A: Trees or plants planted over ground loops will not be affected by the operation of the loops. However, during installation one has to take care not to disrupt the root system.

A: There are four basic types. Your site characteristics will determine the best ground loop type for you: Horizontal loops are typically used where open land is available, soil conditions are favorable and site restoration costs are low. Horizontal loops are installed about six feet deep. Vertical loops are used where space is limited or where grounds disturbance is not acceptable. A drill rig is used to drill vertical holes hundreds of feet deep. A pair of pipes connected together at the bottom is inserted into each bore hole. Pipes are then grouted in place to seal up the ground and ensure good heat transfer. Lake/pond loops are used where a body of water such as a lake or a pond exists nearby. The pipes are sunk to the bottom. The body of water has to meet a number of conditions. Open loop is used where there is an abundant supply of suitable well water. Two wells are required, one to supply the water to the heat pump and the other to return the water to the aquifer.

A: Yes, you can have a driveway, parking lot or just about anything else over the top of the loops.

A: The obvious answer is that if there is a leak then it has to be fixed, same as with any underground infrastructure. However, it is important to understand that in a properly installed loop, a leak is very unlikely. All joints are fused, same as with underground gas pipe installations. Prior to backfilling the system is tested under high pressure, therefore any pipe fusion problems will show up during the test.

A: The pipe will last a very long time. The pipe material is polyethylene, the same material that is now used for underground gas piping, water mains and many other underground services.

A: No loop maintenance is required. The fluid in the loop can be checked as part of heat pump maintenance. This is done from the heat pump and does not involve the loop directly.

A: The temperature of the surrounding ground is constant. Around the loops the temperature fluctuates. In the winter it is colder and in the summer it is warmer than the surrounding ground.

A: Much of the information found on the internet on this subject is for air-conditioning dominant climate such as Florida and the southern part of the US. Sizing and installation methods are different for ground loops whose main function is to dump heat into the ground. In Ontario’s climate the main function of a loop is to extract heat from the ground accounting for much of the difference. Also, sometimes the internet information is wrong for any climate.

A: Yes. The heat pump technology is about 100 years old. The commercial application of heat pumps to ground source systems has been around for about 40 years.

A: The two terms have the exact same meaning. However we prefer to use the less common ground source heat pump terminology. There are geothermal heating systems that take advantage of the very hot temperatures deep within the earth. This is a very different technology from geothermal heat pumps but some people confuse the two systems.

A: In most cases installers are dealers for one particular manufacture or distributer, so naturally they recommend that product. That is the one they have access to and the one they get technical support on. We can supply a range of products from several manufactures, but we recommend leaving the choice of manufacture until later in the design process. The best approach is to design a heat pump system and then pick a heat pump manufacturer that has a product that most closely matches your systems requirements. In most cases several manufactures will be able to supply that product.

A: Many sizes, from less than one ton to six tons are common in residential use. In commercial use, where three-phase power is available, a single heat pump can be almost any size. In reality, one rarely tries to provide all the space heating/cooling from a single source. It is far more efficient to have multiple heat pumps in a large building.

A: A ground source heat pump will save you a lot of money, the amount will depend on several factors. It will save the most in a poorly-insulated house with an expensive energy source. It will save the least in a very well-insulated house with an inexpensive energy source. The savings will also depend on the design and type (water-to-water or water-to-air) of heat pump installation. In every case the savings are significant, as are the environmental benefits.

A: The modern air conditioning system dates back to 1902 when Willis Carrier submitted drawings for what became recognized as the first modern air conditioning system. Prior to this air conditioning was accomplished with ice. Tonnage as a measure of cooling capacity comes from this “ice” period. From high school physics we know that it takes 143 BTU to melt one pound of ice that is at a temperature of 32F.The BTU, the British Thermal Unit, is a unit for the measure of energy. Therefore, if there was a one ton block of ice, that is 2,000 lb of ice, in a room it would take 286,000 BTU (143 X 2,000) to melt this ice. If all of this ice melted in one hour then the cooling effect in the room that this would produce would take place at 11,917 BTU/hr (286,000 / 24). This was rounded off to 12,000 BTU/hr and referred to as one ton of cooling. Even though the ton got its start as a measure of cooling capacity, it is also used as a measure of heating capacity. One ton of heating is equal to 12,000 BTU/hr. The other unit used in heating and air conditioning is the watt. One ton is equal to 3,517 Watts

A: A ground source heat pump does not need a back up heating system, it can reliably provide 100% of the heating requirement. However back up or supplemental heating is often installed. Sometimes it makes sense to do so often it does not. The supplemental heat has to be provided when the heat pump system is undersized on purpose. In that case, the heat pump is sized to provide the bulk of the heating requirement, but the last little bit of capacity, which is only needed for a few days each year, is provided by other, cheaper to install means. Usually by an electric heater in the ductwork or in the buffer tank. It is a cost saving measure, and sometimes makes sense in smaller to average size houses that have a single heat pump. However the supplemental heat method is often used by installers to hide the fact that they are not able to size the system properly. Also a smaller ground source heat pump system is cheaper to install so it can make an expensive quote seem reasonable.

A: No burning of fossil fuels means reduction of CO2 gas that is released into the atmosphere. It is a significant reduction but it is not an elimination of CO2 production since some of the electricity that is used to run the heat pump is produced by burning of natural gas. Nevertheless the installation of a ground source heat pump will reduce the carbon footprint of your building more than any other single piece of equipment.

A: Very little maintenance is needed in a properly installed system. Typically there are fewer repairs required than with a boiler or furnace system since no ignition is involved. There are also fewer repairs required than with a conventional air conditioning system since all the mechanical and electrical components are protected from the elements. In fact the heat pump typically has a longer life than conventional heating and cooling equipment.

A: Yes, an existing boiler or furnace can be replaced by a heat pump. However in some cases there is more to it than just a replacement of the utility room equipment. The distribution system often has to have modifications done to it as well in order to make the overall system function well. Those issues are very site specific, but usually have to do with operating temperatures and flow rates in the distribution system. That is true for both forced air and hydronic systems.

A: Yes, both systems have a different set of strengths and weaknesses and therefore they compliment each other well in a combined installation.

A: In practical terms the single number efficiency ratings mean little to the end user because performance is measured under artificial conditions, and the same measurement method is not used consistently by all manufacturers. It is similar to the fuel efficiency ratings for automobiles but even more misleading. Manufactures produce other performance data that is more useful for optimizing system performance. The real world performance of your heat pump system will be determined more by the quality of design and installation than by the numerical value of the efficiency number provided by the manufacturer.