THE WHOLE TRUTH ABOUT GEOTHERMAL HEAT PUMPS

WHAT IS A HEAT PUMP?

Generally, a heat pump is a refrigeration machine that uses electrical energy to transfer heat from one place to another. On this basis, ANY conventional air conditioner using the refrigeration cycle is a HEAT PUMP. A refrigerator, a cold water drinking fountain, a car air conditioner etc.

WHAT ARE THE COMPONENTS OF A GEOTHERMAL SYSTEM?

The three main parts are the heat pump itself which includes the compressor, blower, air and water coils, the liquid heat exchange medium which is either well water, pond, lake or river water, or a buried earth loop filled with water and glycol, and the air delivery system (ductwork).

WHAT ARE THE BENEFITS OF USING GEOTHERMAL HEATING & COOLING OVER CONVENTIONAL SYSTEMS?

Geothermal Heat Pumps have been in practical use for over 50 years. Extensive studies have proven that LIQUID SOURCE, (GEOTHERMAL) Heat Pumps have a life almost double that of conventional air type units such as conventional air conditioners. The energy cost savings are extraordinary when compared to fossil fuels. Geothermal can save you up to 20% over natural gas and up to 60% over propane or fuel oil depending on the cost of electricity in your area. There is no other heating/cooling system available today that can give you pure fresh filtered warm and cool air. WHY? Because there are no gas, oil or propane lines in your home, which means no combustion gasses and no chimney. Since there are no fossil fuels involved, there is no danger from carbon monoxide, leaking raw gas, or air pollution.

HOW DOES IT HEAT?

It removes heat from water and converts it to hot air exactly the same way a cold water drinking fountain removes the heat from the water and discharges the heat out the side or back of the drinking fountain.

HOW DOES IT COOL?

The system is simply reversed. Heat is extracted from the air inside your home and transferred to water and put back in the ground. All you do is select the temperature that makes your home as cool as you like.

CAN A HEAT PUMP ALSO HEAT WATER FOR MY HOME?

Many Geothermal manufacturers add hot water assist modules to supply domestic hot water heating year-round. Some manufacturers make another hot water option. In addition to heating and cooling your home, this hot water generator has a very large capacity to include heating radiant floors, jacuzzi baths, hot tubs and swimming pools.

CAN I USE A HEAT PUMP FOR RADIANT FLOOR HEAT?

Yes, there are units made specifically for radiant floor applications like a conventional gas boiler.

HOW EFFICIENT IS A GEOTHERMAL HEAT PUMP?

This varies by the cost of electricity, oil and propane in your area. Generally on an average, a geothermal heat pump can produce heat with average savings of 10-15% over natural gas, 40% savings over fuel oil, and 50% savings over propane. Air conditioning savings average 40-60% over conventional systems.

WHAT IS AN OPEN LOOP SYSTEM?

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 and the water is disposed of in an appropriate manner. Since groundwater is a relatively constant all year around, it is highly efficient and an excellent heat source.

DO I NEED TO INSTALL A CLOSED GROUND LOOP?

Closed ground loop systems should be considered when GROUND WATER is unavailable (no well), the ground water supply is insufficient or of poor quality (sulfur, biological iron), regulations prohibit the use of ground water, or drilling for the disposal of ground water is impractical. The OPEN LOOP well system, when compared to a closed ground loop, will provide higher operating efficiencies, resulting in lower heating/cooling costs, smaller unit size, lower installation costs, and a payback in less than 3 years. If the homeowner has sizable property, a well, a place to discharge or leach the water, and local codes permit surface discharge, the OPEN LOOP system is the first choice. An average 2000 square foot house needs only 10 GPM for the house and heat pump.

IF I DON'T USE A CLOSED LOOP, AM I WASTING WATER?

NO! This is a common misconception. Water is the most common and abundant resource on earth. The earth's hydrological cycle is the continuous circulation of moisture and water on our planet. When water (rain, snow) hits the earth it continues to move down into the ground. Runoff water on the surface of the earth serves to form and recharge underground aquifers. With an open loop system, you are simply returning the water to the aquifers where it came from. Keep in mind, that if we were wasting water, the EPA, DOE and DNR would not permit these installations over the last 50 years.

DOES AN OPEN LOOP SYSTEM CAUSE ENVIRONMENTAL DAMAGE?

