New Geo-heat Exchanger Technology: Harnessing the
Power of the Earth
ir conditioning is one of the largest sources of energy consumption, leading to high energy bills and taxing the sources of energy in any given city. But what if there was a better, more natural way to harness the natural heat from underground? Utilizing that natural energy is at the core of Virtual Harmony’s newest offering.
Virtual Harmony designs and supplies air conditioning systems for buildings and agricultural applications through the use of ground source heat pump technology. The company’s latest technology centers around a new geo-heat exchanger that is installed horizontally.
The core value of this technology addresses a pain point for today’s energy consumers and suppliers. While geo-heat exchange technology has been touted as the most energy-efficient and eco-friendly approach to heating and cooling, initial cost has always gotten in the way. This company’s technology solves this problem, by enabling heat exchanging units to be close to the surface. This allows the heat to be secondarily used for snow melting and farming applications.
The US EPA says that ground source heat pumps are the most energy-efficient, environmentally clean and cost-effective space conditioning systems available today. Such pumps take advantage of the naturally occurring difference between the above-ground air temperature and the subsurface soil temperature to move cool or warm air throughout a structure, depending on the season.
Major Features and Advantages
I. Easy Installation
The new geo-heat exchanger is installed horizontally underground, about three to five meters down, using an excavator. In contrast, existing geo-heat exchangers are installed by boring machines in boreholes, about 50 to 100 meters deep. The new geo-heat exchanger is more desirable due to its heat transfer characteristics, coefficient of performance (COP), initial costs, operating costs and even long equipment life. The horizontal installation makes the whole process easier with an excavator. Sites in which the new geo-heat exchangers will be placed must meet pre-specified thermal capacity requirements.
II. Lower Initial Cost
The initial cost of the new geo-heat exchanger is 20 to 40 percent of the initial costs for existing geo-heat exchangers. Constructed from welded steel pipes, the digging process is horizontal, easily accomplished by a water contractor using a power shovel. Then, the water contractor puts the new heat exchanger in the hole. In contrast, the process to install the conventional heat exchanger requires a boring machine operated by special technical workers, which adds to the cost. In conclusion, the digging fee for the new heat exchanger is far more affordable than the digging fee for the conventional heat exchanger.
The new geo-heat exchangers are ideal for use in air conditioning and, cooling/heating systems in buildings and houses. They can also be used for systems designed to melt snow on roads or in parking lots. Additionally, they can be used in agricultural systems or as heat exchangers in thermal systems.
IV. Better Performance Rate
In fact, performance is 14 times greater than existing geo-heat exchangers, the best heat exchange performance in the world in the experiment conducted in Iwaki city of Fukushima prefecture illustrated in the graph "Temperature Raising Test by Thermal Response Test Method".
V. Energy Savings
Energy savings are high due to lower operational costs associated with the new geo-heat exchanger, stemming from 50 percent less energy consumed compared with existing geo-heat exchangers.
VI. High Product Life Cycle
The life span of the product is more than 20 years. This is due to the fact that it is buried underground and covered with concrete.
In an effort to further the prospect of renewable energy, Virtual Harmony wishes to partner with companies that locally manufacture new geo-heat exchangers under its own technical supervision. It also wants to transfer new geo-heat exchanger technologies to a partner company that will agree to manufacture and install exchangers without Virtual Harmony’s support. From lower initial cost to higher performance rates, Virtual Harmony’s geo-heat exchange technology is gaining acceptance in the industry.
Applications for the new geo-heat exchangers in renewable energy geo-exchange systems supplied by Virtual Harmony.
Through the use of an excavator, the new geo-heat exchanger is installed horizontally underground, at a depth of about three to five meters.
On the other hand, existing geo-heat exchangers are installed in boreholes, created by boring machines, at a depth of about 50 to 100 meters.
Compared to existing geo-heat exchangers, the new geo-heat exchanger has competitive advantages due to its heat transfer characteristics, coefficient of performance (COP), initial costs, operating costs, equipment life, and other features.
Sample applications for the new geo-heat exchanger are described below.
