View Full Version : free cooling issue

16-05-2006, 01:21 AM
Hi sirs,
As we all know, oil price rises rapidly and it should keep going.
Comfort AC consumes too much energy, if we can innovate our residence type,maybe we can find the way out,for example, can we build the house underground which is close to the annual average temp and save much energy for keep same comfort. Is it feasible ,how do u think?:p .Hope u give your ideas:)

best regards

US Iceman
16-05-2006, 04:26 AM
An interesting topic.

Houses built into the side of a hill or buried on three sides (+ the roof) offers a very sustainable & green (environmentally clean and low impact) design.

Several considerations come to mind:

1) Use insulated & poured concrete for high mass building structure to retard heat flow.
2) Enhanced ventilation system will be required for humidity control and fresh air makeup.
3) The use of natural lighting through skylights will provide a more open feeling.
4) Radiant floor heating would probably be the best to prevent cold floor syndrome.
5) A GSHP could provide very economical cooling and heating with a very reduced capacity system.

Here is some additional information:




For those that could not fathom living underground I could also suggest the use of poured concrete walls above ground. The walls could be prefabricated using insulated wall panels where the concrete is poured into the wall sections. No metal forms are used in this process. The insulated wall sections are the forms.

The concrete walls offer high mass and low heat transmission and could be built to withstand hurricane force winds or possibly even earthquake resistant.

Here are several links:


16-05-2006, 06:26 AM
I'm member of an organisation (Dutsch speaking) translated 'Passive house building'
They use the German software PHPP which I bought some years ago to calculate most parameters for building a house.
Do once a search on Passive house building.

I visited several houses but they're not so cheap to build
Isolation (PU) of 30 cm (1 foot PU) in the walls and roof, 3 double glazing, special ventilation system with heat reclaim (a forced ventilation system in every home is now an obligation in new houses in Belgium), cooling the house wit plastic pipe (large diameter) burried in the ground, rainwater reclaim, now windows at the north side (for the northern hemisphere of course :) ),...

A little bit further is a house with zero nergy.
Also, do once a search on 'Zero energy housing or building.
But this implements also a special way of living.

16-05-2006, 06:58 AM
It is also possible to use a Geothermal heat pump for circulating water or brine in the underground and get free cooling at a temperature of 18C in summer.

17-05-2006, 02:06 AM
what type terminal you use? cooling panel or other?


17-05-2006, 06:51 AM
5) A GSHP could provide very economical cooling and heating with a very reduced capacity system.

what's about the research of GSHP, does that integrates Geothermal heat pump with solar absorption system? although it can achieve energy saving, the invest is too expensive. hope for reply..
ur sincerely

17-05-2006, 02:46 PM
To expensive...depends on which energy-source you compare it and what price you have to pay for another energy source, price you will have to pay in the future, heating days/year,...
If it was so uneconomical, why so many GSHP are installed in Austria (+/- 70 % of the new home heatin gsystems) Switzerland, Denmark, Sweden, the Netherlands?

Why the US Army renovated more than 4000 homes on 1site with GSHP's?

17-05-2006, 03:29 PM
Well, Peter, people use to think in term of capital expenditure, and not long term savings and long view thinking. This is why GHP or GSHP seem expensive.
Then, when oil will be over...

US Iceman
17-05-2006, 09:03 PM
If you look at underground homes the earth temperature will moderate the heating and cooling required for the home.

If this was combined with a GSHP the capacity of the GSHP would be very small I believe. In addition, if a radiant floor system were to be used the installed costs could offset the total cost of a conventional HVAC system.

I think this has some merit, but it will take some out of the box thinking to present a cost effective solution.

I think the tricky part is convincing people to look at the long operational costs (total cost of ownership) versus the first time cost using conventional equipment.

If we wait until the oil is gone it will be too late.:(

18-05-2006, 01:51 AM
If we wait until the oil is gone it will be too late.
Agree. House building tech affect the energy consuming very largely . I wonder how to apply GSHP for apartment (main residence type in China). If there's feasible ways, it should be a big business:)

best regards

18-05-2006, 06:31 AM
I saw in the Netherlands a central GSHP (ground/water) which served several houses (+/- 10 houses/GSHP), so you can do this also with an apartment.

18-05-2006, 08:23 AM
I mean it's better to combine the ground source with building constructions.No need for taking large area of land. Is there mature application ways?


18-05-2006, 09:27 AM
More than mature. But consultants and architects are still on payroll of boilers and oil burners manufacturers

US Iceman
18-05-2006, 02:45 PM
If you are using a GSHP then you will need some land area whether you are using bore-holes or ground loops. You also need to be aware of the underground water movement as this can transfer a lot of heat.

The spacing of bore-holes and ground loops is dependent on the soils ability to transfer heat. If the spacing is too close you can create hot spots in the ground when dumping heat to the soil over a long time.

There are a lot of papers written on this (most are from the Netherlands as they seem to be pushing this technology).

On the other hand, if the building heating and cooling loads are such that you can cool the interior core of the building when simultaneous cooling is needed on the perimeter, you can use a water-source heat pump to transfer heat from one area to another without the ground.