NO! They are pollution free. The heat pump merely removes 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.

WHERE WILL I DISCHARGE THE WATER IF I DON'T USE A CLOSED LOOP SYSTEM?

There are several environmentally friendly options for discharging water. Water can be discharged into a pond, stream, creek, run-off ditch, swamp, wet lands, or it can be leached back into the ground. A dry well is another option. Discharging water will depend upon your soil type, natural water shed, and the size of the property. Keep in mind that you do not need a pond or lake, etc. to discharge water. The open loop system is the easiest, most efficient, and least expensive.

WHAT IF I HAVE A HIGH IRON CONTENT IN MY WATER, WON'T THAT BUILD UP IN MY SYSTEM?

Generally all well water contains assorted iron and minerals but are what is known to be suspended or dissolvable in solution. The only exception is bacterial iron which, although can form a sticky substance in the pipes, is harmless and can be treated by chlorinating the well. An improperly installed system can have a serious negative affect when using well water. What is generally not understood is that if water is aerated, all of these particles will fall out of solution and form a buildup in the pipes. Installing a bladder suspension pressure tank solves that problem. As the water enters the tank the bladder expands, forming a barrier between the water and air as well as maintaining pressure. This DOES NOT ALLOW THE WATER TO BE AERATED. As long as air and water do not mix as in the case with these pressure tanks, generally there are no problems. Installing the solenoid valve on the discharge line is also important to inhibit iron build up. When a water source is not available, a properly designed loop will work exceptionally well.

WHAT ABOUT COMFORT?

Geothermal heat pumps are no different than any other heating system, in that they provide heating and cooling at a certain rated air flow. Therefore, your comfort level is determined by the quality of your delivery system (duct work). IMPORTANT NOTE: Your duct work is the most important part of your geothermal heating and cooling system. i.e. If you have a great heart but your arteries are plugged, it renders the heart useless. It is the same with geothermal heating and cooling and your duct delivery system. Spend the extra few dollars on a well designed and properly installed delivery system and you will experience total comfort, no hot and cold spots, and very low energy bills.

I HEARD THAT HEAT PUMPS WON’T GIVE YOU ENOUGH HEAT IN THE WINTER. IS THIS TRUE?

Years ago, the term "heat pump" generally referred to AIR-To-AIR Heat Pumps. These machines remove heat from the outdoor air where a geothermal unit removes the heat from ground water. If the outside air temperature was 20 degrees - it was extremely difficult to heat the inside of a home. The Geothermal Heat Pump is a WATER-To-AIR heat pump. The heat source for a geothermal is underground where the temperature is very constant and stable even in very cold months.

WHAT ABOUT INSULATION?

R-Value is a measure of how well an insulation product resists heat or cold. R-Value is the result of a laboratory test in which insulation material is sandwiched between a cool and warm surface. The ability of the material to resist temperature difference results in an R-Value for that material. U-Value is a measure of air infiltration. Both factors should be taken into consideration. Generally heating and cooling costs are based on new home sites with R-19 walls and R-38 ceiling. Heat loss and air filtration will affect heating & cooling costs. We have found that blown-in insulation (wet cellulose) has a higher "effective R-Value", and the homes are heated and cooled more efficiently than traditional fiberglass. Years of experience have proven blown-in insulation, such as NuWool, guarantees reduced heating & cooling costs, increased payback, and increased comfort levels. This type of insulation deserves investigation by anyone considering a new building venture.

WHAT ARE EFFICIENCY RATINGS?

Geothermal heat pumps efficiencies use a COP (Coefficient of Performance) to measure heating efficiencies and EER's to measure cooling efficiencies. Simply stated, COP's and EER's to a heat pump is like miles per gallon to an automobile. Where a fossil fuel furnace may be 60-90% efficient, a geothermal heat pump is about 350%.

HOW DO WE KNOW WHO IS TELLING THE TRUTH ABOUT THEIR UNIT’S EFFICIENCY?

This is an important question. All manufacturers must have their equipment tested by a certified third party for capacities and efficiencies. That third party is known as ARI (American Refrigeration Institute). This information is available on the web under www.ari.org. Since we are master distributors for Hydron, we have included a sample comparison based on current, published ARI data.

