Introduction
Ground Source Heat Pumps

This introduction to GSHP is done in the form of questions and answers. This material is Copyrighted by IGSHPA and has been used with their permission. It has also been modified when necessary and appropriate changes have been made so that generic answers would apply to the specifics of Yavapai Plumbing & Heating, The State of Arizona, public utilities like APS, etc.

General:

Terminology:

Almost always referred to as a GeoThermal Heat Pump…the correct name is Ground Source Heat Pump (GSHP). This is to differentiate it from the true use of the term GeoThermal which uses the extreme heat from deep within the earth for electrical generating power plants.

How efficient is a GSHP?

The GSHP is one of the most efficient residential and commercial heating and cooling systems available today, with heating efficiencies 50 to 70% higher than other heating systems and cooling efficiencies 20 to 40% higher than available air conditioners. That directly translates into savings for you on your utility bills.

Can one system provide both space heating and cooling for my home?

Yes. A GSHP is a true heat pump and by merely reversing the direction in which the refrigerant flows it change from heating to cooling. All that is required by you is to change your thermostat from one mode to other.

What about heating hot water?

Using a desuperheater, some GSHPs can save you up to 50% on your water-heating bill by preheating tank water.

How much space does a GSHP unit require?

Most of a GSHP installation is underground. Inside the house, the heat pump units are about the same size as a traditional heating and cooling unit.

How long will my GSHP system last?

GSHPs are durable and highly reliable. The GSHP contains fewer mechanical components, and all components are either buried in the ground or located inside the home, which protects them from outside conditions. The underground pipe carries up to a 50-year warranty.

How noisy is the GSHP unit?

GSHPs are very quiet, providing a pleasant environment inside & outside of the home. GSHPs have no noisy fan units to disturb outdoor activities, on or near the patio.

How safe are GSHPs?

GSHP systems are safe and protected. With no exposed equipment outdoors, children or pets cannot injure themselves or damage exterior units. GSHPs have no open flame, flammable fuel or potentially dangerous fuel storage tanks.

What about comfort?

A GSHP system moves warm air (90-105(F) throughout your home or business via standard ductwork. An even comfort level is created because the warm air is moved in slightly higher volumes and saturates the building with warmth more evenly. This helps even out hot or colds spots and eliminates the cold air blasts common with fossil fuel furnaces.

Savings / Costs:

How will I save money with a GSHP?

GSHPs save money, both in operating costs and maintenance costs. Investments can be recouped in as little as three years. There is a positive cash flow, since the energy savings usually exceeds payment on the system.

How much does a GSHP cost?

The initial investment for a GSHP system is greater than that of a conventional system. However, when you consider the operating costs of a GeoThermal heating, cooling, and water heating system, energy savings quickly offset the initial difference in purchase price.

What other costs are there besides the GSHP system?

You can expect an installation charge for any electrical work, ductwork, water hook-up, and other provisions or adaptations to your home that are required. Your installer can estimate these costs in advance.

Installation:

Are GSHP systems difficult to install?

Most units are easy to install, especially when they are replacing another forced-air system. This is known as a retrofit. GSHPs can be installed in areas unsuitable for fossil fuel furnaces because there is no combustion and thus no need to vent exhaust fumes. Ductwork must be installed in homes without an existing air distribution system. Your dealer or installer can assess the cost of installing ductwork.

What are the advantages and disadvantages of the horizontal and vertical installations, respectively?

Horizontal installations are slightly easier and slightly less expensive, requiring lower-cost equipment. However, they require much larger property size due to the amount of pipe that has to be laid horizontally. Plus since the pipe is closer to the service it requires longer lengths due to seasonal variations in soil temperature and moisture content. YP&H and their Accredited Installer will be able to help you decide which configuration best meets your specific needs.

How can I be sure the pipe is installed properly?

Use a reputable contractor. Don’t be afraid to ask for and use references. Reputable dealers and loop installers will be happy to give names and phone numbers for you to call and confirm their capabilities. Find out where the installer received training, whether he or she is IGSHPA-accredited (YP&H has an IGSHPA Accredited Installer).

Environment / Climate:

How do GSHPs protect the environment?

GSHP systems conserve natural resources by providing climate control very efficiently-thus also lowering emissions. GSHPs also minimize ozone layer destruction by using factory-sealed refrigeration systems, which will seldom or never have to be recharged.

Do soil freezing conditions create any problems?

Not if a system is properly designed and installed. The three to four foot depths allow the sun to melt the frozen soil during the summer. Adequate length per ton capacity prevents objectionable soil movement.

Does this mean that in extremely cold climates additional heat sources are necessary?

All systems require an emergency backup. Heat pumps can provide all the heat necessary even in the coldest weather. An economic analysis by your contractor should dictate what portion of the heat should be provided by the heat pump and what portion by auxiliary means.

Concerning Your Home:

Will my existing ductwork function with this system?

Yes, in most cases. Your dealer or installer will be able to determine ductwork requirements and if any minor modifications are needed.

Will an underground loop affect my lawn or landscape?

No. Research has shown that loops have no adverse effects on grass, trees, or shrubs. Most horizontal installations require trenches about six inches wide. Temporary bare areas can be restored with grass seed or sod. Vertical loops require little space and do not damage lawns significantly.

Introduction Ground Source Heat Pumps