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A: 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 to the home. Top

Q: How is heat transferred between the earth and home?
A: 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 (groundwater or an anti-freeze solution) and is pumped to the heat pump or heat exchanger. There, the heat is used to heat your home. In summer the process is reversed and indoor heat is extracted from your home and transferred to the earth through the liquid. Top

Q: How much does Geothermal cost?

A: The cost of a geothermal system varies from project to project. Every home is different and there are several key factors that determine the cost. These include size of the home, size and type of windows, direction the home faces, location of the well field, type of loop system, duct work, insulation type, new construction or retro fit. We use software to calculate a Manual J heat load. That is how we properly size the equipment. Top

Q: What does a system like this cost?
A: A system for the typical home will cost more than if you bought a separate furnace and central air-conditioning system. But you wouldn't really be comparing apples to apples. To get an accurate comparison of costs you need to consider the following:
· Payback, or how long it takes to recover the difference in costs between the two systems using energy savings. Payback for most geothermal heat-pump systems runs two to six years.
· Energy efficiency of the two systems. To get an accurate picture, make sure efficiency claims are substantiated. Your lifestyle and how well your home is insulated affect how economical a system will be.
· Total operating savings from heating, cooling and domestic hot water must be combined to get an accurate picture of total energy savings.
· Energy costs and availability, both present and future.
· Maintenance costs and system reliability.
· System lifespan. Top

Q: I have a 2400 square foot home, what kind of system do I need?

A: Again, every home is different and there are several factors we use to determine a Manual J heat load. These factors include direction the home faces, size and type of windows, size of home, finished basement, and insulation type. After calculating the heat load, we can determine the size of the equipment to install. This will tell us how much loop to put in and how to determine the cost of the system. Top

Q: Can a geothermal system be retrofit?

A: Yes. The process is similar to new construction in several ways. First, we still calculate an accurate heat load using Manual J. Second, we correctly size the equipment to meet the home’s needs. The last part is analyzing the current duct work, including the cold air returns. Loops are put into the ground and brought into the house, the same as a new construction project. The geothermal unit will replace the current furnace and air conditioning units. Top

Q: You mentioned heating and cooling. Does it do both?
A: One of the things that makes a 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 either groundwater or an underground loop system. Top

Q: What types of loops are available?
A: There are two main types: open and closed. Top

Q: Who installs the loops?

A: Morrell Company installs the loops. In fact, we are the only geothermal installer in the Des Moines area that is both a licensed mechanical contractor as well as a licensed well contractor. This means that at Morrell Company, we see a project through from start to finish without any sub-contracting. Top

Q: What is a closed-loop system?
A: The term "closed-loop" is used to describe a geothermal heat pump system that uses a continuous loop of special buried plastic pipe as a heat exchanger. The pipe is connected to the indoor heat pump to form a sealed, underground loop through which an antifreeze solution is circulated. Unlike an open-loop system that consumes water from a well, a closed-loop system recirculates its heat transferring solution in pressurized pipe. Top

Q: Where can this loop be located?
A: That depends on land availability and terrain. Most closed-loops are trenched horizontally in yards adjacent to the home. But any area near a home or business with appropriate soil conditions and adequate square footage will work. Top

Q: What is a geothermal heat pump?
A: 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. Top

Q: Do I need separate ground loops for heating and cooling?
A: 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. Top

Q: Does the underground pipe system really work?
A: 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. But it's only been in the last few years that new heat pump designs and improved pipe materials have been combined to make geothermal heat pumps the most efficient heating and cooling systems available. Top

Q: How deep and long will my trenches be?
A: Trenches are normally four to six feet deep and up to 400 feet long, depending on how many pipes are in a trench. One of the advantages of a horizontal loop system is being able to lay the trenches according to the shape of the land. As a rule of thumb, 500-600 feet of pipe is required per ton of system capacity. A well -insulated, 2,000-square-foot home would need about a three-ton system with 1,500-1,800 feet of pipe.

Horizontal Loops
These are often considered when adequate land surface is available. Pipes are placed in trenches that range in length from 100 to 400 feet. Top

Q: How many pipes are in a trench?
A: Normally, a run of pipe is laid at five feet then looped back over itself at three feet once the bottom pipe is covered with soil. This allows more length of pipe to be put in one trench and has no adverse affect on system efficiency. Other loop designs use four or six pipes and allow for shorter trenches if land area is limited. Top

Q: What if I don't have enough room for a horizontal loop?
A: Closed-loop systems can also be vertical. Holes are bored to about 175-225 feet per ton of heat pump capacity. U-shaped loops of pipe are inserted in the holes. The holes are then backfilled with bentonite grout.