Because the new geo-heat exchanger is installed horizontally, installations are easy with an excavator. Sites for the new geo-heat exchangers must meet certain thermal capacity requirements. Ideally, users will secure a large area for the exchangers, in case large thermal capacity is required.
1. The new geo-heat exchangers can be used for air-conditioning and cooling/heating systems in buildings and houses.
Air Conditioners for Buildings and Houses
2. The new geo-heat exchangers can be used in systems for melting snow on roads or in parking lots. Systems for Melting Snow on Roads or in Parking Lots
3. The new geo-heat exchangers can be used in agricultural systems.
The New Geo-heat Exchanger in an Agricultural System
4. The geo-heat exchangers can be used as heat exchangers in thermal systems.
We have a big advantage with the cost and performance of this renewable energy business, because we have a patent for this new technology that has excellent cost performance, outstanding energy savings, simple manufacturing and easy installation all over the world.
Recorded increased temperature rise by more than 14 times compared to conventional technology under constant thermal load in the experiment conducted in Iwaki city of Fukushima prefecture illustrated in the next graph.
2. Running cost (energy savings)
About 50% of the conventional technology. Please refer to the “Performance” item.
3. Initial Cost
Less than 50% (20% to 40%) of the conventional technology. Please refer to the “Performance” item.
4. Product life cycle
More than 20 years (equivalent to a house).
Because the new heat exchanger is buried underground and covered with concrete, the life cycle of the new heat exchanger is more than 20 years. Its life is same or even longer than that of a house.
5. Easy digging by power shovels and installations by water contractors all over the world.
6. Cost Comparison
(1) For air conditioner
The initial cost of the new heat exchanger is estimated at $20,000 to $40,000 per 20kW output, including manufacturing, digging, and setting fees. The graph below shows the cost comparison to other systems. “Original ground source” on the graph is the system with the new heat exchanger.
(2) For snow melting systems
Virtual Harmony evaluated the cost of the new heat exchanger for snow melting systems. The initial and running costs of the system with the new heat exchanger for 20 years is estimated to be less than $1k per 1 m2 of snow melting area. The graph below shows the cost comparison with other systems.
*Note: Virtual Harmony made the graph; added the original data of “New Heat Exchanger” which Virtual Harmony measured and assessed to the data published by Hokkaido Regional Development Bureau of Ministry of Land, Infrastructure, Transport and Tourism, and then translated Japanese into English. “New Heat Exchanger” on the graph is the snow melting system with new heat exchanger.
1. Performance is greater than 14 times that of existing geo-heat exchangers in the experiment conducted in Iwaki city of Fukushima prefecture illustrated in the graph “Temperature Raising Test by Thermal Response Test Method”.
In temperature rise tests using thermal response testing, the temperature rise of the new geo-heat exchanger is more than 14 times that of existing geo-heat exchangers. This data represent the best heat exchange performance in the world.
*Note: Virtual Harmony made the graph based on the empirical data tested embedding the actual geo-heat exchanger in the ground (3 meters below the ground) in Iwaki city of Fukushima prefecture. As of 20 September 2018, the geo-heat exchanger had been buried and the test equipment had been also connected.
The red curve is for existing geo-heat exchangers.
The black curve is for the new geo-heat exchangers.
As shown in the graph, the new one is 14.4 times better than existing ones after eight hours under continuous heat load.
*Note: This effect result can fluctuate depending on the conditions for installation, temperature of the installed site, and so on.
2. Economic rationale based on the performance test results.
*Note: The COP fluctuates depending on a construction environment.
(1) The energy savings (operational costs) from the new geo-heat exchanger come from the 50% less energy that is consumed than with existing geo-heat exchangers.
Virtual Harmony rates the Coefficient of Performance (COP) for the new geo-heat exchanger connected to a heat pump, while referring to the COP graph.
*Note: Virtual Harmony referred to the graph made by NIPPON PMAC CO., LTD. with permission of NIPPON PMAC CO., LTD.
