General
1. How does a geothermal system work? |
| The earth naturally absorbs 50% of the Sun’s energy and stores it as clean renewable energy, thus the temperature in the earth remains constant throughout the entire year. In Palestine and Jordan, for example, the temperature in the earth is at a constant 17 degrees Celsius throughout the entire year. In the winter, the 17 degrees constant ground temperature is warmer than the 4 degrees outside air, thus by pumping water into a system of pipe installed deep in the earth, we can absorb heat from the warmer ground, channel it to an electrically powered geothermal heat pump, which takes the heat, compresses it and outputs it to the building at 45C. In the summer the same exact system is simply reversed. The 17 degrees constant temperature in the ground is now cooler than the 36C outside hot air, thus we take the buildings heat, returning chilled water to the building, and reject the buildings heat down to the cooler earth. |
2. What makes a geothermal system different from conventional systems? |
| A geothermal system utilizes the energy stored in the earth, to heat and cool homes and buildings. Electricity is used only to operate the heat-pump unit and circulation pump which are required to facilitate the heat transfer between the building and the earth. So, unlike conventional systems, geothermal systems do not burn fossil fuel to generate heat--they simply transfer heat to and from the earth. |
3. How efficient is a geothermal system and what are the savings? |
|
A geothermal system is more than three times as efficient as the most efficient conventional system. Because geothermal systems do not burn combustible fuel to make heat, they provide three to four units of energy for every one unit used to power the system. When compared to diesel or gas boilers for heating, geothermal systems save 70% on energy consumption. When compared to chillers or mini-split units cooling units, geothermal system save roughly 55% on energy consumption.
According to the U.S. Environment Protection Agency geothermal system are “the most energy efficient, environmentally friendly, cost-effective space conditioning systems available”.
4.What are the benefits of a geothermal system?
Lower Operating Costs: A geothermal system operates more efficiently than ordinary heating and air conditioning systems - up to 70%.
Comfortable: Because the unit uses the relatively stable temperature of the earth as an energy source, you are assured of constant, even winter heating and better humidity control in the summer.
Safe and Clean: No flame, no fuel, no odors, just safe reliable operation year after year.
Flexibility: The same heat pump unit can provide heating, central air conditioning and hot water.
Economical Water Heating: Water heating can be a significant energy expense. Geothermal heat pump units can reduce the high cost of water heating by as much as 66%.
Attractive: The completely self-contained indoor unit needs no noisy, unsightly outside condensing unit.
Environment: The system emits no carbon dioxide, which is considered a major contributor to environmental air pollution.
Long Life: Geothermal heat pumps have a long service of around 20 years and geothermal ground loops are guaranteed to last over 50 years.
|
5. What does geothermal mean to the environment? |
| Because geothermal systems work with nature, not against it, they minimize the threats of acid rain, air pollution and the greenhouse effect. Geothermal systems are completely environmentally friendly. An environmentally friendly refrigerant is used inside the heat-pump. |
6. Do geothermal systems require much maintenance? |
|
No. In fact, geothermal systems are practically maintenance free. When installed properly, the buried ground loop will last for generations. And the other half of the operation--the heat-pump unit’s fan, compressor and pump--is housed indoors, protected from the harsh weather conditions. Usually, periodic checks and filter changes are the only required maintenance for water-to-air heat-pump units.
7. Are geothermal systems installed in new constructions only or can they be installed in existing buildings?
Geothermal systems can be installed in new construction or existing building. Of course, with new constructions, geothermal system will cost less as parts of the ground where the ground -loop will be drilled will already be excavated. Geothermal system can be installed in existing buildings by replacing the old system – such an installed is called a retro-fit installation.
|
| [Top]
Questions about a geothermal heating/cooling system
1. What is the capacity (size) of the heating and cooling system that is being proposed?
|
| Heating and cooling units are designed to provide or reject specific amounts of heat energy per hour. The terms "BTUH", or “kW/h” or “tons of refrigeration” refers to how much heat can be produced or rejected by the unit in an hour. Before you can determine what size heating/cooling unit, you must have a heat loss/heat gain calculation done on the building or home. From that, an accurate determination can be made on the size of the heating/cooling system you’ll need. Most conventional systems are substantially oversized for heating/cooling requirements, resulting in increased operating cost. |
2. Is the efficiency rating on heating and cooling equipment actual or just a manufacturer’s average? |
|
All types of heating and cooling systems have a rated efficiency. Fossil fuel furnaces have a percentage efficiency rating. Natural gas, propane and fuel oil furnaces have efficiency ratings based on laboratory conditions.
