Geothermal Heat Pumps - FAQ

1. What does a Geothermal Heat Pump System cost to install?

The best way to begin this answer is to say that it will cost more than a conventional system. How much more depends on where you live and which Geothermal Heat Pump system you use.

2. How does the cost of geothermal heating compare to other heating methods?

This has a great deal to do with your local rates for electricity and other fuels. The comparison involves the efficiency of the device, the type of fuel used and the cost of that fuel. Obviously, it is necessary to know the total amount of heat required for the year to calculate annual savings. With oil and gas prices on the rise, Geothermal heat pump systems have become one of the most cost-effective options ofr heating and cooling your home.

3. How much of the job can I do myself?

Very little. The performance of a geothermal heat pump system is determined by the quality of the installation. Assuring that proper backfilling is done around the pipe, fusing of the polyethylene piping, flushing the system and purging air from it, all require skills, tools and equipment only available to properly trained contractors. Ground loops are not do-it-yourself projects.

4. Should I use a vertical, horizontal or open loop?

The answer to this question is dependent on your situation. Let’s look first at whether to go open loop or closed loop.

Open loop geothermal systems are best applied in situations where the house is, or will be, served by its own water well.

A slightly larger well pump is installed to provide for the water required by the heat pump.

A major consideration is the disposal of the water. Existing geothermal heating systems have used ponds, lakes, rivers, irrigation ditches, and return (or injection) wells.

Surface disposal is obviously the least expensive option; but, even if a disposal well is required, the initial cost is likely to be much less than the cost of a closed loop geothermal system.

Water quality is also an important issue. Since the water is used directly in the heat pump, the issue of corrosion and/or scaling can be a problem. If the water is hard (>100 ppm) or contains hydrogen sulphide (rotten egg smell), a closed loop system would be a better choice.

If the water is of good quality and the house is to be served by a well for domestic water, serious consideration should be given to the open loop approach.

If the system is to be a closed loop design, the choice between vertical and horizontal system is sometimes a difficult one to grapple with.

The major advantage of the vertical design is that it places the loop in a much more thermally stable zone. Soil at 100 ft is not subject to the same temperature fluctuations as soil at a 4 or 5 ft depth.

As a result, the vertical design offers the potential of supplying the heat pump warmer water in winter and cooler water in summer.