HOW LONG IS THE PAYBACK PERIOD?

Generally the payback period is 1 to 3 years on open loops, and 5 to 7 years on closed loop systems. Payback will also vary depending upon the insulation used and how well the delivery systems (duct work) are designed.

WHERE ARE GEOTHERMAL UNITS INSTALLED?

There are thousands of homeowners across the country utilizing geothermal today. To date, several large scale GHP projects have been completed. New Jersey's Richard Stockton College is home to the world's largest GHP system. This 1600 ton installation is used by the College to heat and cool its classrooms and administrative buildings. The 400,000 sq. ft. state capital in Oklahoma City is climate regulated with 277 independently controlled units. More than 200 schools in Texas, Missouri, and Kentucky now utilize GHP systems. A groundwater heat pump system heats and cools St. Paul Town Square in Minnesota, and has saved between $300,000 and $400,000 in annual fuel costs. The Campbell Soup Company in Maryland is studying the energy in newly found geothermal water at its frozen food processing plant. (This information is courtesy of Fortune Magazine.)

ARE THERE ADDITIONAL ELECTRICAL REQUIREMENTS?

This is determined by the size of the home, system options and its geographic location. Example: A 3500 sq.ft. home in Michigan would need a 230V 40 amp circuit for the heat pump compressor section and a 230V 60 amp circuit for the emergency backup heat module, plus a 15 to 20 amp circuit for the well pump.

ARE THERE ANY INCENTIVES TO INSTALL THIS SYSTEM?

This varies depending on who your electrical supplier is. In southeast Michigan, Detroit Edison offers a lower utility rate (D1.7) for geothermal systems. This includes your electric hot water heater, well pump, and geothermal unit. Check with your local utility company.

WHAT IF I AM ON A CRAWL SPACE & DON’T HAVE A BASEMENT?

You will need a minimum of a 48" crawl space to place a unit, install duct work and have room to service the equipment. This space should be insulated.

WHERE DO I LOCATE THE SYSTEM IN THE BASEMENT?

The geothermal system should be centralized in the lower level to assure proper take offs and transitions in the duct delivery system. A 36 inch clearance is recommended around the unit for serviceability. Your hot water heater should be within 5-15 ft of the geothermal unit to tie in the Domestic Hot Water Assist Package. Secondary units in very large homes can be placed in an attic space, keeping in mind that there needs to be access and the area must be insulated.

DO I NEED TO SOFTEN THE WATER TO THE GEOTHERMAL SYSTEM?

NO - Geothermal heat pumps need an un-conditioned water source.

DO I NEED TWO HOT WATER HEATER TANKS?

If this is alluding to having a primary "tempering tank" tied to the heat pump, the answer is NO! Regardless of what you have heard from your utility company, contractor, plumber, or electrician, it is not cost effective to install a tempering tank! A single 80 gallon is more than adequate for the average home and the most cost effective. There are exceptions based on the size of the home, the number of people living there, does the home have a fill and dump hot tub etc. This application may require more than one hot water tank.

WHY DO I NEED A PRESSURE TANK & WHAT DOES IT DO?

The 80 gallon (minimum) pressure tank acts as the buffer between your geothermal unit and the well pump. The tank has a 25-30 gallon draw down of water that the geothermal will use FIRST before the well pump starts. This prevents the "On-Off" cycling (called short cycling) and extends the life of your well pump. This must be a bladder suspension type tank such as a Wel-Mate 25 or Wel-X-Trol 302, so that the water entering your geothermal system is not aerated.

WHAT SIZE WELL AND WELL PUMP DO I NEED FOR GEOTHERMAL?

This varies depending on the geographical location. In Michigan, generally a 4" well with a 1/2 to 3/4 HP submersible pump for homes up to 3500 sq. ft. will be adequate. Larger homes may have different requirements. We suggest you work with your well driller to determine what will best suit your home and all water requirements.

HOW MUCH WATER DO I NEED?

A 3500 sq. ft. home generally will need 10 to 12 gpm for both domestic (bathrooms, laundry, kitchen, etc.) and your geothermal heat pump.

HOW MUCH MAINTENANCE IS INVOLVED?

Very little maintenance is required. Most units come with filters that are simply cleaned and put back into the unit. Checking the filters and ensuring that they are clean is important to the system.