Vertical Loops
These are the ideal choice when available land surface is limited. Drilling equipment is used to bore small-diameter holes from 75 to 300 feet deep. Top

Q: How long will the loop pipe last?
A: Closed-loop systems should only be installed using high-density polyethylene pipe. Properly installed, these pipes will out last the home. They are inert to chemicals normally found in soil and have good heat conducting properties. PVC pipe should not be used under any circumstances. Top

Q: What if my loop leaks?

A: A properly installed loop won’t leak. At Morrell Company, we use heat fusion on all of our joints. High-grade materials such as polyethylene pipe are a Morrell standard. Polyethylene pipe has a 50-year manufacturer’s warranty as well as a 100-year ground life. Top

Q: Will an earth loop affect my lawn or landscape?
A: No. Research has proven that loops have no adverse effect on grass, trees or shrubs. Most horizontal loop installations use trenches about six inches wide. This, of course, will leave temporary bare areas that can be restored with grass seed or sod. Vertical loops require little space and result in minimal lawn damage. Top

Q: Can I reclaim heat from my septic system disposal field?
A: No. An earth loop will reach temperatures below freezing during extreme conditions and may freeze your septic system. Such usage is banned in many areas. Top

Q: If the loop falls below freezing, will it hurt the system?
A: No. The antifreeze solution in the loop will keep it from freezing down to about 10 degrees F. Three types of antifreeze solution are acceptable: propylene glycol, calcium chloride and methyl alcohol. Top

Q: Can I install an earth loop myself?
A: It's not recommended. In addition to thermal fusion of the pipe, good earth-to-coil contact is very important for successful loop operation. Nonprofessional installations may result in less than optimum system performance. Top

Q: I have a pond near my home. Can I put a loop in it?
A: Yes, if it's deep enough and large enough. A minimum of six feet in depth at its lowest level during the year is needed for a pond to be considered. In pond loops, copper, polyethylene or polybutylene pipe can be used.

Pond (Lake) Loops
These are very economical to install when a body of water is available, because excavation costs are virtually eliminated. Coils of pipe are simply placed on the bottom of the pond or lake. Top

Q: What do I do with the discharge water?
A: There are a number of ways to dispose of water after it has passed through the heat pump. The open discharge method is the easiest and least expensive. Open discharge simply involves releasing the water into a stream, river, lake, pond, ditch or drainage tile. Obviously, one of these alternatives must be readily available and must possess the capacity to accept the amount of water used by the heat pump before open discharge is feasible.

A second means of water discharge is the return well. A return well is a second well bore that returns the water to the ground aquifer. A return well must have enough capacity to dispose of the water passed through the heat pump. A new return well should be installed by a qualified well driller. Likewise, a professional should test the capacity of an existing well before it is used as a return.Top

Q: What Is an open-loop system?
A: The term "open-loop" is commonly used to describe a geothermal heat pump system that uses groundwater from a conventional well as a heat source. The groundwater is pumped into the heat pump unit where heat is extracted, then the water is disposed of in an appropriate manner. Since groundwater is a relatively constant temperature year-round, it is an excellent heat source.

Open loops
These use groundwater as a direct energy source. In ideal conditions, an open-loop application can be the most economical type of geothermal system. Top

Q: How much groundwater does an open-loop system need?
A: Geothermal heat pumps used in open-loop systems need differing amounts of water depending on the size of the unit and the manufacturer's specifications. The water requirement of a specific model is usually expressed in gallons per minute (gpm) and is listed in the specifications for that unit. Your heating con-tractor should be able to provide this information. Generally, the average system will use 6-10 gpm while operating.

Your well and pump combination should be large enough to sup-ply the water needed by the heat pump in addition to your domestic water requirements. You will probably deed to enlarge your pressure tank or modify your plumbing to supply adequate water to the heat pump. Top

Q: What problems can be caused by poor water quality?
A: Poor water quality can cause serious problems in open-loop systems. Your water should be tested for hardness, acidity and iron content before a heat pump is installed. Your contractor or equipment manufacturer can tell you what level of water quality is acceptable.