Geothermal heat pumps, as well as all other types of heat pumps, have efficiencies rated according to their coefficient of performance or COP. A COP is a ratio between the energy consumed by the system and the energy produced by the system. Most geothermal heat pump systems have COPs of 3.5 - 4.5. That means for every one unit of energy used to power the system, three and one-half to four and one-half units are supplied as energy. Where a fossil fuel furnace may be 50-90 percent efficient, a geothermal heat pump is about 400 percent efficient. Some geothermal heat pump manufacturers and electric utilities use computers to accurately determine the operating efficiency of a system for your home or building. |
3. Is MENA Geothermal qualified to design and install geothermal systems? |
| Yes. MENA Geothermal engineers have over 15 years of experience in the design and installation of HVAC mechanical systems. Furthermore, MENA employs the only engineers certified as Accredited Installers by the International Ground Source Heat Pump Association (IGSHPA), and as Commercial Geothermal Designers by the Canadian GeoExchange Coalition (CGC) in the Middle East and North Africa Region. MENA’s engineers are graduates from the world’s most accredited engineering programs including the University of Waterloo in Canada. |
4. How long is the payback period for your geothermal heat pump system? |
| To figure this accurately, you must know how much per year you’ll save in energy costs with a geothermal system in comparison with a conventional heating system and central air conditioner. To calculate your return on investment (payback in number of years), divide the annual savings into the additional investment . In Palestine and Jordan for example, the payback period on a geothermal system is roughly 5 – 7 years. When you install a geothermal system in a new home, the monthly savings in operating costs will generally offset the additional monthly cost in the mortgage, resulting in a monthly positive cash flow immediately. Keep in mind that energy savings is only one of the many benefits you receive from a geothermal system |
5. If a home has a radiator distribution system, do air ducts need to be installed? |
| Not always. It may be desirable to install geothermal heat pump room units. For some small homes, one room unit would provide most of the heating and cooling needs. Radiator units could then be used for supplemental heat.. |
| [Top] |
| |
| |
| |
| |
| |
|
Heat Pumps: What are they and how do they work?
1. What is a geothermal heat pump?
|
| A geothermal heat pump is an electrically-powered device that uses the natural heat storage ability of the earth and/or the earth’s groundwater to heat and cool your home or business. |
2. How does it work? |
| Like any type of heat pump, it simply moves heat energy from one place to another. Your refrigerator works using the same scientific principle. By using the refrigeration process, geothermal heat pumps remove heat energy stored in the earth and/or the earth’s groundwater and transfer it indoors |
3. How is heat transferred between the earth and the home or building? |
| The earth has the ability to absorb and store heat energy. To use that stored energy, heat is extracted from the earth through a liquid medium (usually water) and is pumped to the heat pump or heat exchanger. There, the heat is absorbed by a heat-pump, compressed, and outputted at a very high temperature to heat the air. In summer, the process is reversed and indoor heat is extracted from indoors and transferred to the earth through the liquid medium. |
4. Does it do both heating and cooling? |
| One of the things that makes a geothermal heat pump so versatile is its ability to be a heating and cooling system in one. You can change from one mode to another with a simple flick of a switch on your indoor thermostat. In the cooling mode, a geothermal heat pump takes heat from indoors and transfers it to the cooler earth through an underground loop system. |
5. Do I need separate ground loops for heating and cooling? |
| No. The same loop works for both. All that happens when changing from heating to cooling, or vice versa, is that the flow of heat is reversed |
6. What types of loops are available? |
| There are two main types: open and closed. The next two sections will give you specifics about each |
7. Does the underground pipe system really work? |
|
The buried pipe, or "ground loop," is the most recent technical advancement in heat pump technology. The idea to bury pipe in the ground to gather heat energy began in the 1940s.The type of pipe that is used in the ground loop is High Density Polyethylene Plastic (HDPE) which is highly durable and guaranteed to last for many decades.
|
| [Top]
Closed-loop systems
|
