Frequently Asked Questions (FAQs)

This section contains FAQs and Glossary of Terms - Scroll down to the bottom for the Glossary.

If you have a question not covered in this section please email us from the Contact Us section.

The Basics

What is a geothermal heat pump?

A geothermal or “ground-source” heat pump is an electrically powered device that uses the natural heat storage ability of the earth to heat and cool your home or business. 

How does it work?

Like any type of heat pump, it simply moves heat energy from one place to another. The geothermal heat pump removes heat energy stored in the earth and/or the earth’s groundwater and transfers it to the home. Click here to read more...

How is heat transferred between the earth and the home?

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 (water) and is pumped to the heat pump 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.

You mentioned heating and cooling. Does it do both?

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 flip of a switch on your indoor thermostat. Plus, a geothermal heat pump can assist in heating water year-round. 

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 inside the unit. 

What types of loops are available?

There are two main types: open and closed.

What is a closed-loop system?

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 water or an anti-freeze solution – depending on where you live – 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.

Where can this loop be located?

That depends on land availability and terrain. Closed-loops are trenched horizontally in yards adjacent to the home if the yard is large enough. Or, for smaller yards, the loops can be installed vertically using a drill rig, much like a water well installation.

How deep and long will my horizontal trenches be?

Trenches are normally four to six feet deep [1.2 1.8 meters]. 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, 125 – 300 feet of trench are required per ton of heat pump capacity [11 – 27 meters per kW of capacity].

What if I don’t have enough room for a horizontal loop?

Closed-loop systems can also be vertical. Holes are bored to about 150 – 300 feet per ton of heat pump capacity [13 – 27 meters per kW of capacity]. U-shaped loops of pipe are inserted in the holes. The holes are then back-filled with a sealing solution (grouting material).

How long will the loop pipe last?

Closed-loop systems should only be installed using the appropriate high-density polyethylene pipe. Properly installed, these pipes will last over 50 years. They are inert to chemicals normally found in soil and have good heat conducting properties. PVC pipe should not be used under any circumstances.

How are the buried pipe sections of the loop joined?

The only acceptable method to connect pipe sections is by thermal fusion. Pipe connections are heated and fused together to form a joint stronger than the original pipe. Mechanical joining of pipe for an earth loop is never an accepted practice. The use of barbed fittings, clamps and glued joints is certain to result in loop failure due to leaks.

Are all geothermal heat pumps alike?

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°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

Will I have to add insulation to my home if I install one of these systems?

Geothermal heat pumps will reduce your heating and cooling costs regardless of how well your home is insulated. However, insulating and weatherizing are key factors in realizing the most savings from any type of heating and cooling system.

Can a geothermal heat pump also be used to heat water?

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 preheating 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.

Is a geothermal heat pump difficult to install?

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. 

Can geothermal heat pump be added to my fossil fuel furnace? 

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.

I have ductwork, but will it work with this system?

In all probability, yes. Your installing contractor should be able to determine ductwork requirements and any minor modifications if needed.

Do I need to increase the size of my electric service?

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 services may be large enough in some cases. Your electric utility or contractor can determine your service needs. 

Should I buy a heat pump large enough to heat with no supplemental heat on the coldest days of the year?

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.

Our Readers asked:

What does it cost to install ?

Geothermal, like other central heating and/or cooling systems can be installed in a number of configurations including forced air, hydronic baseboard, and radiant floors for distribution. A geothermal system usually cost somewhat more than a conventional fossil fuel system with air conditioning to install but has a lower operation cost and no fuel deliveries. There are also no atmospheric emissions of carbon monoxide, carbon dioxide, and hydrocarbons with a geothermal system. For more general or specific information for your property please click Contact Us. 

How does the cost of heating with a geothermal system compare to other heating modes ?

Geothermal systems cost less to operate than electric, electric heat pumps, oil, kerosene, natural and propane gas. 

Will an earth loop affect my lawn or landscape?

No. Research has proven that loops have no adverse effect on grass, trees or shrubs. Most horizontal loop installations use trenches about 3 feet [1 meter] or less 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.

Can I reclaim heat from my septic system disposal field?

No. Depending upon your geographic location, an earth loop will reach temperatures below freezing during extreme conditions and may freeze your septic system. Such usage is banned in many areas.

If the loop falls below freezing, will it hurt the system?

No. The antifreeze solution used in loops that operate at low temperatures will keep it from freezing. In Canada, three types of antifreeze solution are acceptable: propylene glycol, methyl alcohol, and ethyl alcohol.

Can I install an earth loop myself?

It’s not recommended. In addition to thermal fusion of the pipe, good pipe-to-soil contact is very important for successful loop operation. Nonprofessional installations may result in less than optimum heat pump performance.

I have a pond near my home. Can I put a loop in it?

Yes, if it’s deep enough and large enough. A minimum of 8 – 10 feet [2.5 – 3 meters] in depth at its lowest level during the year is needed for a pond to be considered. In pond loops, polyethylene pipe must be used. Generally, a minimum of 1/2 acre [0.2 hectare] pond is required to provide adequate surface area for heat transfer.

Can I heat my pool ? 

Yes, for an indoor, enclosed pool. For an outdoor pool a solar pool heater is a better option.

I have oil or gas hot water home heating (radiators). Can I convert to geothermal?

Converting a home or building with hot water heat is not as easy.

Fossil fuel systems for hydronic (warm water) heating include either copper & aluminum hot water baseboards, cast iron radiators, or radiant heat. All of them are designed to operate at from 180 - 200 °F. Geothermal systems, though much more efficient operate at between 100 - 120 °F, and are not compatible with distribution systems originally designed for much higher temperatures. You would need almost 3 times the size radiators, baseboards, or length of radiant tubing. Converting a home or building basically means starting from scratch.  The up side is that you get a system that is much more efficient, has a lower heating cost, and can have zoned heating and central air conditioning as well. 