I think the biggest roadblock to using a different technology is that people have to think. You cannot just assume something will work. The only limit to getting this done is imagination and good engineering practices. (Oh yes, money and emotions too :D )

19-05-2006, 09:09 AM
yeah,GSHP surely takes some land. I imagine to use building's base working with borehole hx. No need much extra land area:) I've heard this concept,but not seen related practices. Anyone knows it?
BTW,GSHP initial cost is more than 2 times as air source HP in our country, is there any comparison in your place? How to confirm the advantage of GSHP?

best regards

19-05-2006, 03:52 PM
In my neck of the woods (southern Indiana,USA) when GSHP is applied to a house on a small lot we drill verical runs. Depending on soil type, water table, etc, the depth can be anywhere between 125' to 250'. We will use one run per ton.

Something to consider when looking at the possibilty of a earth-bermed or underground house is finding a financial institution that will loan money against one.

I haven't investigated the mortgage situation lately so I don't know if things are any better. A decade ago banks did not want anything to do with earth construction. They probably felt that type house would be hard to resale.

Best regards...

20-05-2006, 09:13 AM
Dear Lc Shi
A smart answer for apartment houses will be (TAC)Task Ambience Conditioner.It is system conisting of a miniature AC/heat pump with controls suitable for cooling/heating the bed volume ( 2x 2.2x1.2M) instead of the(5x3x3M) whole room and the connected mass.The bed need to have an old faishoned canopy with a little insulation.
Cooling and heating system can run on a battery during nights and the battery gets charged during the day with a 500 watt solar panel/electric power.
I am doing the design for a TAC for an Asian client .I will be glad to answer specific questions if any

22-05-2006, 01:04 AM
Hi Darshi
What you mentioned is interesting:) The system includes TAC and the special bed. I'm not sure how about the real application. Pls tell us more:)

best regards

17-06-2006, 04:18 AM
Dear Lc Shi,
The applications are for low energy and sustainable cooling in remote communities. The refrigerator compressors are most energy efficient and reliable, field proven components. Soon we are talking about refrigerators consuming one kW per day.
The product is aimed at small income families, bachelors, hostels, and Hospital beds especially for burn wards, tourist camps and many more
You could expand on that.
Imagine the market in countries like china and India.
Do you think we could collaborate on the project? You get it produced in China and I will find the markets.
Let me know if you or your company is interested to manufacture.
I am game.

18-06-2006, 02:02 AM
In Coober Pedy Australia where opals are mined there are many "houses" built underground to escape the heat of the day.

03-07-2007, 12:38 AM
search on the internet for icy ball. That will answer your queries

04-07-2007, 11:31 PM
In Holland we are building a lot of these systems, even on large buildings. We just build one for the new library in Amsterdam using 4 watercooled screws and two wells.
During summer time we provide cool water and put the heat extracted back in the ground. In winter it's reversed and we heat the building.

I even have one at home i use to preheat the water and heat the garage and house in winter and use the cold leaving water during summer to cool! Works very well!

I have a heater (Remeha Quinta 35c) installed after the heat pump boiler to get the water to 70 dgr C and reduce it to 58 at the taps to ensure all bacteria are dead and for back-up if the heat pump fails!

It's true a lot of research is done in Holland, but still a lot of people won't "burn" there hands on one since it's difficult getting it to work the way it should. There's much fine tuning needed after installation and getting the wells to load and unload in a good fashion!

Futhermore the government is keeping a close eye on these systems since there are laws about how much energy one can drain and put back!

Holland is a country of laws and laws to enforce laws!

05-07-2007, 07:22 AM
Interesting Sanderh.
But your country is encouraging at least this way of environmentally heating.
This can't be said from Belgium.

Regarding the wells, it's also regulated in Belgium but not to protect or reduce the energy one can draw out of a well but to prevent that the underneath waterlayers are disturbed.

Are you pumping in summer the cold water direct through your house or is it the HP which makes cold water for the house with a ground-well cooled condenser?

I played with the idea of pumping in summer only the cold water through coils and then not use the compressor, this all connected to a closed vertical loop system in copper.

05-07-2007, 04:50 PM
well i have two wells. One is closed circuit (tubes in the well) and used for the heat pump. the leaving water i can direct to the house and garage for cooling and then back to the well. The orther i use if the primary well gets to cold and for watering the lawn and grassland for the horse!

05-07-2007, 09:57 PM
I played with the idea of pumping in summer only the cold water through coils and then not use the compressor, this all connected to a closed vertical loop system in copper.

Is a good option. My well will deliver between 10 and 12 degrees C. But I prefer using PE pipes because the water, at least where I live, contains a lot of iron and could potentially cause problems on copper pipes.

I use the 3-layered alu-pex for all the transport pipes and a single, harder one, in the well. The single one has a low heat resistance and the triple one a high one and is better suited for all the lines in the ground since it's more tough!

17-07-2007, 11:16 AM
My well will deliver between 10 and 12 degrees C.

Can some one help in finding the underground water temperatures in Asia.
I have tried with many organizations such Geo physical research institutes,Geological survey etc. any leads?
Where does the information in Holland flow from?
any help is welcome:confused:

17-07-2007, 03:44 PM
Can some one help in finding the underground water temperatures in Asia.
I have tried with many organizations such Geo physical research institutes,Geological survey etc. any leads?
Where does the information in Holland flow from?
any help is welcome:confused:

From the ones making the wells, they now best! (usually!)