Mineral deposits can build up inside the heat pump's heat ex-changer. Sometimes a periodic cleaning with a mild acid solution is all that's needed to remove the build-up.

Impurities, particularly iron, can eventually clog a return well. If your water has a high iron content you should be sure that the discharge water is not aerated before it's injected into a return well.

Finally, you should opt against using water from a spring, pond, lake or river as a source for your heat pump system unless it's proven to be free of excessive particles and organic matter. They can clog a heat pump system and make it inoperable in a short time. Top

Q: Does an open-loop system cause environmental damage?
A: No. They are pollution free. The heat pump merely removes heat from or adds heat to the water. No pollutants are added whatsoever. The only change in the water returned to the environment is a slight increase or decrease in temperature.

Some people are concerned that open-loop systems contribute to the depletion of our ground water resources. This issue is not critical in some parts of North America because of abundant supplies of groundwater. Top

Q: Are there any laws that apply to open-loop installations?
A: In some localities, all or parts of the installation may be subject to local ordinances, codes, covenants or licensing requirements. Check with local authorities to determine if any restrictions apply in your area. Top

Q: Are all geothermal heat pumps alike?
A: No. There are different kinds of geothermal heat pumps designed for specific applications. Many geothermal heat pumps, for example, are intended for use only with higher temperature ground water encountered in open-loop systems. Others will operate at entering water temperatures as low as 25 degrees F which are possible in closed-loop systems.

Most geothermal heat pumps provide summer air conditioning, but a few brands are designed only for winter heating. Sometimes these heating-only systems incorporate a groundwater-cooled coil that can provide cooling in moderate climates.

Geothermal heat pumps can also differ in the way they are designed. Self-contained units combine the blower, compressor, heat exchanger and coil in a single cabinet. Split systems allow the coil to be added to a forced-air furnace and utilize the existing blower. Top

Q: Can a geothermal heat pump also heat water for my home?
A: Yes. Using what's called a desuperheater, some types of geothermal heat pumps can save you up to 50 percent on your water-heating bill by pre-heating tank water. Desuperheaters are standard on some units, optional on others. Some geothermal models can provide all of your hot water needs on demand at the same high efficiencies as the heating/cooling cycles. Top

Q: Is a geothermal heat pump difficult to install?
A: Most units are easy to install, especially when they are replacing another forced-air system. They can be installed in areas unsuitable for fossil fuel furnaces because there is no combustion, thus, no need to vent exhaust gases.

Ductwork must be installed in homes that don't have an existing air distribution system. The difficulty of installing ductwork will vary and should be assessed by a contractor. Top

Q: Can a geothermal heat pump be added to my fossil fuel furnace?
A: Split systems can easily be added to existing furnaces for those wishing to have a dual-fuel heating system. Dual-fuel systems use the heat pump as the main heating source and a fossil fuel furnace as a supplement in extremely cold weather if additional heat is needed.

Q: I have ductwork, but will it work with this system?
A: In all probability, yes. Your installing contractor should be able to determine ductwork requirements and any minor modifications, if needed. Top

Q: Do I need to increase the size of my electric service?
A: Geothermal heat pumps don't use large amounts of resistance heat, so your existing service may be adequate. Generally, a 200-amp service will have enough capacity, and smaller amp ser-vices may be large enough in some cases. Your electric utility or contractor can determine your service needs. Top

Q: Should I buy a heat pump large enough to heat my home with no supplemental heat?
A: Your contractor should provide a heating and cooling load calculation (heat loss, heat gain) to guide your equipment selection. Geothermal heat pumps are sized to meet your cooling requirements. Depending on your heating needs, a geothermal heat pump will supply 80-100 percent of your design heating load. Sizing the heat pump to handle your entire heating needs may result in slightly lower heating costs, but the savings may not offset the added cost of the larger heat-pump unit. Also, an oversized unit can cause dehumidification problems in the cooling mode, resulting in a loss of summer comfort. Top

Q: Do geothermal heat pumps have outdoor units?
A: No. The equipment goes inside your home, usually in the basement, garage or crawl space. Because it's indoors, the lifespan of the compressor and major components are greatly extended, most having a lifespan of 20 years or more. Top

Q: How efficient is a geothermal heat pump?
A: They are more than three times as efficient as the most efficient fossil fuel furnace. Instead of burning a combustible fuel to make heat, they simply move heat that already exists. By doing that, they provide three units of energy for every one unit us-ed to power the heat-pump system. Top

