low-energy device. Air conditioners and dehumidifiers take a lot of power to operate, both function pretty much the same.

The first air conditioner operated on compressing and expanding air, I believe.

A swamp cooler uses evaporating water to cool a heat exchanger. The evaporating water does not have to be vented into the house, that would raise humidity.

For a dry cool using minimum power, running water over a heat exchanger just might do the trick. The cooler side of the exchanger should condense the humidity in the house, if it gets cool enough. As the inside air gives up its humidity, it should lose it's latent heat, right?

The trick is to get the water to evaporate on the heat exchanger, not just run off. One cute trick was the butter keeper made of quarry tile ceramic, real porous stuff. As the tile absorbed and evaporated water, the butter was kept cool.

Maybe a quarry tile roof sprinkled with water would be cool.

He's just getting started. I have to admit, I like his avatar slogan.

Ah you mis-begotten person. If the air speed is increased..it has a greater cooling effect, as humidity on the skin is dried/partially evaporated.

So yes - swamp coolers in the Congo!

As a more expensive alternative..a sloping tunnel could be dug but remaining un-lined. The intake has an induction fan, which 'blows' the air toward the house, which can then be distributed as per 'normal'

If all you want is air speed then forget the cooler and just use a fan.

How well a swamp cooler works depends on the humidity - high humidity areas are last choice for this device

The tunnel ideas are green fantasy fiction - some people have even done it but there are too many things wrong, 1)rate of heat transfer, 2) bugs, 3) mildew & mold and on and on

Is your location suitable for digging down about 8 - 10 feet. Then you could suck up the cool air from the underground, and run a dehumidifier. This would be similar to a heat pump.

I have a dehumidifier in the basement of our house in Minnesota that runs all summer.

Without it, I would have standing water on the floor. Mine is connected to a drain. You might have to empty the tray periodically if you can't use a hose.

One thought:

Extractor fans at the highest points of the ceiling and vents in the floor to draw the cooler air from under the house ( assuming the house is built on stumps of course and not on a slab!).

Make the floor vents adjustable and close them in winter.

Bill

Use the air cooler which surely increase humidity, but use ceiling fans also , you will find comfort. Only air cooler will not give you the comfort level. Secondly see what you can do to the room from point of view of heat ingress. Put reflective films on windows , use reflective paints on wall. Other wise use white wash/color outside and on roof. Spray with water on outside walls and also on roof in the afternoon. Go tall trees nearby ,so that you get shade on this area. If there is an area opposite windows , then paint it black , so that sunrays falling on it make it hot and air coming in contact moves up , creating a negative pressure , if window is open facing it a nice cross ventilation you can get cooler air without any cost. Many buildings to day create dark central area in building with sunrays heating the area and creating natural ventilations in adjacent rooms. Now find out what suits you best.

The first thing to do is to make sure that heat is kept away from the house.

Extra insulation.

Reflective materials.

Shading of sun from the outside of the house.

If done well, you may not need any further cooling.

All good points Andy. Additionally -

If possible, use natural drafts to move air through the home - at least in periods that are not too hot.

The idea of using cool from the ground normally has very limited application and you have to be cautious of mold and bacteria. The heat transfer rate from the cooler soil to the warmer air is to slow to be effective without a lot of volume.

The swamp coolers work fine in hot dry areas. In hot moist areas they are of very limited value.

You could dig a shallow well of 20 feet deep, put in a 1" pipe with foot valve and using a small 12v low volume pump like is in a travel trailer, pump ground water through a conventional air handler with supply and return ducting in the hallway.

If the ground water pipe in insulated all the way to the air handler the water should still be cool enough to dry the air in the hall by condensing the moisture on the condensing unit and also to cool it.

Put the return air grill high up if the ceiling is cathedral and the return grills at 8' above the floor.

If the ceiling is flat, put the return air grille at one end of the hall which is the warmest and the return grills down the center of the hall ceiling but no closer than of thea third of the length of the hallway.

Have you considered Thermguard as an Insulation medium? Works well in summer & winter. Where do you stay?

Regards.

Neels.

An interesting possibility is solar (heat) powered absorption cooling. This system makes ice at night from solar heat collected during the day. Running a chiller off an ice reservior would be fairly simple, and the unit is designed fro construction in the developing world. It's not the simplest appraoch, but a good pioneering effort that might be very important.

http://www.energy-concepts.com/isaac

Air Handling Units: They do not cool the Air (or Heat it) by themselves. They need a media that circulate inside them via a heat Exchange unit.

Because of this, you could circulate cold water into the heat exchange unit to cool the air flowing across. Any condensation that occur on the air handler heat exchange surface does not increase the humidity since this is water removed from the air. In fact it is dehumidifying the air in a way. The relative Humidity of the air will probably remain the same or increase a little due to the cooling (lower temperature, higher saturation).

To cool the water (if you don't want to use a gas cycle compressor), you can use a cooling tower to circulate the water and cool it by evaporation. the efficiency of the system will depend on the external air condition of temperature and humidity RH%. if dry and hot, the differential temperature achieved will be higher.....

agree with you but not completely.

We need more info. Is the Hall on what floor

Also Air handler is limited in its operation to Control temp.

You have to explain where is it located, city etc. Also 600 sft is surounded by what? Is it on one side of the house, is it in the basement. Why you want to control is not possible with Air handler alone. Evaporative cooling can be done but not without knowing how long is summer season and also the occupancy.