CAN I USE THE UNIT FOR HEATING DURING NEW CONSTRUCTION?

No, the geothermal system should never be used as a temporary heating measure during construction. Dry wall dust and dirt can harden on the coils and can cause future problems with the unit. We highly recommend than an alternative heating method be used during this time.

CAN I USE A PROGRAMMABLE THERMOSTAT TO ADJUST TEMPERATURES THROUGHOUT THE DAY?

Programmable thermostats can be used but are not recommended. Geothermal systems operate more efficiently when set at a constant temperature. Programmable thermostats allow for the emergency heating back up (strip heat) to come on when changing temperature settings 3 degrees or more. The money saved by turning the heat down is off set by the costs of bringing the house up to temperature using both the unit and back up heater. For best efficiency and lower utility bills, set the thermostat at one constant setting.

THE WHOLE TRUTH ABOUT DUAL SPEED COMPRESSOR OR DUAL COMPRESSOR UNITS WITH DC INFINITE VARIABLE SPEED FAN MOTORS.

The dual speed/dual compressor units with ECM variable speed blowers are not cost effective nor do they perform at all close to manufacturers' claims. (On the test stand yes, in real life, a resounding NO.) Let us look a little closer at a real life application. The following is assuming the contractor installs a delivery system that is sized for no more than 1200 FPM on supply and 900 FPM for return, proper transitions including SMACNA El's or turning vanes when space dictates. So what is so bad about these two speed/dual compressor units? It is 98 degrees F in July, 98 percent humidity and your highly efficient, wonderful two speed machine is running on one compressor with the fan on low speed because your contractor sized the unit for air conditioning. Now physics come in to play here. A duct system sized for a 5 ton unit, 2000 CFM at a .10 external static pressure, the air velocity is about 1150 feet per minute. When you run on one compressor or low speed, the blower slows down to 1000 CFM. You have now lost most of the pressure that forces air out of the ducts to break up and mix with the stratified air within the each room. The air velocity coming out of the registers is half of the normal rate and the air is cold. Results, the cold air oozes out of all the diffusers and flows across the house on the floor. This low air velocity does not allow the air to be mixed which results in stratification, or in other words, the hot air is stuck at the top of the house and the cold air is laying on the floor. It's all about physics. Cold air is like water, it falls to the ground. Hot air rises like "hot air balloons". The thermostat is never satisfied, consequently, the inhabitants have frost bitten feet while wearing Willie Nelson sweat bands. Now we have heard much rationalizing about what this or that unit does to avoid the problem. One well known manufacturer said: "if after 20 minutes the thermostat is not satisfied, the fan speeds up to 2000 CFM". Well that takes care of the stratification, but creates another problem. The evaporator coil now gets too warm and the unit stops removing humidity --taking care of the sensible load only. We have heard all sorts of answers but when science, physics, logic and reasoning are applied, that dog just won't hunt. We're sure some of you reading this will disagree but we welcome your comments. Incidentally, this point was driven home at a Detroit Edison open house several years ago. Our engineer took his $300.00 digital temperature probe where it indicated the floor temperature at 67 degrees F and the temperature at the thermostat (60 inches above the floor) was 76 degrees F. The unit had been running all day and could not satisfy the thermostat. The supply duct was dripping with condensation. Your comments are always welcome.

WHAT DOES THE GOVERNMENT SAY ABOUT ALL OF THIS GEOTHERMAL STUFF?

"A study by the Environmental Protection Agency: Space Conditioning: The Next Frontier (Office of Air and Radiation, 430-R-93-004), found that GeoExchange Systems are much more efficient than competing fuel technologies when ALL losses in the fuel cycle, including waste heat at the power plants during the generation of electricity, are accounted for. High-efficiency GeoExchange systems are on average 48 percent more efficient than the best gas furnaces and more than 75 percent more efficient than oil furnaces. The best GeoExchange systems even outperformed the best gas technology, gas heat pumps, by an average of 36 percent in the heating mode and 43 percent in the cooling mode".

The Department of Energy has endorsed Geothermal Heat Pumps because they are environmentally friendly and they conserve fossil fuels. Ground water is a renewable energy source. Geothermal Heat Pumps use a small amount of electricity while extracting most of the cooling and heating energy from the earth.