Morrell Company award winning He

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