Q: What about comfort?
A: A geothermal heat pump system moves warm air (90 degrees - 105 degrees) throughout your home via a standard duct network Typically, a very even comfort level is found throughout the home. This is because the warm air is moved in slightly higher volumes and, therefore, saturates the home with warmth more evenly. This helps even out hot or cold spots and eliminates the cold air blast common with fossil fuel furnaces. It's also a great comfort to know that you've reduced your energy consumption while using an inexhaustible energy source - the earth. Top

Q: Can I get a tax credit for installing this system?
A: It depends on where you live. Some states and provinces do have tax credits for installing geothermal systems. Check with your electric utility, Department of Commerce or Ministry of Revenue for further details. Top

Q: Which system is best, open- or closed-loop?
A: The net results in operating cost and efficiency are virtually the same. Which system to choose depends mainly on whether you have an adequate groundwater supply and means of disposal. If you do, an open loop can be used very effectively. If not, either a horizontal or vertical closed-loop system is your best choice.

Over a period of years, a closed-loop system will require less maintenance because it's sealed and pressurized, eliminating the possible build-up of minerals or iron deposits.

Regardless of the type of heating system you may be considering for your home or business, there are specific questions you should ask the dealer/installer. These questions deal with finding out the actual efficiency of the system, any operating limitations it may have, and the bottom line of operating costs. The answers here are meant as a guide for what you should try to find out with your questions. Top

Q: What is the Btu size of the furnace that's being proposed?
A: Furnaces are designed to provide specific amounts of heat energy per hour. The term "Btuh" refers to how much heat can be produced by the unit in an hour. Before you can know what size furnace you'll need, you must have a heat loss/heat gain calculation done on your home. From that, an accurate determination can be made on the size of the heating system you'll need. Most fossil fuel furnaces are substantially oversized for home heating requirements, resulting in increased operating costs. Top

Q: Is the efficiency rating actual or just a manufacturers average?
A: 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. To get an accurate installed efficiency rating, factors such as flue gas heat losses, cycling losses caused by over sizing, blower fan electrical usage, etc., must be included.

Geothermal heat pumps, as well as all other types of heat pumps, have efficiencies rated according to their coefficient of performance or COP. It's a scientific way of determining how much energy the system produces versus how much it uses.

Most geothermal heat pump systems have COPs of 2.5-3.5. That means for every one unit of energy used to power the system, two and one-half to three and one-half units are supplied as heat. Where a fossil fuel furnace may be 50-90 percent efficient, a geothermal heat pump is about 300 percent efficient. Some geothermal heat pump manufacturers and electric utilities use computers to accurately determine the operating efficiency of a system for your home. Top

Q: Will the minimum entering water temperature have an affect on which heat pump I buy?
A: Yes. If you have an open-loop system, your Entering Water Temperatures (EWTs) may range from the 70s in the southern United States to the 40s in Canada. All heat pumps can handle temperatures in the moderate to warm ranges. A closed-loop system, on the other hand, will encounter EWTs below freezing. Not all geothermal heat pumps will operate efficiently at those temperatures. It's important for you to know what EWTs your heat pump will handle. Top

Q: Are the dealer and loop installers qualified?
A: Don't be afraid to ask for references from dealers. A reputable dealer won't hesitate to give you names and numbers to call to confirm his capabilities. The same with the loop installer. Top

Q: Will open- or closed-loop be best for you?
A: That depends on several factors, as stated earlier. A dealer should be willing to install what's best for you, not for him. Top

Q: Will the loop joints be heat fused?
A: The only acceptable method for joining sections of the special pipe used for closed-loop systems is heat fusion. Any other method will eventually result in failure of the loop. Top

Q: How long is the payback period for your geothermal heat pump system?
A: To figure this accurately, you must know how much per year you'll save in energy costs with a geothermal system and the difference in costs between it and a conventional heating system and central air conditioner. As an example: If you'll save $700 per year with a geothermal system and the cost difference is $2,000, your payback will be less than three years. Top

Q: If a home has ceiling cable heat or baseboard heat, do air ducts need to be installed?
A: 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. Ceiling cable or baseboard units could then be used for supplemental heat. Top

Q: If I want to know more about geothermal heat pump systems, whom should I contact?
A: Call Morrell Company at 1-800-550-5667!

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