According to Mr. Hisao Yamanobe (President of Virtual Harmony Ltd.), “Virtual Harmony estimated the COP of the cooling system with the new geo-heat exchanger connected to the heat pump, based on the COP graph of a heat pump air conditioning system by Japan PMAC.
Because the temperature in the ground differs slightly depending on the region, here, Virtual Harmony estimated the COP for cooling in Japan. In Japan, the underground temperature is generally said to be 15 °C. The temperature in the ground is 15 °C in the beginning of operation, and so the temperature of the circulating fluid going to the heat pump is 15 °C. It can be said that the temperature of the circulating fluid corresponds to the water temperature in the graph above.
According to the demonstration test with the new heat exchanger, the temperature of the circulating fluid rose by about 5 °C after operation for 8 hours, raising the temperature to 20 ° C. If we estimate the COP based on the Japan PMAC’s air conditioning system from these temperatures, we can see from the COP curve that at rated frequency operation, the COP of the heat pump is calculated to be 11.6 on average (average of COP14.2 at the beginning of operation with water temperature at 15 °C and COP8.9 after 8 hours of operation with water temperature at 20 °C).
It has been shown by the demonstration test that the temperature rise of the circulating fluid is very limited and slow with the new heat exchanger.
When the temperature rise of the circulating fluid going through the heat exchanger is limited, it is possible to operate the heat pump with less energy (at low frequency). This is because the heat pump does not need to spend the extra energy to raise the temperature of the circulating liquid rapidly.
If we look at the COP curve at minimum frequency operation, the COP of the heat pump is calculated to be 14.1 on average (average of COP16.0 at the beginning of the operation with water temperature at 15 °C and COP12.2 after 8 hours of operation with water temperature at 20 °C).
With the conventional geo-heat exchanger, it is said that they are generally operated at 32 °C to 35 °C, with a COP of less than 5, usually around 3 to 4. We expect that the COP with the new geo-heat exchanger can be twice that of the COP with the conventional geo-heat exchanger. Therefore, the operating cost with the new geo-heat exchanger can be calculated to be less than 50% compared with the conventional geo-heat exchanger.
However, in tropical areas, the ground temperature is higher than in Japan, and thus the COP will be lower than in Japan as the graph above. Also, the outside air temperature exceeds 35 °C, which exceeds the heat pump usage range and is also different from the condition assumed in the above graph. In this case, it can be expected that the COP will be considerably lower than 3. In tropical areas, we need to consider this factor.”
This technology is state of the art.
The New Energy and Industrial Technology Development Organization (NEDO) and Iwaki City supported Virtual Harmony from 2014 to 2016, and Virtual Harmony invented the new ground source heat exchanger in 2016. NEDO’s evaluation committee determined in 2016 that the new heat exchanger was technically reasonable. The patent for the new heat exchanger was registered in Japan in 2017 (Registration No.: 6170228) and Virtual Harmony has applied for international patents.
One university in Tokyo was interested in the new heat exchanger. Last year, the university bought the new heat exchanger to research and develop the ground source technology by the new heat exchanger, because the university has confidence that the new heat exchanger’s technology is simple and authentic, and that testing the heat exchanger doesn’t require much cost. The university understands that the technology of the new heat exchanger holds the possibility of bringing society to a post-carbon stage. The university believes that people/everyone around the world will be able to understand it and implement it easily.
Leakage from the new heat exchanger while operating the ground source system, caused by manufacturing error in welding or machining, etc. The new heat exchanger needs a leakage test by air.
2. Poor performance
Poor performance of the heat exchanger caused by installation error. The installation of the new heat exchanger needs to be managed and controlled.
Information on patent related to this technology
Registration number 6170228 in Japan
|Name||Virtual Harmony Ltd.|
|Address||4-1 Suwacho, Onahama, Iwaki, Fukushima 971-8161 Japan|
JPY 10,000,000 (As of May 2nd, 2006)
|Number of employees||2 (As of April 1st, 2010)|
|Date of company foundation||
April 8th, 1973
|The type of business||
Number of employees for international operation
City , Country
Name of company (if applicable)
Modality of business transaction
Virtual Harmony would like to enter into a partnership agreement with a company that will locally manufacture new geo-heat exchangers under our technical supervision. In the near future, Virtual Harmony desires to transfer new geo-heat exchanger technologies to a partner country that will manufacture and install exchangers without our support.