I have steam, cast iron radiators. Can they be converted to operate on geothermal?

No, steam systems operate from the boiling point of 100 degrees (220°F) and geothermal systems, though much more efficient cannot deliver at this temperature.

I've heard geothermal systems blow cold air in Winter?

Your Grandfather's old fossil fuel oil or gas furnace heated the air that passed through it somewhere between 15 and 35 degrees (60 and 100°F) every pass of air. It literally "fried" the moisture out of it. It also delivered this air with curtain shaking, cat chasing high velocities. With it's 1.5 to 2 air changes per hour you were either too cold or too hot, with very uneven temperatures throughout the house. Geothermal systems are designed to stringent standards for air changes per hour and only 7 and 10 degrees (20 - 25°F) temperature rise every pass of air. With higher volume, lower velocities (cat friendly) you are comfortable, and don't know how you got there. So, geothermal systems deliver warm air, not hot air. If the room temperature is 21 degrees (70°F) the average delivered air temperature should be around 33 degress (90°F). The bottom line is it will heat your home for a lot less than any other automatic method.  

How efficient is the air conditioning side of a geothermal system? 

About twice as efficient as a conventional central air system. Think, how hard is it to cool a home or building with 10 degree (50°F) water being used as the cooling medium, hot outside air. That means that when you have a 3 ton system it's always a 3 ton system, even at 40 degrees outside. Conventional systems are rated at 30 degrees (85°F) outdoor air and system capacity drops off with temperature rises above that mark. Geothermal systems have a constant 10 degree (50°F) "condenser", so it is always the most efficient with 100% of it's capacity.

I have a wood or coal stove. Can I incorporate it into a geothermal system?

Yes, any heat generated within the shell of the house can be used to heat the whole home, evenly. The ducts and installed low velocity fan will deliver that heat to all areas served by the system. Many of our customers do just that. They will set the geothermal thermostat for the lowest temperature they would like the home if the fire goes out, then turn the fan on distribute the wood / coal heat. During the night when the fire goes out and the house cools down the geothermal comes on to maintain the setting.

Geothermal Systems have a reputation for heating a home inexpensively, just how inexpensive are they to operate?

Energy costs vary around the Province from region to region so a truly accurate energy cost picture created today may be out of date by the next month or even the next week.

So how is the consumer to know what a Geothermal System can do for them?

From the early eighties, Ontario Hydro was one of many North American utilities that monitored Geothermal Systems extensively throughout the Province. Their conclusion was as follows,"Geothermal Systems are the most energy efficient heating and cooling systems available today" – Ontario Hydro. It has been proven beyond any shadow of a doubt and independently verified, many many times over that geothermal systems provide homeowners with the lowest operating cost for heating cooling and domestic hot water production. Various publications supporting this fact are available from Ontario Hydro and the Federal Government on-line; some you can link to from this site.

Consumers will see varied savings from Geothermal System installations across Southern Ontario because fuel prices vary so much. For example, there was a in significant difference in the cost of propane between London and Waterloo Region by January and February 2001, when the prices peaked. In London, propane was available for around 66 cents per litre, in Harriston, just North of Waterloo, some customers were reporting the same product costing around 79 cents per litre.

You can't expect fuel suppliers to all charge the same price to deliver fuel, but you can expect their prices to increase when your fuel demand increases in winter – at the time when you need heat the most.

 

Glossary of Terms

Closed-loop heat pump system

A heat pump system that uses a loop of buried plastic pipe as a heat exchanger. Loops can be horizontal or vertical. 

COP (Coefficient of Performance)

The ratio of heating provided by a heat pump (or other refrigeration machine) to the energy consumed by the system under designated operating conditions. The higher the COP, the more efficient the system.

Compressor

The central part of a heat pump system. The compressor increases the pressure and temperature of the refrigerant and simultaneously reduces the volume while causing the refrigerant to move through the system.

Cycling losses

The actual efficiency of a heating or cooling system is reduced due to startup and shutdown losses. Oversizing a heating or cooling system increases cycling losses. 

EER (Energy Efficiency Ratio)

The ratio of cooling provided by a heat pump (or other refrigeration machine) to the energy consumed by the system under designated operating conditions. The higher the EER, the more efficient the system.

Fossil fuel

Any of several types of combustible fuels formed from the decomposition of organic matter. Examples are natural gas, propane, fuel oil, and coal.

Geothermal heat pump

A heat pump that uses the earth as a heat source and heat sink.

Heat exchanger

A device designed to transfer heat between two physically separated fluids or mediums of different temperatures.

Heat pump

A mechanical device used for heating and cooling which operates by moving heat from one location to another. Heat pumps can extract heat from air, water, or the earth. They are classified as either air-source or ground-source (geothermal) units.

Heat sink

The medium - air, water or earth - which receives heat rejected from a heat pump.

Heat source

The medium - air, water or earth - from which heat is extracted by a heat pump.

Hot water generator

A device for recovering superheat from the compressor discharge gas of a heat pump or central air conditioner for use in heating or preheating potable water.

Open-loop heat pump system

A heat pump system that uses groundwater from a well. The water is returned to the environment.

Payback

A method of calculating how long it will take to recover the difference in costs of two different heating and cooling systems by using the energy and maintenance cost savings from the more efficient system.

Supplemental heating

A heating system used during extremely cold weather when additional heat is needed to moderate indoor temperatures. May be in the form of electric resistance or fossil fuel.