CSIRO Australia researched a system 30 to 50 years ago which used two plenums each nearly full of rocks. In turn the rocks were wet by water sprays, the water was turned off, then outdoor air was blown over them. The evaporation chills and dries the rocks so they are then connected from and to the hall (in your case) by ducts via a fan and the hall air is chilled by circulating over the chilled rocks.

The second plenum of rocks is in the opposite mode. The timing of the phases of spray-drive pumps (which draw water from sumps with their water level maintained by float/ball valves, under the rocks so also receiving excess water from the sprays), fans and control dampers can be by time or by temperature with humidity also sensed. Since the dampers will be a major cost it may be be better to reverse air direction on the two phases and use 'non return valves' made with open bottom bags, one end sealed around the duct wall; the open end secured at, one point, with a shortrope to the duct wall.

The lower cost of control and sensing equipment since CSIRO's work now makes the system worth considering.

Look it up sometime - 1) how many m3 of stone storage, 2) how much air flow, 3) how effective etc.

You will be surprised to find the answer to be 1) lots and 2) not much and 3) not very.

Not to mention the potential for mold & mildew in the stone chamber.

GSHP units do something similar using water but there is a heat exchanger between the cooling source and the dwelling.

Think outside the box- Sell the house and buy a home on the beach in Muanda. The sea breezes will make you glad you did!

"Cool and dry"

I do not understand what you mean by "conventional air coolers"? Unless you are talking about evaporative air coolers (Swamp coolers).

All air conditioning systems will dry, as well as cool the air. The greatest mistake people make about AC is that they think it is all about cooling. It is called "Air Conditioning" for a reason. The next mistake, is the bigger the unit the better. This results in a very cool place with miserable humidity. 24deg C with 30RH is nice. 20deg C with 70RH is brutal. Lots of people move to Arizona for a reason.

The primary purpose of AC is to lower the enthalpy of the air that is being conditioned.

Get rid of the humidity with the welcome benefit of cooling the air.

Thinking outside the square,

Plant trees that will give shade and draw your ventilation air through the foliage

Hello to WAWAUS: I do appreciate you responding to me. I just kind of missed your point in this forum.

By the way : I do love trees, as I find them quite tasty.

Trees will provide shade to minimise direct solar heating and air drawn through the foliage is cooled by the foliage.

I grew up in tropical north Queensland where we had two large Mango trees in the back yard - under the trees was always 5 - 10 degrees cooler than anywhere else, and the back of the house shaded by one of the trees was always much cooler than the rest of the house.

I understand about using trees in order to reduce the cooling load. I encourage my customers to at least think about planting them.

The biggest thing is that they require a long time to grow to a suitable size to effect the heat load. Most people are not willing to wait 30-40 years for the benefit.

Where I live, it's called the greater Toronto area. This has the highest population in Canada. Every year the building lots for homes get smaller and smaller. The area around those homes are next to null. Even a sapling in their yard would take up what little space they have, not to mention a mature tree.

I understand, The councils here in Melbourne Australia are just as shortsighted - nowhere outside for kids to play among plants and in the dirt is not good for their long term health - physical, mental or social.....

I could not agree with you more. I have seen Hamsters with more space.

My house was built about 40 years ago and has a decent size yard. It is at least functional for two German Shepherds. That is if you do not mind the trampled to nothing grass, and as fall is here, and it has rained a lot, the perimeter of the yard is now just red clay mud. Did I mention the land mines that they deposit in strategic areas?

If I had the ability to leave where I am, in a heart beat I would be about 200 KM north and into the lower central section Of Ontario. I could have a very nice home and 100 acres of woods around me, and some quiet.

Alas my work requires me to be in close proximity of the densest population area.

I concur, my house and block are 1960's vintage, extensively modified, but with minimal encroachment on the block ( we went up).

I have a 15,000 litre water tank hidden down the back yard behind the garage and garden shed and solar panels on the roof (both HW and PV), no pets so there is some room for my son to kick a soccer ball without damaging the gardens too much....I enjoy a little space, more would be better, but in a city close to electronic engineering jobs it is the best we can do!

Regards
Bill

The most economical and efficient way to cool and dehumidify a home in the Congo is through geothermal transfer. This requires very little energy consumption. I will assume that since you are in the Congo, your home is on Stilts or Piles. You will need nothing more than legnths of PVC pipe, elbows and a small fan. Using the temperature of the subsoil, you can move air through these "pipes" at a slow rate, average ground temperature at a depth of 2 feet should be less than 60 degrees. The inside walls of the pvc pipe attracts the water vapor from the air like a glass of Ice Tea on your table. If the pipes are buried at a 1% grade, all the water will drain back to the inlet point and cool, dry air comes out the end entering the hall. The fan brings the air flow into the hall. To determine how much pipe is needed. The cubic area of the room should be considered instead of floor area.

Geothermal is good if you have a lot of it, pipe and temperature difference. A small heat exchanger buried in the ground can saturate the area with heat. Ground has very slow conductivity of heat, so after a while the ground gets hot and doesn't cool off for a very long time.

If you can draw water from a cold well you have a chance. Once the water has absorbed as much heat as it can, you can pump it down another well, the further away from the cold well the better. Or just let it go for irrigation.

Regarding geothermal - Some have suggested some very minimal attempts to use geothermal to cool. All are in the right direction but lightweight.

Somewhat like laying a water hose in the sun and declaring 'my home has a solar water heater'.

There is a lot of good information on the net about geothermal heating, cooling and air conditioning. The proper name should be ground linked rather than geothermal as that word really refers to hot water from down below.

Russ