Licensing of patent
- Virtual Harmony has the patent for a new geo-heat exchanger, which is a renewable source energy. Virtual Harmony offers companies all over the world exclusive regional licenses for the patent and related technologies for the new geo-heat exchanger.
The existing patent is registered in Japan, and the company has applied for international patents.
- Virtual Harmony is looking for licensees that will design and manufacture new geo-heat exchangers, then install them underground by themselves, with the technical support that Virtual Harmony offers. Finally, licensees should conduct their ground source heat pump businesses and lead economic development in their countries.
Licensees and Virtual Harmony will collaborate on the ground source heat pump business and take on the challenge of building a post-carbon society together.
Schematic illustration of the technology
The patent for the new heat exchanger is based on the most orthodox heat transfer engineering theory. Theory says that, to increase thermal energy, thermal conductivity should be greater and the heat transfer area should be larger.
- To make thermal conductivity greater
The new patented heat exchangers are made from welded steel pipes. Conventional heat exchangers are made from polyethylene. The thermal conductivity of steel is about 60 times greater than the thermal conductivity of polyethylene.
- To make the new heat transfer area larger
The diameter of the new heat exchanger is more than 500mm. This is larger than the conventional heat exchanger, with a diameter of 34mm. On the area of heat transfer, the new heat exchanger is more than 10 times larger than the conventional heat exchanger.
- Other techniques
The new heat exchangers are laid horizontally, 3m to 5m deep, underground. The conventional heat exchangers are installed in boreholes. Horizontal digging is much cheaper than the boring needed for the conventional heat exchanger.
The new patented heat exchangers are set slightly inclined to the horizontal. The effect produces convection within the new heat exchangers.
The improvement is shown in the table below.
Table The improvement of the new heat exchanger compared with the conventional heat exchanger.
The new heat exchanger is steel. The new exchanger is bigger than the conventional one. The thermal conductivity and heat transfer area are improved.
The new exchanger has the inlet pipe and outlet pipe shifted from centerline of the flange and is laid at an incline.
This has the effect of increasing thermal transfer by convection effect and turbulence effect.
The new heat exchanger is covered with concrete.
This has the effect of decreasing thermal resistance.
★ The Procedure Is Very Simple
1. Design a heat exchanger according to customers’ required thermal energy.
2. Manufacture the heat exchanger at ironworks in town.
3. Dig horizontally to a depth of 3m to 5m underground with a power shovel. A water contractor can do this easily.
4. Set the heat exchanger in the hole dug by a power contractor.
5. A power contractor covers the hole surrounding the heat exchanger with concrete.
6. A power contractor covers the hole with sand.
7. A power contractor connects it to heat pump with piping.
★ Simple Technology
- The new heat exchanger has a very simple structure that anyone can easily understand.
- The principal theory of the new heat exchanger is based on orthodox theory that university students can easily understand.
- The structure is simple, so everyone can understand/develop the ground source system with the new heat exchanger.
4. Non-high-tech companies can conduct a ground source business, manufacturing heat
exchangers and installing them by themselves without high-tech capabilities. This business can be
undertaken in developing countries, which will develop their economies.
★ Preferable for Cooling Air Condition in Warm Countries
- On the COP of the heat pump, Cooling COP = Warming COP － 1.
This means that cooling is worse than warming on the heat pump.
- The temperature in warm countries is higher than 30℃. So the COP with conventional heat exchangers is estimated at lower than 3 or 2. The current COP is not preferable in warm countries at the present time.
- When the new heat exchanger is applied in warm countries, COP of 6 can be expected. If COP can be improved from 3 to 6, the energy savings will be 50%. The effect of this energy saving is huge.
*Please mention that you saw UNIDO's website when making the first contact with the company.
- Low carbon & energy conservation : Renewable energy